dask.array.diag — Dask documentation (original) (raw)
dask.array.diag¶
dask.array.diag(v, k=0)[source]¶
Extract a diagonal or construct a diagonal array.
This docstring was copied from numpy.diag.
Some inconsistencies with the Dask version may exist.
See the more detailed documentation for numpy.diagonal if you use this function to extract a diagonal and wish to write to the resulting array; whether it returns a copy or a view depends on what version of numpy you are using.
Parameters
varray_like
If v is a 2-D array, return a copy of its k-th diagonal. If v is a 1-D array, return a 2-D array with v on the k-th diagonal.
kint, optional
Diagonal in question. The default is 0. Use k>0 for diagonals above the main diagonal, and k<0 for diagonals below the main diagonal.
Returns
outndarray
The extracted diagonal or constructed diagonal array.
See also
Return specified diagonals.
diagflat
Create a 2-D array with the flattened input as a diagonal.
Sum along diagonals.
Upper triangle of an array.
Lower triangle of an array.
Examples
import numpy as np
x = np.arange(9).reshape((3,3))
x
array([[0, 1, 2], [3, 4, 5], [6, 7, 8]])
np.diag(x)
array([0, 4, 8]) np.diag(x, k=1)
array([1, 5]) np.diag(x, k=-1)
array([3, 7])
np.diag(np.diag(x))
array([[0, 0, 0], [0, 4, 0], [0, 0, 8]])