You are right, it is pretty bad, giving all nan and inf results if asked to process more than one page
format long g
D = cat(3, [1 2; 3 4], [2 -1; 3 5]) + 1i*cat(3, [20 19; 18 17], [-1 5; 7 9])
P = [0 0 1 0
1 0 0 0
0 0 0 1
0 -1 0 0];
P11 = P(1:2,1:2);
P12 = P(1:2,3:4);
P21 = P(3:4,1:2);
P22 = P(3:4,3:4);
arg1 = pagemtimes(P11,D) + P12
arg2 = pagemtimes(P21,D) + P22
Dpage = pagemrdivide(arg1, arg2)
Dpage2 = cat(3, pagemrdivide(arg1(:,:,1), arg2(:,:,1)), pagemrdivide(arg1(:,:,2), arg2(:,:,2)))
nnz(isnan(arg1))
nnz(isnan(arg2))
nnz(isnan(Dpage))
nnz(isnan(Dpage2))
The debugging confirms that it is not the fault of pagemtimes, and confirms that if you only do one page at a time that the problem does not occur.
