---
title: math.mod() function
description: >
  `math.mod()` returns a floating-point remainder of `x/y`.
menu:
  flux_v0_ref:
    name: math.mod
    parent: math
    identifier: math/mod
weight: 101
---

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`math.mod()` returns a floating-point remainder of `x/y`.

The magnitude of the result is less than `y` and its sign agrees
with that of `x`.

**Note**: `math.mod()` performs the same operation as the modulo operator (`%`).
For example: `4.56 % 1.23`

##### Function type signature

```js
(x: float, y: float) => float
```

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For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
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## Parameters

### x
({{< req >}})
x-value to use in the operation.



### y
({{< req >}})
y-value to use in the operation.




## Examples

- [Return the modulo of two values](#return-the-modulo-of-two-values)
- [Use math.mod in map](#use-mathmod-in-map)

### Return the modulo of two values

```js
import "math"

math.mod(x: 4.56, y: 1.23)// 0.8699999999999997


```


### Use math.mod in map

```js
import "math"

data
    |> map(fn: (r) => ({_time: r._time, _value: math.mod(x: r.t1, y: r.t2)}))

```

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#### Input data

| _time                | t1    | t2    |
| -------------------- | ----- | ----- |
| 2021-01-01T00:00:00Z | -2.18 | 19.85 |
| 2021-01-01T00:00:10Z | 10.92 | 4.97  |
| 2021-01-01T00:00:20Z | 7.35  | -3.75 |
| 2021-01-01T00:00:30Z | 17.53 | 19.77 |
| 2021-01-01T00:00:40Z | 15.23 | 13.86 |
| 2021-01-01T00:00:50Z | 4.43  | 1.86  |


#### Output data

| _time                | _value             |
| -------------------- | ------------------ |
| 2021-01-01T00:00:00Z | -2.18              |
| 2021-01-01T00:00:10Z | 0.9800000000000004 |
| 2021-01-01T00:00:20Z | 3.5999999999999996 |
| 2021-01-01T00:00:30Z | 17.53              |
| 2021-01-01T00:00:40Z | 1.370000000000001  |
| 2021-01-01T00:00:50Z | 0.7099999999999995 |

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