Generate combinations with scaleable code
2 次查看(过去 30 天)
显示 更早的评论
I have a tight piece of code which generates a 16x4 matrix which essentially is 16 vectors with 4 elements each and i want all the combinations where the vector elements are -1 or 1
[a1,a2,a3,a4] = ndgrid([1 -1],[1 -1],[1 -1],[1 -1]);
a_all_combos = [a1(:),a2(:),a3(:),a4(:)]
clear a1 a2 a3 a4
The code yields the following output:
1 1 1 1
-1 1 1 1
1 -1 1 1
-1 -1 1 1
1 1 -1 1
-1 1 -1 1
1 -1 -1 1
-1 -1 -1 1
1 1 1 -1
-1 1 1 -1
1 -1 1 -1
-1 -1 1 -1
1 1 -1 -1
-1 1 -1 -1
1 -1 -1 -1
-1 -1 -1 -1
However, this code does not scale-up nicely if I want nine-element vectors, yielding a
x9 matrix.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1246477/image.png)
Would welcome any suggestions on how to do this concisely.
0 个评论
采纳的回答
the cyclist
2022-12-29
There happens to be a quite obfuscated way to do this:
n = 9;
a_all_combos = 2*(dec2bin(0:2^n-1) - '0') - 1
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Matrices and Arrays 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!