# isMonotonicDecreasing {#ismonotonicdecreasing}

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

## Syntax {#syntax}

`isMonotonicDecreasing(X)`

## Arguments {#arguments}

**X** is a scalar/vector.

## Details {#details}

Check whether the elements in *X* are monotonically decreasing.

## Examples {#examples}

```
a = [10,8,6,4,2]
isMonotonicDecreasing(a);
// output: true

a = [10,8,6,7,2]
isMonotonicDecreasing(a);
// output: false

a = [10,8,6,6,4,2]
isMonotonicDecreasing(a);
// output: true

a = [10,8,6,NULL,4,2]
isMonotonicDecreasing(a);
// output: false

a = [10,8,6,4,2,NULL]
isMonotonicDecreasing(a);
// output: true
```

Related functions: [isMonotonicIncreasing](isMonotonicIncreasing.md), [isMonotonic](isMonotonic.md)

