Displaying 20 results from an estimated 4000 matches similar to: "Find multiple elements in a vector"
2009 Jul 14
5
Nested for loops
Hi,
I have spent some time locating a quite subtle (at least in my
opinion) bug in my code. I want two nested for loops traversing the
above-diagonal part of a square matrix. In pseudo code it would
something like
for i = 1 to 10
{
for j = i+1 to 10
{
// do something
}
}
However, trying to do the same in R, my first try was
for (i in 1:10)
{
for (j in (i+1):10)
{
//
2009 Jul 18
1
Building a big.matrix using foreach
Hi there!
I have become a big fan of the 'foreach' package allowing me to do a
lot of stuff in parallel. For example, evaluating the function f on
all elements in a vector x is easily accomplished:
foreach(i=1:length(x),.combine=c) %dopar% f(x[i])
Here the .combine=c option tells foreach to combine output using the
c()-function. That is, to return it as a vector.
Today I discovered the
2009 Jul 20
5
heatmap plot
Dear R community!
I am trying to create a heatmap based on the following data. As you can see the diagonal (0,0 to 10,10) is always 0). If I run the heatmap command like i posted it I get a graph with horizontal lines.
What is my mistake?
> heatmap(activity.matrix, Rowv = NA, Colv = NA, scale="column", xlab="x Compounds", ylab="y Compounds",
2009 Sep 30
5
Rounding error in seq(...)
Hi,
Today I was flabbergasted to see something that looks like a rounding
error in the very basic seq function in R.
> a = seq(0.1,0.9,by=0.1)
> a
[1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
> a[1] == 0.1
[1] TRUE
> a[2] == 0.2
[1] TRUE
> a[3] == 0.3
[1] FALSE
It turns out that the alternative
> a = (1:9)/10
works just fine. Are there any good guides out there on how to deal
2009 Jul 13
2
graph: axis label font
Hi,
excuse me for my english, i am using R on windows and i have to do several
graphs with axis labels and the axis text thicks has a specified font type,
(Arial) and a specified font size. How can i do these? Thank you in advance
--
View this message in context: http://www.nabble.com/graph%3A-axis-label-font-tp24463974p24463974.html
Sent from the R help mailing list archive at Nabble.com.
2009 Jul 17
2
Re placing null values (#NULL!)
I am stumped. I have a data set with multiple columns and about 65,000 case.
Some of the cases have a "#NULL!" value so for dataframe "Props_":
access_emp pct_vacant TAVAIL park PARKACRES totlandare
4538 52.15 #NULL! 0 1 22.99 74,129.70400
4539 52.15 .09 0 1 22.99 982,850.80400
10292 54.20
2009 Jul 20
2
kmeans.big.matrix
Hi,
I'm playing around with the 'bigmemory' package, and I have finally
managed to create some really big matrices. However, only now I
realize that there may not be functions made for what I want to do
with the matrices...
I would like to perform a cluster analysis based on a big.matrix.
Googling around I have found indications that a certain
kmeans.big.matrix() function should
2009 Aug 13
2
randomForest question--problem with ntree
Hi,
I would like to use a random Forest model to get an idea about which variables from a dataset may have some prognostic significance in a smallish study. The default for the number of trees seems to be 500. I tried changing the default to ntree=2000 or ntree=200 and the results appear identical. Have changed mtry from mtry=5 to mtry=6 successfully. Have seen same problem on both a Windows
2009 Aug 16
5
Plot(x,y)
Hi ,
I am using the plot function for some data , and the plot is coming back
pure black , with scales on the side .
Regards
Malcolm
[[alternative HTML version deleted]]
2009 Jul 16
4
loading a file in R in mac OS X
Hello,
Please forgive me that this question is so basic, but i have not been able
to find a solution in any of the basic R introductions, in the R wiki, or in
the stats textbook i'm using to learn R. I run R on a macintosh, and i have
not been able to load any data files yet. For instance, if I have a data
table in a file called schools.txt on my desktop, i've been trying to load
the
2009 Jul 16
5
Transformation of data!
Hi Colleagues,
Could you please help?
I get as the output of my calculations following
[1] 0.000000e+00 1.890000e-04 3.933000e-05 1.701501e-04 2.040456e-04
[6] 3.119242e-04 2.545665e-04 1.893930e-03 1.303112e-03 9.880183e-04
[11] 1.504378e-03 1.549246e-03 5.877690e-04 4.771359e-04 8.528219e-04
How is it possible to transform the data to get a vector as following
10
2009 Sep 11
4
R on Multi Core
Hi,
Our discussions about 64 bit R has led me to another thought.
I have a nice dual core 3.0 chip inside my Linux Box (Running Fedora 11.)
Is there a version of R that would take advantage of BOTH cores??
(Watching my system performance meter now is interesting, Running R will
hold a single core at 100% perfectly, but the other core sites idle.)
Thanks!
--
Noah
2009 Aug 17
6
graph label greek symbol failure
Readers,
Previous questions about this requirement have been for m$ users, my
failure occurs using linux.
I have tried to add the delta (?) symbol to the y axis label and the
result is &D, using the command:
...ylab="?t"...
Any advice please?
rhelp at conference.jabber.org
mandriva 2008
r 251 (27-06-07)
2009 Jul 20
2
I might be dumb : a simple question about "foreach"
Hi list,
My attention was drawn to the foreach package by recent posts...I
decided to have a look...
I'm using R.2.9.1 on Windows, I have downloaded the foreach package
today (v 1.2.1), together with iterators (v. 1.0.1) and codetools (v.0.2-2).
Full of hope I try the most simple thing of all out of the package
vignette :
> x <- foreach(i = 1:3) %do% sqrt(i)
and get :
> Erreur
2009 Jul 20
2
mahalanobis distance
http://www.nabble.com/file/p24569511/mahalanobis.txt mahalanobis.txt
http://www.nabble.com/file/p24569511/concentrations.txt concentrations.txt
Dear Forum members,
I have a problem calculating mahalanobis distances. My data file
mahalanobis.txt and categories file concentrations.txt are attached. I do
the following steps:
x <- as.matrix(read.table("mahalanobis.txt", header=TRUE))
2009 Aug 13
2
Matrix addition function
Hello,
What function can I use for matrices addition? I couldn’t find any information about it in the manual or in the internet.
(A+B suits, when the number of matrixes is small, function sum() doesn’t suit for matrices addition, because it sums all variables in the matrices and produces as an answer single number, not a matrix).
Best regards,
Lina
[[alternative HTML version
2009 Sep 11
3
how to determine if a variable is already set?
Hi,
It might be a primitive question but how it is possible to determine if a variable is initialized in an environment? Suppose that we start a R session and wants to run a script which use the variable i. Which function could evaluate if i is already initialized or not and if not, then ask interactively the user to set it? This is to avoid the error message: object i is not found.
Regards,
2009 Sep 19
2
Use of R in Schools
I am looking for information on experimentation with the use
of R in the teaching of statistics and science in schools. Any
leads would be very welcome. I am certain that there is such
experimentation.
I've made this inquiry on r-sig-teaching, with no response.
John.
John Maindonald email: john.maindonald at anu.edu.au
phone : +61 2 (6125)3473 fax : +61 2(6125)5549
Centre
2009 Jul 24
1
downsampling
Hi,
I am looking for ways to donwsample one-dimensional vectors.
For example,
x=sample(1:5, 115, replace=TRUE)
How do I downsample this vector to 100 entries? Are there any R functions or packages that provide such functionality.
I did find the zoo package and the aggregate() function, but these appear to be rather specific for time-series.
Thanks in advance,
Jan
2009 Jul 21
3
writte file doubt
Hi I wrotte this function but when I get the "tmp.xls" file it shows data
in a rare way. I mean not appears a matrix with 2000 rows and 100 columns.
Can anyone help me, guide me?
kim<-function(){
tmp<-randz<-matrix(rnorm(200000, mean=0,sd=0.01 ),2000,100);
dim(tmp)
write(tmp,file="tmp.xls")
Thanks in advance.
On the other hand, everytime I execute a function