replace part of matrix to another matrix

조회 수: 14 (최근 30일)
mohammed hussein
mohammed hussein 2017년 11월 18일
댓글: mohammed hussein 2017년 11월 19일
Hi i have many matrices in same size , i want to add all of them together in one matrix with replace the last quarter of each one to binning of next one until complete the matrix and the rest will be zeros . for example
a =zeros(5,5)
A=[1 2 ;3 4];
B=[5 6;7 8];
C=[9 10;11 12];
D=[13 14;15 16];
the answer
a=
1 2 0 0 0
3 5 6 0 0
0 7 9 10 0
0 0 11 13 14
0 0 0 15 16
thank you very much for helping

채택된 답변

Stephen23
Stephen23 2017년 11월 18일
편집: Stephen23 2017년 11월 18일
For any size matrices, even combinations of different sizes:
C = {[1,2;3,4],[5,6;7,8],[9,10;11,12],[13,14;15,16]};
num = numel(C);
szr = cellfun('size',C,1);
szc = cellfun('size',C,2);
csr = cumsum([0,szr-1]);
csc = cumsum([0,szc-1]);
M = zeros(1+csr(end),1+csc(end));
for k = 1:num
idr = csr(k)+(1:szr(k));
idc = csc(k)+(1:szc(k));
M(idr,idc) = C{k};
end
Giving:
>> M
M =
1 2 0 0 0
3 5 6 0 0
0 7 9 10 0
0 0 11 13 14
0 0 0 15 16
It works perfectly with any size matrices, e.g.:
C = {[1,2;3,4],[5,6;7,8],[1,2,3;4,5,6;7,8,9],[9,10;11,12],[13,14;15,16]};
gives
M =
1 2 0 0 0 0 0
3 5 6 0 0 0 0
0 7 1 2 3 0 0
0 0 4 5 6 0 0
0 0 7 8 9 10 0
0 0 0 0 11 13 14
0 0 0 0 0 15 16
  댓글 수: 1
mohammed hussein
mohammed hussein 2017년 11월 19일
thank you very much for your answer , this is exactly what i want

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추가 답변 (2개)

Walter Roberson
Walter Roberson 2017년 11월 18일
A=[1 2 ;3 4];
B=[5 6;7 8];
C=[9 10;11 12];
D=[13 14;15 16];
newvals = {A, B, C, D};
a = zeros(5,5);
for K = 1 : length(newvals)
a(K:K+1, K:K+1) = newvals{K};
end

Andrei Bobrov
Andrei Bobrov 2017년 11월 18일
편집: Andrei Bobrov 2017년 11월 18일
In your case (without loop)
k = cat(3,A,B,D,C);
[m,n,q] = size(k);
a = full(gallery('tridiag',q*m/2+1,1,1,1));
ii = ((1:m*n-1) + (0:q-1)'*m*n)';
a(a>0) = k([ii(:);prod([m,n,q])]);
in general case (with for..end loop)
C = {[1,2;3,4],[5,6;7,8],[1,2,3;4,5,6],[9,10;11,12],[13,14;15,16]};
[m,n] = cellfun(@(x)size(x),C(:));
s = sum(m-1) + 1;
a = zeros(s,sum(n-1)+1);
jj = 1;
for ii = 1:numel(m)
id = jj + (0:m(ii)-1)' + s*(0:n(ii)-1);
a(id) = C{ii};
jj = id(end);
end
All for MATLAB >= R2016b

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