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# numpy.ma.where() function – Python

• Last Updated : 05 May, 2020

`numpy.ma.where()` function return a masked array with elements from x or y, depending on condition.

Syntax : numpy.ma.where(condition, x, y)

Parameter :
condition : [array_like, bool] Where True, yield x, otherwise yield y.
x, y : [array_like, optional] Values from which to choose. x, y and condition need to be broadcastable to some shape.

Return : [MaskedArray] An masked array with masked elements where the condition is masked, elements from x where condition is True, and elements from y elsewhere.

Code #1 :

 `# Python program explaining``# numpy.ma.where() function``  ` `# importing numpy as geek ``# and numpy.ma module as ma ``import` `numpy as geek ``import` `numpy.ma as ma``   ` `x ``=` `geek.ma.array(geek.arange(``4.``).reshape(``2``, ``2``), ``                        ``mask ``=``[[``0``, ``1``], [``1``, ``0``]])`` ` `gfg ``=` `geek.ma.where(x > ``5``, x, ``-``3.1416``)``  ` `print` `(gfg)`

Output :

```[[-3.1416 --]
[-- -3.1416]]
```

Code #2 :

 `# Python program explaining``# numpy.ma.where() function``  ` `# importing numpy as geek ``# and numpy.ma module as ma ``import` `numpy as geek ``import` `numpy.ma as ma``   ` `x ``=` `geek.ma.array(geek.arange(``9.``).reshape(``3``, ``3``), ``       ``mask ``=``[[``0``, ``1``, ``0``], [``1``, ``0``, ``1``], [``0``, ``1``, ``0``]])`` ` `gfg ``=` `geek.ma.where(x > ``5``, x, ``-``3.1416``)``  ` `print` `(gfg)`

Output :

```[[-3.1416 -- -3.1416]
[-- -3.1416 --]
[6.0 -- 8.0]]
```

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