Save data from for-loop and their use

Hello,

I have the following problems. I have matrices: SatTrDatax_Norm (4X200) and SatTrDatay_Norm (4x50). I want to apply wavelet decomposition(wavedec) to each line separately. Next, I try to save the results to new matrices (C1,L1,C2,L2). Use for-loop but save the last value in C1,L1,C2,L2.How do I store all values resulting from the for-loop? The second problem concerns reconstruction (wrcoeff). The matrices C1,L1,C2,L2 according to the documentation must be a vector. How is this going to be done? Your help is invaluable.

for i=1:4
[C1,L1]=wavedec(SatTrDatax_Norm(i,:),3,'db1');
[C2,L2]=wavedec(SatTrDatay(i,:),3,'db1');
end
AppTrDxNorm_Sat=wrcoef('a',C1,L1,'db5',3);
D1TrDxNorm_Sat=wrcoef('d',C1,L1,'db5',1);
D2TrDxNorm_Sat=wrcoef('d',C1,L1,'db5',2);
D3TrDxNorm_Sat=wrcoef('d',C1,L1,'db5',3);
%
AppTrDySat=wrcoef('a',C2,L2,'db5',3);
D1TrDySat=wrcoef('d',C2,L2,'db5',1);
D2TrDySat=wrcoef('d',C2,L2,'db5',2);
D3TrDySat=wrcoef('d',C2,L2,'db5',3);

Answer 1

[Shae Morgan]

You just need to index your output and then reference the appropraite index

for i=1:4
[C1(i,:),L1(i,:)]=wavedec(SatTrDatax_Norm(i,:),3,'db1');
[C2(i,:),L2(i,:)]=wavedec(SatTrDatay(i,:),3,'db1');
end

[stelios loizidis]

The above you mentioned to me I tried it and it shows what the following error is: Unable to perform assignment because the indices on the left side are not compatible with the size of the right

side.

[Shae Morgan]

for the reconstruction, you'll need to specify which vector you would like to use from your new C1,L1 and C2,L2 matrices you're making or put it in the for-loop to reconstruct each vector.

e.g.

AppTrDxNorm_Sat = wrcoef('a',C1(1,:),L(1,:),'db5',3);

would use the deconstruction of the first row of the saved C1 and L1 matrices

[stelios loizidis]

Like, I wrote above what you suggest does not work

for i=1:4
[C1(i,:),L1(i,:)]=wavedec(SatTrDatax_Norm(i,:),3,'db1');
[C2(i,:),L2(i,:)]=wavedec(SatTrDatay(i,:),3,'db1');
end

The following error occurs; Unable to perform assignment because the indices on the left side are not compatible with the size of the right slide.

So, I can not proceed with the reconstruction.

[Shae Morgan]

I'm not sure what the problem is: Below works just fine for me in version 2020a

I noticed in your for-loop you call SatTrDatay rather than SatTrDatay_Norm (like you state in your question). That might be part of the problem

SatTrDatax_Norm=rand(4,200);
SatTrDatay_Norm=rand(4,50);

for i=1:4
[C1(i,:),L1(i,:)]=wavedec(SatTrDatax_Norm(i,:),3,'db1');
[C2(i,:),L2(i,:)]=wavedec(SatTrDatay_Norm(i,:),3,'db1'); %Make sure you use the right variable here
end
AppTrDxNorm_Sat=wrcoef('a',C1(1,:),L1(1,:),'db5',3);

Since you didn't provide me any of your data, I had to make up data of my own, so perhaps that's where the problem lies.

[stelios loizidis]

It is OK. There was an error in the calculations. Now everything works. Thank you very much for your valuable help !!!