Matlab, add vector to matrix

Question

I want to add a vector to an existing matrix.

Example:

matrix=[1 2 3 4 5 6 0 7 0] vector = [7 8]

So the target is to find the equal number of vector and matrix for example with:

ismember(matrix,vector)

After that the vector should insert into the matrix like the following:

matrix=[1 2 3 4 5 6 0 7 0 0 8 0]

I don't understand what you want to achieve. You have a MxN matrix and you want to "insert" a vector where the first element of your vector matches a matrix entry? Waht if there is more than one match? Btw, this sounds like a XY-Problem maybe? Please clarify your question — Andy
– Andy, Commented Aug 18, 2017 at 15:03
You should show multiple input output examples if the solution below is insufficient. — Nick J
– Nick J, Commented Aug 18, 2017 at 23:36

jvz · Accepted Answer · 2017-08-18 07:08:08Z

Instead of using ismember, you can better use find with two output arguments:

>> [row, col]=find(matrix==vector(1)) row = 3 col = 2

Using Matlab's automatic matrix expansion, and assuming the vector is a column vector (you can adjust the code accordingly):

>> matrix(row:(row+length(vector)-1),col) = vector matrix = 1 2 3 4 5 6 0 7 0 0 8 0

If the match is not at the edge (i.e., row~=size(matrix,1)), this would not work though, as the vector would override other entries.

You have a idea what i can do if the match is not at the edge? a function to insert the vector and not to override would be nice.
Maybe you should update the problem with a full set of examples of what you're trying to achieve.
@MatthiasR. If this works, consider marking the answer as accepted so this question is shown as closed. Otherwise edit your question to explain why this doesn't answer your question.

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