docs-v2/content/flux/v0/stdlib/universe/pearsonr.md

title	description	menu	weight	flux/v0/tags	introduced
pearsonr() function	`pearsonr()` returns the covariance of two streams of tables normalized to the Pearson R coefficient.	flux_v0_ref name parent identifier pearsonr universe universe/pearsonr	101	transformations aggregates	0.7.0

pearsonr() returns the covariance of two streams of tables normalized to the Pearson R coefficient.

Function type signature

(on: [string], x: A, y: B) => stream[C] where C: Record

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Parameters

x

({{< req >}}) First input stream.

y

({{< req >}}) Second input stream.

on

({{< req >}}) List of columns to join on.

Examples

Return the covariance between two streams of tables

import "generate"

stream1 =
    generate.from(
        count: 5,
        fn: (n) => n * n,
        start: 2021-01-01T00:00:00Z,
        stop: 2021-01-01T00:01:00Z,
    )
        |> toFloat()

stream2 =
    generate.from(
        count: 5,
        fn: (n) => n * n * n / 2,
        start: 2021-01-01T00:00:00Z,
        stop: 2021-01-01T00:01:00Z,
    )
        |> toFloat()

pearsonr(x: stream1, y: stream2, on: ["_time"])

{{< expand-wrapper >}} {{% expand "View example output" %}}

Output data

_value
0.9856626734271221

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