Assign vector to vector with gaps

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baxbear
baxbear on 16 Jul 2016
Commented: baxbear on 22 Jul 2016
Stuff doesn't matter - was tired - start reading at Edit1 - sry
Hello,
I have a matrix of row size m and a matrix of row size n where m > n and x = m - n. I also got a vector k of length x with different row indices of m. Now I want to assign n to m by not touching entries m(k) important is that these rows stay unchanged and in place.
Is there an easy one-liner? like:
m(m ~= x) = n;
or
m(m ~= m(x)) = n;
but seems not to work :(
Hope you can help me.
Thanks in advance.
=================================================================
HERE!:-> @Edit1: Oh, uff was late yesterday and yeah what ever I wrote there is pretty confusing and wrong... so again:
Matrix A of size m * _ where m is the number of rows and matrix B of size n * _ where n is the number of rows. Still true is: m > n and x = m - n and V is a vector with x rows.
Example:
A = [1,1,1; 2,2,1; 3,3,4; 8,3,6; 8,3,0; 8,6,3];
B = [4,2,5; 4,3,2; 6,3,2; 8,0,9];
V = [2; 4];
Result in A:
A = [4,2,5; 2,2,1; 4,3,2; 8,3,6; 6,3,2; 8,0,9];
just for much bigger matrices. Sorry for my unclear post yesterday hope you are still willing to help me.
  2 Comments
Azzi Abdelmalek
Azzi Abdelmalek on 16 Jul 2016
You can make your question clear by posting an example
Image Analyst
Image Analyst on 16 Jul 2016
Edited: Image Analyst on 16 Jul 2016
Your terminology is pretty sloppy. Are m and n the width of the matrix (number of columns which is the "row size" or "row length") or the names of the matrices? Are your matrices really column vectors? Or row vectors?
This is what I have so far but can't go further because of ambiguities in your terminology.
m=10
n=6
x = m-n
vec1 = randi(99, 1, m) % First "matrix" (sample data)
vec2 = randi(99, 1, n) % Second "matrix" (sample data)
k = randperm(m, x) % indexes of m

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Accepted Answer

goerk
goerk on 19 Jul 2016
A = [1,1,1; 2,2,1; 3,3,4; 8,3,6; 8,3,0; 8,6,3];
B = [4,2,5; 4,3,2; 6,3,2; 8,0,9];
V = [2; 4];
% create 'inversion' of V (there may be better ways)
notV = 1:size(A,1); % vector from 1 to number of rows
notV(V) = []; % delete rows which are in V
% over write the rows that are not in V
A(notV,:)=B
  3 Comments
goerk
goerk on 19 Jul 2016
Thanks, that's a nice short solution.
baxbear
baxbear on 22 Jul 2016
Thank you very much :D

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