[anthony05]

I am currently using a UDF for DEFINE_DPM_PROPERTY and it involves an If statement, reading a file, and then modifying a particle property.

So the very simplified file looks like,

DEFINE_DPM_PROPERTY
>if 1 condition
>open file A
else
>open file B

>modify particle property

This works but is extremely slow due to the way the file opens. Is there anyway I can open the file before the UDF loops over every particle?

This was not a problem when I was using DEFINE_PROPERTY since the loop over every cell was contained within a for loop and the file could be opened before this. However if I put the file opening part before DEFINE_DPM_PROPERTY line I get 2 compiler errors since 'If' statements cannot be used outside of a function and my file opening needs an address operator (&) which also seems to not work outside of a function.

The compiler errors I receive are:
error C2143: syntax error : missing ')' before '&'
error C2143: syntax error : missing '{' before '&'
error C2059: syntax error : '&'
error C2059: syntax error : ')'
error C2059: syntax error : 'if'

Thanks in advance to anyone that can help