python/numpy: how to get 2D array column length?
Question:
How do i get the length of the column in a nD array?
example, i have a nD array called a. when i print a.shape, it returns (1,21).
I want to do a for loop, in the range of the column size of the array a. How do i get the value of
Answers:
You can get the second dimension of the array as:
a.shape[1]
this is a simple example, and you can follow it.By the way,the last statement should be corrected as “print b.shape[0]”
You could use np.size(element,dimension).
In your case:
a.shape
>> (1, 21)
np.size(a,0)
>> 1
np.size(a,1)
>> 21
Using the shape and size works well when you define a two dimension array, but when you define a simple array, these methods do not work
For example :
K = np.array([0,2,0])
K.shape[1] and numpy.size(K,1)
produce an error in python :
Traceback (most recent call last):
File "<ipython-input-46-e09d33390b10>", line 1, in <module>
K.shape[1]
IndexError: tuple index out of range
Solution :
It solved by adding a simple option to array,
K = np.array([0,2,0],ndmin = 2)
K.shape[0]
Out[56]: 1
K.shape[1]
Out[57]: 3
np.size(K,0)
Out[58]: 1
np.size(K,1)
Out[59]: 3
More information :
https://codewithkazem.com/array-shape1-indexerror-tuple-index-out-of-range/
How do i get the length of the column in a nD array?
example, i have a nD array called a. when i print a.shape, it returns (1,21).
I want to do a for loop, in the range of the column size of the array a. How do i get the value of
You can get the second dimension of the array as:
a.shape[1]
this is a simple example, and you can follow it.By the way,the last statement should be corrected as “print b.shape[0]”
You could use np.size(element,dimension).
In your case:
a.shape
>> (1, 21)
np.size(a,0)
>> 1
np.size(a,1)
>> 21
Using the shape and size works well when you define a two dimension array, but when you define a simple array, these methods do not work
For example :
K = np.array([0,2,0])
K.shape[1] and numpy.size(K,1)
produce an error in python :
Traceback (most recent call last):
File "<ipython-input-46-e09d33390b10>", line 1, in <module>
K.shape[1]
IndexError: tuple index out of range
Solution :
It solved by adding a simple option to array,
K = np.array([0,2,0],ndmin = 2)
K.shape[0]
Out[56]: 1
K.shape[1]
Out[57]: 3
np.size(K,0)
Out[58]: 1
np.size(K,1)
Out[59]: 3
More information :
https://codewithkazem.com/array-shape1-indexerror-tuple-index-out-of-range/