numpy.MaskedArray.atleast_3d() function is used to convert inputs to masked arrays with at least three dimension.Scalar, 1-dimensional and 2-dimensional arrays are converted to 3-dimensional arrays, whilst higher-dimensional inputs are preserved.
Syntax :
numpy.ma.atleast_3d(*arys)Parameters:
arys:[ array_like] One or more input arrays.Return : [ ndarray] An array, or list of arrays, each with
arr.ndim >= 3
Code #1 :
# Python program explaining # numpy.MaskedArray.atleast_3d() method # importing numpy as geek # and numpy.ma module as ma import numpy as geek import numpy.ma as ma # creating input arrays in_arr1 = geek.array([ 3, -1, 5, -3]) print ("1st Input array : ", in_arr1) in_arr2 = geek.array(2) print ("2nd Input array : ", in_arr2) in_arr3 = geek.array([[1, 2], [ 3, -1], [ 5, -3]]) print ("3rd Input array : ", in_arr3) # Now we are creating masked array. # by making entry as invalid. mask_arr1 = ma.masked_array(in_arr1, mask =[ 1, 0, 1, 0]) print ("1st Masked array : ", mask_arr1) mask_arr2 = ma.masked_array(in_arr2, mask = 0) print ("2nd Masked array : ", mask_arr2) mask_arr3 = ma.masked_array(in_arr3, mask =[[ 1, 0], [ 0, 1], [ 0, 0]]) print ("3rd Masked array : ", mask_arr3) # applying MaskedArray.atleast_3d methods # to masked array out_arr = ma.atleast_2d(mask_arr1, mask_arr2, mask_arr3) print ("Output masked array : ", out_arr) |
Output:
1st Input array : [ 3 -1 5 -3]
2nd Input array : 2
3rd Input array : [[ 1 2]
[ 3 -1]
[ 5 -3]]
1st Masked array : [-- -1 -- -3]
2nd Masked array : 2
3rd Masked array : [[-- 2]
[3 --]
[5 -3]]
Output masked array : [masked_array(data=[[--, -1, --, -3]],
mask=[[ True, False, True, False]],
fill_value=999999), masked_array(data=[[2]],
mask=[[False]],
fill_value=999999), masked_array(
data=[[--, 2],
[3, --],
[5, -3]],
mask=[[ True, False],
[False, True],
[False, False]],
fill_value=999999)]
Code #2 :
# Python program explaining # numpy.MaskedArray.atleast_3d() method # importing numpy as geek # and numpy.ma module as ma import numpy as geek import numpy.ma as ma # creating input array in_arr = geek.array([[[ 2e8, 3e-5]], [[ -45.0, 2e5]]]) print ("Input array : ", in_arr) # Now we are creating a masked array. # by making one entry as invalid. mask_arr = ma.masked_array(in_arr, mask =[[[ 1, 0]], [[ 0, 0]]]) print ("3D Masked array : ", mask_arr) # applying MaskedArray.atleast_3d methods # to masked array out_arr = ma.atleast_3d(mask_arr) print ("Output masked array : ", out_arr) |
Output:
Input array : [[[ 2.0e+08 3.0e-05]] [[-4.5e+01 2.0e+05]]] 3D Masked array : [[[-- 3e-05]] [[-45.0 200000.0]]] Output masked array : [[[-- 3e-05]] [[-45.0 200000.0]]]
