Displaying 20 results from an estimated 3000 matches similar to: "How to simulate correlated data"
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 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
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
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 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
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
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,
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
2005 Dec 04
4
Construct a data.frame in a FOR-loop
Say I have a FOR-loop for computing powers (just a trivial example)
for(i in 1:5)
{
x<-i^2
y<-i^3
}
How can I create a data.frame and a 3D plot of (i,x(i),y(i)), i.e. for
each iteration
Thanks,
Serguei Kaniovski
--
___________________________________________________________________
??sterreichisches Institut f??r Wirtschaftsforschung (WIFO)
Name: Serguei Kaniovski
2005 Dec 06
2
how to extract row& col names from a matrix
Dear all,
I like to extract row names & column names from the named matrix......
like......
a<-matrix(1:6,2)
ro<-c("aa","bb")
co<-c("dd","ee","ff")
dimnames(a)<-list(ro,co)
a
>
dd ee ff
aa 1 3 5
bb 2 4 6
from the above matrix "a"
I like to extract
rownames separately like
2005 Dec 17
1
How to reverse the sequence of axis Y ??
Hello R-users!
My (simple?) doubt: How to reverse the sequence of axis Y ??
the diagram below illustrate my idea...
(default)
|
|
. |
. |
. |
3 |
2 |
1 |
0 +----------------------------
0 1 2 3 ...
like I want...
0 |
1 |
2 |
3 |
. |
. |
. |
|
+----------------------------
0 1 2 3 ...
thanks in advance
klebyn
2005 Dec 06
4
R newbie...
Hello,
I'm a new user...
I have a function :
calculate <- function(x,y)
{
z <- x + y
}
I would like to use the result (z) with another function :
recalculate <- function(...)
{
a <- z^2
}
But R says that z does not exist...
How can I use z in an another function ?
Thank you for your answer...
--
David
[[alternative HTML version deleted]]
2005 Dec 09
3
R-how to group the data
Hello R - users,
This may sound simple to may people:
I have a list of data as follows
type value
y 7
y 7
y 8
y 8
y 8
y 9
y 9
y 9
y 9
y 10
y 10
y 10
y 10
y 11
y 11
y 12
y 12
y 14
y 14
y 14
y 15
y 17
y 20
y 20
y 20
y 20
y 25
2005 Nov 04
2
Simplify iterative programming
Dear,
I am looking for the simplification of a formula to improve the
calculation speed of my program. Therefore I want to simplify the
following formula:
H = sum{i=0..n-1 , [ sum {j=0..m-1 , sqrt ( (Ai - Bj)^2 + (Ci -
Dj)^2) } ] }
where:
A, C = two vectors (with numerical data) of length n
B, D = two vectors (with numerical data) of length m
sqrt = square root
Ai = element of A with index
2005 Dec 06
2
Writing a list to a file !
Hi All,
This may be trivial in R but I have been trying with
out any success. I have a list of 100 elements each
having a sub list of different length. I would like to
write the list to a ASCII file. I tried with
write.table(), after converting my list to a matrix.
Now it looks like
Robert c("90", "50", "30")
John c("91", "20",