Displaying 20 results from an estimated 3000 matches similar to: "bootstrapping a matrix and calculating Pearson's correlation coefficient"
2010 Apr 24
1
Multiple Correlation coefficient (spearman, Kenall)
Hi,
I'm currently trying to find/define a relationship between one dependent and
several independant variables.
The problem is that i cannot use the normal multiple regression/correlation
in Spss because the data is not normal distributed.
i calculated the spearman roh and Kendalls tau Correlation and also some
partial correlations in R.
Now i wanna find out the the multiple correlation
2010 Jun 09
1
Finding the bootstrapped coefficient of variation and the stderr on the CV(boot)
Dear R-Helpers,
I am trying to bootstrap the coefficient of variation on a suite of
vectors, here I provide an example using one of the vectors in my
study. When I ran this script with the vector x <-c(0.625,
0.071428571, 0.133333333, 0.125, 0), it returned CV(boot) [the second
one], and stderr(boot) [the second one] without problem. However, when
I ran it with the vector in the
2012 Mar 04
1
rpart package, text function, and round of class counts
I run the following code:
library(rpart)
data(kyphosis)
fit <- rpart(Kyphosis ~ ., data=kyphosis)
plot(fit)
text(fit, use.n=TRUE)
The text labels represent the count of each class at the leaf node.
Unfortunately, the numbers are rounded and in scientific notation rather
than the exact number of examples sorted by that node in each class.
The plot is supposed to look like
2008 Mar 06
2
Principle component analysis function
Dear All,
In a package, I want to use PCA function. The structure I used follow this
page: http://www.statmethods.net/advstats/factor.html.
fit<-principle(mydata, nfactors=9, rotation=TRUE)
or:
result<-PCA(mydata)
But I don't known why R language in my computer noticed: "not found
principle", "not found PCA".
I download and installed
2010 Jul 27
1
as.dendrogram for DICE coefficient.
Hi R,
I was using 'as.dendrogram' with the DIST coefficient, where the smaller
values of the DIST coefficient, say that the objects are closer to each
other, while the larger values of the coefficient say that the objects
are far from each other.
But now, I have my coefficient as the DICE coefficient(in some sense
similar to correlation coefficient), where the larger coefficient
2011 Jan 28
3
how to get coefficient and scores of Principal component analysis in R?
Dear All,
It might be a simple question. But I could not find the answer from function “prcomp” or “princomp”. Does anyone know what are the codes to get coefficient and scores of Principal component analysis in R?
Your reply will be appreciated!
Best
Zunqiu
[[alternative HTML version deleted]]
2002 Nov 21
1
Pearson's correlation coefficient?
How do I get non-squared correlation coefficient in some more
sensible way than
sqrt(summary(lm(y~x))$r.squared)?
Thanks
Matej
--
Matej Cepl, matej at ceplovi.cz,
Finger: 89EF 4BC6 288A BF43 1BAB 25C3 E09F EF25 D964 84AC
138 Highland Ave. #10, Somerville, Ma 02143, (617) 623-1488
The difference between death and taxes is death doesn't get worse
every time Congress meets
-- Will
2012 Feb 08
0
glm.fit and pearson's correlation coefficient
I did a linear correlation of data using glm.fit and stored the output in the
object "f":
f <- glm.fit(x, y, w)
I am intereseted in estimating the quality of the correlation. I am used to
do it using pearson correlation coefficient "r" or "r^2". Can I extract this
coefficient from the output of glm.fit?
Is there another number in the output of glm.fit that
2010 Apr 21
1
Can I compare two clusters without using their distance-matrix (dist()) ?
Hello all,
I would like to compare the similarity of two cluster solutions using a
validation criteria (such as Hubert's gamma coefficient, the Dunn index the
corrected rand index and so on)
I see (from here:http://www.statmethods.net/advstats/cluster.html) that
the function cluster.stats() in the fpc package provides a mechanism
for comparing 2 cluster solutions - *BUT* - it requires me to
2010 May 03
1
rpart, cross-validation errors question
I ran this code (several times) from the Quick-R web page (
http://www.statmethods.net/advstats/cart.html) but my cross-validation
errors increase instead of decrease (same thing happens with an unrelated
data set).
Why does this happen?
Am I doing something wrong?
# Classification Tree with rpart
library(rpart)
# grow tree
fit <- rpart(Kyphosis ~ Age + Number + Start,
2013 Jul 02
1
Recursive partitioning on censored data
I am interested in applying a "classification tree" analysis where the
response variable is a censored variable (survival data).
I've discovered the package 'party' through this page:
http://www.statmethods.net/advstats/cart.html. However, as my sample is not
very big I would like to apply 'bootstrap' and use 'random forests', but
with my censored response
2011 Sep 08
1
"rpart" or "tree" function issue
I am trying to create a classification tree using either tree or rpart
functions but when it comes to plotting the results the formatting I get is
different than what I see in all the tutorials (like
http://www.youtube.com/watch?v=9XNhqO1bu0A or
http://www.youtube.com/watch?v=m3mLNpeke0I&feature=related or
http://www.statmethods.net/advstats/cart.html "tree for kyphosis"). I am
2010 May 05
1
rcorr p-values for pearson's correlation coefficients
Hi! All,
To find co-expressed genes from a expression matrix of dimension (9275
X 569), I used rcorr function from library(Hmisc) to calculate pearson
correlation coefficient (PCC) and their corresponding p-values. From
the correlation matrix (9275 X 9275) and pvalue matrix (9275 X 9275)
obtained using rcorr function, I wanted to select those pairs whose
PCC's are above 0.8 cut-off and then
2008 Mar 05
2
Principle component analysis
Thanks to Mr.Liviu Androvic and Mr.Richard Rowe helped me in PCA.
Because I have just learn R language in a few day so I have many problem.
1) I don't know why PCA rotation function not run although I try many times.
Would you please hepl me and explain how to read the PCA map (both of
rotated and unrotated) in a concrete example.
2) Where I can find document relate: Plan S(A), S(A*B),
2010 Jul 08
1
Histogram Principal component analysis in R
Hi,
I am trying to do a Principal component analysis on histogram data.
Basically, I have a group of subjects and for each of them, I have a column
of bin-counts (vis-a-vis intervals) and a corresponding column of
frequencies (or normalized frequencies). The bin counts are the same for all
the subjects. I also have a group-averaged histogram (with the same bin
counts and a column of frequencies)
2010 Oct 22
1
question about decision trees
Hi, I have seen that R has a implementation of decision trees; however,
after I have the tree with the classification:
R Quinlan's trivial example of the "golf" decision tree.
Outlook Temperature Humidity Windy PlayDontPlay 1 sunny 85 85 false
DontPlay
2 sunny 80 90 true DontPlay
3 overcast 83 78 false Play
4 rain 70 96 false Play
...
What's next? I mean, what is this
2010 Oct 30
1
compare quality of clustering methods?
Hi,
Suppose I want to compare the results of two clustering methods, what
is the best way to do it? Thanks
Regards,
-k
2008 Mar 03
2
Problem with PCA
I have an exercise. With 3 kinds of yohourt a,b,c. There are 25
participatients estimate 3 norms: taste (va,vb,vc), structure (ca,cb,cc) and
price (ga,gb,gc) and give the mark from 1 to 5. I don't know how to PCA this
data. Please help me!
I attached the data file follow:
Va Vb Vc Ca Cb Cc Ga Gb Gc
4 2 4 5 5 5 4 4 2
2 2 4 3 2 5 4 5 1
2 2 1 2 3 3 3 1 4
1 1 2 2 3 3 4 3 2
3 4 4 4 3 1 2 1 2
1 1 1
2017 Aug 16
1
Bias-corrected percentile confidence intervals
Hi folks,
I'm trying to estimate bias-corrected percentile (BCP) confidence
intervals on a vector from a simple for loop used for resampling. I am
attempting to follow steps in Manly, B. 1998. Randomization, bootstrap
and monte carlo methods in biology. 2nd edition., p. 48. PDF of the
approach/steps should be available here:
https://wyocoopunit.box.com/s/9vm4vgmbx5h7um809bvg6u7wr392v6i9
If
2012 Apr 11
1
inference for customized regression in R?
Hi all,
Are there functions in R that could help me do the following?
We have a special type of regression which is called Geometric Mean
Regression.
We have done some search and found the following:
https://stat.ethz.ch/pipermail/r-help/2011-July/285022.html
The question is: how to do the statistical inference on GMR results?
More specifically, we are looking for the prediction interval: