similar to: system() not accepting strings from cat()

Displaying 20 results from an estimated 5000 matches similar to: "system() not accepting strings from cat()"

2009 Mar 25
2
"[.data.frame" and lapply
Dear all, Trying to extract a few rows for each element of a list of data.frames, I'm puzzled by the following behaviour, > d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5))) > str(d) > > lapply(d, "[", i= c(1)) # fine, this extracts the first columns > lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?! > > library(plyr)
2009 Mar 25
2
"[.data.frame" and lapply
Dear all, Trying to extract a few rows for each element of a list of data.frames, I'm puzzled by the following behaviour, > d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5))) > str(d) > > lapply(d, "[", i= c(1)) # fine, this extracts the first columns > lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?! > > library(plyr)
2009 Apr 14
2
subset dataframe by rows using character vector?
Dear List, I'm stuck on what seems like a simple indexing problem, I'd be very grateful to anyone willing to help me out. I queried a dataframe which returns a character vector called "plot". I have another dataframe from which I want to subset or select only those rows that match "plot". I've tried subset, and also the "which" command. plot
2008 Jun 18
2
highest eigenvalues of a matrix
DeaR list, I happily use eigen() to compute the eigenvalues and eigenvectors of a fairly large matrix (200x200, say), but it seems over-killed as its rank is limited to typically 2 or 3. I sort of remember being taught that numerical techniques can find iteratively decreasing eigenvalues and corresponding orthogonal eigenvectors, which would provide a nice alternative (once I have the
2009 Jun 25
3
grid.polygon() + color gradient
Hi, I wonder whether there is a way to generate a polygon (a triangle in my case) with color gradient using grid.polygon() in package grid? I tried something like library(grid) grid.polygon(x=c(0, 0.5, 1), y=c(0.5, 1, 0.5), gp=gpar(col=NA, fill=colorRampPalette(c("green", "lightgray"), space="Lab")(200))) But am only
2008 Apr 03
1
data.frame or list
Dear R list, I'm having difficulties in choosing between a list or a data.frame, or an array for the storage and manipulation of my data (example follows). I've been using the three for different purposes but I would rather like to know which is more adapted to what task. Here is the data I'm currently working on: 200 observations, each observation being a vector of length
2008 Feb 03
1
distances between points in R^3
Dear R helpers, I'm trying to write a numerical scheme for a boundary integral method to solve an electromagnetic problem. This requires the computation of the distance between points at the surface of an object (a sphere, in my example). Here is my code, > require(rgl) > r<-1 > size<-10 > theta<-seq(0,2*pi,length=size*2) > phi<-seq(0,pi,length=size) > pc
2008 Nov 09
1
[Rd] Re Bessel functions of complex argument
Dear all, I'm writing a code that requires Bessel functions with complex argument. Searching the list, I found the continuation of a thread I initiated a few months ago: http://tolstoy.newcastle.edu.au/R/e4/devel/08/03/0746.html As I understand, the most promising option would be to use the fortran or C implementation of Amos,
2009 Apr 16
3
segment between points on different plots
Hi, I need to draw a line segment between two points on different plots in the same multigraph.I've tried looking at the zoominplot function in plotrix but havent understood much.any help is appreciated ~Aks [[alternative HTML version deleted]]
2008 Feb 18
2
question on function arguments
Hi, I have two small issues with my R code, no big deal but curiosity really. Here is a sample code, > > x <- rnorm(1:10) > > foo <- function(a = 1, b = list(x = c(1:10), y = c(1:10))){ > > for (ii in seq(along=b$y)){ > > print(x[ii] + b$x[ii]) > } > > > } > > foo() # default OK > > foo(b=list(x=1, y=c(1:10))) # only the first
2009 Mar 09
3
How to write a function that accepts unlimited number of input arguments?
Dear R-helpers: I am an R newbie and have a question related to writing functions that accept unlimited number of input arguments. (I tried to peek into functions such as paste and cbind, but failed, I cannot see their codes..) Can someone kindly show me through a summation example? Say, we have input scalar, 1 2 3 4 5 then the ideal function, say sum.test, can do
2009 Mar 27
3
Ploting a matrix
Hi evrybody, in a matrix consisting of 49 columns, I would like to plot all columns against the first in 48 different graphs. Can you help me? Thank you in advance Sebastian -- *************************************************************************************************************** Dipl. Biol. Sebastian Krug PhD - student IFM - GEOMAR Leibniz Institute of Marine Sciences Research
2008 Apr 26
6
quasi-random sequences
Dear list useRs, I have to generate a random set of coordinates (x,y) in [-1 ; 1]^2 for say, N points. At each of these points is drawn a circle (later on, an ellipse) of random size, as in: > N <- 100 > > positions <- matrix(rnorm(2 * N, mean = 0 , sd= 0.5), nrow=N) > sizes<-rnorm(N, mean = 0 , sd= 1) > plot(positions,type="p",cex=sizes) My problem is to
2009 May 27
3
Axis label spanning multiple plots
Hello I need to plot 3 graphs in a single column; the top two plots have the same title, and I would like it to be written only once, centered horizontally and spanning the two plots. Something like t +------------+ | | i | | | | t +------------+ l +------------+ | | e | | | | 1 +------------+ t
2008 Jul 03
1
ggplot2 legend for vertical lines
Dear all, The following example code produces a graph with ggplot2, to which I add several vertical lines of arbitrary colors. I am not satisfied with the legend: it automatically adds some vertical lines which I'd rather not see (they confuse the reader rather than add information in this case). > library(ggplot2) > dfr <- data.frame(values = sin(1:50/10), > fact =
2009 Mar 14
3
[OT] two question about color space.
Hi there, I try to plot visible light spectrum (380nm~780nm) with color corresponding to the specific wavelength. However, I don't find a function that could do this. Another question, it's possible to plot a color space chromaticity diagram like this: http://upload.wikimedia.org/wikipedia/commons/thumb/0/02/CIExy1931.svg/300px-CIExy1931.svg.png Thanks in advance! Jinsong
2008 Apr 12
1
lm() of one matrix against another
Hello R list, I have two matrices of identical dimensions, and I want to fit a straight line for each pair of columns and plot the resulting lines. I got it to work with a for loop, but there must be a better way, > n<-5 > N<-10 > > data.x<-matrix(1:(n*N),ncol=n) > data.y<-matrix(1:(n*N) + rnorm(n*N,sd=1),ncol=n) > >
2009 Apr 03
2
Help pasting string as object name
I have a data frame containing monthly observations of the 'density' of each US state, recorded in variables named "density.AL", "density.AK", "density.AZ", and so on for all 50 states. The data frame (called d) also contains a variable called "Date" which is encoded as a string in the format "Jan-09", "Feb-09", etc. I also have
2008 Feb 14
1
write output in a custom format
Hi, I need to create a text file in the following format, > 1 100.0 0 > 0 0 > 1 1 > 0 0 > 1 1 > # > 1 100.0 0 > 0 0 > 0 1 > 1 0 > 1 1 ... where # is part of the format and not a R comment. Each block (delimited by #) consists of a first line with three values, call it dose, and a list of (x,y) coordinates which are a matrix or data.frame, >
2008 Dec 10
4
tapply within a data.frame: a simpler alternative?
Dear list, I have a data.frame with x, y values and a 3-level factor "group", say. I want to create a new column in this data.frame with the values of y scaled to 1 by group. Perhaps the example below describes it best: > x <- seq(0, 10, len=100) > my.df <- data.frame(x = rep(x, 3), y=c(3*sin(x), 2*cos(x), > cos(2*x)), # note how the y values have a different