Displaying 20 results from an estimated 2000 matches similar to: "Generating data from Null Distribution"
2010 Jul 30
3
simple table/matrix problem
Hi
Given three vectors
x <- c(fish=3, dogs=5, bats=2)
y <- c(dogs=1, hogs=3)
z <- c(bats=3, dogs=5)
How do I create a multi-way table like the following?
> out
x y z
bats 2 0 3
dogs 5 1 5
fish 3 0 0
hogs 0 3 0
('out' is a matrix).
See how the first line shows 'x' has 2 bats, 'y' has zero bats, and 'z'
has 3 bats
and so on for each
2009 Sep 08
5
sparse vectors
Hi
I deal with long vectors almost all of whose elements are zero.
Typically, the length will be ~5e7 with ~100 nonzero elements.
I want to deal with these objects using a sort of sparse
vector.
The problem is that I want to be able to 'add' two such
vectors.
Toy problem follows. Suppose I have two such objects, 'a' and 'b':
> a
$index
[1] 20 30 100000000
2009 Jun 12
1
bundle deprecation
Hi
I read that bundles are to be deprecated in 2.10.
The BACCO bundle contains three packages
(emulator, calibrator, approximator) which I
am happy to unbundle.
But the 'BACCO' moniker has some considerable
cachet for me in terms of recognizability (eg
with grant-giving bodies), as it has become an umbrella
term for a whole bunch of related statistical
functionality of which the three
2009 Jan 22
1
pdf() and pch problems
Hi
R-2.8.1, Suse 11.1
I'm having problems with pdf(). In the following
transcript, file 'f.pdf' does not use the expected symbols for the plot.
It uses a 'q' letter instead of the open circle I get when
viewing the graphics window.
I also get the same under r47678.
Does anyone else get this?
le112:~/scratch/R-2.8.1% R --vanilla --quiet
>
2009 Jan 22
1
pdf() and pch problems
Hi
R-2.8.1, Suse 11.1
I'm having problems with pdf(). In the following
transcript, file 'f.pdf' does not use the expected symbols for the plot.
It uses a 'q' letter instead of the open circle I get when
viewing the graphics window.
I also get the same under r47678.
Does anyone else get this?
le112:~/scratch/R-2.8.1% R --vanilla --quiet
>
2010 Nov 10
1
S4 package warning
Hello everyone. R-2.12.0, suse linux 11.3.
I am debugging a package that uses S4 methods
and R CMD check gives the following warning:
> Warning in methods::findMethods(g, env) :
> non-generic function 'mdm' given to findMethods()
> See the information on DESCRIPTION files in the chapter 'Creating R
> packages' of the 'Writing R Extensions' manual.
I
2009 Jan 22
1
reshape() problems
Hi
I have a data frame with timeseries information like this:
year cell Q1 Q2 Q3 Q4
1940 1 1.2 1.4 1.4 1.9
1941 1 2.9 2.1 3.4 2.4
1942 1 2.7 3.2 1.5 2.6
1940 2 1.4 2.1 2.6 2.4
1941 2 2.4 1.4 1.4 3.4
1942 2 1.4 2.4 2.5 4.4
where the Qs mean 'quarter'. I want to extract from
2010 Jun 29
3
table() of a factor
Hi
suppose I have a factor 'x':
> x <- as.factor(c(rep("a",3),"b","d"))
> table(x)
x
a b d
3 1 1
>
>
But this is not what I want because
I need to include the fact that the count of "c" is zero.
I can't just change the levels of x:
> levels(x) <- c("a","b","c","d")
>
2009 Oct 16
1
generalization of tabulate()
Hi
I want a generalization of tabulate() which works on rows of a matrix.
Suppose I have an integer matrix 'observation':
> observation
y1 y2 y3
1 4 0
1 4 0
2 0 3
4 1 0
0 5 0
0 1 4
2 0 3
Each row corresponds to a (multivariate) observation. Note that the
first two rows are identical: this means that data "c(1,4,0)" was
observed twice.
Now suppose I can list the sample
2010 Jan 26
1
add points to 3D plot using p3d {onion}
Hi,
Can anyone guide me as to how I can add points to a p3d() plot from
the onion package?? I want to plot points with different colors on the
same 3D plot.? Perhaps I can do this without adding points but somehow
directing the 'h' parameter to give different color to points based on
a factor I assign to them?
FYI, I can do this using using scatterplot3d() and points3d(), but
these plots
2008 Dec 11
1
Complex integration in R
Dear R-user
I need a function to approximate a complex integration. My function is:
aprox2=function(s,x,rate){
dexp(x,rate)*exp(-s*x)
}
where argument s is a complex number. I can't use the integrate function
because it's only used with "numeric" arguments
Does anyone know some function to approximate complex integrals?
Thanks
Borja
[[alternative HTML version deleted]]
2009 Mar 02
2
Goldbach partitions code
Folks,
I put up a brief note describing my naive attempts to compute Goldbach
partitions, starting with a brute-force approach and refining
progressively.
http://jostamon.blogspot.com/2009/02/goldbachs-comet.html
I'd welcome your suggestions on improvements, alternatives, other
optimisations, esp. to do with space vs time tradeoffs.
Is this an example interesting enough for
2009 Oct 13
2
S4 tutorial
I'm looking for some tutorial on S4. I only find the following one,
which is not in English. Can somebody let me know if there is any
introductory material? I'm very familiar with OO and C++. If there is
some material that suits my background, it will be great.
https://stat.ethz.ch/pipermail/r-help/2009-January/184108.html
2008 Nov 19
2
Multidimensional array with R
Hi there
I know, I'm sure you discussed this stuff 100 times, but I really have
a basic understanding problem, if and how do I create a
multidimensional array in R. I'm coming from MATLAB and there it's as
easy as you ever could imagine.
Ok, so, I want to have an array, where I can fill in data from a Excel
spreadsheet. The array should be addressed like this:
2009 Dec 11
3
how to creat a matrix
Dear R family
I am attempting to create a matrix. e.g.,
0 0 0 0 1
1 0 0 0 0
0 1 0 0 0
0 0 1 0 0
0 0 0 1 0
How could I write a R program?
Later I want to extend it to a N by N case.
Thanks in advance
best
Moohwan
2009 Nov 12
1
S4 objects in the data directory
Hi
[R-2.10.0; suse linux]
I am having difficulty creating S4 objects in the data directory of a
package. I want
to create a bunch of simple S4 objects for use in the examples section
of the Rd files.
It says in R-exts that:
" R code should be ?self-sufficient? and not make use of extra
functionality provided by the package, so that the data file can also be
used without having to load
2008 Dec 05
1
Lexical Permutation Algorithm in R
Hi all
Here is a rather naive implementation of the SEPA algorithm for generating lexical permutations:
lexperm3 <- function(x, n=length(x)) {
perms <- list()
k <- 1
perms[[k]] <- x
k <- k + 1
for (y in 1:(factorial(n)-1)) {
i <- n-1
while (x[i] > x[i+1] && i > 0) {
i <- i - 1
}
# i is largest index st x[i] > x[i+1]
j <- n
#
2008 Nov 14
1
Generating unique permutations of a vector
Hi all,
I try to generate sets of strategies that contain probability
distributions for a defined number of elements, e.g. imagine an
animal that can produce 5 different types of offspring and I want to
figure out which percentage of each type it should produce in order to
maximize its fitness. In order to do so, I need to calculate the fitness
for all potential strategies. As an example, if I
2010 Sep 24
3
boundary check
Dear R,
I have a covariates matrix with 10 observations, e.g.
> X <- matrix(rnorm(50), 10, 5)
> X
[,1] [,2] [,3] [,4] [,5]
[1,] 0.24857135 0.30880745 -1.44118657 1.10229027 1.0526010
[2,] 1.24316806 0.36275370 -0.40096866 -0.24387888 -1.5324384
[3,] -0.33504014 0.42996246 0.03902479 -0.84778875 -2.4754644
[4,] 0.06710229 1.01950917
2009 Dec 17
4
Fishers exact test at < 2.2e-16
In an effort to select the most appropriate number of clusters in a
mixture analysis I am comparing the expected and actual membership of
individuals in various clusters using the Fisher?s exact test. I aim
for the model with the lowest possible p-value, but I frequently get
p-values below 2.2e-16 and therefore does not get exact p-values with
standard Fisher?s exact tests in R.
Does anybody know