Displaying 20 results from an estimated 2000 matches similar to: "how to draw cumulative histogram"
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,
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 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 Nov 23
2
wilcoxon.test?
Hello there,
I would like to do a Wilcoxon matched pairs signed rank sum test in R
and tried the function wilcoxon.test. Is it in the "base" library? If
not, please let me know which library it is in.
Thank you in advance for your help
Lisa Wang
Biostatistician
Princess Margaret Hospital
Toronto, Ca
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 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
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 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
2007 Jun 20
2
how to create cumulative histogram from two independent variables?
Hi all,
I am extremely newbie to R. Can anybody jump-start me with any clues as to
how do I get a cumulative histogram from two independent variables,
cumhist(X,Y) ?
-jose
[[alternative HTML version deleted]]
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 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
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
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 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
2003 Jun 24
4
cumulative frequency distribution plot
Does R do cumulative frequency distribution plots?
--
Tommy E. Cathey, Senior Scientific Application Consultant
High Performance Computing & Scientific Visualization
SAIC, Supporting the EPA
Research Triangle Park, NC
919-541-1500 EMail: cathey.tommy at epa.gov
My e-mail does not reflect the opinion of SAIC or the EPA.
Federal Contact - John B. Smith
919-541-1087 - smith.johnb at epa.gov
2003 Jul 08
3
Characters and Numeric Values in One Matrix
Dear R-Users,
I want to ask a question for a colleague of mine. He wants to put a
character vector and a numeric vector into one matrix and still have the old
character and numeric type for the respective columns.
Unfortunately, I am just starting using R and I could not help him.
Is there an easy and straightforward way to do this in R?
Maybe a little example facilitates understanding our