Displaying 20 results from an estimated 3000 matches similar to: "wilcoxon.test?"
2004 Jul 21
2
How to do a "go to " in a loop in R
Hi there,
I'm writing a function which involves a loop. What to write in the "?"
place would allow it skips the "for loop" and goes to "a[i]<-0".
a<-b[s>3,]
if (nrow(a)==0) ?????????????
for (i in 1:nrow(a)){
a[i]<-1
}
a[i]<-0
Lisa Wang
Cancer Informatics,
Ontario Cancer Institute/Princess Margaret Hospital,
2006 Dec 07
2
How to use read.xls in R
Hello there,
In gdata package, read.xls is to be used for reading excel data (from
windows).
The following is my code:('C:/session/sampledata.xls' is where the file
is stored)
data1<-read.xls('C:/session/sampledata.xls',sheet=1)
and I got the following error message:
Error in system(cmd, intern = !verbose) : perl not found
Could you please tell me what I have done wrong and
2005 Dec 15
5
How to simulate correlated data
Hello there,
I would like to simulate X --Normal (20, 5)
Y-- Normal (40, 10)
and the correlation between X and Y is 0.6. How do I do it in R?
Thank you very much
Lisa Wang Msc.
Princess Margaret Hospital
Toronto, Ca
2005 Nov 08
3
how to draw cumulative histogram
Hello there,
I am using R to plot some cumulative histogram for my data. Please help
in this case.
Thank you
Lisa Wang
Princess Margaret Hospital
Toronto
phone 416 946 4501 ext.4883
2005 Jun 28
2
How to sort a dataframe by one variable
Hi there,
Could anybody help me on how to sort a dataframe by one variable in the
dataframe?
Thank you
Lisa Wang
Princess Margaret Hospital
Toronto, Ca
tel: 416 946 4501
2006 Feb 09
2
latent class modle for rater agreement
Hello there,
I would like to test the agreement amongst 6 raters for nominal data on
a scale from 1-4, and conduct a latent class analysis in R. How should
the data be formatted and what code should I use?
Thank you very much
Lisa Wang
Princess Margaret Hospital
Biostatistics
tel:416 946 4501
2006 Mar 08
2
How to plot the xaxis label at 45 degree angle?
Hello there,
I would like to plot a graph with the x axis's label displayed at a 45
angle to the x axis instead of horizontal to it as the label is very
long. What should I do?
Thank you for your help in advance
Lisa Wang
Princess Margaret Hospital
Toronto, Ca
2005 Jun 09
1
question on boot
Hello there:
Dear Dr. Murdoch,
I'm a statistician at Princess Margaret Hospital. Could you please help
me with the bootstrapping?
Can boot function (along with boot.ci) handle multivariate statistics?
My intention is that I want to group the outcome data and evaluate the
proportion of patients who are positive for a marker within each group.
(i.e. I have two variables, a predictor and
2004 Sep 09
1
Blom's approximation to rankits?
Hello,
My name is Lisa and I'm a statistician at Princess Margare Hospital. I
wonder if there is any function in R that calculate the Normal rankits
based on Blom's approximation?
Thank you very much
Lisa Wang Msc.
Princess Margaret hospital
Toronto, Ca
2006 Jan 04
2
How to produce this graphic
Hello there,
I would like to produce a plot of x<-c(4,5,6),which is the mean of each
group and y<-c('groupA','groupB','groupC').
plot (x,y) can not produce any graphics because y is not numerical.
What should I do to produce this graphic?
Thank you in advance
Lisa Wang
Princess Margaret Hospital
Toronto,Ca
2004 Dec 06
1
The survival rate at a certain time
Hello there,
I am doing analysis on survival data. How do I pick out a probability of
survival at a chosen landmark time(for example, 3 years, 4 years) from
the result of "survfit"? or any other functions? As I know, the result
of 'survfit' only have the probabilities for all event or cencor time.
Thank you very much
Lisa Wang
Princess Margaret Hospital
Toronto, Ca
tel:
2005 May 18
2
Why can't I download "window binary" zip packages
Hello there,
I tried so many times to download windows binary zip package but it told
me that I don't have the access to do so. It worked for me a few months
ago. Please help me with it.
Thank you
Lisa Wang Msc.
Princess Margaret Hospital
Toronto , Canada
tel: (416) 946 4501 ext.5201
2006 Feb 13
1
LCA in e1071
Hello there,
In the e1071 package,'lca' function only works for binary data for
Latent class analysis. Am I right?
I would like to test the agreement amongst 6 raters for nominal data
ona scale from 1-4, and conduct a latent class analysis. What package
and what function may I use?
Thank you very much
Lisa Wang
Princess Margaret Hospital
tel: 416 946 4501
2004 Jul 19
2
Evaluating the Yield of Medical Tests
Hello,
I'm a biostatistician in Toronto. I would like to know if there is
anything in survival analysis developed in R for the method "Evaluating
the Yield of Medical Test" (JAMA. May 14,1982--Vol 247, No.18 Frank E.
Harrell, Jr,PhD; Robert M. Califf, MD; David B. Pryor, MD;Kerry L.Lee,
PhD; Robert A. Rosait,MD.)
Hope to hear from you and thanks
Lisa Wang, MSc
Project Organiser
2004 Sep 09
2
GEE model
Hello there,
My name is Lisa and I'm doing analysis using genelized linear model-GEE
model because I have some repeated measurements on the same patients (in
a bilateral eye disease case). It would be very appreciated if you could
shed some light on what function to use in R.
Thank you very much
Lisa Wang Msc.
Toronto,Ca
2005 Sep 30
3
'mean' function
Hello,
Could you please let me know how to see the "mean" function in R . The
following is what I see when type in "mean" and "enter"
mean
function (x, ...)
UseMethod("mean")
<environment: namespace:base>
I would like to see how the function is writen.
Thanks a lot
Lisa Wang
Toronto, Ca
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2004 Oct 15
1
categorical varibles in coxph
Hello,
I wonder when I do coxph in R:
coxph( Surv(start, stop, event) ~ x, data=test)
If x is a categorical varible (1,2,3,4,5), should I creat four dummy
varibles for it? if yes, how can I get the overall p value on x other
than for each dummy variable?
Thanks
Lisa Wang
Princess Margaret Hospital
Phone 416 946 4501
2009 Feb 02
1
wilcoxon test with bonferroni correction
Hi!
I need to run a wilcoxon (Mann-whitly, in fact) test with bonferroni
correction, as I am running 10 consecutive wilcoxon test not
independent, and I know that bonferroni will partially correct for
this problem, but I have no idea how to do it with R, I have been
looking in the archive but couldn't understand how to do it.
The format I am using at the moment is
r4_o <-
[1]
2012 Nov 25
2
Finding the Degrees of Freedom in a Wilcoxon Test
Dear R-ers,
I am currently running some Wilcoxon tests in R-64.
How do I find the degrees of freedom in the output I am receiving?
> wilcox.test(good$TRUE, good$x4a, paired=FALSE)
Wilcoxon rank sum test with continuity correction
data: good$TRUE and good$x4a
W = 2455, p-value < 2.2e-16
alternative hypothesis: true location shift is not equal to 0
Thank you,
Stephen.
2005 Jan 22
1
Wilcoxon test for mixed design (between-within subjects)
Hallo,
is there any extension of the pairwise Wilcoxon test to a dependent
samples layout with replicates (or, in other terms, a one-way layout
with blocking and replicates)?
The Wilcoxon method with matched pairs works for the case of dependent
samples with one observation per block, while the Mann-Whitney test
works for independent samples, thus one single block and replicated
observations. Is