CIsam file data types and Informix SE

I am importing data from CIsam files and have been reasonably successful. However I'm unsure as to what datatypes I should be using when it comes to numerics. What are the corresponding data types for Informix SE float double intger long? If I just set up a schema and copy the CIsam datafiles to the appropriate .dat and idx files, all works well in most cases. However I have some weird data in there which is, I suspect because I've used the wrong datatypes. Thanks, Kate