[R-sig-hpc] parallel code using snowfall

[Mario Valle]

sfExport(f)


On 24-Mar-10 10:55, Carl Boettiger wrote:
> Dear r-sig-hpc,
>
> I am puzzled why my parallel command loses track of my function definitions
> during the call.  For instance, consider the following codeblock:
>
>
> sfInit(parallel=TRUE, cpus=2)
> f<- function(x){ dnorm(x, 1, 2) }
> g<- function(x){ 2*f(x)}
> sfSapply(1:10, g)
>
>
> This fails to run, giving the error:
> Error in checkForRemoteErrors(val) :
>    2 nodes produced errors; first error: could not find function "f"
>
> even though it runs fine in serial, with sfInit(parallel=F). Why does the
> package loose track of f?  This becomes quite problematic when writing
> functions such as g that depend on functions provided by other packages,
> etc.  Any suggestions or possible workarounds?
>
> Thanks for your help,
>
> Carl
>

-- 
Ing. Mario Valle
Data Analysis and Visualization Group            | 
http://www.cscs.ch/~mvalle
Swiss National Supercomputing Centre (CSCS)      | Tel:  +41 (91) 610.82.60
v. Cantonale Galleria 2, 6928 Manno, Switzerland | Fax:  +41 (91) 610.82.82