# How to calculate the absolute value of each element of an array or matrix in python with numpy ?

Examples of how to calculate the absolute value of each element of an array or matrix in python with numpy:

### Calculate the absolute value for a 1D matrix

Let's first create a 1d matrix with some negative values:

````import numpy as np`

`A = np.linspace(-5.0, 4.0, num=10)`
```

returns

````array([-5., -4., -3., -2., -1.,  0.,  1.,  2.,  3.,  4.])`
```

To calculate the absolute value of each element of A, a solution is to use numpy.absolute

````B = np.absolute(A)`
```

returns then

````array([5., 4., 3., 2., 1., 0., 1., 2., 3., 4.])`
```

Note: create some visualization with matplotlib:

Matrix A:

````import matplotlib.pyplot as plt`

`plt.plot(np.arange(A.shape[0]),A)`

`plt.title("How to calculate the absolute value \n of each element of an array \n or matrix in python with numpy")`

`plt.grid()`

`plt.savefig("absolute_01.png", bbox_inches='tight', dpi=100)`

`plt.show()`
```

gives

Matrix B:

````import matplotlib.pyplot as plt`

`plt.plot(np.arange(B.shape[0]),B)`

`plt.title("How to calculate the absolute value \n of each element of an array \n or matrix in python with numpy")`

`plt.savefig("absolute_02.png", bbox_inches='tight', dpi=100)`

`plt.grid()`

`plt.show()`
```

gives

### Another example with a 2d matrix

Let's create a 2d with some negative values:

````A = np.random.randint(-10,10,size=(4,4))`
```

returns for example

````array([[-6, -7, -7,  2],`
`             [-7,  1, -6, -8],`
`             [-3,  5,  9, -4],`
`             [ 0,  0, -6, -4]])`
```

Then to calculate the absolute value of each element of A:

````B = np.absolute(A)`
```

gives

````array([[6, 7, 7, 2],`
`             [7, 1, 6, 8],`
`             [3, 5, 9, 4],`
`             [0, 0, 6, 4]])`
```

Examples of how to visualize the results with matplotlib:

````import matplotlib.pyplot as plt`

`plt.imshow(A)`

`plt.title("How to calculate the absolute value \n of each element of an array \n or matrix in python with numpy")`

`plt.grid()`

`plt.colorbar()`

`plt.savefig("absolute_03.png", bbox_inches='tight', dpi=100)`

`plt.show()`
```

gives

````import matplotlib.pyplot as plt`

`plt.imshow(B)`

`plt.title("How to calculate the absolute value \n of each element of an array \n or matrix in python with numpy")`

`plt.grid()`

`plt.colorbar()`

`plt.savefig("absolute_04.png", bbox_inches='tight', dpi=100)`

`plt.show()`
```

gives

Image

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