Re: Problems with an apparent compiler-senstive model

From: Leonid Gibiansky leonidg@metrumrg.com Subject: Re: [NMusers] Problems with an apparent compiler-senstive model Date: Sun, 30 Jul 2006 16:18:33 -0400 Max, Floating point error message should be cured somehow. Two most often reasons are huge values in the exponents and divisions by zero. In the code, there should be a defense against each of these causes (if you face the problem). For example, if you have error ~ 1/F then do something like IPRED=F IF(F.LT.0.0001) IPRED=0.0001 error ~ 1/IPRED This is just an example but often it helps to look on each division and make sure that the denominator cannot be negative. Same things with the power operator: only positive values should be exponentiated. Even zero in some power can give an error because of rounding error (when zero is interpreted as very small negative number). Another common reason is expression like CL=TCL*EXP(ETA(1)) When ETA(1) is huge, it can result in error. You can use MYETA=ETA(1) IF(ETA(1).GT.20) MYETA=20 CL=TCL*EXP(MYETA) or IF(ETA(1).GT.20) EXIT CL=TCL*EXP(ETA(1)) I would try to check the code with the idea to identify places where exactly floating point error can be observed. Leonid