similar to: switch and factors

Dear list, I'm trying to use the reshape package to perform a merging operation on a list of data.frames as illustrated below, > a <- 1:10 > example <- list( data.frame(a=a, b=sin(a)), data.frame(a=a, > b=cos(a)) ) > > melt(example, id = a) this produces the desired result, where the data.frames have been coerced into one with a common identifier variable

Dear all, In mucking around with ggplot2, I've hit the following snag, library(ggplot2) # this returns a grob, OK GeomAbline$icon() # lines[GRID.lines.9] # this returns the function icon, OK GeomAbline$icon # proto method (instantiated with ): function (.) # linesGrob(c(0, 1), c(0.2, 0.8)) # <environment: 0x13e6800> Now I want to wrap this in a function, getIcon <-

Dear list, I've written a small utility function to add arbitrary legend(s) to a lattice graph (or a combination of them), much like the legend function of base graphics. I though perhaps it could be useful to someone else, or improved by suggestions. I understand this goes against the lattice paradigm somewhat, in that you short-cut the link between group variables and the

Dear list, The dichromat package defines a dichromat function which "Collapses red-green color distinctions to approximate the effect of the two common forms of red-green colour blindness, protanopia and deuteranopia." library(dichromat) library(grid) colorStrip <- function (colors = 1:3, draw = TRUE) { x <- seq(0, 1 - 1/length(colors), length = length(colors)) y <-

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)

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)

Dear list, I wish to visualise some 4D data as a kind of colour / translucent cloud in 3D. I haven't seen such plots in R (but perhaps I missed a feature of rgl). The easiest option I found would be to export the data in povray's df3 (density file) format and visualise it with povray. The format specification baffles me a little, http://www.povray.org/documentation/view/3.6.1/374/ ;

Dear all, I'm trying to write tabular data to a text file, these data will be the input of a Fortran program. The format needs to be "(i7,2x,7(e15.7,2x))". I have not been able to find a clean way of producing this output with write.table. I searched for a "write.fortran" function similar to read.fortran() in package utils but I couldn't find any. Below is a small

Dear list, I am puzzled by this, substitute(expression(x), list(x = factor(letters[1:2]))) # expression(1:2) Why do I get back the factor levels inside the expression and not the labels? The following work as I expected, substitute(expression(x), list(x = letters[1:2])) # expression(c("a", "b")) substitute(x, list(x = factor(letters[1:2]))) # [1] a b # Levels: a b

Dear all, I'm puzzled by the following example inspired by a recent question on R-help, cc <- textConnection("user_id website time 20 google 0930 21 yahoo 0935 20 facebook 1000 25 facebook 1015 61 google 0940") d <- read.table(cc, head=T) ; close(cc) table(d$user_id) # count the

Dear all, I got a couple of warnings using panel.levelplot.raster, In panel.levelplot.raster(..., interpolate = TRUE) : 'y' values are not equispaced; output will be wrong although I was quite sure my data were equally spaced (indeed, I created them with seq()). A closer look at the source code reveals that the function tests for exact uniformity in grid spacing, if

Dear list, In a little numbers game, I've hit a performance snag and I'm not sure how to code this in C. The game is the following: how many 8-digit numbers have the sum of their digits equal to 17? The brute-force answer could be: maxi <- 9 # digits from 0 to 9 N <- 5 # 8 is too large test <- 17 # for example's sake sum(rowSums(do.call(expand.grid, c(list(1:maxi),

Dear list, I read in ?plotmath that I can use bgroup to draw scalable delimiters such as [ ] and ( ). The same technique fails with < > however, and I cannot find a workaround, grid.text(expression(bgroup("<",atop(x,y),">"))) Error in bgroup("<", atop(x, y), ">") : invalid group delimiter Regards, baptiste sessionInfo() R version

Dear list, I read in ?plotmath that I can use bgroup to draw scalable delimiters such as [ ] and ( ). The same technique fails with < > however, and I cannot find a workaround, grid.text(expression(bgroup("<",atop(x,y),">"))) Error in bgroup("<", atop(x, y), ">") : invalid group delimiter Regards, baptiste sessionInfo() R version

Dear list, I have the following example, from which I am hoping to retrieve numeric values of the factor levels (that is, without the brackets): > > x <- seq(1, 15, length=100) > y <- sin(x) > > my.cuts <- cut(which(abs(y) < 1e-1), 3) > levels(my.cuts) hist() does not suit me for this, as it does not necessarily respect the number of breaks. getAnywhere

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

Dear list, I'm seeking some advice regarding a particular numerical integration I wish to perform. The integrand f takes two real arguments x and y and returns a vector of constant length N. The range of integration is [0, infty) for x and [a,b] (finite) for y. Since the integrand has values in R^N I did not find a built-in function to perform numerical quadrature, so I wrote my own after

Dear all, I'm puzzled by the behavior of stringHeight in the grid package. Consider the following test, library(grid) test <- function(lab="dog", ...){ g1 <- textGrob(lab) g2 <- rectGrob(height=grobHeight(g1), width=grobWidth(g1)) gg <- gTree(children=gList(g1,g2), ...) print(c("height:", convertUnit(stringHeight(lab), "mm",

Suppose df is a dataframe with one named row of numeric observations. I want to coerce df into a named vector. as.vector does not work as I expected: as.vector(df) returns the original dataframe, while as.vector(df,mode="numeric") returns an unnamed vector of NAs. This works: > v <- as.numeric(as.matrix(df)); names(v) <- names(df); I just wanted check if there

Dear all, I am puzzled by the following behavior of the new grid.cap() function, which appears to run out of time when capturing the output of a graphic. It works fine if I introduce a Sys.sleep(1) before executing more code, library(grid) quartz() grid.circle(gp=gpar(fill="black")) gg <- grid.cap() dev.new() grid.raster(gg) ## completely blank gg[gg!="white"] ## indeed