[R] Passing Inf from R to C using .C("myLibC"...

Duncan Murdoch murdoch at stats.uwo.ca
Thu Apr 24 15:36:20 CEST 2008

On 4/24/2008 9:01 AM, Ardia David wrote:
> Dear all,
> How can I pass '-Inf' and 'Inf' values from R to C code using the 
> function '.C(...)'. When running my code, I get an error since C does 
> not recognize -Inf and Inf values. Of course, I could use instead a very 
> low (or high) number, but I was wondering whether a more elegant 
> solution exists. Thanks for your help.

C doesn't have any problem, but many C functions do, so .C by default 
prevents you from doing this.  However, if you know that it is safe, use 
the NAOK arg to .C and special values will get through.  (The name NAOK 
may not suggest it also means Inf is okay, but the docs do clearly say 

Duncan Murdoch

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