Syntax error Stack arrays in sequence vertically (row wise) in Numpy

Stack arrays in sequence vertically (row wise) in Numpy



To stack arrays in sequence vertically (row wise), use the ma.row_stack() method in Python Numpy. This is equivalent to concatenation along the first axis after 1-D arrays of shape (N,) have been reshaped to (1,N). Rebuilds arrays divided by vsplit. Returns the array formed by stacking the given arrays, will be at least 2-D.

This function makes most sense for arrays with up to 3 dimensions. For instance, for pixel-data with a height (first axis), width (second axis), and r/g/b channels (third axis). The functions concatenate, stack and block provide more general stacking and concatenation operations. It is applied to both the _data and the _mask, if any.

The parameters are the arrays that must have the same shape along all but the first axis. 1-D arrays must have the same length.

Steps

At first, import the required library −

import numpy as np
import numpy.ma as ma

Create a new array using the array() method −

arr = np.array([[200], [300], [400], [500]])
print("Array...
", arr)

Type of array −

print("
Array type...
", arr.dtype)

Get the dimensions of the Array −

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

To stack arrays in sequence vertically (row wise), use the ma.row_stack() method −

resArr = np.ma.row_stack (arr)

Resultant Array −

print("
Result...
", resArr)

Example

# Python ma.MaskedArray - Stack arrays in sequence vertically (row wise)

import numpy as np
import numpy.ma as ma

# Create a new array using the array() method
arr = np.array([[200], [300], [400], [500]])
print("Array...
", arr) # Type of array print("
Array type...
", arr.dtype) # Get the dimensions of the Array print("
Array Dimensions...
",arr.ndim) # To stack arrays in sequence vertically (row wise), use the ma.row_stack() method in Python Numpy resArr = np.ma.row_stack (arr) # Resultant Array print("
Result...
", resArr)

Output

Array...
[[200]
[300]
[400]
[500]]

Array type...
int64

Array Dimensions...
2

Result...
[[200]
[300]
[400]
[500]]
Updated on: 2022-02-03T12:13:18+05:30

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