Displaying 20 results from an estimated 3000 matches similar to: "(no subject)"
2003 Feb 13
1
(no subject)
Dear R helpers,
I have a curious problem, which is that a program I have written in R
crashes R, unpredictably. When I say that the program crashes R, I mean
that it causes R to terminate, completely. But, the operating system
(Windows) continues OK.
The program loops around a randomForest regression. I am trying to use
randomForest to predict the diagnosis for a set of patients with dementia.
I
2004 Mar 19
2
How to collect trees grown by rpart
Jonathan,
Try making a list instead of an array. See ?list. Also, did you look into
random forests? I'm not sure what you want to do, but there might be
methods there to do some of the work for you.
Sean
On 3/19/04 1:12 PM, "Jonathan Williams"
<jonathan.williams at pharmacology.oxford.ac.uk> wrote:
> I would like to collect the trees grown by rpart fits in an array,
2003 Dec 30
1
odd results from polr vs wilcoxon test
Dear R helpers,
I would like to ask why polr occasionally generates results that look very
odd.
I have been trying to compare the power of proportional odds logistic
regression with
the Wilcoxon test. I generated random samples, applied both tests and
extracted and
compared the p-values, thus:-
library(MASS)
c1=rep(NA,100); c2=c1
for (run in 1:100)
{
dat=c(rbinom(20,12,0.65),rbinom(20,12,0.35))
2003 Jan 20
2
Too many e-mails
Oh dear - I joined the R help mailing list last week,
in order to ask a specific question. I did not realise
that I would start to receive all e-mails to and from
the mailing list. Is there a way of letting me receive
only the answers to my own questions? If not, then can
you remove me from the mailing list?
Thanks,
Jonathan Williams
Jonathan Williams
OPTIMA
Radcliffe Infirmary
Woodstock Road
2004 May 27
2
Is it possible to read jpeg files into R?
Hi Helpers,
Does anyone know how to read jpeg, bmp or png files into R?
I have some photos of brain scans and I want to quantify
some aspects of their size. I might be able to do this
with the 'locator' function, if I could figure out how
to read the files in and make them into an image that
I can display on the R Windows device. I have experimented
with readBin, using a simple
2003 Jan 17
1
Survr error
I am trying to analyse recurrent failure times using survfitr
from the survrec package. To do this, I need to "Create a survival
recurrent object" using Survr. But, when I do this, I get an error
"Error in Survr(r1d[, 1], r1d[, 5], r1d[, 6]) : data doesn't match".
Here, r1d[,1] is the identifier for each case, r1d[,5] is the time
of recurrence, r1d[,6] is the status
2004 Mar 11
3
making operators act on rows of a data frame
Dear R helpers,
I wish to use the "sum" operator for each row of a data frame.
However, it appears that the operator acts on the entire data
frame, over all columns. What is the best way to obtain row-
wise operation?
The following code shows my attempts so far, and their problems:-
test1=array(rbinom(120,1,0.5),c(20,3))
test1[,3]=NA
sum(test1[,1:2])
test1[,3][sum(test1[,1:2])>=2]=1
2003 Aug 11
0
Designing and incorporating a digital filter
I have a time series of data from an electroencephalogram (EEG).
I wish to filter the data to get rid of 50Hz mains 'hum'. I have
'designed' a combination bandpass and notch filter using a web-
site. The site returns the filter in "ANSI C" source code. It is:-
/* Digital filter designed by mkfilter/mkshape/gencode A.J. Fisher
Command line:
2004 Mar 15
2
imputation of sub-threshold values
Is there a good way in R to impute values which exist,
but are less than the detection level for an assay?
Thanks,
Jonathan Williams
OPTIMA
Radcliffe Infirmary
Woodstock Road
OXFORD OX2 6HE
Tel +1865 (2)24356
2004 Apr 27
0
Extracting labels for residuals from lme
Dear R-helpers,
I want to try to extract residuals from a multi-level
linear mixed effects model, to correlate with another
variable. I need to know which residuals relate to
which experimental units in the lme. I can show the
labels that relate to the experimental units via the
command
ranef(fit0)$resid
which gives:
604/1/0 -1.276971e-05
604/1/1 -1.078644e-03
606/1/0 -7.391706e-03
606/1/1
2003 May 19
1
plotting a simple graph
I am having great difficulty plotting what should be a simple graph.
I have measured 1 'y' and 5 'x' variables in each of two groups.
Linear regression shows significant differences in the slopes of the
regression for each 'x' variable between the two groups.
All that I want to do is to plot one graph that shows the scatterplot
for the three groups (each group represented
2004 Apr 27
3
R hang-up using lm
Dear R-helpers,
I have found a slightly annoying problem when trying to
plot lines on graphs. I first created my data using
tapply, thus:-
y1=as.vector(fit1$coef$random$id)
x1=tapply(o1,id,median,na.rm=T)
x2=tapply(o2,id,median,na.rm=T)
#then I plot the data, thus:-
plot(x1[x2==0],y[x2==0])
#if I now try to fit the linear regression, R 'hangs up'
2004 Feb 19
3
suppressing non-integer labels for plot x-axis
Dear R-helpers,
I am having difficulty making R plot only integer labels on the x-axis
of a simple graph. I want to plot the median values of a score on each
of three occasions. Non-integer occasions are impossible. But, R keeps
labelling the x-axis with half-occasions, despite my attempts to stop
this using the "xaxs" and "xaxp" parameters of 'plot'.
p1=c(1,2,3);
2002 Aug 29
0
yet another MDCT question
mdct.c, lines 436 onward (part of mdct_backward) state
{
DATA_TYPE *oX1=out+n2+n4;
DATA_TYPE *oX2=out+n2+n4;
DATA_TYPE *iX =out;
T =init->trig+n2;
do{
oX1-=4;
oX1[3] = MULT_NORM (iX[0] * T[1] - iX[1] * T[0]);
oX2[0] = -MULT_NORM (iX[0] * T[0] + iX[1] * T[1]);
oX1[2] = MULT_NORM (iX[2] * T[3] - iX[3] * T[2]);
oX2[1] =
2002 Jun 29
1
NMB problem
I'm configuring Samba on a Red Hat Linux 7.2 server, for access from a
Windows 2000 client. My server name is DEMENTIA, and it's IP address is
192.168.0.5. I've confirmed with ifconfig that the server's broadcast
address is 192.168.0.255.
I'm having a problem with NMB that I seem to have isolated to the
following symptoms -
After starting NMBD, I can lookup the server name
2005 Oct 27
1
Repost: Examples of "classwt", "strata", and "sampsize" i n randomForest?
"classwt" in the current version of the randomForest package doesn't work
too well. (It's what was in version 3.x of the original Fortran code by
Breiman and Cutler, not the one in the new Fortran code.) I'd advise
against using it.
"sampsize" and "strata" can be use in conjunction. If "strata" is not
specified, the class labels will be used.
2010 Oct 07
0
Using MDSplot from randomForest to classify samples
I am using randomForest to classify (relapse vs non-relapse) patients. I
have built a forest using a training data and now want to predict classes in
a test dataset. Instead of using the resulting randomForest object. I was
wondering if there is a way to use the MDSplot. From looking at the MDS plot
it seems like I could draw some lines through the plot to define 'high
risk',
2011 Jun 03
1
Surv(): Stop time must be > start time, NA created
I am writing to get a better handle on a warning I am getting from a coxph analysis I am doing.
I am analysing age of onset of dementia *after* the onset of parkinson disease. My data looks like:
age.park age.dem age.death censor x1 x2 x3 x4
1 76 87 88 0 16 33 E3 E3
2 75 84 84 0 33 36 E3 E3
3 77 81 81 1 NA NA
2001 Dec 20
2
Supplemental group support in smb.conf
Hi,
I have a share in my smb.conf file that I want to share to members of a
supplemental group, but I keep getting a network error.
here is the share:
[mp3s]
comment = MPEG3 Encoded Audio
path = /usr/share/mp3
public = no
browsable = no
valid users = +mp3users
writable = yes
create mask = 0644
I have a group called mp3users that inside my /etc/group file looks like
this:
2012 Jan 25
1
Error in predict.randomForest ... subscript out of bounds with NULL name in X
RF trains fine with X, but fails on prediction
> library(randomForest)
> chirps <-
c(20,16.0,19.8,18.4,17.1,15.5,14.7,17.1,15.4,16.2,15,17.2,16,17,14.1)
> temp <-
c(88.6,71.6,93.3,84.3,80.6,75.2,69.7,82,69.4,83.3,78.6,82.6,80.6,83.5,76
.3)
> X <- cbind(1,chirps)
> rf <- randomForest(X, temp)
> yp <- predict(rf, X)
Error in predict.randomForest(rf, X) : subscript