Return the masked array data as a string containing the raw bytes and set the row major order of the result in Numpy

NumpyServer Side ProgrammingProgramming

To return the array data as a string containing the raw bytes in the array, use the ma.MaskedArray.tobytes() method in Numpy.

The fill_value parameter is the value used to fill in the masked values. Default is None, in which case MaskedArray.fill_value is used.

The order parameter is the Order of the data item in the copy. Default is ‘C’.

  • ‘C’ - C order (row major).

  • ‘F’ - Fortran order (column major).

  • ‘A’ - Any, current order of array.

  • None - Same as ‘A’.

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\n", maskArr)
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)

Return the array data as a string containing the raw bytes in the array, use the ma.MaskedArray.tobytes() method in Numpy. The Order of the data item in the copy is set using the "order" parameter. The 'C' order is for C order i.e. row major −

print("\nResult...\n",maskArr.tobytes(fill_value = 1111, order = 'C'))

Example

# Python ma.MaskedArray - Return the array data as a string containing the raw bytes in the array and
# set the row major order of the resultant data

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("\nArray 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\n", maskArr)
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 return the array data as a string containing the raw bytes in the array, use the ma.MaskedArray.tobytes() method in Numpy
# The "fill_value" parameter ios the value used to fill in the masked values.
# Default is None, in which case MaskedArray.fill_value is used.
# The Order of the data item in the copy is set using the "order" parameter
# The 'C' order is for C order i.e. row major
print("\nResult...\n",maskArr.tobytes(fill_value = 1111, order = 'C'))

Output

Array...
[[49 85 45]
[67 33 59]]

Array type...
int64

Array Dimensions...
2

Our Masked Array
[[49 85 --]
[67 -- 59]]

Our Masked Array type...
int64

Our Masked Array Dimensions...
2

Our Masked Array Shape...
(2, 3)

Elements in the Masked Array...
6

Result...
b'1\x00\x00\x00\x00\x00\x00\x00U\x00\x00\x00\x00\x00\x00\x00W\x04\x00\x00\x00\x00\x00\x00C\x00\x00\x00\x00\x00\x00\x00W\x04\x00\x00\x00\x00\x00\x00;\x00\x00\x00\x00\x00\x00\x00'
raja
Updated on 02-Feb-2022 08:01:59

Advertisements