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Adding one matrix with another matrix in MATLAB

I am trying to add a matrix with a different matrix in MATLAB.

The first matrix looks like this:

0.0963928845397177  1.30250820960714
-0.830468497619261  1.40991150001902
-0.352252185662263  -1.66254297035808
-0.174775039544099  1.94368447839214
-0.480653419481013  -1.08469845223762
0.836836711417678   0.226818975021420
2.53834934138902    1.09892920248474
-1.32333425148040   0.147188752472257
0.128340263343307   2.29566581301284
-1.44237915336114   2.75255787759549

The second matrix looks like this:

[1 2]

I want to add a second matrix with the first matrix => the value 0.0963928845397177 + 1 and 1.30250820960714 + 2. I want to add 1 to the first column and 2 to the second column.

What I have tried:

secondmatrix .+ firstmatrix

But it doesn't work.

You need to be guided.

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6 answers


You can do it:

A = ones(5,2)
B=[1,2]
C = A+repmat(B,size(A,1),1)


or

C = [A(:,1)+B(1,1) A(:,2)+B(1,2)]
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It is probably best avoided repmat

if you can for efficiency if you are going to use this with large matrices. Similar to the approach [A(:,1)+b(1) A(:,2)+b(2)]

. I'm a fan bsxfun

:



bsxfun(@plus, A, b)
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Either Jommy suggested , or you can replicate a smaller matrix to make it the same size and then add like this:

C = A + repmat(B,[size(A,1),1]);
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try it

 sum_ = first_matrix + repmat(second_matrix,size(first_matrix,1),1);
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Matlab provides a function for what you want to do, bsxfun , which "Applies a one-by-item binary operation to two arrays with single color expansion enabled"

Sample code:

result_matrix = bsxfun(@plus, firstmatrix, secondmatrix);
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If A

is a large matrix and B

is a small one you can write

C = [A(:,1)+B(1) A(:,2)+B(2)];

Another possibility is

C = A + repmat(B, [length(A) 1]);
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