How can I find the dimensions of a matrix in Python

Question

How can I find the dimensions of a matrix in Python  Len A  returns only one variable   Edit   close   dataobj get data timestamps  symbols  closefield    Is  I assume  generating a matrix of integers  less likely strings   I need to find the size of that matrix  so I can run some tests without having to iterate through all of the elements  As far as the data type goes  I assume it s an array of arrays  or list of lists

User · Answer

You simply can find a matrix dimension by using Numpy:

import numpy as np

x = np.arange(24).reshape((6, 4))
x.ndim

output will be:

It means this matrix is a 2 dimensional matrix.

x.shape

Will show you the size of each dimension. The shape for x is equal to:

(6, 4)

User · Answer

Suppose you have a which is an array  to get the dimensions of an array you should use shape   import numpy as np a   np array   3 20 99   -13 4 5 26   0 -1 20   5 78 -19    a shape  The output of this will be  4 3

User · Answer

To get just a correct number of dimensions in NumPy   len a shape    In the first case   import numpy as np a   np array    1 2 3   1 2 3     12 3 4   2 1 3     print  shape     np shape a   print  dimensions     len a shape     The output will be   shape     2  2  3  dimensions    3

User · Answer

As Ayman farhat mentioned  you can use the simple method len matrix  to get the length of rows and get the length of the first row to get the no  of columns using len matrix 0       gt  gt  gt  a   1 5 6 8   1 2 5 9   7 5 6 2    gt  gt  gt  len a  3  gt  gt  gt  len a 0   4   Also you can use a library that helps you with matrices  numpy     gt  gt  gt  import numpy   gt  gt  gt  numpy shape a   3 4

User · Answer

m     1  1  1  0   0  5  0  1   2  1  3  10    print len m  len m 0      Output      3 4

User · Answer

The number of rows of a list of lists would be  len A  and the number of columns len A 0   given that all rows have the same number of columns  i e  all lists in each index are of the same size

User · Answer

The correct answer is the following   import numpy  numpy shape a

User · Answer

If you are using NumPy arrays  shape can be used  For example     gt  gt  gt  a   numpy array    1 2 3   1 2 3     12 3 4   2 1 3        gt  gt  gt  a   array     1   2   3              1   2   3                12   3   4              2   1   3       gt  gt  gt  a shape   2  2  3

User · Answer

You may use as following to get Height and Weight of an Numpy array   int height   arr shape 0  int weight   arr shape 1    If your array has multiple dimensions  you can increase the index to access them

[python] How can I find the dimensions of a matrix in Python?

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