Python duplicate list values from index to another

Question

Let's say I have this numpy array :

first_array = [[1. 0. 0. 0. 0.]
               [1. 0. 0. 0. 0.]
               [0. 1. 0. 0. 0.]
               [0. 0. 1. 0. 0.]
               [0. 0. 1. 0. 0.]
               [0. 0. 1. 0. 0.]
               [0. 0. 0. 0. 1.]]

and I have this 2 lists :

index_start = [50, 80, 110, 120, 150, 180, 200]
index_end= [70, 90, 115, 140, 170, 190, 220]

I want to create a new 2D numpy output_array where I iterate by column first_array and duplicate each value of every row from an index_start to an index_end.

1st iteration - For example first_array[[1,1]] = 1, index_start[1] = 50 and index_end[1]=70 then the first column of my output_array will have the value 1 from index 50 to 70.

2nd iteration - Then first_array[[2,1]] = 1, index_start[2] = 80 and index_end[2]=90 then the first column of my output_array will have also the value 1 but from index 80 to 90.

3rd iteration - first_array[[2,3]] = 1, index_start[3] = 110 and index_end[3]=115 then the second column of my output_array will have the value 1 from index 110 to 115 and so on.

Here's what I have tried but this is giving me wrong result :

first_array = [[1, 0, 0, 0, 0,],
               [1, 0, 0, 0, 0,],
               [0, 1, 0, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 0, 0, 1,]]
index_start = [50, 80, 110, 120, 150, 180, 200]
index_end= [70, 90, 115, 140, 170, 190, 220]
last_index = max(index_start+index_end)
output_array = np.zeros((last_index, 5))

for i in range(len(index_start)):
    for j in range(last_index):
        for k in range(5):
            output_array[index_start[i]:index_end[i]]=first_array[i][k]

Mejdi Dallel · Accepted Answer · 2019-11-14 11:04:37Z

2

It's working now. I forgot to add the k column index at the output_array. Here's the final working code if anyone needed this.

first_array = [[1, 0, 0, 0, 0,],
               [1, 0, 0, 0, 0,],
               [0, 1, 0, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 1, 0, 0,],
               [0, 0, 0, 0, 1,]]
index_start = [50, 80, 110, 120, 150, 180, 200]
index_end= [70, 90, 115, 140, 170, 190, 220]
last_index = max(index_start+index_end)
output_array = np.zeros((last_index+1, 5))

for i in range(len(index_start)):
    for k in range(5):
        output_array[index_start[i]:index_end[i]+1, k]=first_array[i][k]

edited Nov 14, 2019 at 11:04

answered Nov 14, 2019 at 10:57

Mejdi Dallel

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