Plotting sparsity pattern of a matrix

Hi Guys,

I want to visualize the sparsity pattern of a sparse matrix using the function spy().All elements in this matrix is approximated to 4th digit (example : 0.0031,0.0000). The spy() function does not identify 0.0000 or -0.0000 s as absolute zeros. I mean the pattern seems to be dense. How can I overcome this issue? please help me.

Answer 1

[Matt J]

spy(abs(yourMatrix)>=0.0001)

[Fayas Ahamed]

Thanks Matt. this works for me.

Answer 2

[KSSV]

YOu can plot the required sparsity using different colors and markers. This might help.

A = rand(10) ; 
figure
hold on
spy(A<0.5,'r')
apy(A>0.5,'b')

[Fayas Ahamed]

Thanks KSSV. This is a good answer.