I have been trying executing my data for sparse matrix, and i have been following the example that can be execute but for my data it cant where my data is A is 25x10 and B is 10x1 to solve for x but when i try to solve it shows that A is 10x25 and B is 1x10 and cant be executed.

Answers (1)

Torsten
Torsten on 14 May 2023
Edited: Torsten on 14 May 2023

0 votes

Don't post pictures, post your code in plain ascii so that we are able to copy and execute it.
Your A in the picture you posted has 10 rows and 25 columns, thus is 10x25, not 25x10.
Similarily, the B in the picture you posted has 1 row and 25 columns, thus is 1x25.
You want to solve for X in
A*X = B
where A is 25x10 and B is 10x1 ?
That's not possible: B must be 25x1 to get X as 10x1.

4 Comments

A = sparse ([1,0,0,1,0,1,0,0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,1,1; 1,1,0,0,1,1,0,0,0,0,1,1,1,1,0,0,1,1,0,1,0,1,1,0,0; 1,0,1,0,1,0,0,0,1,1,1,0,1,1,0,1,0,0,0,1,0,0,1,0,0; 1,1,0,1,0,1,1,1,0,0,0,1,1,0,0,1,0,1,0,0,1,0,0,1,0; 1,1,1,0,1,1,1,1,0,1,1,1,1,1,0,1,0,0,1,1,1,1,1,1,0; 1,1,0,1,0,1,1,1,1,0,1,1,0,0,0,1,1,1,1,0,1,0,0,0,0; 0,1,0,0,1,0,1,0,1,0,0,0,1,1,0,1,1,1,0,0,0,0,0,0,0; 1,1,1,0,0,1,0,1,0,0,0,1,1,1,1,1,1,0,0,0,1,1,0,0,1; 1,0,1,0,0,1,1,1,0,0,0,0,1,1,0,0,1,1,1,1,0,0,0,0,0; 0,1,0,1,0,0,0,1,0,1,1,1,0,0,0,1,1,0,0,0,0,1,0,0,0]);
B = sparse ([4986 5265 5469 5247 5277 4717 5410 5115 5251 4676]);
A is the randomize value i get for my 5x5 matrix which i made 10 samples where i want to make it 10 rows and 25 columns for those 10 samples and a matrix
B is the value i got from those samples
and i want to solve for x
and im doing this for my radiation imaging using compressed sensing
and i have question am i using the right command for my imaging using compresses sensing? and can i insert my data into the l1 norm? is the matrix above already included l1 norm? can i use the value x for my imaging if i can execute the above matrix? or do you have any suggestion?
Disclaimer i have 0 knowledge in matlab Thank you in advance
the upper picture is just me trying and error
Torsten
Torsten on 15 May 2023
Edited: Torsten on 15 May 2023
Your question was about the dimensions of A and B in
A*X = B
so that the equation can be solved for X.
If A is (nxm) and B is (nx1), you'll usually get a "solution" X of size (mx1).
For the other questions, you should open a new task and describe your problem more comprehensible. I have no experience in image processing.
I see alright thank you for your explanation and time good sir.

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