Use specific value in a dataset array

I have imported a file from excel. I am now trying to do few calculations based on each value in the spreadsheet. For example, if x and y are two columns in the dataset, I want Matlab to choose the corresponding values of the other column. i.e if x=a, then choose corresponding y=P from the dataset as specified in the imported excel spreadsheet and perform calculations for z=1-y and I want it to do it for every value of x. Is there a specific way to do this? Thanks.

[José-Luis]

Yes, there is.

Looks like you need to read about indexing, more particularly logical indexing.

It is easier to get help if you show some effort beforehand.

[AHN]

Thank you for the reply. I am new to Matlab, I will read about logical indexing and get back.Thanks.

[José-Luis]

No worries and welcome to Matlab.