R help - Feb 2008 - Gini index of frequencies in a data frame

Dear All,
I wish to calculate the Gini index (ineq from same package) and some other
indices for the diameter distribution of each plot (df dgtot).

dgtot:
    IDPlot    Diameter(cm) 
1        4 34.0
2        4 23.0
3        4 38.0
...
51       5 16.0
52       5  8.0
53       5  9.0
...
5301      140 25.0
5302      140 12.0
5303      140  7.0

I use:
> aggregate(dgtot,by=list(dgtot$IDSupr),FUN=ineq(dsp))
where
dsp <- function(x) # compute frequency distribution for each plot
{
 cd<-seq(5,max(x),by=2)
 Fi <<- table(cut(x, br = seq(5, max(x)+1, 2), right = FALSE))
 K <- length(names(Fi))
}

but, the result was:
Error in sort.int(x, na.last = na.last, decreasing = decreasing, ...) :
'x' must be atomic

I'm at the beginning in R and I kindly request your experienced help.

Thank you,
Marius
 Teodosiu










     
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Marius,

several remarks which might help you to improve your code (and your style
of asking questions):
> I wish to calculate the Gini index (ineq from same package) and some
> other indices for the diameter distribution of each plot (df dgtot).
>
> dgtot:
>     IDPlot    Diameter(cm)
I would recommend to use names that would also work as variable names,
especially if you're a beginner, i.e., better use "Diameter"
omitting the
"(cm)".
> I use:
> > aggregate(dgtot,by=list(dgtot$IDSupr),FUN=ineq(dsp))
The argument FUN must be a function (as the name tries to convey). Above,
you evaluate the function which leads to the error because you can't do
  ineq(dsp)
because dsp is a function which makes no sense as the first argument of
ineq().
> dsp <- function(x) # compute frequency distribution for each plot
> {
>  cd<-seq(5,max(x),by=2)
>  Fi <<- table(cut(x, br = seq(5, max(x)+1, 2), right = FALSE))
>  K <- length(names(Fi))
> }
This is really not good programming style with "<<-" and without
explicitely returning something useful. Probably, you want to return Fi,
but I'm not sure...
> I'm at the beginning in R and I kindly request your experienced help.
Have a look at the R introduction or some some book which gets you
started. If you want to ask anything on R-help...
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
This also tells you to choose a meaningful subject. Your problem was not
at all about the "ineq" package which shouldn't have been too
difficult to
find out.

hth,
Z