how to avoid writing a script for every input again

I have a series of species and I need to get a matrix of each component using a for loop. I have to repeat the code for each species, though it does not seem to be a sensible way. I tried to use for loop to avoid the repetition but the thing is for loop replace the previous ones.

[James Tursa]

The general advice here would be to write a function that contains the code common to the processing you need to do.

[KSSV]

Write your code into a function......call the code and store the value for every loop. Show us your code..we will help you.