Displaying 20 results from an estimated 5000 matches similar to: "Multidimensional array with R"
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
>
2011 Apr 06
1
[LLVMdev] GSoC 2011: Fast JIT Code Generation for x86-64
Thanks for all the replies!
I wanted to closely resemble what the CACAO VM[1] backend did with
success for a long time: for every CACAO IR instruction, there is a
sequence of x86 instructions that get written directly to the executable
memory. In CACAO, registers are used while available, then everything is
spilled. Relocations are resolved and patched in a second go.
It seems this is similar to
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
2010 Jan 06
2
Generating data from Null Distribution
Hello everyone,
Can someone tell me exactly how to generate data from a null distribution
for the fisher exact test? I know I have to use the hypergrometric but
exactly what commands do I use?
Jim
[[alternative HTML version deleted]]
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
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
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
#
2012 May 14
3
How to apply a function to a multidimensional array based on its indices
Hello. I have a 4 dimensional array and I want to fill in the slots with
values which are a function of the inputs. Through searching the forums here
I found that the function "outer" is helpful for 2x2 matrices but cannot be
applied to general multidimensional arrays. Is there anything which can
achieve, more efficiently than the following code, the job I want?
K <-
2011 Oct 21
2
Converting data frame into multidimensional array
Consider the following data frame
X <- data.frame(Titanic)
Does anyone know of an easy way to convert X into a multidimensional
array? Example that doesn't work
X <- as.array(X, dim=c(4,2,2,2))
To do what I need, X needs to be converted into an array of dimensions
c(4,2,2,2) in this case, not a table.
Thanks in advance.