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Python | Replace negative value with zero in numpy array
• Last Updated : 17 Oct, 2019

Given numpy array, the task is to replace negative value with zero in numpy array. Let’s see a few examples of this problem.

Method #1: Naive Method

 `# Python code to demonstrate``# to replace negative value with 0``import` `numpy as np`` ` `ini_array1 ``=` `np.array([``1``, ``2``, ``-``3``, ``4``, ``-``5``, ``-``6``])`` ` `# printing initial arrays``print``(``"initial array"``, ini_array1)`` ` `# code to replace all negative value with 0``ini_array1[ini_array1<``0``] ``=` `0`` ` `# printing result``print``(``"New resulting array: "``, ini_array1)`
Output:
```initial array [ 1  2 -3  4 -5 -6]
New resulting array:  [1 2 0 4 0 0]
```

Method #2: Using `np.where`

 `# Python code to demonstrate``# to replace negative values with 0``import` `numpy as np`` ` `ini_array1 ``=` `np.array([``1``, ``2``, ``-``3``, ``4``, ``-``5``, ``-``6``])`` ` `# printing initial arrays``print``(``"initial array"``, ini_array1)`` ` `# code to replace all negative value with 0``result ``=` `np.where(ini_array1<``0``, ``0``, ini_array1)`` ` `# printing result``print``(``"New resulting array: "``, result)`
Output:

```initial array [ 1  2 -3  4 -5 -6]
New resulting array:  [1 2 0 4 0 0]
```

Method #3: Using `np.clip`

 `# Python code to demonstrate``# to replace negative values with 0``import` `numpy as np`` ` `# supposing maxx value array can hold``maxx ``=` `1000`` ` `ini_array1 ``=` `np.array([``1``, ``2``, ``-``3``, ``4``, ``-``5``, ``-``6``])`` ` `# printing initial arrays``print``(``"initial array"``, ini_array1)`` ` `# code to replace all negative value with 0``result ``=` `np.clip(ini_array1, ``0``, ``1000``)`` ` `# printing result``print``(``"New resulting array: "``, result)`
Output:
```initial array [ 1  2 -3  4 -5 -6]
New resulting array:  [1 2 0 4 0 0]
```

Method #4: Comparing the given array with an array of zeros and write in the maximum value from the two arrays as the output.

 `# Python code to demonstrate``# to replace negative values with 0``import` `numpy as np``  ` `ini_array1 ``=` `np.array([``1``, ``2``, ``-``3``, ``4``, ``-``5``, ``-``6``])``  ` `# printing initial arrays``print``(``"initial array"``, ini_array1)``  ` `# Creating a array of 0``zero_array ``=` `np.zeros(ini_array1.shape, dtype``=``ini_array1.dtype)``print``(``"Zero array"``, zero_array)`` ` `# code to replace all negative value with 0``ini_array2 ``=` `np.maximum(ini_array1, zero_array)`` ` `# printing result``print``(``"New resulting array: "``, ini_array2)`
Output:
```initial array [ 1  2 -3  4 -5 -6]
Zero array [0 0 0 0 0 0]
New resulting array:  [1 2 0 4 0 0]
```

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