Select values from 20 x 15 matrix based on a row vector 1 x 15

Question

Parthu P 2019-11-7

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评论： Steven Lord 2019-11-7

I'm trying to extract values from matrix A (20 x 15) which are less than values in matrix B (1 x 15). Matrix B has 15 columns with threshold values determined from newspaper analysis. How to extract values from each column of matrix A which are less than values from corresponding columns from matrix B?

I have tried C = A < B; but I'm not able to fix matrix dimension error.

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Steven Lord 2019-11-7

Which release of MATLAB are you using? It may be relevant particularly if you're using a release prior to release R2016b, when we introduced implicit expansion.

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Answer 1

JESUS DAVID ARIZA ROYETH 2019-11-7

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solution:

A(A>=B)=nan;
disp(A)
c=num2cell(A,1);
for k=1:size(c,2)
    c{k}(isnan(c{k}))=[];
    disp(['Column ' num2str(k)])
    disp(c{k})    
end

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Parthu P 2019-11-7

Thanks for reply.

Actually I have tried the simillar loop before but I'm not able to fix dimension error related to B.

For example, in "C = A < B"

If I make "C = A < B (:,1)" or "C = A < B (:,15)". It read B value in either 1st or 15th column and apply it to all the columns. How do i put right dimensions for "B (. . . . . )", so that it reads correct B value for corresponding individual columns of matrix A?

JESUS DAVID ARIZA ROYETH 2019-11-7

在 MATLAB Online 中打开

This works well for the dimensions you indicated, could you save your workspace and attach it? look at an example:

A=rand(20,15);
B=rand(1,15);
A(A>B)=nan;
disp(A)
c=num2cell(A,1);
for k=1:size(c,2)
    c{k}(isnan(c{k}))=[];
    disp(['Column ' num2str(k)])
    disp(c{k})    
end