Numpy MaskedArray.reshape() function | Python (original) (raw)
Last Updated : 03 Oct, 2019
numpy.MaskedArray.reshape()
function is used to give a new shape to the masked array without changing its data.It returns a masked array containing the same data, but with a new shape. The result is a view on the original array; if this is not possible, a ValueError is raised.
Syntax :
numpy.ma.reshape(shape, order)
Parameters:
**shape:**[ int or tuple of ints] The new shape should be compatible with the original shape.
order : [‘C’, ‘F’, ‘A’, ‘K’, optional] By default, ‘C’ index order is used.
–> The elements of a are read using this index order.
–> ‘C’ means to index the elements in C-like order, with the last axis index changing fastest, back to the first axis index changing slowest.
–> ‘F’ means to index the elements in Fortran-like index order, with the first index changing fastest, and the last index changing slowest.
–> ‘A’ means to read the elements in Fortran-like index order if m is Fortran contiguous in memory, C-like order otherwise.
–> ‘K’ means to read the elements in the order they occur in memory, except for reversing the data when strides are negative.Return : [ reshaped_array] A new view on the array.
Code #1 :
import
numpy as geek
import
numpy.ma as ma
in_arr
=
geek.array([
1
,
2
,
3
,
-
1
])
print
(
"Input array : "
, in_arr)
mask_arr
=
ma.masked_array(in_arr, mask
=
[
1
,
0
,
1
,
0
])
print
(
"Masked array : "
, mask_arr)
out_arr
=
mask_arr.reshape(
2
,
2
)
print
(
"Output 2D masked array : "
, out_arr)
Output:
Input array : [ 1 2 3 -1] Masked array : [-- 2 -- -1] Output 2D masked array : [[-- 2] [-- -1]]
Code #2 :
import
numpy as geek
import
numpy.ma as ma
in_arr
=
geek.array([[[
2e8
,
3e
-
5
]], [[
-
45.0
,
2e5
]]])
print
(
"Input array : "
, in_arr)
mask_arr
=
ma.masked_array(in_arr, mask
=
[[[
1
,
0
]], [[
0
,
0
]]])
print
(
"3D Masked array : "
, mask_arr)
out_arr
=
mask_arr.reshape(
1
,
4
)
print
(
"Output 2D masked array : "
, out_arr)
print
()
out_arr
=
mask_arr.reshape(
4
, )
print
(
"Output 1D 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 2D masked array : [[-- 3e-05 -45.0 200000.0]]
Output 1D masked array : [-- 3e-05 -45.0 200000.0]