find index values in a 3D matrix above a threshold

Hi,

I have two 3D matrices of same size. Say, A contain values ranging from 0 to 1 and B contains certain discreate values.

I want to filter out values above certain threshold from A and use corresponding index values to replot B matrix for further calculation.

Can anyone help me out?

Answer 1

[Bjorn Gustavsson]

To find indices to values larger than 1 do:

[i1,i2,i3] = find(A>threshold);

After that you might have to loop over the indices or perhaps you can do your processing with linear indexing. Have a look into sub2ind.

HTH

[madhan ravi]

why use find? By the way the values are from 0 to 1 , why was >1 when it will return an empty array?

[Bjorn Gustavsson]

Because I was to lazy to type threshold, edited it now to clarify for every level of matlab-user. Find used since it is not clear what further steps the OP wanted to do. Another possibility is:

idx = A(:)>thresh;