Product sum function OR similar

[deleted_user]

Two questions:

1. When calculating the probability values from the system of equations(parameter estimates/variable values) for a categorical model, I am seeing code that includes Y=B1+(Var1='xxx' * B2)+..., for example. How does SAS interpret that...meaning what does it do with Var1='xxx', evaluate it to 0 or1? I'd like to modify the code to dynamically(and therefore generically) calculate the Y value without explicit reference to each Var value. I was thinking about an array of variables/values and the parameter estimate array. Is that the most efficient option for large datasets?

2. The first question is somewhat contingent on the answer to this one...is it possible to create a sum of products when arrays are involved without employing IML or is that in fact what I should use...is it efficient for a large dataset.
Probabilities will then be used for forecasting.

Any assistance appreciated.

[ChrisNZ]

>evaluate it to 0 or1?
Correct. This is a boolean.

1-How about[pre]
do i=1 to 20;
Y=B1+(Var{i}='xxx' * B2)+...,
end;[/pre]

2-
>is it possible to create a sum of products when arrays are involved without employing IML
Yes it is. Your question is too vague.