# Remove axes of length one from the masked array in Numpy

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To remove axes of length one in Python, use the ma.MaskedArray.squeeze() method in Numpy. Returns the input array, but with all or a subset of the dimensions of length 1 removed. This is always a itself or a view into a. Note that if all axes are squeezed, the result is a 0d array and not a scalar.

A masked array is the combination of a standard numpy.ndarray and a mask. A mask is either nomask, indicating that no value of the associated array is invalid, or an array of booleans that determines for each element of the associated array whether the value is valid or not.

## Steps

At first, import the required library −

import numpy as np
import numpy.ma as ma

Create an array with int elements using the numpy.array() method −

arr = np.array([[49, 85, 45], [67, 33, 59]])
print("Array...\n", arr)
print("\nArray type...\n", arr.dtype)

Get the dimensions of the Array −

print("Array Dimensions...\n",arr.ndim)


Create a masked array and mask some of them as invalid −

maskArr = ma.masked_array(arr, mask =[[0, 0, 1], [ 0, 1, 0]])
print("\nOur Masked Array type...\n", maskArr.dtype)

Get the dimensions of the Masked Array −

print("\nOur Masked Array Dimensions...\n",maskArr.ndim)


Get the shape of the Masked Array −

print("\nOur Masked Array Shape...\n",maskArr.shape)

Get the number of elements of the Masked Array −

print("\nElements in the Masked Array...\n",maskArr.size)


To remove axes of length one, use the ma.MaskedArray.squeeze() method in Numpy −

print("\nResult...\n",np.squeeze(maskArr))
print("\nShape...\n",np.squeeze(maskArr).shape)

## Example

# Python ma.MaskedArray - Remove axes of length one

import numpy as np
import numpy.ma as ma

# Create an array with int elements using the numpy.array() method
arr = np.array([[, , ]])
print("Array...\n", arr)
print("\nArray type...\n", arr.dtype)

# Get the dimensions of the Array
print("\nArray Dimensions...\n",arr.ndim)

# Create a masked array and mask some of them as invalid

# Get the dimensions of the Masked Array

# Get the shape of the Masked Array

# Get the number of elements of the Masked Array

# To remove axes of length one, use the ma.MaskedArray.squeeze() method in Numpy
print("\nShape...\n",np.squeeze(maskArr).shape)

## Output

Array...
[[

]]

Array type...
int64

Array Dimensions...
3

[[
[--]
]]

Our Masked Array type...
int64

Our Masked Array Dimensions...
3

Our Masked Array Shape...
(1, 3, 1)

Elements in the Masked Array...
3

Result...
[15 -- 45]

Shape...
(3,)