Displaying 20 results from an estimated 10000 matches similar to: "Vector Manipulation"
2006 Jun 20
2
glm beta hypothesis testing
In summary.glm I'm trying to get a better feel for the z output. The
following lines can be found in the function
1 if (p > 0) {
2 p1 <- 1:p
3 Qr <- object$qr
4 coef.p <- object$coefficients[Qr$pivot[p1]]
5 covmat.unscaled <- chol2inv(Qr$qr[p1, p1, drop = FALSE])
6 dimnames(covmat.unscaled) <- list(names(coef.p), names(coef.p))
2006 May 12
3
Maximum likelihood estimate of bivariate vonmises-weibulldistribution
Thanks Dimitris!!! That's much clearer now. Still have a lot of work to
do this weekend to understand every bit but your code will prove very
useful.
Cheers,
Aziz
-----Original Message-----
From: Dimitrios Rizopoulos [mailto:Dimitris.Rizopoulos at med.kuleuven.be]
Sent: May 12, 2006 4:35 PM
To: Chaouch, Aziz
Subject: RE: [R] Maximum likelihood estimate of bivariate
2008 Jul 25
3
Help with rep
Hi
Is it possible to use the rep command (or maybe some other "shortcut") to create a vector with the following format:
4 3 4 2 3 4 1 2 3 4
Any help is much appreciated.
Thanks
Jacob
Jacob L van Wyk
Department of Statistics
University of Johannesburg, APK
Box 524
Auckland Park 2006
South Africa
Office Tel: +27 11 559 3080
Fax: +27 11 559 2832
[[alternative HTML version
2006 Sep 22
2
A simple resampling problem
Dear UseRs
I would like to show my students how to use "resampling" to solve the
following simple problem:
If a family has two children of which one is a boy, what is the
probability that the other child is also a boy.
The answer is (obviously) 1/3, and can be show easily using the usual
methods.
But I would like to get the students to think of resampling, by doing
the following:
2007 Aug 20
1
Select rows of matrix
Hi
I would appreciate if anyone could help me with an elegant solution of
the following:
I have a matrix that contain a small number of -Inf values.
How can form a new matrix from the old one that excludes all the rows
with -Inf values ?
Thank you.
Jacob
Dept of Statistics
University of Johannesburg
South Africa
[[alternative HTML version deleted]]
2007 Apr 16
2
Matrix manipulation
Hi,
This is a very basic question, but apparently I am too stupid for it.
I have a large matrix A, and I need to avoid for loops. How could I
apply a function f(a,r,c) on each element of A, using the subscript (row
and column) of a as the other arguments?
Thanks in advance,
Markku Karhunen
National Public Health Institute,
Finland
2005 Oct 20
2
String manipulation
R-help,
I have a data frame which contains a character string column that is
something like;
II11
II18
II23
III1
III13
III16
III19
III2
III7
IV10
IV11
IV12
IX16
IX4
V12
V18
V2
V20
V23
V4
VII14
VII18
VII21
VII26
VII28
VII33
VII4
VII48
VII5
....
....
....
I want to apply a function (e.g mean) by grouping according to the
roman part of the string, i.e,
by I
by V
by VII
...
...
and so on.
I have
2007 Sep 29
3
Data manipulation
Hello,
I am beginner in R and I would like to solve the following problem:
Suppose that we have three files to be red in R d1, d2, and d3
> d1
id x1 x2
1 1 4 n
2 2 3 h
3 3 0 f
> d2
id x1 x2
1 1 2 r
2 2 3 u
3 3 1 f
> d3
id x1 x2
1 1 2 a
2 2 1 w
Is there any library or function that one can read this datasets like
for(i in 1:3)
d[i] <-
2007 Dec 20
2
factor manipulation: edgelist to a matrix?
Hello All,
I have had considerable bad luck with attempting the following with for
loops. Here is the problem:
# Suppose we have a data.frame with the following data, which can be
considered a type of edgelist (for those with networks backgrounds):
#
# V1 V2
# 1 A
# 1 A
# 1 B
# 2 A
# 3 C
# 3 A
# 3 C
# 3 B
#
# I want the output of the function to produce a matrix, such that #each
factor of
2008 Apr 09
4
apply lm() for all the columns of a matrix
Hi all,
My question is not really urgent. I can write a loop and solve the
problem. But I know that I'll be in a similar situation many more times so
it would be useful to find out the answer
Is there a fast way to perform linear fit to all the columns of a matrix?
(or in the one dimension of a multi-dimensional array.) I'm talking about
many single linear fits, not about a multiple fit.
2005 Sep 25
2
getting variable length numerical gradient
Hi all.
I have a numerical function f(x), with x being a vector of generic
size (say k=4), and I wanna take the numerically computed gradient,
using deriv or numericDeriv (or something else).
My difficulties here are that in deriv and numericDeric the function
is passed as an expression, and one have to pass the list of variables
involved as a char vector... So, it's a pure R programming
2006 Mar 02
2
'...' passed to both plot() and legend()
Dear R-devels,
I'd like to create a plot method for a class of objects that passes
the '...' argument to both plot() and legend(), e.g.,
x <- list(data = rnorm(1000))
class(x) <- "foo"
plot.foo <- function(x, legend = FALSE, cx = "topright", cy = NULL,
...){
dx <- sort(x$data)
plot(dx, dnorm(dx), type = "l", ...)
if (legend)
2005 May 19
2
plot question
hi all:
xlim and ylim are used to define the interval limits of a plot. I'm interested in the scale of values between this limits.
suppose xlim=c(0,10)
we can have e.g.
0 5 10
0 2 4 6 8 10
0 1 2 3 4 5 6 7 8 9 10
which is the parameter that allows me to modify this?
thanks in advance
alexandre
2007 Jan 21
5
Integration + Normal Distribution + Directory Browsing Processing Questions
Hi everyone,
I am new to R, but it's really great and helped me a lot!
But now I have 2 questions. It would be great, if someone can help me:
1. I want to integrate a normal distribution, given a median and sd.
The integrate function works great BUT the first argument has to be a
function
so I do integrate(dnorm,0,1) and it works with standard m. and sd.
But I have the m and sd given.
2006 Nov 09
4
Plotting symbols with two positions?
Thanks a lot to Demitris for a prompt answer some minutes ago on another
tread (see below). To avoid excess mails on the list, I move onto next
question:
I have another small plotting problem that confuses me. I want to plot
results from a field trial series, using the numbers of the trials as
symbols in the plot.
pch = as.character(trial_no)
works fine, but truncates the trial number to the
2005 Jan 21
2
chi-Squared distribution
Dear Rs:
outer(1:3, 1:3, function(df1, df2) qf(0.95, df1, df2))
I compare this F distribution results with the table, the answers were perfect. But I need to see for chi-sqaured distribution. When I employed the similar formula
outer(1:3, 1:3, function(df1, df2) qchisq(0.95, df1, df2)) , I am getting unexpected results. I need to see the following values:
p=0.750 .....
1 1.323
2004 Jun 25
3
String manipulation
Hi,
let's see, if someone can help my with this one:
I have the string as follows:
> str<-("one","two","three")
Now I want to concatenate the items to one string, seperateted by space or
something else,
>str
>"one, two, three"
If possible without a loop.
My actual goal ist to create string like
>str.names
>"female = names1, male
2004 Aug 26
5
GLMM
I am trying to use the LME package to run a multilevel logistic model
using the following code:
------------------------------------------------------------------------
-------------------------------------------
Model1 = GLMM(WEAP ~ TSRAT2 , random = ~1 | GROUP , family = binomial,
na.action = na.omit )
------------------------------------------------------------------------
2008 Jan 02
2
Multivariate response methods question
Hi Everyone,
I have some data that predicts both a nominal and ordinal response
variable. I was wondering what packages in R would help me analyze the
data?
I was also curious if anyone could recomend me some textbooks that
would help with the analysis of such data? I have the 5th edition of
"Applied Multivariate Statistical Analysis" by Richard A. Johnson and
Dean W. Wichern
2005 Jan 21
2
chi-Squared distribution in Friedman test
Dear R helpers:
Thanks for the previous reply. I am using Friedman racing test. According the the book "Pratical Nonprametric Statistic" by WJ Conover, after computing the statistics, he suggested to use chi-squared or F distribution to accept or reject null hypothesis. After looking into the source code, I found that R uses chi-sqaured distribution as below:
PVAL <-