如何从一组现有数组构造一个新的numpy数组？

Question

I have 12 numpy arrays, 5 of size (3, 121) and 7 of size (3, 120), ordered 0-11; call them a0, a1, ..., a11. I would like to construct a single new array built specifically in the following way:

newArray = [a0_00, a1_00, a2_00, ..., a11_00, a0_01, a1_01, ..., a11_01, a0_02...]

that is, I want to take the first column from each of the 12 arrays and add them, in order, to my new array, then take the second column of each of the 12 arrays and and those, and so on...

what I've most recently tried just repeats the first 12 values from each array through the entire new array, timedata...

for i in range(len(files)):
    data = loadtxt(files[i], skiprows=4, delimiter=',').T[0:,:]
    timedata[i::12] = data[0,0]

I've tried nested for loops and indexing the arrays in different ways but have not gotten anything to work so far... Any ideas would be greatly appreciated.

thank you

Answer 1

You basically have a jagged array that is 12 x 3 x (120 or 121). If the last column of the a05 through a11 were filled this would be a bit easier. Instead, you can iterate through the columns from 0 to 120; and iterate through the arrays; and add the column to the new array only if it exists.

Here is some sample code. Note that I used lengths of 11 and 12 instead of 120 and 121, but the idea is the same.

import numpy as np

np.random.seed(1000)
a01 = np.random.randint(0,10, (3,12))
a02 = np.random.randint(0,10, (3,12))
a03 = np.random.randint(0,10, (3,12))
a04 = np.random.randint(0,10, (3,12))
a05 = np.random.randint(0,10, (3,12))
a06 = np.random.randint(0,10, (3,11))
a07 = np.random.randint(0,10, (3,11))
a08 = np.random.randint(0,10, (3,11))
a09 = np.random.randint(0,10, (3,11))
a10 = np.random.randint(0,10, (3,11))
a11 = np.random.randint(0,10, (3,11))
arrayList = [a01, a02, a03, a04, a05, a06, a07, a08, a09, a10, a11]
cols = np.sum([a.shape[1] for a in arrayList])
newArray = np.zeros((3,cols))

arrIndex = 0
for i in range(12):
    for a in arrayList:
        try: 
            newArray[:,arrIndex] = a[:,i]
            arrIndex = arrIndex + 1
        except IndexError:
            pass