From ef92659856f4f4a8b4381f662981ec7bde3b81f3 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 16 Jul 2019 15:31:10 -0600
Subject: [PATCH 01/17] added doubleExponentialMovingAverate() function,
 resolves #329

---
 .../transformations/aggregates/doubleema.md   | 67 +++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
new file mode 100644
index 000000000..12f7ecc6a
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
@@ -0,0 +1,67 @@
+---
+title: doubleEMA() function
+description: >
+  The `doubleEMA()` or `doubleExponentialMovingAverage()` function calculates the
+  exponential moving average of values grouped into `n` number of points,
+  giving more weight to recent data at double the rate of `exponentialMovingAverage()`.
+menu:
+  v2_0_ref:
+    name: doubleEMA
+    parent: built-in-aggregates
+weight: 501
+related:
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
+  - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#exponential-moving-average, InfluxQL EXPONENTIAL_MOVING_AVERAGE()
+---
+
+The `doubleEMA()` or `doubleExponentialMovingAverage()` function calculates the
+exponential moving average (EMA) of values grouped into `n` number of points,
+giving more weight to recent data at double the rate of
+[`exponentialMovingAverage()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/).
+
+_**Function type:** Aggregate_  
+
+```js
+doubleExponentialMovingAverage(
+  n: 5,
+  columns: ["_value"]
+)
+
+// OR
+
+doubleEMA(
+  n: 5,
+  columns: ["_value"]
+)
+```
+
+##### Double exponential moving average rules:
+- A double exponential moving average is defined as `doubleEMA = 2 * EMA_N - EMA of EMA_N`.
+    - `EMA` is an exponential moving average.
+    - `N = n` is the period used to calculate the EMA.
+- A true double exponential moving average requires at least `2 * n - 1` values.
+  If not enough values exist to calculate the double EMA, it returns a `NaN` value.
+- `doubleEMA()` inherits all [exponential moving average rules](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/#exponential-moving-average-rules).
+
+## Parameters
+
+### n
+The number of points to average.
+
+_**Data type:** Integer_
+
+### columns
+Columns to operate on. _Defaults to `["_value"]`_.
+
+_**Data type:** Array of Strings_
+
+## Examples
+
+#### Calculate a five point double exponential moving average
+```js
+from(bucket: "example-bucket"):
+  |> range(start: -12h)
+  |> doubleExponentialMovingAverage(n: 5)
+```

From 481652c9d908084a514b69b3644aca44e860ee75 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 16 Jul 2019 15:34:26 -0600
Subject: [PATCH 02/17] added related links to moving average functions

---
 .../built-in/transformations/aggregates/movingaverage.md        | 2 ++
 .../built-in/transformations/aggregates/timedmovingaverage.md   | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
index 60c08af83..1af19070a 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
@@ -9,6 +9,8 @@ menu:
 weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/ 
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
index acaedcbe8..1809552ac 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
@@ -10,6 +10,8 @@ menu:
 weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 

From 1dc00f2ec8f7d5e577f4c80907788688603fcd56 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 23 Jul 2019 15:42:48 -0600
Subject: [PATCH 03/17] added new date package functions

---
 .../flux/functions/date/microsecond.md        | 31 +++++++++
 .../flux/functions/date/millisecond.md        | 31 +++++++++
 .../flux/functions/date/nanosecond.md         | 31 +++++++++
 .../reference/flux/functions/date/quarter.md  | 31 +++++++++
 .../reference/flux/functions/date/truncate.md | 57 ++++++++++++++++
 .../reference/flux/functions/date/week.md     | 31 +++++++++
 .../visualization-types/single-stat.md        | 65 -------------------
 7 files changed, 212 insertions(+), 65 deletions(-)
 create mode 100644 content/v2.0/reference/flux/functions/date/microsecond.md
 create mode 100644 content/v2.0/reference/flux/functions/date/millisecond.md
 create mode 100644 content/v2.0/reference/flux/functions/date/nanosecond.md
 create mode 100644 content/v2.0/reference/flux/functions/date/quarter.md
 create mode 100644 content/v2.0/reference/flux/functions/date/truncate.md
 create mode 100644 content/v2.0/reference/flux/functions/date/week.md
 delete mode 100644 content/v2.0/visualize-data/visualization-types/single-stat.md

diff --git a/content/v2.0/reference/flux/functions/date/microsecond.md b/content/v2.0/reference/flux/functions/date/microsecond.md
new file mode 100644
index 000000000..6a1226250
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/microsecond.md
@@ -0,0 +1,31 @@
+---
+title: date.microsecond() function
+description: >
+  The `date.microsecond()` function returns the microsecond of a specified time.
+  Results range from `[0-999999]`.
+menu:
+  v2_0_ref:
+    name: date.microsecond
+    parent: Date
+weight: 301
+---
+
+The `date.microsecond()` function returns the microsecond of a specified time.
+Results range from `[0-999999]`.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.microsecond(t: 2019-07-17T12:05:21.012934584Z)
+
+// Returns 12934
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
diff --git a/content/v2.0/reference/flux/functions/date/millisecond.md b/content/v2.0/reference/flux/functions/date/millisecond.md
new file mode 100644
index 000000000..cc3645240
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/millisecond.md
@@ -0,0 +1,31 @@
+---
+title: date.millisecond() function
+description: >
+  The `date.millisecond()` function returns the millisecond of a specified time.
+  Results range from `[0-999999]`.
+menu:
+  v2_0_ref:
+    name: date.millisecond
+    parent: Date
+weight: 301
+---
+
+The `date.millisecond()` function returns the millisecond of a specified time.
+Results range from `[0-999]`.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.millisecond(t: 2019-07-17T12:05:21.012934584Z)
+
+// Returns 12
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
diff --git a/content/v2.0/reference/flux/functions/date/nanosecond.md b/content/v2.0/reference/flux/functions/date/nanosecond.md
new file mode 100644
index 000000000..21f42bdd7
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/nanosecond.md
@@ -0,0 +1,31 @@
+---
+title: date.nanosecond() function
+description: >
+  The `date.nanosecond()` function returns the nanosecond of a specified time.
+  Results range from `[0-999999999]`.
+menu:
+  v2_0_ref:
+    name: date.nanosecond
+    parent: Date
+weight: 301
+---
+
+The `date.nanosecond()` function returns the nanosecond of a specified time.
+Results range from `[0-999999999]`.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.nanosecond(t: 2019-07-17T12:05:21.012934584Z)
+
+// Returns 12934584
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
diff --git a/content/v2.0/reference/flux/functions/date/quarter.md b/content/v2.0/reference/flux/functions/date/quarter.md
new file mode 100644
index 000000000..87576ce4c
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/quarter.md
@@ -0,0 +1,31 @@
+---
+title: date.quarter() function
+description: >
+  The `date.quarter()` function returns the quarter of the year for a specified time.
+  Results range from `[1-4]`.
+menu:
+  v2_0_ref:
+    name: date.quarter
+    parent: Date
+weight: 301
+---
+
+The `date.quarter()` function returns the quarter of the year for a specified time.
+Results range from `[1-4]`.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.quarter(t: 2019-07-17T12:05:21.012Z)
+
+// Returns 3
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
diff --git a/content/v2.0/reference/flux/functions/date/truncate.md b/content/v2.0/reference/flux/functions/date/truncate.md
new file mode 100644
index 000000000..c9f7db136
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/truncate.md
@@ -0,0 +1,57 @@
+---
+title: date.truncate() function
+description: >
+  The `date.truncate()` function truncates a time to a specified unit.
+menu:
+  v2_0_ref:
+    name: date.truncate
+    parent: Date
+weight: 301
+---
+
+The `date.truncate()` function truncates a time to a specified unit.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.truncate(
+  t: 2019-07-17T12:05:21.012Z
+  unit: 1s
+)
+
+// Returns 2019-07-17T12:05:21.000000000Z
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
+
+### unit
+The unit time to truncate to.
+
+_**Data type:** Duration_
+
+{{% note %}}
+Only use `1` and the unit of time to specify the `unit`.
+For example: `1s`, `1m`, `1h`.
+{{% /note %}}
+
+## Examples
+```js
+import "date"
+
+date.truncate(t: "2019-06-03T13:59:01.000000000Z", unit: 1s)
+// Returns  2019-06-03T13:59:01.000000000Z
+
+date.truncate(t: "2019-06-03T13:59:01.000000000Z", unit: 1m)
+// Returns  2019-06-03T13:59:00.000000000Z
+
+date.truncate(t: "2019-06-03T13:59:01.000000000Z", unit: 1h)
+// Returns  2019-06-03T13:00:00.000000000Z
+
+```
diff --git a/content/v2.0/reference/flux/functions/date/week.md b/content/v2.0/reference/flux/functions/date/week.md
new file mode 100644
index 000000000..8e1bede7b
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/week.md
@@ -0,0 +1,31 @@
+---
+title: date.week() function
+description: >
+  The `date.week()` function returns the ISO week of the year for a specified time.
+  Results range from `[1-53]`.
+menu:
+  v2_0_ref:
+    name: date.week
+    parent: Date
+weight: 301
+---
+
+The `date.week()` function returns the ISO week of the year for a specified time.
+Results range from `[1-53]`.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.week(t: 2019-07-17T12:05:21.012Z)
+
+// Returns 29
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_
diff --git a/content/v2.0/visualize-data/visualization-types/single-stat.md b/content/v2.0/visualize-data/visualization-types/single-stat.md
deleted file mode 100644
index 10c49e303..000000000
--- a/content/v2.0/visualize-data/visualization-types/single-stat.md
+++ /dev/null
@@ -1,65 +0,0 @@
----
-title: Single Stat visualization
-list_title: Single stat
-list_image: /img/2-0-visualizations-single-stat-example.png
-description: >
-  The Single Stat view displays the most recent value of the specified time series as a numerical value.
-weight: 205
-menu:
-  v2_0:
-    name: Single Stat
-    parent: Visualization types
----
-
-The **Single Stat** view displays the most recent value of the specified time series as a numerical value.
-
-{{< img-hd src="/img/2-0-visualizations-single-stat-example.png" alt="Single stat example" />}}
-
-Select the **Single Stat** option from the visualization dropdown in the upper right.
-
-## Single Stat behavior
-The Single Stat visualization displays a single numeric data point.
-It uses the latest point in the first table (or series) returned by the query.
-
-{{% note %}}
-#### Queries should return one table
-Flux does not guarantee the order in which tables are returned.
-If a query returns multiple tables (or series), the table order can change between query executions
-and result in the Single Stat visualization displaying inconsistent data.
-For consistent results, the Single Stat query should return a single table.
-{{% /note %}}
-
-## Single Stat Controls
-To view **Single Stat** controls, click the settings icon ({{< icon "gear" >}})
-next to the visualization dropdown in the upper right.
-
-- **Prefix**: Prefix to be added to the single stat.
-- **Suffix**: Suffix to be added to the single stat.
-- **Decimal Places**: The number of decimal places to display for the single stat.
-    - **Auto** or **Custom**: Enable or disable auto-setting.
-
-###### Colorized Thresholds
-- **Base Color**: Select a base or background color from the selection list.
-- **Add a Threshold**: Change the color of the single stat based on the current value.
-  - **Value is**: Enter the value at which the single stat should appear in the selected color.
-    Choose a color from the dropdown menu next to the value.
-- **Colorization**: Choose **Text** for the single stat to change color based on the configured thresholds.
-  Choose **Background** for the background of the graph to change color based on the configured thresholds.
-
-## Single Stat examples
-
-### Show human-readable current value
-The following example shows the current memory usage displayed has a human-readable percentage:
-
-###### Query memory usage percentage
-```js
-from(bucket: "example-bucket")
-  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
-  |> filter(fn: (r) =>
-      r._measurement == "mem" and
-      r._field == "used_percent"
-  )
-```
-
-###### Memory usage as a single stat
-{{< img-hd src="/img/2-0-visualizations-single-stat-memor.png" alt="Graph + Single Stat Memory Usage Example" />}}

From 22bcd1c9510e88b70a6ff024e0b905b997fcc3ec Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 23 Jul 2019 15:48:51 -0600
Subject: [PATCH 04/17] re-added single stat graph doc that was unintentially
 removed

---
 .../visualization-types/single-stat.md        | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 content/v2.0/visualize-data/visualization-types/single-stat.md

diff --git a/content/v2.0/visualize-data/visualization-types/single-stat.md b/content/v2.0/visualize-data/visualization-types/single-stat.md
new file mode 100644
index 000000000..10c49e303
--- /dev/null
+++ b/content/v2.0/visualize-data/visualization-types/single-stat.md
@@ -0,0 +1,65 @@
+---
+title: Single Stat visualization
+list_title: Single stat
+list_image: /img/2-0-visualizations-single-stat-example.png
+description: >
+  The Single Stat view displays the most recent value of the specified time series as a numerical value.
+weight: 205
+menu:
+  v2_0:
+    name: Single Stat
+    parent: Visualization types
+---
+
+The **Single Stat** view displays the most recent value of the specified time series as a numerical value.
+
+{{< img-hd src="/img/2-0-visualizations-single-stat-example.png" alt="Single stat example" />}}
+
+Select the **Single Stat** option from the visualization dropdown in the upper right.
+
+## Single Stat behavior
+The Single Stat visualization displays a single numeric data point.
+It uses the latest point in the first table (or series) returned by the query.
+
+{{% note %}}
+#### Queries should return one table
+Flux does not guarantee the order in which tables are returned.
+If a query returns multiple tables (or series), the table order can change between query executions
+and result in the Single Stat visualization displaying inconsistent data.
+For consistent results, the Single Stat query should return a single table.
+{{% /note %}}
+
+## Single Stat Controls
+To view **Single Stat** controls, click the settings icon ({{< icon "gear" >}})
+next to the visualization dropdown in the upper right.
+
+- **Prefix**: Prefix to be added to the single stat.
+- **Suffix**: Suffix to be added to the single stat.
+- **Decimal Places**: The number of decimal places to display for the single stat.
+    - **Auto** or **Custom**: Enable or disable auto-setting.
+
+###### Colorized Thresholds
+- **Base Color**: Select a base or background color from the selection list.
+- **Add a Threshold**: Change the color of the single stat based on the current value.
+  - **Value is**: Enter the value at which the single stat should appear in the selected color.
+    Choose a color from the dropdown menu next to the value.
+- **Colorization**: Choose **Text** for the single stat to change color based on the configured thresholds.
+  Choose **Background** for the background of the graph to change color based on the configured thresholds.
+
+## Single Stat examples
+
+### Show human-readable current value
+The following example shows the current memory usage displayed has a human-readable percentage:
+
+###### Query memory usage percentage
+```js
+from(bucket: "example-bucket")
+  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
+  |> filter(fn: (r) =>
+      r._measurement == "mem" and
+      r._field == "used_percent"
+  )
+```
+
+###### Memory usage as a single stat
+{{< img-hd src="/img/2-0-visualizations-single-stat-memor.png" alt="Graph + Single Stat Memory Usage Example" />}}

From ce94a620572c6ec3446761fec2172a3c4c558d83 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 23 Jul 2019 16:32:07 -0600
Subject: [PATCH 05/17] added relativeStrengthIndex function doc, resolves #339

---
 .../aggregates/movingaverage.md               |  10 --
 .../aggregates/relativestrengthindex.md       | 105 ++++++++++++++++++
 2 files changed, 105 insertions(+), 10 deletions(-)
 create mode 100644 content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
index ee4687b40..d95951548 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
@@ -52,16 +52,6 @@ from(bucket: "example-bucket"):
   |> movingAverage(n: 5)
 ```
 
-#### Calculate a ten point moving average
-```js
-movingAverage = (every, period, column="_value", tables=<-) =>
-  tables
-    |> window(every: every, period: period)
-    |> mean(column: column)
-    |> duplicate(column: "_stop", as: "_time")
-    |> window(every: inf)
-```
-
 #### Table transformation with a two point moving average
 
 ###### Input table:
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
new file mode 100644
index 000000000..36d0c7b0a
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
@@ -0,0 +1,105 @@
+---
+title: relativeStrengthIndex() function
+description: >
+  The `relativeStrengthIndex()` function is a momentum indicator that compares the
+  magnitude of recent increases and decreases of values over a period of time period
+  to measure the speed and change of data movements.
+menu:
+  v2_0_ref:
+    name: relativeStrengthIndex
+    parent: built-in-aggregates
+weight: 501
+related:
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
+  - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#relative-strength-index, InfluxQL RELATIVE_STRENGTH_INDEX()
+---
+
+The `relativeStrengthIndex()` function is a momentum indicator that compares the
+magnitude of recent increases and decreases of values over a period of time period
+to measure thepeed and change of data movements.
+
+_**Function type:** Aggregate_  
+
+```js
+relativeStrengthIndex(
+  n: 5,
+  columns: ["_value"]
+)
+```
+
+##### Relative strength index rules:
+- The general equation for calculating a relative strength index (RSI) is
+  `RSI = 100 - (100 / (1 + (AVG GAIN / AVG LOSS)))`.
+- For the first value of the RSI, `AVG GAIN` and `AVG LOSS` are simple `n`-period averages.
+- For subsequent calculations:
+  - `AVG GAIN` = `((PREVIOUS AVG GAIN) * (n - 1)) / n`
+  - `AVG LOSS` = `((PREVIOUS AVG LOSS) * (n - 1)) / n`
+- `relativeStrengthIndex()` ignores `null` values.
+
+## Parameters
+
+### n
+The sample size of the algorithm.
+
+_**Data type:** Integer_
+
+### columns
+Columns to operate on. _Defaults to `["_value"]`_.
+
+_**Data type:** Array of Strings_
+
+## Examples
+
+#### Calculate a five point relative strength index
+```js
+from(bucket: "example-bucket"):
+  |> range(start: -12h)
+  |> relativeStrengthIndex(n: 5)
+```
+
+#### Table transformation with a ten point RSI
+
+###### Input table:
+| _time | A    | B    | tag |
+|:-----:|:----:|:----:|:---:|
+| 0001  | 1    | 1    | tv  |
+| 0002  | 2    | 2    | tv  |
+| 0003  | 3    | 3    | tv  |
+| 0004  | 4    | 4    | tv  |
+| 0005  | 5    | 5    | tv  |
+| 0006  | 6    | 6    | tv  |
+| 0007  | 7    | 7    | tv  |
+| 0008  | 8    | 8    | tv  |
+| 0009  | 9    | 9    | tv  |
+| 0010  | 10   | 10   | tv  |
+| 0011  | 11   | 11   | tv  |
+| 0012  | 12   | 12   | tv  |
+| 0013  | 13   | 13   | tv  |
+| 0014  | 14   | 14   | tv  |
+| 0015  | 15   | 15   | tv  |
+| 0016  | 16   | 16   | tv  |
+| 0017  | 17   | null | tv  |
+| 0018  | 18   | 17   | tv  |
+
+###### Query:
+```js
+// ...
+  |> relativeStrengthIndex(
+    n: 10,
+    columns: ["A", "B"]
+  )
+```
+
+###### Output table:
+| _time |   A  |   B  | tag |
+|:-----:|:----:|:----:|:---:|
+|  0011 | 100  | 100  |  tv |
+|  0012 | 100  | 100  |  tv |
+|  0013 | 100  | 100  |  tv |
+|  0014 | 100  | 100  |  tv |
+|  0015 | 100  | 100  |  tv |
+|  0016 |  90  |  90  |  tv |
+|  0017 |  81  |  90  |  tv |
+|  0018 | 72.9 |  81  |  tv |

From 9f2cd6bb510ea8b57db961d33a2ce9a8c803b1dd Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Wed, 24 Jul 2019 15:06:16 -0600
Subject: [PATCH 06/17] updated RSI function doc to address PR feedback

---
 .../aggregates/relativestrengthindex.md            | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
index 36d0c7b0a..8ffb36750 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
@@ -1,9 +1,8 @@
 ---
 title: relativeStrengthIndex() function
 description: >
-  The `relativeStrengthIndex()` function is a momentum indicator that compares the
-  magnitude of recent increases and decreases of values over a period of time period
-  to measure the speed and change of data movements.
+  The `relativeStrengthIndex()` function measures the relative speed and change of
+  values in an input table.
 menu:
   v2_0_ref:
     name: relativeStrengthIndex
@@ -16,9 +15,8 @@ related:
   - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#relative-strength-index, InfluxQL RELATIVE_STRENGTH_INDEX()
 ---
 
-The `relativeStrengthIndex()` function is a momentum indicator that compares the
-magnitude of recent increases and decreases of values over a period of time period
-to measure thepeed and change of data movements.
+The `relativeStrengthIndex()` function measures the relative speed and change of
+values in an input table.
 
 _**Function type:** Aggregate_  
 
@@ -32,7 +30,7 @@ relativeStrengthIndex(
 ##### Relative strength index rules:
 - The general equation for calculating a relative strength index (RSI) is
   `RSI = 100 - (100 / (1 + (AVG GAIN / AVG LOSS)))`.
-- For the first value of the RSI, `AVG GAIN` and `AVG LOSS` are simple `n`-period averages.
+- For the first value of the RSI, `AVG GAIN` and `AVG LOSS` are averages of the `n` period.
 - For subsequent calculations:
   - `AVG GAIN` = `((PREVIOUS AVG GAIN) * (n - 1)) / n`
   - `AVG LOSS` = `((PREVIOUS AVG LOSS) * (n - 1)) / n`
@@ -41,7 +39,7 @@ relativeStrengthIndex(
 ## Parameters
 
 ### n
-The sample size of the algorithm.
+The number of values to use to calculate the RSI.
 
 _**Data type:** Integer_
 

From 93d4b284f798e1c61052bb35f82fa2c0c9cab538 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Wed, 24 Jul 2019 15:56:13 -0600
Subject: [PATCH 07/17] added the flux runtime package, resolves #352

---
 .../flux/functions/runtime/_index.md          | 22 +++++++++++++++++++
 .../flux/functions/runtime/version.md         | 20 +++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 content/v2.0/reference/flux/functions/runtime/_index.md
 create mode 100644 content/v2.0/reference/flux/functions/runtime/version.md

diff --git a/content/v2.0/reference/flux/functions/runtime/_index.md b/content/v2.0/reference/flux/functions/runtime/_index.md
new file mode 100644
index 000000000..b940e379a
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/runtime/_index.md
@@ -0,0 +1,22 @@
+---
+title: Flux runtime package
+list_title: Runtime package
+description: >
+  The Flux runtime package includes functions that provide information about the
+  current Flux runtime. Import the `runtime` package.
+menu:
+  v2_0_ref:
+    name: Runtime
+    parent: Flux packages and functions
+weight: 202
+v2.0/tags: [runtime, functions, package]
+---
+
+The Flux runtime package includes functions that provide information about the
+current Flux runtime. Import the `runtime` package:
+
+```js
+import "runtime"
+```
+
+{{< children type="functions" show="pages" >}}
diff --git a/content/v2.0/reference/flux/functions/runtime/version.md b/content/v2.0/reference/flux/functions/runtime/version.md
new file mode 100644
index 000000000..84333887b
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/runtime/version.md
@@ -0,0 +1,20 @@
+---
+title: runtime.version() function
+description: The `runtime.version()` function returns the current Flux version.
+menu:
+  v2_0_ref:
+    name: runtime.version
+    parent: Runtime
+weight: 401
+---
+
+The `runtime.version()` function returns the current Flux version.
+
+_**Function type:** Miscellaneous_  
+_**Output data type:** String_
+
+```js
+import "runtime"
+
+runtime.version()
+```

From 87ba42544a20be1043b9be162bd698af9fa5f54e Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Fri, 26 Jul 2019 11:16:06 -0600
Subject: [PATCH 08/17] fixed bad frontmatter

---
 .../built-in/transformations/aggregates/movingaverage.md    | 6 +-----
 .../transformations/aggregates/timedmovingaverage.md        | 3 ---
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
index 6691c7b02..742bce355 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
@@ -9,12 +9,8 @@ menu:
 weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
-<<<<<<< HEAD
-  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/ 
-  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
-=======
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
->>>>>>> flux-0.38
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
index 2dec95128..1809552ac 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
@@ -11,10 +11,7 @@ weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
-<<<<<<< HEAD
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
-=======
->>>>>>> flux-0.38
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 

From 004a623107da9dfe698396f2466f9c91943e3891 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Fri, 26 Jul 2019 15:04:01 -0600
Subject: [PATCH 09/17] added tripleEMA(), udpated params on existing moving
 avg docs

---
 .../transformations/aggregates/doubleema.md   | 46 ++++++-------
 .../aggregates/exponentialmovingaverage.md    | 43 +++++-------
 .../aggregates/movingaverage.md               | 37 ++++------
 .../aggregates/timedmovingaverage.md          |  1 +
 .../transformations/aggregates/tripleema.md   | 68 +++++++++++++++++++
 5 files changed, 121 insertions(+), 74 deletions(-)
 create mode 100644 content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
index 12f7ecc6a..2c11353cf 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
@@ -1,9 +1,9 @@
 ---
 title: doubleEMA() function
 description: >
-  The `doubleEMA()` or `doubleExponentialMovingAverage()` function calculates the
-  exponential moving average of values grouped into `n` number of points,
-  giving more weight to recent data at double the rate of `exponentialMovingAverage()`.
+  The `doubleEMA()` function calculates the exponential moving average of values
+  grouped into `n` number of points, giving more weight to recent data at double
+  the rate of `exponentialMovingAverage()`.
 menu:
   v2_0_ref:
     name: doubleEMA
@@ -11,30 +11,20 @@ menu:
 weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
-  - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#exponential-moving-average, InfluxQL EXPONENTIAL_MOVING_AVERAGE()
+  - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#double-exponential-moving-average, InfluxQL DOUBLE_EXPONENTIAL_MOVING_AVERAGE()
 ---
 
-The `doubleEMA()` or `doubleExponentialMovingAverage()` function calculates the
-exponential moving average (EMA) of values grouped into `n` number of points,
-giving more weight to recent data at double the rate of
-[`exponentialMovingAverage()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/).
+The `doubleEMA()` function calculates the exponential moving average of values in
+the `_value` column grouped into `n` number of points, giving more weight to recent
+data at double the rate of [`exponentialMovingAverage()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/).
 
 _**Function type:** Aggregate_  
 
 ```js
-doubleExponentialMovingAverage(
-  n: 5,
-  columns: ["_value"]
-)
-
-// OR
-
-doubleEMA(
-  n: 5,
-  columns: ["_value"]
-)
+doubleEMA(n: 5)
 ```
 
 ##### Double exponential moving average rules:
@@ -52,16 +42,22 @@ The number of points to average.
 
 _**Data type:** Integer_
 
-### columns
-Columns to operate on. _Defaults to `["_value"]`_.
-
-_**Data type:** Array of Strings_
-
 ## Examples
 
 #### Calculate a five point double exponential moving average
 ```js
 from(bucket: "example-bucket"):
   |> range(start: -12h)
-  |> doubleExponentialMovingAverage(n: 5)
+  |> doubleEMA(n: 5)
+```
+
+## Function definition
+```js
+doubleEMA = (n, tables=<-) =>
+  tables
+    |> exponentialMovingAverage(n:n)
+    |> duplicate(column:"_value", as:"ema")
+    |> exponentialMovingAverage(n:n)
+    |> map(fn: (r) => ({r with _value: 2.0 * r.ema - r._value}))
+    |> drop(columns: ["ema"])
 ```
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
index da132b4ab..4694eb75c 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
@@ -1,8 +1,8 @@
 ---
 title: exponentialMovingAverage() function
 description: >
-  The `exponentialMovingAverage()` function calculates the exponential moving average
-  of values grouped into `n` number of points, giving more weight to recent data.
+  The `exponentialMovingAverage()` function calculates the exponential moving average of values
+  in the `_value` column grouped into `n` number of points, giving more weight to recent data.
 menu:
   v2_0_ref:
     name: exponentialMovingAverage
@@ -11,19 +11,18 @@ weight: 501
 related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema/
   - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#exponential-moving-average, InfluxQL EXPONENTIAL_MOVING_AVERAGE()
 ---
 
-The `exponentialMovingAverage()` function calculates the exponential moving average
-of values grouped into `n` number of points, giving more weight to recent data.
+The `exponentialMovingAverage()` function calculates the exponential moving average of values
+in the `_value` column grouped into `n` number of points, giving more weight to recent data.
 
 _**Function type:** Aggregate_  
 
 ```js
-exponentialMovingAverage(
-  n: 5,
-  columns: ["_value"]
-)
+exponentialMovingAverage(n: 5)
 ```
 
 ##### Exponential moving average rules:
@@ -43,11 +42,6 @@ The number of points to average.
 
 _**Data type:** Integer_
 
-### columns
-Columns to operate on. _Defaults to `["_value"]`_.
-
-_**Data type:** Array of Strings_
-
 ## Examples
 
 #### Calculate a five point exponential moving average
@@ -60,23 +54,20 @@ from(bucket: "example-bucket"):
 #### Table transformation with a two point exponential moving average
 
 ###### Input table:
-| _time | A    | B    | C    | tag |
-|:-----:|:----:|:----:|:----:|:---:|
-| 0001  | 2    | null | 2    | tv  |
-| 0002  | null | 10   | 4    | tv  |
-| 0003  | 8    | 20   | 5    | tv  |
+| _time | tag | _value |
+|:-----:|:---:|:------:|
+| 0001  | tv  | null   |
+| 0002  | tv  | 10     |
+| 0003  | tv  | 20     |
 
 ###### Query:
 ```js
 // ...
-  |> exponentialMovingAverage(
-    n: 2,
-    columns: ["A", "B", "C"]
-  )
+  |> exponentialMovingAverage(n: 2)
 ```
 
 ###### Output table:
-| _time | A    | B    | C    | tag |
-|:-----:|:----:|:----:|:----:|:---:|
-| 0002  | 2    | 10   | 3    | tv  |
-| 0003  | 6    | 16.67| 4.33 | tv  |
+| _time | tag | _value |
+|:-----:|:---:|:------:|
+| 0002  | tv  | 10     |
+| 0003  | tv  | 16.67  |
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
index 742bce355..5e8186c7e 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
@@ -11,18 +11,17 @@ related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema/
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 
-The `movingAverage()` function calculates the mean of values grouped into `n` number of points.
+The `movingAverage()` function calculates the mean of values in the `_values` column
+grouped into `n` number of points.
 
 _**Function type:** Aggregate_  
 
 ```js
-movingAverage(
-  n: 5,
-  columns: ["_value"]
-)
+movingAverage(n: 5)
 ```
 
 ##### Moving average rules:
@@ -39,11 +38,6 @@ The number of points to average.
 
 _**Data type:** Integer_
 
-### columns
-Columns to operate on. _Defaults to `["_value"]`_.
-
-_**Data type:** Array of Strings_
-
 ## Examples
 
 #### Calculate a five point moving average
@@ -66,23 +60,20 @@ movingAverage = (every, period, column="_value", tables=<-) =>
 #### Table transformation with a two point moving average
 
 ###### Input table:
-| _time |   A  |   B  |   C  |   D  | tag |
-|:-----:|:----:|:----:|:----:|:----:|:---:|
-|  0001 | null |   1  |   2  | null |  tv |
-|  0002 |   6  |   2  | null | null |  tv |
-|  0003 |   4  | null |   4  |   4  |  tv |
+| _time | tag | _value |
+|:-----:|:---:|:------:|
+| 0001  | tv  | null   |
+| 0002  | tv  | 6      |
+| 0003  | tv  | 4      |
 
 ###### Query:
 ```js
 // ...
-  |> movingAverage(
-    n: 2,
-    columns: ["A", "B", "C", "D"]
-  )
+  |> movingAverage(n: 2 )
 ```
 
 ###### Output table:
-| _time |   A  |   B  |   C  |   D  | tag |
-|:-----:|:----:|:----:|:----:|:----:|:---:|
-|  0002 |   6  |  1.5 |   2  | null |  tv |
-|  0003 |   5  |   2  |   4  |   4  |  tv |
+| _time | tag | _value |
+|:-----:|:---:|:------:|
+| 0002  | tv  | 6      |
+| 0003  | tv  | 5      |
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
index 1809552ac..d9b435213 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage.md
@@ -12,6 +12,7 @@ related:
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
   - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema/
   - https://docs.influxdata.com/influxdb/latest/query_language/functions/#moving-average, InfluxQL MOVING_AVERAGE()
 ---
 
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md
new file mode 100644
index 000000000..6618acab7
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md
@@ -0,0 +1,68 @@
+---
+title: tripleEMA() function
+description: >
+  The `tripleEMA()` function calculates the exponential moving average of values
+  grouped into `n` number of points, giving more weight to recent data with less lag
+  than `exponentialMovingAverage()` and `doubleEMA()`.
+menu:
+  v2_0_ref:
+    name: tripleEMA
+    parent: built-in-aggregates
+weight: 501
+related:
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/timedmovingaverage/
+  - /v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/
+    - https://docs.influxdata.com/influxdb/v1.7/query_language/functions/#triple-exponential-moving-average, InfluxQL TRIPLE_EXPONENTIAL_MOVING_AVERAGE()
+---
+
+The `tripleEMA()` function calculates the exponential moving average of values in
+the `_value` column grouped into `n` number of points, giving more weight to recent
+data with less lag than
+[`exponentialMovingAverage()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/)
+and [`doubleEMA()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema/).
+
+_**Function type:** Aggregate_  
+
+```js
+tripleEMA(n: 5)
+```
+
+##### Triple exponential moving average rules:
+- A triple exponential moving average is defined as `tripleEMA = (3 * EMA_1) - (3 * EMA_2) + EMA_3`.
+  - `EMA_1` is the exponential moving average of the original data.
+  - `EMA_2` is the exponential moving average of `EMA_1`.
+  - `EMA_3` is the exponential moving average of `EMA_2`.
+- A true triple exponential moving average requires at least requires at least `3 * n - 2` values.
+  If not enough values exist to calculate the triple EMA, it returns a `NaN` value.
+- `tripleEMA()` inherits all [exponential moving average rules](/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage/#exponential-moving-average-rules).
+
+## Parameters
+
+### n
+The number of points to average.
+
+_**Data type:** Integer_
+
+## Examples
+
+#### Calculate a five point triple exponential moving average
+```js
+from(bucket: "example-bucket"):
+  |> range(start: -12h)
+  |> tripleEMA(n: 5)
+```
+
+## Function definition
+```js
+tripleEMA = (n, tables=<-) =>
+	tables
+		|> exponentialMovingAverage(n:n)
+		|> duplicate(column:"_value", as:"ema1")
+    |> exponentialMovingAverage(n:n)
+		|> duplicate(column:"_value", as:"ema2")
+		|> exponentialMovingAverage(n:n)
+		|> map(fn: (r) => ({r with _value: 3.0 * r.ema1 - 3.0 * r.ema2 + r._value}))
+		|> drop(columns: ["ema1", "ema2"])
+```

From a9e553ed44f9a03be55d6a5a5f377f79bd09c0b1 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Fri, 26 Jul 2019 15:52:58 -0600
Subject: [PATCH 10/17] added keepFirst param to difference function

---
 .../transformations/aggregates/difference.md  | 27 ++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
index f864f6626..d7d45b091 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
@@ -17,7 +17,11 @@ _**Function type:** Aggregate_
 _**Output data type:** Float_
 
 ```js
-difference(nonNegative: false, column: "_value")
+difference(
+  nonNegative: false,
+  column: "_value",
+  keepFirst: false
+)
 ```
 
 ## Parameters
@@ -34,6 +38,13 @@ Defaults to `"_value"`.
 
 _**Data type:** String_
 
+### keepFirst
+Indicates if the first row should be kept.
+If `true`, the difference will be `null`.
+Defaults to `false`.
+
+_**Data type:** Boolean_
+
 ## Subtraction rules for numeric types
 - The difference between two non-null values is their algebraic difference;
   or `null`, if the result is negative and `nonNegative: true`;
@@ -90,6 +101,20 @@ from(bucket: "example-bucket")
 | 0004  | 6      | tv  |
 | 0005  | null   | tv  |
 
+
+#### With keepFirst set to true
+```js
+|> difference(nonNegative: false, keepfirst: true):
+```
+###### Output table
+| _time | _value | tag |
+|:-----:|:------:|:---:|
+| 0001  | null   | tv  |
+| 0002  | null   | tv  |
+| 0003  | -2     | tv  |
+| 0004  | 6      | tv  |
+| 0005  | null   | tv  |
+
 <hr style="margin-top:4rem"/>
 
 ##### Related InfluxQL functions and statements:

From b381781d19cba2024db4f0c8f7d80259668ccf0c Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Mon, 29 Jul 2019 10:49:49 -0600
Subject: [PATCH 11/17] updated difference function doc to address PR feedback

---
 .../functions/built-in/transformations/aggregates/difference.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
index d7d45b091..3e52efdba 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/difference.md
@@ -39,7 +39,7 @@ Defaults to `"_value"`.
 _**Data type:** String_
 
 ### keepFirst
-Indicates if the first row should be kept.
+Indicates the first row should be kept.
 If `true`, the difference will be `null`.
 Defaults to `false`.
 

From a2c9de850a849d73e16d1b09fb57542b49734d2e Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Mon, 5 Aug 2019 13:21:51 -0600
Subject: [PATCH 12/17] added date.year function

---
 .../reference/flux/functions/date/year.md     | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 content/v2.0/reference/flux/functions/date/year.md

diff --git a/content/v2.0/reference/flux/functions/date/year.md b/content/v2.0/reference/flux/functions/date/year.md
new file mode 100644
index 000000000..b2e2a80b4
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/date/year.md
@@ -0,0 +1,29 @@
+---
+title: date.year() function
+description: >
+  The `date.year()` function returns the year of a specified time.
+menu:
+  v2_0_ref:
+    name: date.year
+    parent: Date
+weight: 301
+---
+
+The `date.year()` function returns the year of a specified time.
+
+_**Function type:** Transformation_  
+
+```js
+import "date"
+
+date.year(t: 2019-07-17T12:05:21.012Z)
+
+// Returns 2019
+```
+
+## Parameters
+
+### t
+The time to operate on.
+
+_**Data type:** Time_

From ba7bcd645239cc53d4b4761e7909ca15a8cff2e8 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 6 Aug 2019 14:11:46 -0600
Subject: [PATCH 13/17] added holtWinters function

---
 .../transformations/aggregates/doubleema.md   |   2 +-
 .../aggregates/exponentialmovingaverage.md    |   2 +-
 .../transformations/aggregates/holtwinters.md | 114 ++++++++++++++++++
 .../aggregates/movingaverage.md               |   2 +-
 .../aggregates/relativestrengthindex.md       |   2 +-
 .../transformations/aggregates/tripleema.md   |   2 +-
 6 files changed, 119 insertions(+), 5 deletions(-)
 create mode 100644 content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
index 2c11353cf..88a99ef58 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/doubleema.md
@@ -27,7 +27,7 @@ _**Function type:** Aggregate_
 doubleEMA(n: 5)
 ```
 
-##### Double exponential moving average rules:
+##### Double exponential moving average rules
 - A double exponential moving average is defined as `doubleEMA = 2 * EMA_N - EMA of EMA_N`.
     - `EMA` is an exponential moving average.
     - `N = n` is the period used to calculate the EMA.
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
index 4694eb75c..c543ab342 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/exponentialmovingaverage.md
@@ -25,7 +25,7 @@ _**Function type:** Aggregate_
 exponentialMovingAverage(n: 5)
 ```
 
-##### Exponential moving average rules:
+##### Exponential moving average rules
 - The first value of an exponential moving average over `n` values is the
   algebraic mean of `n` values.
 - Subsequent values are calculated as `y(t) = x(t) * k + y(t-1) * (1 - k)`, where:
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md
new file mode 100644
index 000000000..46829e1da
--- /dev/null
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md
@@ -0,0 +1,114 @@
+---
+title: holtWinters() function
+description: >
+  The `holtWinters()` function applies the Holt-Winters forecasting method to input tables.
+aliases:
+  - /v2.0/reference/flux/functions/transformations/aggregates/holtwinters
+menu:
+  v2_0_ref:
+    name: holtWinters
+    parent: built-in-aggregates
+weight: 501
+related:
+  - https://docs.influxdata.com/influxdb/latest/query_language/functions/#holt-winters, InfluxQL HOLT_WINTERS()
+---
+
+The `holtWinters()` function applies the Holt-Winters forecasting method to input tables.
+
+_**Function type:** Aggregate_  
+_**Output data type:** Float_
+
+```js
+holtWinters(
+  n: 10,
+  seasonality: 4,
+  interval: 30d,
+  withFit: false,
+  timeColumn: "_time",
+  column: "_value",
+)
+```
+
+The Holt-Winters method predicts [`n`](#n) seasonally-adjusted values for the
+specified [`column`](#column) at the specified [`interval`](#interval).
+For example, if `interval` is `6m` and `n` is `3`, results include three predicted
+values six minutes apart.
+
+#### Seasonality
+[`seasonality`](#seasonality) delimits the length of a seasonal pattern according to `interval`.
+If your `interval` is `2m` and `s` is `3`, then the seasonal pattern occurs every
+six minutes or every three data points.
+If there is no seasonality in the data, set `seasonality` to `0`.
+
+#### Space values evenly in time
+`holtWinters()` expects values evenly spaced in time.
+To ensure this, it applies the following rules:
+
+- `interval` is used to divide the into buckets based time.
+- If a bucket includes many values, the first value is used.
+- If a bucket includes no values, a missing value (`null`) is added for that bucket.
+
+By default, `holtWinters()` uses the first value in each time bucket.
+Use [`window()`](/v2.0/reference/flux/functions/built-in/transformations/window/)
+and [selectors](/v2.0/reference/flux/functions/built-in/transformations/selectors/)
+or [aggregates](/v2.0/reference/flux/functions/built-in/transformations/aggregates/),
+or use [`aggregateWindow()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow)
+to specify other values to use in the `holtWinters()` calculation.
+
+#### Fitted model
+The `holtWinters()` function applies the [Nelder-Mead optimization](https://en.wikipedia.org/wiki/Nelder%E2%80%93Mead_method)
+to include "fitted" data points in results when [`withFit`](#withfit) is set to `true`.
+
+#### Null timestamps
+`holtWinters()` discards rows with `null` timestamps before running the Holt-Winters calculation.
+
+#### Null values
+`holtWinters()` treats `null` values as missing data points and includes them in the Holt-Winters calculation.
+
+
+## Parameters
+
+### n
+The number of values to predict.
+
+_**Data type: Integer**_
+
+### seasonality
+The number of points in a season.
+Defaults to `0`.
+
+_**Data type: Integer**_
+
+### interval
+The interval between two data points.
+
+_**Data type: Duration**_
+
+### withFit
+Return [fitted data](#fitted-model) in results.
+Defaults to `false`.
+
+_**Data type: Boolean**_
+
+### timeColumn
+The time column to use.
+Defaults to `"_time"`.
+
+_**Data type: String**_
+
+### column
+The column to operate on.
+Defaults to `"_value"`.
+
+_**Data type: String**_
+
+## Examples
+
+##### Use aggregateWindow to prepare data for holtWinters
+```js
+from(bucket: "example-bucket")
+    |> range(start: -7y)
+    |> filter(fn: (r) => r._field == "water_level")
+    |> aggregateWindow(every: 379m, fn: first).
+    |> holtWinters(n: 10, seasonality: 4, interval: 379m)
+```
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
index de1bc07ab..3ee8221c2 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/movingaverage.md
@@ -24,7 +24,7 @@ _**Function type:** Aggregate_
 movingAverage(n: 5)
 ```
 
-##### Moving average rules:
+##### Moving average rules
 - The average over a period populated by `n` values is equal to their algebraic mean.
 - The average over a period populated by only `null` values is `null`.
 - Moving averages skip `null` values.
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
index 8ffb36750..d8f08460b 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/relativestrengthindex.md
@@ -27,7 +27,7 @@ relativeStrengthIndex(
 )
 ```
 
-##### Relative strength index rules:
+##### Relative strength index rules
 - The general equation for calculating a relative strength index (RSI) is
   `RSI = 100 - (100 / (1 + (AVG GAIN / AVG LOSS)))`.
 - For the first value of the RSI, `AVG GAIN` and `AVG LOSS` are averages of the `n` period.
diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md
index 6618acab7..cb084a607 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/tripleema.md
@@ -29,7 +29,7 @@ _**Function type:** Aggregate_
 tripleEMA(n: 5)
 ```
 
-##### Triple exponential moving average rules:
+##### Triple exponential moving average rules
 - A triple exponential moving average is defined as `tripleEMA = (3 * EMA_1) - (3 * EMA_2) + EMA_3`.
   - `EMA_1` is the exponential moving average of the original data.
   - `EMA_2` is the exponential moving average of `EMA_1`.

From 6b1342916e4686e80a377ec32ef03d798f769076 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 6 Aug 2019 14:52:36 -0600
Subject: [PATCH 14/17] marked date.year as draft

---
 content/v2.0/reference/flux/functions/date/year.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/content/v2.0/reference/flux/functions/date/year.md b/content/v2.0/reference/flux/functions/date/year.md
index b2e2a80b4..d420ed839 100644
--- a/content/v2.0/reference/flux/functions/date/year.md
+++ b/content/v2.0/reference/flux/functions/date/year.md
@@ -7,6 +7,7 @@ menu:
     name: date.year
     parent: Date
 weight: 301
+draft: true
 ---
 
 The `date.year()` function returns the year of a specified time.

From 8c9fd6a5245aad1ed24bc09a1d93019f771ed40a Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 6 Aug 2019 15:48:35 -0600
Subject: [PATCH 15/17] added flux 0.38.0 release notes

---
 content/v2.0/reference/release-notes/flux.md | 26 +++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/content/v2.0/reference/release-notes/flux.md b/content/v2.0/reference/release-notes/flux.md
index ffb1490e1..f3c011dbc 100644
--- a/content/v2.0/reference/release-notes/flux.md
+++ b/content/v2.0/reference/release-notes/flux.md
@@ -11,13 +11,37 @@ aliases:
 ---
 
 {{% note %}}
-_The latest release of InfluxDB v2.0 alpha includes **Flux v0.37.2**.
+_The latest release of InfluxDB v2.0 alpha includes **Flux v0.38.0**.
 Though newer versions of Flux may be available, they will not be included with
 InfluxDB until the next InfluxDB v2.0 release._
 {{% /note %}}
 
 ---
 
+## v0.38.0 [2019-08-06]
+
+### Features
+- Update selectors to operate on time columns.
+- Add `relativeStrengthIndex()` transformation.
+- Add double and triple exponential average transformations (`doubleEMA()` and `tripleEMA()`).
+- Add `holtWinters()` transformation.
+- Add `keepFirst` parameter to `difference()`.
+- DatePart equivalent functions.
+- Add runtime package.
+- Add and subtract duration literal arithmetic.
+- Allow `keep()` to run regardless of nonexistent columns.
+  If all columns given are nonexistent, `keep()` returns an empty table.
+- Scanner returns positioning.
+
+### Bug fixes
+- Function resolver now keeps track of local assignments that may be evaluated at runtime.
+- Fixed InfluxDB test errors.
+- Add range to tests to pass in InfluxDB.
+- Allow converting a duration to a duration.
+- Catch integer overflow and underflow for literals.
+
+---
+
 ## v0.37.2 [2019-07-24]
 
 -  _General cleanup of internal code._

From a04c0f344fb4ef1bc8e93717ad93d7d4fc53dc41 Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 6 Aug 2019 16:20:24 -0600
Subject: [PATCH 16/17] added selector info to aggregateWindow, resolves #371

---
 .../transformations/aggregates/aggregatewindow.md | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow.md
index c82f5ee3b..5127800f3 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow.md
@@ -10,7 +10,8 @@ menu:
 weight: 501
 ---
 
-The `aggregateWindow()` function applies an aggregate function to fixed windows of time.
+The `aggregateWindow()` function applies an aggregate or selector function
+(any function with a `column` parameter) to fixed windows of time.
 
 _**Function type:** Aggregate_  
 
@@ -25,7 +26,7 @@ aggregateWindow(
 )
 ```
 
-As data is windowed into separate tables and aggregated, the `_time` column is dropped from each group key.
+As data is windowed into separate tables and processed, the `_time` column is dropped from each group key.
 This function copies the timestamp from a remaining column into the `_time` column.
 View the [function definition](#function-definition).
 
@@ -42,7 +43,7 @@ The [aggregate function](/v2.0/reference/flux/functions/built-in/transformations
 _**Data type:** Function_
 
 {{% note %}}
-Only aggregate functions with a `column` parameter (singular) work with `aggregateWindow()`.
+Only aggregate and selector functions with a `column` parameter (singular) work with `aggregateWindow()`.
 {{% /note %}}
 
 ### column
@@ -84,10 +85,10 @@ from(bucket: "example-bucket")
     fn: mean
   )
 ```
-###### Specifying parameters of the aggregate function
-To use `aggregateWindow()` aggregate functions that don't provide defaults for required parameters,
-for the `fn` parameter, define an anonymous function with `columns` and `tables` parameters
-that pipe-forwards tables into the aggregate function with all required parameters defined:
+###### Specify parameters of the aggregate function
+To use functions that don't provide defaults for required parameters with `aggregateWindow()`,
+define an anonymous function with `column` and `tables` parameters that pipe-forward
+tables into the aggregate or selector function with all required parameters defined:
 
 ```js
 from(bucket: "example-bucket")

From 6a85f883b46daefb54c897429bfab7d439132cae Mon Sep 17 00:00:00 2001
From: Scott Anderson <scott@influxdata.com>
Date: Tue, 6 Aug 2019 16:36:46 -0600
Subject: [PATCH 17/17] upated holtWinters doc to address PR feedback

---
 .../transformations/aggregates/holtwinters.md | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md
index 46829e1da..7301ce089 100644
--- a/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md
+++ b/content/v2.0/reference/flux/functions/built-in/transformations/aggregates/holtwinters.md
@@ -36,24 +36,25 @@ values six minutes apart.
 
 #### Seasonality
 [`seasonality`](#seasonality) delimits the length of a seasonal pattern according to `interval`.
-If your `interval` is `2m` and `s` is `3`, then the seasonal pattern occurs every
-six minutes or every three data points.
-If there is no seasonality in the data, set `seasonality` to `0`.
+If your `interval` is `2m` and `seasonality` is `4`, then the seasonal pattern occurs every
+eight minutes or every four data points.
+If data doesn't have a seasonal pattern, set `seasonality` to `0`.
 
 #### Space values evenly in time
 `holtWinters()` expects values evenly spaced in time.
-To ensure this, it applies the following rules:
+To ensure `holtWinters()` values are spaced evenly in time, the following rules apply:
 
-- `interval` is used to divide the into buckets based time.
+- Data is grouped into time-based "buckets" determined by the `interval`.
 - If a bucket includes many values, the first value is used.
 - If a bucket includes no values, a missing value (`null`) is added for that bucket.
 
-By default, `holtWinters()` uses the first value in each time bucket.
-Use [`window()`](/v2.0/reference/flux/functions/built-in/transformations/window/)
-and [selectors](/v2.0/reference/flux/functions/built-in/transformations/selectors/)
-or [aggregates](/v2.0/reference/flux/functions/built-in/transformations/aggregates/),
-or use [`aggregateWindow()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow)
-to specify other values to use in the `holtWinters()` calculation.
+By default, `holtWinters()` uses the first value in each time bucket to run the Holt-Winters calculation.
+To specify other values to use in the calculation, use:
+
+- [`window()`](/v2.0/reference/flux/functions/built-in/transformations/window/)
+  with [selectors](/v2.0/reference/flux/functions/built-in/transformations/selectors/)
+  or [aggregates](/v2.0/reference/flux/functions/built-in/transformations/aggregates/)
+- [`aggregateWindow()`](/v2.0/reference/flux/functions/built-in/transformations/aggregates/aggregatewindow)
 
 #### Fitted model
 The `holtWinters()` function applies the [Nelder-Mead optimization](https://en.wikipedia.org/wiki/Nelder%E2%80%93Mead_method)
@@ -65,7 +66,6 @@ to include "fitted" data points in results when [`withFit`](#withfit) is set to
 #### Null values
 `holtWinters()` treats `null` values as missing data points and includes them in the Holt-Winters calculation.
 
-
 ## Parameters
 
 ### n