Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
jlh wrote: > > Hi, > > In IDL the expression for NaN (Not a Number ) is : > !values.f_nan. Does anyone know if there is an equivalent expression > in pvwave ? > > Thanks, > > Jacob Jacob, Trying to do various translation tasks between WAVE and IDL, I recently had the same question as you. The answer is simple as you will see below. You simply need to have the IMSL mathematics package being standard in PV-WAVE Advantage. This package includes the function MACHINE() which can be used as follows: values = MACHINE(/Float) ; Get the single-precision, floating-point machine constants. This call supplies a ;structure whose elements might be inspected ba calling values using the /STRUCTURE keyword. One of the elements of values will then be "values.nan"! info,values,/STRUCTURE ; As an example for the data assignment of variables look at the following line which assigns a 3-element vector "a" using the intended "NaN" as well as additionally negative-infinite values. a = [values.nan,3.0,values.neg_inf] This means in PV-WAVE you can use exactly the same function as in IDL "!values.f_nan" by calling the function "values.nan". That's it. Regards, DIRK. -- _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Dirk Engelbart DWD - Observat.Lindenberg engelbart@mol.dwd.d400.de _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/