# cdfExp {#cdfexp}

**Parent topic:**[Functions](../../Functions/category.md)

## Syntax {#syntax}

`cdfExp(mean, X)`

## Arguments {#arguments}

**mean** is the mean of an exponential distribution.

**X** is a numeric scalar or vector.

## Details {#details}

Return the value of the cumulative distribution function of an exponential distribution.

## Examples {#examples}

```
cdfExp(1, [-1, 0, 0.5, 1, 2]);
// output: [0, 0, 0.393469, 0.632121, 0.864665]

cdfExp(1, [0.1, 0.3, 0.5, 0.7, 0.9]);
// output: [0.095163, 0.259182, 0.393469, 0.503415, 0.59343]
```

