How to correct for loop?

sarfse

Answer 1

[Andrei Bobrov]

A = [ 1     0     0     4
     1     0     3     4
     1     2     0     4
     1     2     3     4];
D = [         0   22.2794   33.7859   45.0000
   22.2794         0   15.4008   23.0367
   33.7859   15.4008         0   14.9726
   45.0000   23.0367   14.9726         0];

d = size(A);
B = nonzeros(A');
jj = [B(1:end-1),B(2:end)];
jj = jj(diff(jj,1,2) > 0,:);
k = cumsum([true;diff(jj(:,1))<=0]);
idx = sub2ind(d,jj(:,1),jj(:,2));
t = jj(:,1) == 1;
p = 50*t;
p(~t) = 180;
result = accumarray(k,D(idx).*p);