All Questions
Tagged with numpy multidimensional-array
2,102
questions
1
vote
1
answer
71
views
How do I effectively compute pairwise quantities in numpy?
I want to compute pairwise quantities, e.g. distances between two points.
A simple example would be
import numpy as np
N = 9
x = np.linspace(0,1,N)
y = np.abs(x - x[:,None]) # pairwise 1d eucdlidian ...
- 23
0
votes
0
answers
54
views
Interpolate y-value given x-value and data value in a 2D array
I am working with a 2D dataset with the x and y dimensions representing two separate variables, and the combined 2D grid representing a third variable. Here's a visual example of the dataset
and the x ...
4
votes
2
answers
112
views
Optimal multiplication of two 3D arrays having a variable dimension
I would like to multiply tensors R = {R_1, R_2, ..., R_M} and X = {X_1, X_2, ..., X_M} where R_i and X_i are 3×3 and 3×N_i matrices, respectively. How can I make maximum use of NumPy functionalities ...
- 143
0
votes
1
answer
91
views
How to understand transpose operation on a 3D or Higher Dimensional Array
Consider a 3D array array_3d with shape (3, 2, 2):
array_3d = np.array([
[[ 0, 1],
[ 2, 3]],
[[ 4, 5],
[ 6, 7]],
[[ 8, 9],
[10, 11]]
])
array_3d.shape = (3, 2, 2)
...
0
votes
0
answers
19
views
error: all the input arrays must have same number of dimensions, but the array at index 0 has 1 dimension(s) and the array at index 1 has 2 dimensions [duplicate]
Getting the below error while executing the code for the ravdess dataset
/usr/local/lib/python3.10/dist-packages/librosa/core/spectrum.py:266: UserWarning: n_fft=2048 is too large for input signal of ...
- 1
1
vote
2
answers
124
views
ValueError: could not broadcast input array from shape A into shape B
I used Python with Numpy to create an array filled with numbers from a tuple, and set it up to be a 4x4 matrix.
numbers = (-8, -3, -5, 0, 4, 5, 6, 10, 7,8, 9, 100, 10, 11, 12, 1000)
numbers_array = ...
- 11
2
votes
3
answers
53
views
Numpy slicing on a zero-padded 2D array
Given a 2D Numpy array, I'd like to be able to pad it on the left, right, top, bottom side, like the following pseudo-code. Is there anything like this already built into Numpy?
import numpy as np
a =...
- 44.9k
0
votes
1
answer
45
views
NumPy ndarray non contiguous memory layout
I need some help in understanding the equations involved in finding the index of an element in an ndarray. I have been reading the Book "Guide to NumPy" by Travis A Oliphant. Link to the ...
0
votes
1
answer
30
views
3d numpy array output, meant to emulate an image, can't convert to Image
I am creating an autostereogram with the function make_autostereogram. It is being output as a 3d NumPy array (rows, colums, RGB).
It is then input into the Pillow function fromarray(). It has array ...
- 173
-1
votes
1
answer
59
views
Numpy Broadcasting - Need complete understanding
I am trying to understand Numpy Broadcasting.
So I want to understand why is the below code working?
a = np.arange(4).reshape(2,2)
b = np.arange(6).reshape(3,2)
a = a[:, np.newaxis]
a + b
I mean if ...
0
votes
1
answer
39
views
Why are my numpy array elements being cast to lists?
import numpy as np
ar1 = np.array([[[1,2,3],[4,5,6]],[[1,2,3],[4,5,6]]])
ar2 = np.array([[[1,2,3],[4,5,6]],[[1,2,3,4],[4,5,6,7]]])
print(ar1)
print(ar2)
When I run this the second array prints out ...
- 13
0
votes
1
answer
67
views
How can I speed up the processing of my nested for loops for a giant 3D numpy array?
I created a very large 3D numpy array called tr_mat. The shape of tr_mat is:
tr_mat.shape
(1024, 536, 21073)
Info on the 3D numpy array: First and before going into the actual code, I would like to ...
- 415
1
vote
3
answers
97
views
Implementing 2D sliding window over np.array without overlaps (tiling, mean pooling)
I'm trying to implement 2D sliding window of cubic shape (k,k), to so I can iterate over a frame (n,m,3) and calculate the mean over the pixel values in each window.
I want each iteration, that the ...
- 57
0
votes
1
answer
66
views
Fix this numpy-function so it accepts multidimensional inputs
I am trying to compute the following function:
geo-decay-function:
in numpy, has to be vectorized. The catch in this case is that it should work for multidimensional inputs. E.g., x having dimensions ...
- 1
1
vote
1
answer
111
views
Implementing 1D interpolation on a 3D Array in Numpy or Xarray
I have been attempting to find a way to utilize np.interp() to interpolate the innermost dimension of a 3D array:
Say I have a 3D array with shape: (lat,lon,depth) = (3,3,4) as a toy example:
...
