# How to Replace Negative Values with Zero in NumPy

You can use the following basic syntax to replace negative values with zero in NumPy:

```my_array[my_array < 0] = 0
```

This syntax works with both 1D and 2D NumPy arrays.

The following examples show how to use this syntax in practice.

## Example 1: Replace Negative Values with Zero in 1D NumPy Array

The following code shows how to replace all negative values with zero in a NumPy array:

```import numpy as np

#create 1D NumPy array
my_array = np.array([4, -1, 6, -3, 10, 11, -14, 19, 0])

#replace negative values with zero in array
my_array[my_array < 0] = 0

#view updated array
print(my_array)

[ 4  0  6  0 10 11  0 19  0]
```

Notice that each negative value in the original array has been replaced with zero.

## Example 2: Replace Negative Values with Zero in 2D NumPy Array

Suppose we have the following 2D NumPy array:

```import numpy as np

#create 2D NumPy array
my_array = np.array([3, -5, 6, 7, -1, 0, -5, 9, 4, 3, -5, 1]).reshape(4,3)

#view 2D NumPy array
print(my_array)

[[ 3 -5  6]
[ 7 -1  0]
[-5  9  4]
[ 3 -5  1]]
```

We can use the following code to replace all negative values with zero in the NumPy array:

```#replace all negative values with zero in 2D array
my_array[my_array < 0] = 0

#view updated array
print(my_array)

[[3 0 6]
[7 0 0]
[0 9 4]
[3 0 1]]```

Notice that all negative values in the original 2D array have been replaced with zero.