Displaying 20 results from an estimated 36 matches for "mnair".
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nair
2007 Aug 07
5
small sample techniques
If my sample size is small is there a particular switch option that I need to use with t.test so that it calculates the t ratio correctly?
Here is a dummy example?
รก =0.05
Mean pain reduction for A =27; B =31 and SD are SDA=9 SDB=12
drgA.p<-rnorm(5,27,9);
drgB.p<-rnorm(5,31,12)
t.test(drgA.p,drgB.p) # what do I need to give as additional parameter here?
I can do it manually but
2007 Oct 04
5
combining vectors on unequal length
If I have two vectors
X<-1:10
Y<-1:5
When I combine them using cbind, the shorter one is repeated and both are made of the same length. Is there a methods that does this without duplicating the shorter one. I want to use this to store the data back to a file.
Thanks ../Murli
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2009 Jul 14
4
Trig functions strange results
I am trying to calculate coordinate transformations and in the process of debugging my code using debug I found the following
Browse[1]> direction[i]
[1] -1.570796
Browse[1]> cos(direction[i])
[1] 6.123032e-17
Browse[1]> cos(-1.570796)
[1] 3.267949e-07
Browse[1]> direction[i]
[1] -1.570796
Browse[1]> cos(direction[i])
[1] 6.123032e-17
Browse[1]> cos(-1.570796)
[1] 3.267949e-07
2007 Jul 27
2
manipulating arrays
Can I insert an element in an array at a particular position without
destroying the already existing element?
X<-c(1,2,3,4,5)
I want to insert an element between 1 and 2.
Thanks ../Murli
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2009 Jul 24
2
computing the radius of an arc
Hi!!
I am interesting in computing the radius of an arc that best approximates a curve. Is there an R function that I can use to draw an arc?
Nothing useful came up when I searched help.search. Does anyone have any suggestion to do this?
Thanks ../Murli
2009 May 29
2
strsplit
I am trying split a string and use one part of it to label graphs. I am using strsplit for that. While I am able to split it, how do I access the separated parts.
> filName<-"chrI_2223"
>part<- strsplit(filName,"\\_")
> part
[[1]]
[1] "chrI" "2223"
> part[1]
[[1]]
[1] "chrI" "2223"
I looked up the help archive but did
2007 Sep 14
3
x-axis order
Hi all,
I have a time series which contain data collected weekly from week 26
to week 25 the following year. How do I plot this data, so that the
x-axis is displaying the week numbers, ordered as in the data?
Thanks in advance,
Gustaf
---
x<-c(26:52,1:25)
y<-rnorm(52)+1:52
plot(x,y) ## How do I get the x axis to be ordered by the current
ordering of x?
--
Gustaf Rydevik, M.Sci.
tel:
2006 Sep 06
2
biplot label size
Which is the parameter that is used to decrease the size of ylabs
plotted in biplot? I tried playing with cex and cex.lab I am not getting
it right
pc <- princomp(USArrests)
biplot(pc, xlabs = rep("", nrow(USArrests)),ylabs=(colnames(USArrests)))
Thanks../Murli
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2006 Sep 07
1
labeling graphs
I am trying to add text at specific location on my graph. I know this
can be done in R but I can't recollect.
I was trying using locator() to identify the position and use identify()
but I can get it to work. Can someone jog my memory?
Thanks ../Murli
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2007 Mar 13
1
Rcmd and memory
I am running a recursive feature selection wrapper on svm for a large
data set. The routine gets progressively slower. I am deleting the
objects not required. Is there anything else you advise me look for?
I tried running it from the command line but it does not print anything
on the screen. I did not specify any output file and was expecting the
screen to be the default. Can any one help me
2007 Mar 18
1
multcomp
I used the multcomp package sometime back for doing multiple
comparisons. I see that it has been updated and the methods like simint
are no longer supported. When I run the program it prompts to me to use
glht. How do I get the lower and upper conf int and the pValues using
glht? Does anyone have an example?
Thanks ../Murli
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2008 Feb 06
1
filling data into objects
I am trying to generate artificial data for feature selection. Basically trying to generate a total of 1000 features with 100 that are informative and rest are uninformative.
Informative.data.class1<-rnorm(100,0.25,1)
Uninformative.data.class1<-rnorm(900,0,1)
Informative.data.class2<-rnorm(100, -0.25,1)
Uninformative.data.class2<-rnorm(900,0,1)
The above will give me one set of data
2008 Jun 25
1
stringdot
Hi!!
I am trying to figure out how to use the string kernel "stringdot" in kernlab.
k <- function(x,y) {
(sum(x*y) +1)*exp(-0.001*sum((x-y)^2))
}
class(k) <- "kernel"
data(promotergene)
## train svm using custom kernel
gene.k <- ksvm(Class~.,data=promotergene,kernel=k,C=10,cross=5) # works fine in this case
gene.rbf <-
2006 Jul 24
1
Saving R objects
I am trying to find the best way to save the follwoing object I am creating
library(multcomp)
data(recovery)
Dcirec<-simint(minutes~blanket, data=recovery, conf.level=0.9, alternative="less")
I am probably not doing it the most efficient way I think.
Here is what I am doing
a<-print(Dcirec)
write(a,file="mult_test.dat", append=T)
or
save(Dcirec,
2007 Jun 26
3
inter-rater agreement index kappa
Is there a function that calculates the inter-rater agreement index
(kappa) in R?
Thanks ../Murli
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2008 Sep 16
1
boxplot labelling levels
I want the levels to appear in the boxplot instead of 1 and 2. What do I need to do for that? Here is the dummy code.
x<-runif(100,50,80)
x1<-runif(100,70,80)
True.positives<-c(x,x1)
splice<-factor(c(rep("Human.AA.200",100),rep("Human.AA.100",100)))
splice<-factor(splice,levels=c("Human.AA.200","Human.AA.100"))
2007 Sep 12
0
Solution: Sysmaster and Asterisk
Hello Guys,
After adding money into my sysmaster phone account I am able to make calls
outside.thnx
_____
From: Mani Nair [mailto:mnair at nvloisp.com]
Sent: Friday, September 07, 2007 9:16 AM
To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
Subject: Sysmaster and Asterisk
Hello Guys,
I am unable to make calls to outside number from some of my extensions.
Internally I am able to make and receive calls...
2008 Jun 04
1
dotchart
I am trying to plot the following data using dotchart
intersect.data<-structure(list(X = structure(c(1L, 3L, 8L, 9L, 10L, 11L, 12L,
13L, 14L, 15L, 2L, 4L, 5L, 6L, 7L), .Label = c("1-100", "1001-1100",
"101-200", "1101-1200", "1201-1300", "1301-1400", "1401-1500",
"201-300", "301-400", "401-500",
2009 Sep 23
1
dotchart to barplots
Hi,
I am trying to plot the following data so that it can be visually represented well. I tried the dotchart but I felt it was too spread out. Then I tried the barplot which is good enough for me. Is there a way to give the labels for the y-axis as in the dot chart? Also, I feel the grey level is confusing, so is there options for designs within the bars? I cannot use color as the journal wants
2009 Jul 15
1
Matrix multiplication precision
Hi!!
I am trying to multiply 5 matrices and then using the inverse of that matrix for further computation. I read about precision problems from the archives and the suggestion was to use as.numeric while computing the products. I am still having problems with the results. Here is how I am using it
#Mn.mat<-(T.mat %*% Rz.mat %*% Q.mat %*% Rz.mat %*% T.mat) # I was doing this in one step