Subtract values of a row vector to each column of a matrix.

Hello guys,

I have written a small code attempting to remove an offset from a set of signals stored in a matrix. I need to subtract for each value of a column of a matrix (120x10) the value contained in a single row vector (1x10). Basically each column of the matrix represents an independent signal.

I have put together some code but I'm not obtaining what expected.

Here 'data' is a matrix (120x10) whereas 'columnMeans' is a row vector (1x10). Each column of the row vector should be used for the subtraction of the corresponding column of the matrix. I'm not even sure whether for loop is necessary.

for i=1:10
data_new=data-columnMeans(i)
end

Answer 1

[madhan ravi]

Hi, I have attached an example:

columnMeans=randi([1 10],1 ,10);

data=randi([1 30],120,10);

[m,n] = size(data);

for i=1:m

    data_new(i:i,:)=data(i:i,:)-columnMeans(:,:)

end

data_new

size(data_new)

Answer 2

[Gul Rukh Khan]

Thanks, for the Answer,

I have another problem, I want to subtract 1st pixel value in 10x10 matrix from the next to the right as well as to the down pixel. and also to store it in r(x,y) matrix. How, I will do it? Please, this command, is not working properly.

for x=1:10

for y=1:10

r (x,y) = (aa(x,y)-(aa(x,y)));

x=x+1;

end

end

Answer 3

[Brooks Li]

No need to do the for loop.

Just

data_new = data - columnMeans;

will simply work.