Sum of index elements

Hi, I have a matrix A(641x481) with numbers 0<x<3 and others matrix B,C,D and F with the same size of matrix A. I need create a matrix G, but depending the value of the element in A, the value in G will be the sum of different combinations of B,C, D and F. For example

    If A(i,j) < 0.25; so  G(i,j) = B(i,j) + C(i,j);
    If 0.25< A(r,s)<1; so G(r,s) = B(r,s) + D(r,s);
    etc

Thanks

Answer 1

[Azzi Abdelmalek]

A=rand(4,5);
[n,m]=size(A)
B=rand(n,m)
C=rand(n,m)
D=rand(n,m)
G=zeros(n,m)
idx1=A < 0.25
G(idx1) = B(idx1) + C(idx1)
idx2=0.25<A & A<1; 
G(idx2) = B(idx2) + D(idx2)

[Azzi Abdelmalek]

A=rand(641,481);
[n,m]=size(A);
B=rand(n,m);
C=rand(n,m);
D=rand(n,m);
G=zeros(120686,1);
idx1=A < 0.25;
G(idx1(:)) = B(idx1(:)) + C(idx1(:));
idx2=0.25<A <1; 
G(idx2(:)) = B(idx2(:)) + D(idx2(:));

Answer 2

[cob]

Hi Azzi, I did exactly this but my matrix G instead of having 641x481 elements like the older ones, it has 120686X1 elements. I need to preserve the matrix shape to plot a distribution's plot after. Thanks

[Azzi Abdelmalek]

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