'Filling an empty matrix with a for loop

I am trying to create a 3195x71 matrix in Python using iterations and equations. The code is referenced below:-

##Creating an empty matrix
import numpy as np
CC_FINAL = np.empty((3195,71))
for i in range(3195):
    eB1_s = eB1[i]
    Ys = Y.iloc[i]
    Y_s = Ys.values.reshape(1,71)
    CC_s = np.dot(eB1_s,Y_s)
    CClist=CC_s
    CCdf=pd.DataFrame(CClist) 
    CC_final_demand_s=np.add(CC_s,HC,size=(1,71))
    print(CC_final_demand_s)
    Final_DD = np.concatenate((CC_FINAL,CC_final_demand_s))
print(Final_DD)

The equation CC_final_demand_s=np.add(CC_s,HC,size=(1,71)) checks out and I get my desired output. The output is to look like this (upto 71 columns, 3195 times)

 0           1             2            3           4   \
1  5913403.203026  214.118854  15892.865306  5379.204602  333.111413   

          5          6            7          8          9          10  \
1  499.54388  27.436068  8302.752527  293.54779  30.622154  87.851813   

             11            12          13         14         15          16  \
1  10121.788307  38874.323567  120.792053  46.108922  20.592629  727.064092   

           17            18            19            20        21        22  \
1  7838.86962  30496.167176  92945.842897  40627.994136  4.506425  8.177975

But when I'm trying to combine the results from the equation above into the empty matrix, something does not seem to be working correct. I get the correct dimensions for Final_DD but the output is not right. Any suggestions are greatly appreciated!

python numpy

Solution 1:^[1]

You start with CC_FINAL = np.empty((3195,71)) and don't change it. Did you look at its values? I suspect you don't understand what np.empty does.

In the loop you do

Final_DD = np.concatenate((CC_FINAL,CC_final_demand_s))

That is joining the (3195,71) array with a (1,71) array producing a (3196,71), where most of the rows are garbage. You do that again and again, without changing CC_FINAL or preserving Final_DD. You just concatenate on a different CC_final_demand_s. You are not "filling" CC_FINAL at all.

Work through the logic in more detail. It may help for make much smaller arrays so you can actually look at the their values.

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Solution 1	hpaulj

'Filling an empty matrix with a for loop

Solution 1:[1]

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Solution 1:^[1]