Superimposing matrices in a specific location

I have two matrices, one 1024x1024 and one 101x101. 95% of the matrices consists of zeros, besides the central circular parts which have values ranging between 0 and 1. When displayed, the matrices show a circle.

I want to superimpose the smaller matrix onto the larger matrix in a specific location from the origin of the larger matrix. How can I extract the values from the smaller matrix and superimpose them onto the larger matrix?

Thanks

Answer 1

[Matt J]

Something like this, perhaps:

[i0,j0]=deal(700,850);  %target location

[I,J,S]=find(smallMatrix);

result = largeMatrix + accumarray([I-51+i0,J-51+j0], S ,[1024,1024]);

[Allie Feinberg]

Thanks so much, this worked!

[Matt J]

Glad to hear it, but please Accept-click the answer to indicate this!