Nested for loops to compile all possible combinations of two vectors

8 views (last 30 days)
I have two vectors and would like to acquire the result of an operation using each combination of the two arrays. The result should look something like this:
1 2 2
1 4 4
1 6 6
2 2 4
2 4 8
... etc.
if vector1 = [1 2 3 ...] and vector2 = [2 4 6 .....].
Here is my attempt:
count = 0;
for i = 1:1:I
for j = 1:1:J
%
alpha = 0.038*i - 8;
thresh = 0.00189*j + 0.01;
% perform some operation to acquire chi
chi = alpha * thresh
% save the chi into a matrix in the order of acquisition
count=count+1;
chi(:,count) = chi % this seems to give the correct 1x(I*J) array
% save all 3 columns into array for the corresponding chi. this is not working. Nearly all entries are 0.
C=zeros(I*J,3);
C(1,count) = alpha;
C(2,count) = threshold;
C(3,count) = chi;
end
count = count + J;
end

Accepted Answer

Bruno Luong
Bruno Luong on 14 Aug 2023
vector1 = [1 2 3 ];
vector2 = [2 4 6 ];
[V1, V2] = meshgrid(vector1, vector2);
A = [V1(:), V2(:), V1(:).*V2(:)]
A = 9×3
1 2 2 1 4 4 1 6 6 2 2 4 2 4 8 2 6 12 3 2 6 3 4 12 3 6 18

More Answers (1)

Steven Lord
Steven Lord on 14 Aug 2023
If upgrading to release R2023a or later were an option you could use the combinations function.
vector1 = [1 2 3 ];
vector2 = [2 4 6 ];
results = combinations(vector1, vector2)
results = 9×2 table
vector1 vector2 _______ _______ 1 2 1 4 1 6 2 2 2 4 2 6 3 2 3 4 3 6

Categories

Find more on Loops and Conditional Statements in Help Center and File Exchange

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!