Displaying 20 results from an estimated 6000 matches similar to: "research question"
2008 Jun 02
4
Beginning Questions
Dear all,
I am new to rails and I am considering it for a project.
What I would like to know (and I couldn''t straightforwardly find an
answer to) is:
- is it possible to develop commercial web applications in which you
can pack a whole web app and send it to a client without disclosing
the source?
- is there any library of existing components already implemented?
- which solutions are
2008 Dec 19
2
error bars
Dear Help
I'm new to R (from matlab)...using windows XP.
I've tried to work out, to no avail, 4 things:
1) rotating the numbers on axes...something to do with par(str) ??
2) how to close a window having opened one e.g. windows(7,7)
3) how to manipulate the key (e.g. dots, lines etc) on the legend. Using pch just gives me the same key for all functions on a plot.
i.e. legend
2005 Jan 07
1
Visualizing complex analytic functions using domain coloring
Hi
has anyone coded up domain colouring for visualizing complex analytic
functions
(such as elliptic functions)?
[
the idea is to depict a complex function f(z) using a filled.contour()
variant
in which the hue is given by Arg(f(z)), and the saturation by Mod(f(z)).
]
--
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
European Way, Southampton SO14 3ZH, UK
tel
2006 Jul 26
2
largest acceptable lookup table in a package
Hi
One of my packages needs a look-up table of pre-calculated
numbers in the data directory.
I would like to have the matrix as large as possible.
What is the largest size matrix that would be an acceptable datafile in
an R package?
[
The table is a square, upper triangular matrix
consisting of logs of Stirling numbers calculated by Maple.
As discussed on the List a few days ago (thanks
2006 Jul 25
2
pari/gp interface
Hi
I'm developing an R package that
needs to execute some code written in pari/gp.
I've used this before from an R package (elliptic) but the interface
is very
basic: the R function creates a string such as the following:
string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q
And then
system(string)
returns the output from gp which then needs to be text processed
2004 Nov 04
1
Specifying error terms in aov and lme
I need to specify error terms properly in a mixed-effects anova model. I
know you can add error terms in aov using Error and can specify random
factors in lme but I am not sure how these get treated.
When making the calculations for fixed and random factors, are the correct
error terms used and how can you get aov or lme to use different error
terms for fixed and random effects?
I'm
2006 Apr 06
1
R CMD check for packages in a bundle
Hi
[MacOsX 10.4.6; R-2.2.1]
I have a bundle that comprises three packages. I want to run R CMD
check on
each one individually, as it takes a long time to run on all three.
I am
having problems.
The bundle as a whole passes R CMD check, but fails when I cd to the
bundle
directory and run R CMD check on a package directory.
The whole bundle passes:
octopus:~/scratch% R CMD check
2006 Nov 17
2
do.call("+", ...)
Hi
How do I make do.call() take "+" as a function for a list of more
than two elements?
Toy problem follows:
f <- function(i){matrix((1:6)^i,2,3)}
# Thus f() returns a matrix of size 2x3; I want to add a whole bunch
of such matrices,
# as in f(1) + f(2) + f(3) + f(4)
# But:
> do.call("+",sapply(1:4,f,simplify=FALSE))
Error in do.call("+",
2005 Jun 13
3
extracting components of a list
Hi
how do I extract those components of a list that satisfy a certain
requirement? If
jj <- list(list(a=1,b=4:7),list(a=5,b=3:6),list(a=10,b=4:5))
I want just the components of jj that have b[1] ==4 which in this case
would be the first and
third of jj, viz list (jj[[1]],jj[[3]]).
How to do this efficiently?
My only idea was to loop through jj, and set unwanted components to
NULL,
2006 Feb 22
3
elements that appear only once
Hi.
I have a factor and I want to extract just those elements that appear
exactly once.
How to do this?
Toy example follows.
> a <- as.factor(c(rep("oak",5) ,rep("ash",1),rep("elm",1),rep
("beech",4)))
> a
[1] oak oak oak oak oak ash elm beech beech beech beech
Levels: ash beech elm oak
> table(a)
a
ash beech elm oak
2007 Mar 19
3
character to numeric conversion
Hi.
Is there a straightforward way to convert a character string
containing comma-delimited
numbers to a numeric vector?
In my application, I use
system(executable.string, intern=TRUE)
which returns a string like
"[0.E-38, 2.096751179214927596171268230,
3.678944959657480671183123052, 4.976528845643001020345216157,
6.072390165503099343887569007, 7.007958550337542210168866070,
2005 Feb 25
3
restoring vector v from v[-i]
Hi
I have a little function that takes a vector v and an integer i. I
want to manipulate
v[-i] (to give v.new, say) and
then put (unmanipulated) v[i] back into the appropriate place. For
example,
f <- function(v,i){
v.new <- v[-i]+10
return(c(v.new[1:(i-1)],v[i],v.new[i:length(v.new)]))
}
(my example is adding 10 to v[-i], but the real version is the solution
of a complicated
2006 Dec 14
4
two connected graphs
Hi
I have two datasets, A and B, consisting of two columns of numbers
representing x and y coordinates.
They have 10 and 6 rows respectively.
I want to plot two scattergraphs, one above the other.
The lower graph to contain A (10 points) and the upper
graph to contain B (six points).
The x-axes of the two graphs must line up.
I then want to draw straight lines that connect points
of B to a
2007 Apr 25
0
Split column of concatenated data
Hi
I have a column of concatenated information stored in an RG object in the limma package and I need to split this information and then paste the first two pieces of data in each case back into two columns of the RG object.
This is how I am currently doing this
gene.info.split<-strsplit(RG$genes$Name,",",fixed=TRUE)
for (h in 1: length(gene.info.split)){
2003 Jul 06
1
Printing multiple graphics devices
Hi
I'm using a function (arrayview from the maanova package) that produces
12 plots, all in separate windows. How can I get each one to print to a
jpeg file as the plots are produced? Alternatively, is it possible to
get dev.print (jpeg.....) to print all open graphics devices to separate
windows?
Thanks in advance,
Nat Street
--
Nathaniel Street
University of Southampton
2004 Nov 18
0
Fwd: Re: 3d scatter plot with drop line
Hi
try this:
p3dpairs <- function(x,x1,
xlim=NULL,ylim=NULL,zlim=NULL,col=par("col"), pch=par("pch"),
cex=par("cex"), ...){
if(is.matrix(x)){
z <- x[,3]
y <- x[,2]
x <- x[,1]
}
if(is.matrix(x1)){
z1 <- x1[,3]
y1 <- x1[,2]
x1 <- x1[,1]
}
if(missing(zlim)) {
z.grid <-
2005 Feb 03
1
Getting "Information matrix" in mixed models
Hello,
I am Hukum Chandra and I'm a statistician. I am using R. I have gone
through R but I could not get the way how to find "Information matrix"
in R. In particular, var-Cov matrix of components of variances in
linear mixed model. Could you please help me in getting the way to
produce it using R?
With best regards
Hukum
===================================
Hukum Chandra
Division
2006 Jul 27
4
inserting rows into a matrix
Hi
I have a little vector function that takes a vector A of strictly
positive integers
and outputs a matrix M each of whose columns is the vector, modified in
a complicated combinatorical way.
Now I want to generalize the function so that A can include zeroes.
Given A,
I want to strip out the zeroes, pass it to my function, and pad M
with rows at positions corresponding to the zeroes
2006 Apr 27
2
summary(lm(x~y)) difference between R-2.2.1 and R-2.3.0
Hi
[macOSX 10.4.6; R-2.3.0]
I have encountered a difference in behaviour between R-2.2.1 and
R-2.3.0 when
performing a linear model. Transcript follows for R-2.3.0 (R-2.2.1
worked as
expected). How to make R-2.3.0 perform as R-2.2.1 did?
> dput(x)
c(29.13, 29.88, 30.09, 29.99, 29.74, 29.64, 29.65, 29.7, 30.04,
29.89, 29.96, 29.65, 28.76, 28.41, 28.38, 29.55, 29.76, 29.75,
29.84,
2006 Aug 29
2
vector S4 classes
In the Green Book, section 7.5 discusses new vector classes and uses
quaternions
as an example of a vector class that needs more than one number per
element.
I would like to define a new class that has a numeric vector and a
logical
vector of the same length that specifies whether the measurement was
accurate.
The following code does not behave as desired:
>