
Thank you, thank you both!  get() is exactly what I needed.  I  
apologize for not putting in reproducible code.  I'm not very good at  
this and was more worried that I would create problems that didn't  
exist (and the files I'm working with are too big).  Again, thank you.

-John

On Feb 4, 2008, at 11:50 AM, Bert Gunter wrote:
?get  (maybe)

If this isn't it and you do not receive satisfactory replies, see the
Posting Guide for how to post a question with reproducible code so that
readers can understand what you mean (as opposed to me being the only  
one
who doesn't understand you).

-- Bert Gunter
Genentech

On Feb 4, 2008, at 11:53 AM, <markleeds@verizon.net>  
<markleeds@verizon.net> wrote:

I think you need get. see ?get. i'm no
expert or i would give more specific info.

get takes something quoted and makes it an object.


Hello all,
   I've run into what I bet is a silly problem; however, I've been
trying to get around it now for a couple weeks and every time I think
I have the answer it still doesn't work.  So I apologize in advance
if this is painfully obvious, but I've run out of ideas and would
really appreciate any input.

My situation is this, I'm importing a number of tab delimited text
files that contain chromatogram data that I am trying to display
adjacent to a dendrogram.  Since I look at multiple files I import
them as file1, file2, file3, etc.  To display them in the order that
comes from the dendrogram I want to use order.dendrogram, which gives
me a vector of numbers that is the order which I want the
chomatograms to be displayed.

Here's the problem:  I want to be able to set up a loop in which use
"file" as the base name then concatenate the number that follows
after it as the value at order.dendrogram[i] in a plot function.  So
something like:

assume there is a dendrogram called peak.dend

numberOfChromatograms<-20
i<-1
ord<-order.dendrogram(peak.dend)

while(i<=numberOfChromatograms){
plot(file[ord[i])
i<-i+1
}

I know that this particular plot function won't work, but for the
purposes of this assume that it would if I just put in the number as
opposed to ord[i].  But when I try this I get an error that "file"
does not exist.

So I thought that the problem was concatenation.  My solution was to
use the paste function:

ord<-order.dendrogram(peak.dend)
ord
  [1] 13 14 17 18  7  8  1  2  3  4 15 16  5  6 23 24 19 20  9 10 11
12 21 22
z<-paste("file",ord[1],sep="")
z
[1] "file13"

But when I try to plot this it won't work.  "Ah ha!" I thought, "it's
the quotes."

so I try to unquote it:

noquote(z)
[1] file13

Yes!  But it still won't plot.  For some reason the statement file13
is not getting evaluated.  If I type in exactly plot(file13) it
works.  If I explicitly store file13 in z

z<-file13
then
plot(z)
it works.

But if I I do the following:

z<-noquote(paste("file",13,sep=""))
then
plot(z)

it will not plot (specifically it tells me that x and y are lengths
differ which tells me that it's not evaluating the result of z, just
inputting it as is).

I've naively tried eval(z), but I get the same result.

So I know this is a stupid problem and as soon as somebody tells me
the answer I'm going to smack my head and say "Duh!", but right now I
don't even know what terms to search for.  Thanks in advance for any
help.

-John

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