Python/Numpy - Extract a 2-d Sub-array from a 2-d array using variables

Question

Ok, So I have a 2-d array of data which has the shape(23025, 1000), it's called 'allfiles'.

I need to go through the array 50 columns at a time and extract them to a sub-array for manipulation. The problem is when i address the array using the code below, it doesn't seem to recognize the variables (a and b). the code i have at the moment is shown below.

    q = 50
    a = np.shape(allfiles)[1] # a = 1000
    for i in range(a):
        b = a + q
        data = allfiles[:,a:b]

When i replace the variables with number, i.e...

    data = allfiles[:,30:80]

It seems to work. So, my question is - is there a way i can pass variables to the array index? If not is there a better way i can create a subarray using variables?

I have tried to find this problem on stack overflow with no luck, but i'm sure i'm not the first person to have this trouble?

Cheers guys, Morgan

eumiro · Accepted Answer · 2011-10-24 12:43:07Z

2

You are getting i from the loop but don't use it.

q = 50

for start in xrange(0, allfiles.shape[1], q):
    data = allfiles[:,start:start+q]
    ...

answered Oct 24, 2011 at 12:43

eumiro

214k36 gold badges307 silver badges264 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user1010836 Over a year ago

Cheers, that sorted everything out for me.

Collectives™ on Stack Overflow

Python/Numpy - Extract a 2-d Sub-array from a 2-d array using variables

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related