Matrix Multiplication

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Eric
Eric on 16 Sep 2011
Basically I have a problem with multiplying my matrices and have No idea howto solve it 1st. Matrix x(t) = sin( 2*pi*t/3) for t = -20:0.01:20 2nd. Matrix N=4000 w=hamming(N)
How do I multiply these two togehter (element by element didnt work when I transposed X and then .*'d it with w)

Answers (2)

Fangjun Jiang
Fangjun Jiang on 16 Sep 2011
use size() function to get the size of your matrix. You'll find out the size of your two matrices are slightly different.

Eric
Eric on 16 Sep 2011
Thankyou for the quick reply, but the problem is still the same. I found out that x = 4001 1, and w was 1 4000, so I changed N to 4001. Now x: 4001 1, and w = 4001 1. However it still gives me an error with the dimensions
  2 Comments
Fangjun Jiang
Fangjun Jiang on 16 Sep 2011
You need to understand the difference between matrix multiplication and element multiplication. A=rand(3,1);B=rand(3,1);C=A.*B;D=A*B';
Fangjun Jiang
Fangjun Jiang on 16 Sep 2011
In your code, x should be 1 by 4000.

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