MATLAB: Two column matrix concatetate

#matrix #concatenatesimulink

Hi,
I want to combine two column matrix together with ‘Matrix Concatenate’. The inputs are 12×1 matrix from “Random Integer Generator” and 4×1 matrix from “Constant”: [1;2;3;4]. The “Random Integer Generator” is configured as frame based, M-ary number = 255, Initial seed = 37, Sample time = 1e-6, Sample per frame = 12.
In simulation I get such output: [137 49 17 101 168 232 138 251 143 53 248 82 1 2 3 4 137 49 17 101 168 232 138 251 143 53 248 82 1 2 3 4 …]
That is, the random matrix repeats several times which should not be. I think the reason is “Matrix Concatenate” uses old matrix between each generated frames. My question is, how to solve this problem cleverly.
Thank you very much Senmeis

Best Answer

  • I think I see the issue.
    You are seeing the same random values for 12 frames. This is because you setup the 12 samples/frame. This means you defined the frame as 12*e-6 seconds and it will not update until the frame finishes.
    There are 2 ways to accomplish what you want:
    1. Set the sample time to 1e-6/12,or
    2. Concatinate 12 blocks (not frame based) at 1e-6