# Saving a value from matrix B, indexed by matrix A

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sprklspring on 8 Jun 2018
Commented: Majid Farzaneh on 12 Jun 2018
Hello all, I have a pretty basic question which causes me problems. I have a 1x100 vector A. Each cell of this vector contains a different number, i.e. A(1,1) = 2010, A(1,2) = 3834, etc. Now, this values of a vector A are indeces, which index a column of vectors contained in all cells of a matrix B; matrix B is an 8x8 cell matrix, and each of its cells contain a 1x4000 vector of numbers. Could you tell me what is your idea of finding values indexed by the vector A in all of the cells of matrix B?
Update from below: all the numbers in 'indeces' vector are supposed to be found in each cell of the 8x8 matrix 'cell', i.e. I expect the output from each cell of the output matrix (the 'What you want' one) to be a vector of 1x132, providing the sample files I attached. Here it seems like I overwrite and save just the 132th value, since the output is just an 8x8 matrix of numbers, instead of 8x8 cell matrix of 1x132 vectors.
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sprklspring on 8 Jun 2018
Here you can see a sample. In 'indeces' we have 132 values in 1x132 vector. These 132 numbers correspond with columns in 'cells', i.e., value 2781 (1,1 in 'indeces') indicates that the value I need to save is stored under column 2781 in 'cells{1}' - in this case, this number is 9. I have 64 cells in my 'cells' matrix, and I need to perform this search and save for every cell, with all of the numbers indicated in 'indeces'.

Majid Farzaneh on 8 Jun 2018
Edited: Majid Farzaneh on 8 Jun 2018
Hi, you can use a for loop for B like this:
for i=1:numel(B)
...
end
Then, determine the index by A, like this:
idx=A(1,1); % for example
Get B values like this:
What_you_want(i)=B{i}(idx)
Majid Farzaneh on 8 Jun 2018
for i=1:numel(B)
idx=A(1,1); % for example
What_you_want(i)=B{i}(idx)
end
At the end you have 64 values in What_you_want matrix for 64 cells in B.

sprklspring on 11 Jun 2018
Thanks Majid! You helped a lot, it's just one questions keeps bugging me: all the numbers in 'indeces' vector are supposed to be found in each cell of the 8x8 matrix 'cell', i.e. I expect the output from each cell of the output matrix (the 'What you want' one) to be a vector of 1x132, providing the sample files I attached. Here it seems like I overwrite and save just the 132th value, since the output is just an 8x8 matrix of numbers, instead of 8x8 cell matrix of 1x132 vectors. Do you know what I mean?
Majid Farzaneh on 12 Jun 2018
You're welcome