`numpy.lib._scimath_impl:_tocomplex`

source: build-install/usr/lib/python3.14/site-packages/numpy/lib/_scimath_impl.py:32

Signature

def _tocomplex(arr)

Summary

Convert its input arr to a complex array.

Extended Summary

The input is returned as a complex array of the smallest type that will fit the original data: types like single, byte, short, etc. become csingle, while others become cdouble.

A copy of the input is always made.

Parameters

arr : array

Returns

: array: An array with the same input data as the input but in complex form.

Examples

import numpy as np

✓

First, consider an input of type short:

a = np.array([1,2,3],np.short)

✓

ac = np.lib.scimath._tocomplex(a); ac

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    ac = np.lib.scimath._tocomplex(a); ac
         ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'numpy.lib.scimath' has no attribute '_tocomplex'

ac.dtype

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    ac.dtype
    ^^
NameError: name 'ac' is not defined. Did you mean: 'a'?

If the input is of type double, the output is correspondingly of the complex double type as well:

b = np.array([1,2,3],np.double)

✓

bc = np.lib.scimath._tocomplex(b); bc

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    bc = np.lib.scimath._tocomplex(b); bc
         ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'numpy.lib.scimath' has no attribute '_tocomplex'

bc.dtype

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    bc.dtype
    ^^
NameError: name 'bc' is not defined. Did you mean: 'b'?

Note that even if the input was complex to begin with, a copy is still made, since the astype() method always copies:

c = np.array([1,2,3],np.csingle)

✓

cc = np.lib.scimath._tocomplex(c); cc

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    cc = np.lib.scimath._tocomplex(c); cc
         ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'numpy.lib.scimath' has no attribute '_tocomplex'

c *= 2; c

✗

array([2.+0.j, 4.+0.j, 6.+0.j], dtype=complex64)

cc

⚠

Traceback (most recent call last):
  File "<doctest numpy.lib._scimath_impl:_tocomplex[0]>", line 1, in <module>
    cc
NameError: name 'cc' is not defined. Did you mean: 'c'?

Aliases

numpy.lib._scimath_impl._tocomplex