Displaying 20 results from an estimated 2000 matches similar to: "how to remove part of the string"
2011 Feb 01
3
Matching patients
May I ask a clinical question? For a trial, we have a treatment group of small
size, say 30 patients. We want to selectmatching control patients from a bigger
group (100 patients) in terms of several clinical variables, such as age, tumor
stage etc. This practice is to select the closest matching set of control cases.
I wonder if R has any routine or package that can help with this problem.
2009 Feb 05
3
how to separate char and num within a variable
Hi all,
I read in a column which looks like "chr1:000889594-000889638", and need to break them into three columns like "chr1:", "000889594" and "000889638". How shall I do in R. Thanks a lot for your suggestions!
Bill
2006 Aug 21
1
Escaping " ' " character
Dear all:
I have a character object x with ' (single-quote)
character.
x <- c('"hydrolase activity","actin
binding","3',5'-cyclic-nucleotide phosphodiesterase
activity")
I want to write a function that will identify ' and
replaces with \'
myf <- function(term){
if (grep("'",term))
{
2011 Jul 27
3
Ordinary Least Products regression in R
Dear all,
Does any one know if any R package or function can do Ordinary Least Products regression? Many thanks!
Bill
2011 Jun 02
1
an efficient way to calculate correlation matrix
Dear all,
I have a problem. I have m variables each of which has n observations. I want to
calculate pairwise correlation among the m variables and store the values in a m
x m matrix. It is extremely slow to use nested 'for' loops if m and n are large.
Is there any efficient alternative to do this? Many thanks for your
suggestions!!
Bill
2002 Sep 09
1
Monotonic interpolation
Has anyone got a function for smooth monotonic interpolation of a
univariate function? I'm after something like the NAG function PCHIM
which does monotonic Hermite interpolation. Alternatively, montononic
cubic spline interpolation.
Please reply directly.
Rob Hyndman
___________________________________________________
Rob J Hyndman
Associate Professor & Director of Consulting
2010 Dec 10
3
(no subject)
Hi R-help,
I am trying to find a way to select five highest values in data frame
according some variable. I will demonstrate:
c
X1 X2
1 1 1
2 1 2
3 1 3
4 1 4
5 1 5
6 1 6
7 1 7
8 1 8
9 1 9
10 1 10
11 2 11
12 2 12
13 2 13
14 2 14
15 2 15
16 2 16
17 2 17
18 2 18
19 2 19
20 2 20
21 2 21
22 2 22
23 2 23
24 2 24
25 2 25
So I
2013 Mar 20
3
highlight overlapping region of two densities
Hi all.
I would like to highlight overlapping regions of two densities and I could
not find a way to do it.
Here is the sample code:
myd <- c(2,4,5, 4,3,2,2,3,3,3,2,3,3,4,2,4,3,3,3,2,2.5,
2, 3,3, 2.3, 3, 3, 2, 3)
myd1 <- myd-2
plot(range(density(myd)$x, density(myd1)$x), range(density(myd)$y,
density(myd1)$y), type = "n")
lines(density(myd), col=1, lwd=4)
2011 Mar 14
2
data.frame transformation
Hi R users,
I have following data frame
df<-data.frame(q1=c(0,0,33.33,"check"),q2=c(0,33.33,"check",9.156),
q3=c("check","check",25,100),q4=c(7.123,35,100,"check"))
and i would like to replace every element that is less then 10 with . (dot)
in order to obtain this:
q1 q2 q3 q4
1 . . check .
2 . 33.33 check 35
2011 Dec 04
3
RODBC connect to Excel (64-bit Windows 7)
Hi to all.
I have a problem to connect to an Excel database using RODBC.
Namely, I am using 64-bit R 2.14.0, under Windows 7 and I tried following:
library(RODBC)
> channel <- odbcConnectExcel("results.xlsx")
Error in odbcConnectExcel("results.xlsx") :
odbcConnectExcel is only usable with 32-bit Windows # ok this is
clear why it doesn't work
> channel
2011 Mar 16
2
export list to csv
Hi everybody.
I have list like this:
l<-list(data.frame(q1=c(1,2,"check"),q2=c(3,"check",5)),
data.frame(q1=c("check",1),q2=c(4,5)))
names(l)<-c("A","B")
rownames(l[[1]])<-c("aa","bb","cc")
rownames(l[[2]])<-c("aa","bb")
Every object has the same number of columns but different number
2011 Apr 12
2
Converting a categorical variable to multiple dichotemous variables
I have a categorical variable in a dataframe similar to the following...
cat
1
1
3
2
4
I need to convert it to 4 dichotemous variables for each observations like...
cat1 cat2 cat3 cat4
1 0 0 0
1 0 0 0
0 0 1 0
0 1 0 0
0 0 0 1
Thanks in advance!
Shane
2011 Aug 10
1
subqueries in sqlQuery function (package RODBC)
Hi R users.
sorry for missing example and if question is to general but I am wondering
if it is possible to execute subqueries in function sqlQuery (package RODBC)
with opened connection with Excel or SQL server 2000. I couldn't find any
example of this.
And if it is possible what should be a correct syntax for this query:
SELECT ct,COUNT(*) as n
FROM (SELECT COUNT(*) AS ct FROM children
2010 Dec 11
2
package sampling
Hi R users.
I have a problem with function strata in sampling packages.
> st0 = strata(dom, stratanames="stratas", size=sample.size,
method="systematic",pik, FALSE)
Error in sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?
In previous version of R 2.9.1 and previous version of package sampling this
code worked
2010 Dec 19
1
package survey
Hi R users,
could someone help me to find out which formulas, for standard error
calculation, are used in following example:
a=data.frame(weights=rep(c(10,1),c(4,1)),fpc=rep(41,5),uk=rep(1,5))
srs<-svydesign(id=~1, weights=~weights, data=a)
srs1<-svydesign(id=~1, weights=~weights,fpc=~fpc, data=a)
svytotal(~uk,srs)
total SE
uk 41 9
svytotal(~uk,srs1)
total SE
uk 41
2011 Dec 08
1
sum of deviations from the weighted mean
Hi all. I tried to calculate sum of deviations from the weighted mean and i
didn't get what i expected - 0. Here is an example:
> wt <- c(10,25,38,22,5)
> x <- 6:10
> wm <- weighted.mean(x,wt)
> (x-wm)*wt
[1] -18.70 -21.75 4.94 24.86 10.65
> sum((x-wm)*wt)
[1] -1.24345e-14
With simple mean I got 0:
> sum(x-mean(x))
[1] 0
Could someone explain me why we
2013 Apr 02
2
speedometer charts in R
Hi useRs.
Does anybody know if there is some function that creates speedometer chart
in R? Or if anybody has proposals where to start looking and which
functions I can modify in order to create this kind of chart?
Thanks for any help
Andrija
[[alternative HTML version deleted]]
2011 Jan 25
1
NA replacing
Hello R user,
I have following data frame:
df=data.frame(id=c(1:10),strata=rep(c(1,2),c(5,5)),y=c(
10,12,10,NA,15,70,NA,NA,55,100),x=c(3,4,5,7,4,10,12,8,3,15))
and I would like to replace NA's with:
instead of first NA tapply(na.exclude(df)$y,na.exclude(df)$strata,sum)[1]*
*7 */tapply(na.exclude(df)$x,na.exclude(df)$strata,sum)[1]
where 7 is the value of x (id=4) in strata 1 where y=NA
2012 Apr 14
1
Error: R for Windows GUI front-end has stopped working
Hi all.
I found one situation, on my OS - Windows 7, where R stops working
with reported error R for Windows GUI front-end has stopped working.
Here is the example:
library(plyr)
DF <- data.frame(x=c(1:3, NA, NA), y=factor(sample(1:3,5,rep=T),levels=1:5))
DF[DF$x<3, ]
#this works properly
ddply(DF, .(y), nrow, .drop=FALSE)
#this causes the problem
ddply(DF[DF$x<3, ], .(y), nrow,
2011 Sep 08
3
generate randomly a value of a vector
Hi everyone,
I have a zero vector of length N and I would like to randomly allocate the
value 1 to one of the values of this vector. I presume I have to use the
uniform distribution but could someone tell me how I should process?
Thanks in advance,
Boris
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