Displaying 20 results from an estimated 1000 matches similar to: "How to get nice trees"
1999 Apr 16
0
A couple of questions
I just installed the 0.64 rpm for Linux and noticed that the links to
function.html and packages.html on .../doc/html/index.html don't go anywhere.
In fact, those pages don't seem to exist. Do I have to do something to generate
them? Also, will the rpm's for the contrib packages be updated to 0.64 level,
or just R-base?
1999 Feb 02
0
Forcing variables into rpart
I would like to force a specific variable to always be the first split criterion
in rpart, somewhat analagous to forcing a variable into a stepwise regression. I
looked in V & R, and in the help files for the rpart package. If it's there,
it's pretty well hidden. Can anyone help me with this?
______________________________________________________________________
Stuart Luppescu
1999 Mar 07
0
coplot has me stumped
I'm having trouble with coplot. I have two conditioning variables, and when I
try to specify two sets of given.values, no matter what I do I get the message,
Error: Object "b.levels" not found.
Here is the section of code:
c.ranges <- co.intervals(schses, number=4, overlap=0)
a.ranges <- co.intervals(as.factor(aa94), number=2, overlap=0)
PredAA <- as.factor(aa94)
2000 Apr 01
1
R with no gui
I have an old IBM Thinkpad 701 that has a 340MB disk and a 486 CPU that's
not good for much anymore, so I thought I'd install R on it and make it a
little useful. I went to *tremendous* pains to upgrade Linux on it without X so
there would be some room to put R. But having done that I find that the binary
is R.X11 and it's looking for (but can't find) libSM.so, which is ordinarily
1999 Mar 02
1
How to set axis labels?
Sorry to bother everyone with such a basic question again, but I can't seem to
set my axis labels. When I use
title(ylab="String")
"String" just overwrites the variable name, producing a mess. When I try to put
ylab="String" in the plot function, like this:
plot(residuals(mschmod) ~ size94, ylab = "Productivity Adjusted for Context")
I get this message:
1999 Mar 02
1
How to set axis labels?
Sorry to bother everyone with such a basic question again, but I can't seem to
set my axis labels. When I use
title(ylab="String")
"String" just overwrites the variable name, producing a mess. When I try to put
ylab="String" in the plot function, like this:
plot(residuals(mschmod) ~ size94, ylab = "Productivity Adjusted for Context")
I get this message:
2000 Mar 04
1
Need Arith.h
I just installed 1.0 (great job, everyone!) and rebuilt all my packages. I have
found an error in making VR_6.1-6.tar.gz:
Installing package `MASS' ...
libs
gcc -I/usr/lib/R/include -mieee-fp -fPIC -O2 -m486 -fno-strength-reduce -g
-c MASS.c -o MASS.o
MASS.c:631: Arith.h: No such file or directory
make: *** [MASS.o] Error 1
The file /usr/lib/R/include/Arith.h used to be there (locate
1999 Jan 28
1
NAs spoil lowess smoothing
Can anyone explain to me what this error message means, why I'm getting it, and
how to fix it?
lines(lowess(xdat, ydat, f=.5), col=3)
Error: NAs in foreign function call (arg 1)
______________________________________________________________________
Stuart Luppescu -=-=- University of Chicago
ºÍʸ ¤ÈÃÒÆàÈþ¤ÎÉã(EUC) -=-=- s-luppescu at uchicago.edu
2000 Jul 28
4
Language element manipulation
I am very confused about this. I want to convert a string to a name so I can
use it to extract an element of a data frame using `$'. Here is my
(non-working) code:
do.graph <- function (meas)
{
fn <- paste("a", meas, ".dat", sep='')
themeas <- read.table(fn, header=F)
ameas <- as.name(paste("a", meas, sep=''))
1999 Mar 02
1
Can't understand error message :-{
I'm sorry if this is a basic question, but I'm stumped. I'm just trying to plot
the residuals from a linear model against another variable in the data frame.
Here are the lines I'm trying to execute:
size <- read.table(file="/u67/abasl70/surveys/annenberg/mega/smschl.dat",
header=T)
sizef <- data.frame(size, row.names=size$unit)
attach(sizef)
mschmod <- lm
2001 Feb 01
3
Rotated mtext
I seem to remember this coming up before, but I can't find it any messages I've
saved or in the archives (searching by subject). I want to rotate mtext so that
it's perpendicular to the right side. I tried srt=90 and lots of other values,
but it seems to be ignored. Is there a way to do this?
______________________________________________________________________
Stuart Luppescu
1999 Sep 17
1
Tukey's biweight
I want to estimate the center of a distribution with lots of outliers in one
tail, and thought I would use a function such as S-plus's location.m() with
psi.fun=bisquare (as per MASS 3 p. 131). However, R seems not have such a
function, so my questions are:
1) Is there an R equivalent to location.m()?
2) Would huber() give me results that are similar (i.e., close enough)?
Thanks.
2000 Dec 08
1
ylim doesn't work in boxplots?
I want to leave a little extra room at the bottom for a legend in a box plot,
but I find that the boxplot function ignores ylim. Is there any way around
this? Thanks.
______________________________________________________________________
Stuart Luppescu -=-=- University of Chicago
$(B:MJ8$HCRF`H~$NIc(B -=-=- s-luppescu at uchicago.edu
2001 Jan 05
1
Trends for many units
I have data on every grade in all elementary schools in Chicago over 5 years. I
would like to estimate a trend over time for each grade in each school. There
are 17,600 data all together (about 460 schools, nearly 8 grades each, over 5
years). Is there a not-so-hard way to do this in R (I was thinking of using
rlm)?
______________________________________________________________________
Stuart
2001 Feb 05
1
Bar widths in barplots don't change
Is the width= parameter in barplot() supposed to work? I couldn't get it to
work in my plot, and even in the example,
data(VADeaths, package = "base")
barplot(VADeaths, width=rep(0.1, 4))
the plot looks identical regardless of what I put in for the width. I looked at
the source for barplot() and it looks like it SHOULD work (but what do I know).
Am I doing something wrong?
2001 Mar 05
1
Model selection with BIC
Is there an efficient way to do linear model selection by choosing the model
with the highest BIC from all possible models?
______________________________________________________________________
Stuart Luppescu -=-=- University of Chicago
$(B:MJ8$HCRF`H~$NIc(B -=-=- s-luppescu at uchicago.edu
http://www.consortium-chicago.org/people/sl.html
http://musuko.uchicago.edu/pubkey.asc
2001 May 24
1
Labels perpendicular to axis
I would like to make my horizontal barplot vertical axis labels perpendicular to
the axis. I tried las=1, srt=90; I even tried yaxt='n' thinking I'd put the
labels in using mtext, but the axis continued to be drawn. Can anyone help me
with this? My barplot() statement looks like this:
barplot(height=foo$rebint[o1], names=foo$Unit[o1], horiz=TRUE,
col=mycolors[foo$type[o1]],
2000 Mar 27
1
Behavior different inside function?
I'm stumped with this. When I execute the lines in the function singly, they
run fine, but when I run the function, I get this error on the read.table()
line:
Error in count.fields(file, sep, quote, skip) :
can't open file fspci1.dat
Can anyone tell my why this should be so? Here is the program:
library(rpart)
wait <- function(str="Press a key when ready...")
2000 Mar 28
1
loess.smooth dumps core
Has the loess.smooth() function changed? It used to work, but now it causes R
to abort with a segmentation fault. I stole the function points.lines() from
V&R 1st ed. pp. 67--68, but now it only works if I remove the line with
loess.smooth. Here's the function I'm using:
points.lines <- function(x, y, ...)
{
cor1 <-round(cor(x, y, use="pairwise"), digits=2)
2000 Aug 11
0
Index of predictive association
I need to calculate an index of predictive association, similar to Goodman and
Kuskal's (1954) for a 2x2x2 array. I have two questions:
1) Is there an easy way to do this in R? (Of course, the answer to this kind of
question is nearly always ``yes.'' Perhaps I should have asked, ``How can I do
this in R?'')
2) Is it reasonable to try this with a 3-dimensional array? The way I