search for: pomchip

Dear R-users, I am trying to produce trellis (png, or jpeg) graphs with transparent background, but I cannot manage to make that happen. I tried to play around with themes but to no avail. Any advise on the following example will be greatly appreciated: Thank you Sebastien #### library(lattice) df <- data.frame(a=rep(1:4,4), b=rep(1:4,4), c=rep(1:4,each=4)) settings <- standard.theme()

Dear R-users, The strsplit function does not exist in S-plus and I would like to use it. How could I reproduce the function in Splus or access to its source code? Thank you in advance, Sebastien

Dear R-users, I would like to know if there is a function (in base R or the extension packages) that would automatically detect the break points in a vector x for later use in the cut function. The idea is to determine the boundaries of the n intervals (n>=1) delimiting clusters of data points which could be considered "reasonably" close, given a numerical vector x with unknown

Dear R-users, In the R internals manual, it is said that one can extract the elements of the dot-dot-dot argument using the special symbols ..1 or ..2. It seems to work just fine but I was wondering if there is a way one can extract or modify the content of the dot-dot-dot argument using a level name instead of its position? For instance, assuming that list(...) returns: $a [1] 1 2 3 4 5

Dear R-users, I have found this not-so-recent post in the archives - http://tolstoy.newcastle.edu.au/R/devel/00a/0291.html - while I was looking for a particular way to reorder factor levels. The question addressed by the author was to know if the read.table function could be modified to order the levels of newly created factors "according to the order that they appear in the data

Dear R-users, I have found on the list several posts addressing the issue of getting data for a list of defined files. However, I found nothing about scanning a given folder and retrieving the list of, let's say, .txt files (I probably used the wrong keywords). Could someone tell me which posts or function help I should look at? Thanks in advance Sebastien

Dear R-users, The following code splits a very simple dataframe into a list, each element of the list being one line of the dataframe. You will see that the split function names each element of the list by using uses the content of a and b and merging them with a "." character. Is there a way to customize this character? a<-1:10 b<-21:30 mydata<-data.frame(a,b)

Hello I apologize in advance if this question has already be posted on the list, although I could not find a relevant thread in the archives. I would like to overlay xyplots using different datasets for each plot. I typically work on the following data.frame (mydata) structure >mydata Drug Time Observed Predicted 1 A 0.05 10

Dear R-users, Is there a easy way to access to a complete listing of available functions from a R session? The help.start() and ? functions are great, but I feel like they require the user to know the answer in advance (especially with respect to function names)... I could not find a easy way to simply browse through a list of functions and randomly pick one function to see what is does. Is

Dear R-users, I am trying to port to R something that I wrote in Matlab to perform model parameter optimization using the Nelder-Mead simplex method (fminsearch). I read the help on ?optim (which seems to be the way to go) as well as a bunch of posts on the topic, but I would like to make sure about something before I spend to much time trying to reproduce something that is not possible. The

Dear R-users, I am using plot symbols given by pch=21:25 in a xyplot. The background color of these symbols can be defined by 'fill' in the panel argument, however I have a hard time to find how to define the same background color in the key. I tried different options like using the auto.key argument and modifying the par.settings, or using normal key argument plus 'fill',

Dear R-users, The help does not give much details on the use of the arguments 'from' and 'to' in the panel.abline function. I have looked in the archives but did not find how to implement them. My different tries failed miserably. E.g, the following code doesn't seem to work, in a sense that the line is not limited to the (0,10) range. Do these arguments really apply to

Dear R-users, The following code splits a very simple dataframe into a list, each element of the list being one line of the dataframe. You will see that the split function names each element of the list by using uses the content of a and b and merging them with a "." character. Is there a way to customize this character? a<-1:10 b<-21:30 mydata<-data.frame(a,b)

Dear R-users, I have created a bunch of R scripts that automatically create multiple plots, all saved in a pdf device. I initially chose pdf output in order to easily access to multiple plots in a single file. Now, I am trying to play with different devices, like png or eps and I realize that the settings I used to have nice plots in a pdf device are giving awful outputs with the other

Dear R-users, I am trying to perform some simulations from a model defined by ordinary differential equations. I would be grateful if someone could indicate some functions/packages/examples I could look at. Thank you in advance. Sebastien

Hello, It looks to me as if the ! logical operator cannot be called when subsetting a data.frame. In the example below, the value column has two factor levels (but my typical datasets have more), and what I am trying to do is to exclude all lines for which the "value" is different from "A". I have got a syntax error message everytime I try to use the subset() function.

Hello, Is there a way to define the width of the axis tick marks on traditionnal plots? I did not find anything specific on this topic in the help and par(lwd=...) does not affect the tick marks. I guess that using axes=FALSE and recreating the axis with the axis() command could do the trick but I wonder if there is no easier way. Thanks in advance Sebastien

Hello everyone, Very quick question: How should I cite the use of R in a publication ? Thanks in advance. Sebastien

Dear R users, I have to import some csv files in which column headers contain the character "~". Following the following import call, the character seems to be replaced by dots in the column names of my data frame. Plus, I cannot query names(mydata) to find the column index which header should contain "~" or "." > mydata <-

Dear R-users, I need to dynamically recognize the index of a given string myStr in a vector of string. The problem is that myStr might contain parenthesis, causing grep not to recognize it the way I want (see below). The help mentions that the pattern used by grep should be in the POSIX format... I guess the problem is here; unfortunately, I am not familiar with the subtleties of the POSIX