For loop in a for loop doesn't work
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So I'm playing with audio data and I have created a script which downsamples an audio file. Now I'm trying to write a script that tries to recompose the original audio copying the value of the data lost with the downsampling. This is my script
prompt = 'Specific matrix ';
matrix = input(prompt); %audio matrix 1 column
prompt = 'Specific frequency destination ';
freqdest = input(prompt);
prompt = 'Specific frequency signal ';
frq = input(prompt);
sstep = freqdest/frq;
X=ones(length(matrix)*sstep,1); %creating the new matrix
for n=1:length(matrix) % n counter matrix total
for m=0:sstep-1
X(n+m)=matrix(n);
end
end
The inside for
for m=0:sstep-1
X(n+m)=matrix(n);
end
Seems not working at all. The script creates correctly the matrix with the right dimension but copy all the value of "matrix" in "X" without launch the script for every value. Why? Has someone a solution? Thanks
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M
2017년 11월 4일
You should be careful when manipulating matix.
M(i,j)
returns the value of the ith row and jth column of the matrix.
In your example you just give one argument to your matrices.
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Walter Roberson
2017년 11월 4일
That is okay. The comments indicate that it is a vector with one column.
Walter Roberson
2017년 11월 4일
X(n+m)=matrix(m);
perhaps? You were always copying the same value, matrix(n)
Jan
2017년 11월 5일
Use the debugger to find out, what's going on: Set a breakpoint inside the loop and step through the code line by line observing the values of the counters.
for n=1:length(matrix) % n counter matrix total
for m=0:sstep-1
X(n+m)=matrix(n);
end
end
Note that e.g. x(2) is assigned by n=1 and m=1 and by n=2 and m=2. Perhaps you want:
X = repmat(matrix, 1, sstep)
or
X = repelem(matrix, 1, sstep)
or perhaps the same with matrix(:) or a transposition.
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