R help - Jun 2010 - Passing the parameter (file name) to png()

I am fitting 3 parameter model to my response matrix and want to generate
item characterstic curve.
I want to specify file name to save item characterstic curve by passing it
as external parameter to the R batch script. The following is the code I
have written for this.

*R Script:*

library(ltm)
cmd_args = commandArgs();
for (arg in cmd_args) cat("  ", arg, "\n", sep="")
respmat <- read.table("C:\\rphp\\responsedata.txt")
fit3pl <- tpm(respmat)
cat("  ", arg, "\n", sep="")
b <- c("C:\\rphp\\",arg)
png(file=b, bg="transparent")
plot(fit3pl,items=c,lwd=3)
dev.off()
rm(respmat,fit3pl,b)
q()

Could you please help me in doing so? I get an error message when R executes
png().

Thanks and Regards,
Maulik

	[[alternative HTML version deleted]]

b <- paste("C:\\rphp\\",arg, sep='')

On Sat, Jun 26, 2010 at 12:55 AM, Maulik Shah <maulik.shah2020 at
gmail.com> wrote:
> I am fitting 3 parameter model to my response matrix and want to generate
> item characterstic curve.
> I want to specify file name to save item characterstic curve by passing it
> as external parameter to the R batch script. The following is the code I
> have written for this.
>
> *R Script:*
>
> library(ltm)
> cmd_args = commandArgs();
> for (arg in cmd_args) cat(" ?", arg, "\n",
sep="")
> respmat <- read.table("C:\\rphp\\responsedata.txt")
> fit3pl <- tpm(respmat)
> cat(" ?", arg, "\n", sep="")
> b <- c("C:\\rphp\\",arg)
> png(file=b, bg="transparent")
> plot(fit3pl,items=c,lwd=3)
> dev.off()
> rm(respmat,fit3pl,b)
> q()
>
> Could you please help me in doing so? I get an error message when R
executes
> png().
>
> Thanks and Regards,
> Maulik
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?