Displaying 20 results from an estimated 3000 matches similar to: "Gamma parametrization"
2008 Nov 24
14
how to test for the empty set
Dear R-help,
I first thought that the empty set (for a vector) would be NULL.
x <- c()
x
However, the documentation seems to make clear that there _many_ empty
sets depending on the vector's mode, namely, numeric(0), character(0),
logical(0), etc. This is borne out by
y <- letters[1:3]
z <- letters[4:6]
intersect(y,z)
which, of course, is non-NULL:
is.null(character(0)) #
2009 May 30
3
setdiff bizarre (was: odd behavior out of setdiff)
Dear R-devel,
Please see the recent thread on R-help, "Odd Behavior Out of
setdiff(...) - addition of duplicate entries is not identified" posted
by Jason Rupert. I gave an answer, then read David Winsemius' answer,
and then did some follow-up investigation.
I would like to change my answer.
My current version of setdiff() is acting in a way that I do not
understand, and a way
2009 May 30
3
setdiff bizarre (was: odd behavior out of setdiff)
Dear R-devel,
Please see the recent thread on R-help, "Odd Behavior Out of
setdiff(...) - addition of duplicate entries is not identified" posted
by Jason Rupert. I gave an answer, then read David Winsemius' answer,
and then did some follow-up investigation.
I would like to change my answer.
My current version of setdiff() is acting in a way that I do not
understand, and a way
2009 May 29
2
Odd Behavior Out of setdiff(...) - addition of duplicate entries is not identified
I think I am using the improved version of setdiff(...) that handles data.frames, so I think some odd behavior was expected but this one is escaping me.
It appears that the the addition of duplicate entries is not caught by the setdiff(...). Is this expected behavior?
If so, is there another method or approach that should be used to identify duplicate row entries between two different data
2009 Dec 15
1
Starting with R and distributions graphics
HI, i'm really new of R and i need some help.
I have to describe some distributions for some dices throw:
- launching 3 dices i need the distribution of the sum of the two higher
values
- launching 4 dices i need the distribution of the occurrences of the same
value
possibly i need a way to compare the two distribution adding the fourth dice
to the first without summing it (only for
2010 Sep 08
2
choose.dir() gone?
Hi,
I fail to find "choose.dir()" in my current R install (see below)? Didn't
that exist at some point? How to achieve "file.choose()" equivalent
functionality for directories?
Thanks for any hints, Joh
> sessionInfo()
R version 2.11.1 (2010-05-31)
x86_64-pc-linux-gnu
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
[3]
2007 Dec 10
1
setdiff for data frames
Hello,
I have been interested in setdiff() for data frames that operates
row-wise. I looked in the documentation, mailing lists, etc., and
didn't find exactly the right thing. Given data frames A, B with the
same columns, the goal is to extract the rows that are in A, but not
in B. Of course, one can usually do setdiff(rownames(A), rownames(B))
but that is cheating. :-)
I played around a
2009 May 14
2
can you tell what .Random.seed *was*?
Dear R-help,
Suppose I write a script that looks something like this:
#### script.R
set.seed(something)
x <- rnorm(100)
y <- runif(500)
# bunch of other stuff
save.image()
### end of script.R
Now, I give you a copy of my script.R (with the set.seed statement
removed, of course) together with the .RData file that was generated
by the save.image() command.
Question:
1) can you tell
2009 Jul 30
1
Logistic regression and R
Hello everybody :-)
I have some data that I want to model with a logistic regression, most
of the independent variables are numeric and the only dependent is
categorical, I was thinking that I could apply a logistic regression
using glm but I wanted to deepen my knowledge of this so I tried to do
some reading and found the "iris" dataset, now I would like to ask two
things, first
2010 Jul 27
2
Introductory statistics and introduction to R
Hi,
I have a bright, diligent second-year graduate student who wants to
learn statistics and R and will, in effect, be taking a tutorial from me
on these subjects. (If you've seen some of my questions on this list,
please don't laugh.) As an undergrad he majored in philosophy, so this
will be his first foray into computer programming and statistics.
I'm thinking of having him use
2010 Oct 12
1
FW: [R] same random numbers in different sessions
From R-help
...
>I notice that you have the IPSUR package loaded; you know, just a
>shot in the dark here, but did you try not loading it?
>
>I ask because the vignette is built by making a special choice for
>set.seed, and the workspace that ships with the package might be
>interacting in an unexpected way.
Is it possible that a package can save a set seed and have the effect
2009 Aug 26
2
faulty formatting of toLatex(sessionInfo())
Dear all
I am writing an Sweave document and have encountered formatting issues
with the "locale" part of toLatex(sessionInfo()). The fact that there
is no spaces between the various "locale" variables means that LaTeX
cannot easily find an appropriate place to break the lines, and some
will get printed off screen.
Below is the text output, and this .pdf document [1] shows the
2009 Jan 04
1
Bivarite Weibull Distribution
HI
Every one
Could some one provide me definitions of following bivariate distributions
gamma, exponencial, Weibull, half-normal , Rayleigh, Erlang,chi-square
thanks
A.S. Qureshi
2008 Jun 04
1
permsn incorrect when x==m (library: prob) (PR#11571)
Full_Name: Obnoxious
Version: 2.7.0
OS: Windows
Submission from: (NULL) (121.223.77.238)
Objective:
Generate all permutations of the elements of x taken m at a time.
Library:
prob
Function:
permsn
Issue:
Does not appear to be working correctly when x==m.
Example:
libary(prob)
permsn(2,1) i.e., x > m
#Gives the correct result of
[,1] [,2]
[1,] 1 2
#Yet
permsn(2,2) i.e., x==m
2007 Sep 16
2
power calculation for repeated measures ANOVA?
Is there a way to calculate power for repeated
measures ANOVA (2 groups x 7 observations)? I have
searched all over, but all I can find is
power.anova.test, but that would not give accurate
results, right?
Thanks,
Matt Bridgman
2007 Dec 21
2
number of count of each unique row
Hi,
I have a matrix of duplicate rows. How to output a list the unique rows with their count? I have used "unique" to have the unique rows, but can't produce the occurences of each unique row.
Thanks
Louis
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2008 Sep 11
2
Plot qnorm
Hi,
I have this problem:
X is hazardous variable N(mean 2, sd=3)
>>question 1) Find the c value, so that P(X>c)=0.10. using R
>>question 2) Graph the function N(2,3) and with this graph, explain what
you do in question number 1.
I just found question number one but not the second one. So, I'd like to
make a plot form this distribution N (2,3) using the functions plot and
2009 May 27
1
R Books listing on R-Project
I was wondering what the criteria were for including books on the Books
Related to R page <http://www.r-project.org/doc/bib/R-books.html>. (There is
no maintainer listed on this page.)
In particular, I was wondering why the following two books are not listed:
* Andrew Gelman, Jennifer Hill, *Data Analysis Using Regression and
Multilevel/Hierarchical Models*. (CRAN package 'arm')
*
2009 Dec 04
3
Combinations and joint probabilities
Dear R helpers
Suppose I have two sets of ranges (interest rates) as
Range 1 : (7 – 7.50, 7.50 – 8.50, 8.50 – 10.00) with respective probabilities 0.42, 0.22 and 0.36.
Range II : (11-12, 12-14, 14-21) with respective probabilities 0.14, 0.56 and 0.30 respectively.
My problem is to form the combinations of these ranges in a decreasing order of joint probabilities. It is assumed that
2008 Oct 01
2
Bivariate normal
Package mvtnorm provides dmvnorm, pmvnorm that can be used to compute
Pr(X=x,Y=y) and Pr(X<x,Y<y) for a bivariate normal.
Are there functions that would compute Pr(X<x,Y=y)?
I'm currently using "integrate" with dmvnorm but it is too slow.