The result you gave above seems not correct.
x=[ NaN
0.250000000000000
0
0
0.250000000000000
0
0
0
0.250000000000000
0
0.250000000000000
0
0
0.250000000000000
NaN
0.250000000000000
0
0
0
0.250000000000000
0.250000000000000
NaN
0.250000000000000
0.760000000000000];
idx = find(isnan(x));
y = x;
idx = [0; idx; length(x)+1];
for i=1:length(idx)-1
y(idx(i)+1:idx(i+1)-1) = cumsum(x(idx(i)+1:idx(i+1)-1));
end
disp(y)
