SPECT/PET image processing code

I was assigned with understanding the inner workings of a matlab code used for SPECT image processing. This code takes multiple raw planar images made at different angular intervals, processes them, and combines them into one data file (it DOES NOT reconstruct a 3-D image). It is a long code, but right now I am just trying to understand it in sections. So I am just looking at the lines of code that run from row 9-74, I have attached it in this post.

In trying to understand this code, I have been doing Internet searches of what functions are etc. Would someone be able to explain what functions and sub functions/nested functions are in the context of this code? Right now I am just concerned about rows 9-74 of the code.

For example the first function in this M-file is called main(). I have a basic understanding of what a matlab function is, but there is no variable within the main()... Just looking for someone to help fill in the blanks for me, because I think I can get the hang of how this thing works with a little help

Answer 1

[richard]

Here is the attachment of the SPECT code

[Star Strider]

The function main() statement is likely there so that other multi-line functions can be used within that script itself. MATLAB only allows functions within other functions, and not in regular script files. (The exception is that anonymous functions are allowed in both script files and function files.)

Answer 2

[Bin Chen]

Could you please send me the codes about SPECT?Thank you