matlab: Sparse Function for any matrix

I am trying to write a sparse function code for any matrix size. For example if i have a matrix:
A = [ 0 0 0 5
0 2 0 0
1 3 0 0
0 0 4 0];
a=size(A);
b=size(A);
c=0;
position=0;
for i=1:a for j=1:b if A(i,j) ~=0
c=c+1;
position=position+1;
S(c,:)=[position,i,j,A(i,j)];
end
end
end
S
S --> is the storage matrix for all the non zero elements for A matrix. In addition to this information(Index,Row Number, Column Number, Value) how do I include two more columns in the matrix which shows the next element in row & the next element in column.

6 Kommentare

James Tursa
James Tursa am 24 Okt. 2013
Can you provide the expected result for the sample matrix you have shown? What do you want stored if there is no next non-zero element in the row or column?
Antony
Antony am 24 Okt. 2013
The expected result is like a linked list representation of the matrix(Index, Value, first in row, First in col, next in row, next in col, row number and col number).
Antony
Antony am 24 Okt. 2013
if there is no next non zero element in the row or column it should scan the rest of the rows and columns
Cedric
Cedric am 24 Okt. 2013
Why don't you create just a display function which fits your needs, but still use MATLAB sparse matrices for computing?
James Tursa
James Tursa am 25 Okt. 2013
@Antony: So you want a linked list that goes by rows, and a separate linked list that goes by columns? And both linked lists have wraparound to next row (or column) and even back to the beginning? Is that what you want?
Antony
Antony am 25 Okt. 2013
@James: Yes.

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Antworten (1)

Azzi Abdelmalek
Azzi Abdelmalek am 24 Okt. 2013

0 Stimmen

Why you don't use sparse function?
B=sparse(A)

1 Kommentar

Antony
Antony am 24 Okt. 2013
The sparse function does not display all the results that I need. I am not worried about the size of the matrix or speed. I want to display more columns to the same sparse matrix according to my requirement.

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