Add element to the matrix in one sentence

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Xin
Xin 2017-6-14
编辑： Andrei Bobrov 2017-6-14
I have a 2D matrix, say A=zeros(10,10). I want to add a vector of number to the matrix. I have the index of the elements, but it is repeated. E.g. the index [5,3,2,5,3,100,5] and the value is some random [1,2,3,4,5,6,7]. I then want to add 1 into 5th element of A, 2 into 3rd element and so on. How do I do this in one line?
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Adam
Adam 2017-6-14
You can vectorize multi-line statements too.
Xin
Xin 2017-6-14
Could you please be more specific. That's what I have been doing but for this problem it is not very straightforward.

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Andrei Bobrov
Andrei Bobrov 2017-6-14
编辑：Andrei Bobrov 2017-6-14
A=zeros(10,10);
ii = [5,3,2,5,3,100,5];
var = 1:7;
[ii,ib] = unique(ii);
A(ii) = var(ib);
or
A([5,3,2,5,3,100,5]) = 1:7
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Andrei Bobrov
Andrei Bobrov 2017-6-14
This is not possible for a double array if only for cell array.
Andrei Bobrov
Andrei Bobrov 2017-6-14
编辑：Andrei Bobrov 2017-6-14
ii = [5,3,2,5,3,100,5];
var = 1:7;
A = reshape(accumarray(ii(:),var(:),[100 1],@(x){x(:)'}),10,[]);

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Guillaume
Guillaume 2017-6-14
编辑：Guillaume 2017-6-14
If I understood correctly
A = zeros(10,10);
indices = [5,3,2,5,3,100,5];
values = [1,2,3,4,5,6,7];
A = A + reshape(accumarray(indices(:), values(:), [numel(A), 1]), size(A))
would be one way to do it. Alternatively,
[uindices, ~, loc] = unique(indices);
sumvalues = accumarray(loc(:), values(:));
A(uindices) = A(uindices) + sumvalues;

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