similar to: Numerical Recipes in R

Displaying 20 results from an estimated 10000 matches similar to: "Numerical Recipes in R"

2007 Apr 05
17
Reasons to Use R
Dear All, The institute I work for is organizing an internal workshop for High Performance Computing (HPC). I am planning to attend it and talk a bit about fluid dynamics, but there is also quite a lot of interest devoted to data post-processing and management of huge data sets. A lot of people are interested in image processing/pattern recognition and statistic applied to geography/ecology, but I
2010 Jul 19
1
Hurst Exponent Estimation
Dear All, I am a novice when it comes to time-series analysis and at the moment I am actually interested in calculating the Hurst exponent of a time series. This question has already been asked quite some time ago http://bit.ly/98dZsi and I trust some progress has been made ever since. I was able to find some functions in the packages http://cran.r-project.org/web/packages/Rwave/index.html
2019 Jul 09
3
[R] Curl4, Quantmod, tseries and forecast
Hi Ralf, I tried the following > install.packages("RCurl") which went OK, but then same story when I tried to install tseries. > sessionInfo() R version 3.6.1 (2019-07-05) Platform: x86_64-pc-linux-gnu (64-bit) Running under: Debian GNU/Linux 10 (buster) Matrix products: default BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.8.0 LAPACK:
2013 Mar 24
3
Parallelizing GBM
Dear All, I am far from being a guru about parallel programming. Most of the time, I rely or randomForest for data mining large datasets. I would like to give a try also to the gradient boosted methods in GBM, but I have a need for parallelization. I normally rely on gbm.fit for speed reasons, and I usually call it this way gbm_model <- gbm.fit(trainRF,prices_train, offset = NULL, misc =
2013 Feb 09
3
Addressing Columns in a Data Frame
Dear All, Probably a one liner, but I am banging my head against the floor. Consider the following DF <- data.frame( x=1:10, y=10:1, z=rep(5,10), a=11:20 ) mn<-names(DF) but then I cannot retrieve a column by doing e.g, DF$mn[2] I tried to play with the quotes and so on, but so far with no avail. Any suggestion is welcome. Cheers Lorenzo
2009 Jul 20
3
Histograms on a log scale
Dear All, I would like to be able to plot histograms/densities on a semi-log or log-log scale. I found several suggestions online http://tolstoy.newcastle.edu.au/R/help/05/09/12044.html https://stat.ethz.ch/pipermail/r-help/2002-June/022295.html http://www.harding.edu/fmccown/R/#histograms Now, consider the code snippet taken from http://www.harding.edu/fmccown/R/#histograms # Get a random
2011 Dec 15
3
From Distance Matrix to 2D coordinates
Dear All, I am struggling with the following problem: I am given a NxN symmetric matrix P ( P[i,i]=0, i=1...N and P[i,j]>0 for i!=j) which stands for the relative distances of N points. I would like use it to get the coordinates of the N points in a 2D plane. Of course, the solution is not unique (given one solution, I can translate or rotate all the points by the same amount and generate
2007 Aug 08
2
Relocating Axis Label/Title --2
Apologies for the previous mail (I sent it off too early by mistake). This is the correct example: rm(list=ls()) D_mean<-seq(-5,5,length=100) y<-exp(-D_mean^2/5) pdf("my.pdf") plot(D_mean,y,type="l",yaxt="n",lty=2,lwd=2,col="black", ylab = list(expression(paste(dN/dlogD[agg]," ["*cm^-3*"]"))), xlab = expression(paste(D[agg],"
2012 Oct 26
2
Stata Database & R
Dear All, I am given some data to analyze. The data is in the form of a Stata database (.dta file). What is the best way to import it into an R dataframe? Is there any particular caveat I should be aware of? Many thanks Lorenzo
2012 Oct 05
2
Test for Random Points on a Sphere
Dear All, I implemented an algorithm for (uniform) random rotations. In order to test it, I can apply it to a unit vector (0,0,1) in Cartesian coordinates. The result is supposed to be a set of random, uniformly distributed, points on a sphere (not the point of the algorithm, but a way to test it). This is what the points look like when I plot them, but other then eyeballing them, can anyone
2013 Mar 25
2
Reassign Multiple Factors to same Factor Value
Dear All, Probably something very easy, but I am looking for the most efficient ways to achieve this. Consider the following snippet y<-c('a','b','c','d','e','f','g') x<-rnorm(length(y)) df<-data.frame(y,x) leading to > df$y [1] a b c d e f g Levels: a b c d e f g Now, I would like to replace levels
2013 Jan 28
1
RandomForest and Missing Values
Dear All, I would like to use a randomForest algorithm on a dataset. The set is not particularly large/difficult to handle, but it has some missing values (both factors and numerical values). According to what I found https://stat.ethz.ch/pipermail/r-help/2005-September/078880.html https://stat.ethz.ch/pipermail/r-help/2007-January/123117.html the randomForest package has a problem with missing
2016 Apr 19
3
Problem with X11
Dear All, I have never had this problem before. I run debian testing on my box and I have recently update my R environment. Now, see what happens when I try the most trivial of all plots > plot(seq(22)) Error in (function (display = "", width, height, pointsize, gamma, bg, : X11 module cannot be loaded In addition: Warning message: In (function (display = "", width,
2004 Apr 25
7
R vs Matlab: which is more "programmer friendly"?
Hi, The department of economics at our university (Budapest) is planning a course on numerical methods in economics. They are trying to decide which software to use for that, and I would like to advocate R. The other alternative is Matlab. I have found comparisons in terms of computational time for matrix algebra, but I don't think that is relevant: the bottleneck for economists is usually
2010 Feb 26
3
Plotting a Trivial Matrix
Dear All, Consider a matrix (N x N) where each entry is either zero or one (can hardly get any simpler). Now, I would like to plot it as a 'chessboard' where every matrix entry is a black (1) or white (0) square. Whatever tool I use to plot it, it should not try to interpolate the data at all. I found some online references http://www.phaget4.org/R/image_matrix.html but probably I can
2010 Dec 19
2
R.matlab memory use
Hi, I am trying to load into R a MATLAB format file (actually, as saved by octave). The file is about 300kB but R complains with a memory allocation error: > library(Rcompression) > library(R.matlab) Loading required package: R.oo Loading required package: R.methodsS3 R.methodsS3 v1.2.0 (2010-03-13) successfully loaded. See ?R.methodsS3 for help. R.oo v1.7.2 (2010-04-13) successfully
2019 Jul 07
2
Curl4, Quantmod, tseries and forecast
Dear All, I have just upgraded to Debian stable 10 and rebuilt most of the R packages. I use the R backported packages from here https://cran.r-project.org/bin/linux/debian/#debian-buster-testing for the core system. I encounter some issues when updating quantmod, tseries and forecast. For instance, see the following > install.packages("tseries") which finally fails with the
2019 Jul 07
2
Curl4, Quantmod, tseries and forecast
Dear All, I have just upgraded to Debian stable 10 and rebuilt most of the R packages. I use the R backported packages from here https://cran.r-project.org/bin/linux/debian/#debian-buster-testing for the core system. I encounter some issues when updating quantmod, tseries and forecast. For instance, see the following > install.packages("tseries") which finally fails with the
2013 Feb 03
3
RandomForest, Party and Memory Management
Dear All, For a data mining project, I am relying heavily on the RandomForest and Party packages. Due to the large size of the data set, I have often memory problems (in particular with the Party package; RandomForest seems to use less memory). I really have two questions at this point 1) Please see how I am using the Party and RandomForest packages. Any comment is welcome and useful.
2006 Oct 18
8
Automatic File Reading
Dear All, I am given a set of files names as: velocity1.txt velocity2.txt and so on. I am sure there must be a way to read them automatically in R. It is really taking me longer to read them than to analyze them. Anybody has a suggestion to help me out with this? Many thanks Lorenzo