Displaying 20 results from an estimated 1200 matches similar to: "Significance of the difference between two correlation coefficients"
2002 Jul 26
3
Fisher r-to-z transformation
Hi everyone,
I want to use the Fisher r-to-z transformation as part of a hypothesis
test of r. I can't find an R function that can do that. Am I missing
it?
-Tim
--
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Henry Sibley HS | http://www.isd197.org | http://www.zope.com
W. St. Paul, MN | | http://slashdot.org
wilson at visi.com | <dtml-var
2009 Sep 08
1
Unexpected behavior in friedman.test and ks.test
I have to start by saying that I am new to R, so I might miss something crucial here. It seems to me that the results of friedman.test and ks.test are "wrong". Now, obviously, the first thing which crossed my mind was "it can't be, this is a package used by so many, someone should have observed", but I can't figure out what it might be.
Problem: let's start with
2007 May 23
2
Fisher's r to z' transformation - help needed
I am trying to use Fisher's z' transformation of the Pearson's r but the
standard error does not appear to be correct. I have simulated an example
using the R code below. The z' data appears to have a reasonably normal
distribution but the standard error given by the formula 1/sqrt(N-3) (from
http://davidmlane.com/hyperstat/A98696.html) gives a different results than
sd(z). Can
2007 May 30
1
test to compare significant correlation increase
Hi!
I am calculating correlation between two variables:
1. X versus Y
2. X versus Y(with a 3 steps lag)
I would like to test if the correlation
increase/decrease from 1 to 2 is significant or not.
Is there any function in R to do this? any hints?
Thanks for help :)
David Ria?o
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California
250-N, The Barn
One Shields
2007 Oct 07
1
Question about aov
Hello R gurus,
I am a beginner with R. I am doing an ANCOVA analysis using 'aov,' and need some help understanding how 'aov' works. I have a dataset (taken from http://faculty.vassar.edu/lowry/ch17pt2.html) looking at hypnotic induction. The variable 'X' is a measure of how susceptible the subject is to being hypnotized, the variable 'Y' is how well the
2003 Aug 06
1
Standard error of standard deviation: bootstrap or theoretical results?
Dear R users,
This is more a statistical question rather than an R question. I'd
appreciate it if you can give me some suggestions.
I have a sample of a time series (sample size 500, fat tail in density). I
am trying to calculate the Standard error of standard deviation of a
sub-block-sample (sample size 250). I take 100 this kind of
sub-block-sample, randomly. For these 100 subsamples, I
2008 Nov 07
1
kruskal test in R
Hi,
i have a question in R,
How and what command you need to do to run a kruskal-wallis test without the built in command 'kruskal.test'?
many thanks.
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2011 Oct 13
8
Remove specific rows in a matrix/data.frame
Hi,
imagine the following matrix/data.frame
Letter Number
a 1
a 1
b 1
b 0
c 0
c 1
d 0
d 0
If the numbers for two identical letters are also identical then I want to
remove either the first or the
second row of that letter. If for a letter the numbers are 1 and 0 I want to
remove the row with the 0.
That means if the code works I would and up with the following
matrix/data.frame
Letter
2009 Mar 30
1
Comparing Points on Two Regression Lines
Dear R users:
Suppose I have two different response variables y1, y2 that I regress separately on the different explanatory variables, x1 and x2 respectively. I need to compare points on two regression lines.
These are the x and y values for each lines.
x1<-c(0.5,1.0,2.5,5.0,10.0)
y1<-c(204,407,1195,27404313)
x2<-c(2.5,5.0,10.0,25.0)
y2<-c(440,713,1520,2634)
Suppose we need to
2011 Oct 06
3
Duplicate elements of a vector
Hi,
let's assume I have the following vector a:
1 5 23
How can I use R to duplicate the elements so that my new vector looks like:
1 1 5 5 23 23
Many thanks,
Syrvn
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2010 Sep 03
5
how to get row name of matrix when result is a vector
Hi,
the R code:
a <- matrix(c(1,5,4,3,7,10,34,4,3,8,6,5,12,17,45,3,2,45,46,47,3,4,22,12,21),
nrow=5)
rownames(a) <- c("a","b","c","d","e")
a
a[which(a[,3] < 8), ]
a[which(a[,3] < 6), ]
produces the following output:
> a
[,1] [,2] [,3] [,4] [,5]
a 1 10 6 3 3
b 5 34 5 2 4
c 4 4 12 45 22
d
2011 Oct 13
3
Create order of numbers based on a given vector
Hello!
If I have a vector vec <- c(FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, FALSE
FALSE)
I can I create the following order of numbers based on vector vec:
1, 2, 2, 3, 3, 3, 4, 5
Whenever there is a FALSE I increase the number (starting with 1).
Whenever there is a TRUE I set the same number as the previous FALSE has
been assigned to.
I would be happy for any input
Cheers,
Syrvn
--
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2011 Aug 23
3
R system command does not work with objects/variables
Hello!
with the R system command I would like to call a perl script which needs an
input directory and an output directory in form of a path. When I put in the
path directly it works. The script line looks as follows:
system("perl '../path1' '../path2' '../path3'")
If I store the path in a variable/object and call the perl script again it
does not run and I
2012 Jul 08
3
list.files() find files beginning with a .
Hello,
when I use list.files with recursive = TRUE and all.files = TRUE, R returns
a list of strings/paths.
>From all those strings I want to keep only the ones starting with a .
I tried using grep to achieve that. However, the problem is that because of
the recursive list.files parameter,
for some files beginning with a . there is a path attached. I think it is
not as simple as it looks
2011 Nov 15
2
Extract pattern from string
Hello,
with Sys.time() you get the following string:
"2011-11-15 16:25:55 GMT"
How can I extract the following substrings:
year <- 2011
month <- 11
day_time <- 15_16_25_55
Cheers,
Syrvn
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2011 Oct 04
1
texi2dvi problem when compiling incorrect Latex code
Hello,
I am working on a big R project using Eclipse/StatET/Texlipse. I'd like to
write a Latex document within that project but DO NOT want to Sweave it.
It's pure Latex. Via the external tools configurations I set up 2 different
versions to ensure that my latex document is processed correctly.
Version 1 (System Call):
library(tools)
setwd("${container_loc}")
file =
2010 Aug 10
2
p-values with pvclust
Hi,
if you look at the first image (Image1) you see that there are 2 main
clusters 7 and 8
I wanted to use pvclust to calculate a p-value whether these clusters are
due to chance
or statistically significant. Unfortunately pvclust does not provide a
p-value for the first
brunch (7 and 8).
So I added a row to my matrix which is very different to the rest of the
data to create an additional
2011 Jul 13
7
Error when writing to Excel files using the packages xlsx and xlsx2
Dear group,
I am working on a rather big project where the output data frames have
dimensions of 3000 x 15 or greater. We are using xlsx and xlsx2 to write the
data.frames to Excel sheets.
Since recently we get the following error, when trying to write the data
frames to the excel sheets:
Error in ls(envir = envir, all.names = private) :
invalid 'envir' argument
We figured out that
2011 Nov 19
1
Eclipse StatET - create own code formatting
Hello,
does anybody know whether it is possible to create its own code formatting
rules?
Defining rules under Eclipse -> Preferences -> R Code Formatting is so
limited.
Cheers,
Syrvn
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2011 Nov 26
1
dir.create() does not create directory
Hello,
I am running Windows 7 and R-2.13 in StatET.
When I try to create a directory it does not print any errors but if I check
outside eclipse if it exists or do a refresh in Eclipse the directory is not
been created. The strange thing is that it happens only to some
sub-folders... On the other hand when I use the normal windows explorer in
one of these sub-folders and create a folder it