[R] ddply function nesting problems

[Jason Rupert]

While putting my R code into functions, I've encountered a ddply function nesting issue and need a bit of advice on the proper way to fix it.  I've tried several approahces, but neither worked and I need to have the ability to include the "cut", "range", and "fullseq" methods within ddply.  (For a bit of that explanation refer to http://finzi.psych.upenn.edu/Rhelp08/2009-February/187331.html)

Thus, in order to preserve that functionality, and put my code within functions, I needed to have an architecture similar to the following implemented, where you end up running:
function_nesting()

Unfortunately this produced errors within the ddply where it does not appear to be recognizing or allowing variables or functions to be processed within side its function.  

Thank you for any advice about how to proceed forward. 


determine_counts<-function()
{

        min_range<-1
        max_range<-30
        bin_range_size<-5
        Me_df<-data.frame(Data = c(1:15), Person = "Me")
        You_df<-data.frame(Data = c(10:20), Person = "You")
        Them_df<-data.frame(Data = c(15:25), Person = "Them")
        Group_df_tmp<-rbind(Me_df,You_df)
        Group_df<-rbind(Group_df_tmp,Them_df)
        Group_df$Person <- factor(Group_df$Person, levels = c("Them", "You", "Me"))
        #counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range(Data), 5)), Person), nrow)
        
         # Approach 1
        counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range(c(Group_df$Data, min_range, max_range)), bin_range_size)), Person), nrow)
        
        # Approach 2
        range_tmp<-range(c(Group_df$Data, min_range, max_range))
        counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range_tmp, bin_range_size)), Person), nrow)
                
                
        names(counts) <- c("Bin", "Person", "Frequency")
        qplot(Person, Frequency, data = counts, fill = Person, geom="bar", stat="identity", width = 0.9, xlab="Person") +  facet_grid(. ~ Bin)
}




function_nesting<-function()
{
        determine_counts()
}



However, if the code is just run straight through without being nested it works fine:

        min_range<-1
        max_range<-30
        bin_range_size<-5 
        Me_df<-data.frame(Data = c(1:15), Person = "Me")
        You_df<-data.frame(Data = c(10:20), Person = "You")
        Them_df<-data.frame(Data = c(15:25), Person = "Them")
        Group_df_tmp<-rbind(Me_df,You_df)
        Group_df<-rbind(Group_df_tmp,Them_df)
        Group_df$Person <- factor(Group_df$Person, levels = c("Them", "You", "Me"))
        #counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range(Data), 5)), Person), nrow)
        counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range(c(Group_df$Data, min_range, max_range)), bin_range_size)), Person), nrow)

Unfortunately this is not within a function, so thanks again for any advice on how to approach this issue.