I have a collection of rectangular matrices which consists of a set of points with associated values. I need to copy this rectangular matrix into a square matrix. The values that get "left out" can be copied into an adjoining square matrix. In this way a rectangular grid can be obtained which consists of a bunch of square matrices. While I can write my own code to do this are there any packages that do it for me ?
I'd say you should probably clarify again. Here are my thoughts, based on your explanation:
From GIS I have a whole set of image files and each of these are tiles. They all have different heights and widths(rectangles). These tiles values on each grid point need be copied and stitched to a "world map". There maybe areas where a tile may not be available(e.g. over oceans). In which case zeroes or other values must be filled in. The world map itself has a bunch of square grids that constitute the coverage. I need to copy values from the original rectangle tile to the square tile making sure the latitude and longitude are identical. As you can see it is not a simple mosaic there is preprocessing prior to mosaicing.
In order to pose your question on Computational Science Stack Exchange, you need to explain some of the GIS-domain-specific language you're using, because many users aren't familiar with GIS. I could see potentially abstracting everything to the point where it really just is some sort of matrix operation, but you have to explain it in those terms, and pose your problem (what you want to do) in those terms. For instance, I don't know what "mosaic-ing" is, and I'm not familiar with tiles, so even though your question could have a simple answer, I can't get through the GIS-specific terminology to figure it out. So right now, I would say your question is off-topic, but if you could explain it in terms of general numerical linear algebra, it would probably be on topic; you should check again on this forum after rephrasing your question.