Hi everyone, I tried to solve this problem but I could not find the 
solution. I have about 105 matrices of equal size in the memory of**R, I 
need to do is extract from these matrices some known positions and 
create a new matrix with these columns. Show you an example with only 
three matrices (but in my case I have hundreds of them).

A=matrix(1:15,5)

[,1] [,2] [,3]

[1,] 1 6 11

[2,] 2 7 12

[3,] 3 8 13

[4,] 4 9 14

[5,] 5 10 15

B=matrix(15:29,5)

[,1] [,2] [,3]

[1,] 15 20 25

[2,] 16 21 26

[3,] 17 22 27

[4,] 18 23 28

[5,] 19 24 29

C=matrix(30:44,5)

[,1] [,2] [,3]

[1,] 30 35 40

[2,] 31 36 41

[3,] 32 37 42

[4,] 33 38 43

[5,] 34 39 44

The positions I wish to extract are 1 and 5 of the first row of each 
matrix (in my case are 25positions) and with this generate a new matrix 
with the form

d=

[,1] [,2] [,3]

[1,] 1 15 30

[2,] 5 19 34

The ideais to builda loop toextract thisinformation from 
hundredsmatrices, butI failed todo so.

Any helpwould be greatthank you very muchin advance

regards
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