Hi Daniel,
It seems you are trying to collect the result of each iteration in to one array.
If this is the case, you can initialize a double array before the for loop, then append the result of each iteration to the end of the array, below is an example(I just assume that you want collect minium cost, you can change is to whatever you want later);
Ly = 8.7; %total length ravine
Lx = 1.1; %width of ravine
Cs = 1e6; %cost of road per km
result = [];
for r = 1.1:0.5:5 %varying ratio between road cost per km and bridge cost per km
Ls = 0.1:0.1:8.6; %varying length of road
Lb = sqrt((Ly-Ls).^2 + Lx.^2); %equation to find length of bridge from the length of road
C =((r*Cs)*(Lb))+(Cs*Ls); %equation for total cost of bridge and road
result(end + 1) = min(C) %minimum value of C for each ratio loop
end
Hope this is helpful.
