similar to: grob questions

Dear list, Can someone explain why the childNames below gives character(0) instead of the (canonical) names of the children grobs of the xaxis gTree ? [1] "major" "ticks" "labels" Many thanks in advance, Tobias ### minimal example code ### library(grid) pushViewport(plotViewport(c(5,4,4,2))) pushViewport(dataViewport(1:5, 1:5)) grid.points(1:5, 1:5)

Dear UseRs called Hadley, or Paul, I am trying to print an edited ggplot2/grid graphics to a metafile. With the commented line below it works, but when I edit the plot by uncommenting the line, it fails, because it's illegal to have 2 graphics in a metafile. It works with pdf, but even then I get two plots, which is a nuisance. I found a workaround by using windows(); savePlot, but it only

Hi All, I have been able to modify the x-axis to start at zero by adding xlow and xhigh parameters; that was pretty simple. I have been unable to find the location of the code that would turn off the information weighting of the box size (I have smaller randomized trials getting less weight than a much larger non-randomized trial). The function is forestplot() from rmeta. Thanks for any

Dear list, As a minimal test of a more complex grid layout, I'm trying to find a clean and efficient way to arrange text grobs in a rectangular layout. The labels may be expressions, or text with a fontsize different of the default, which means that the cell sizes should probably be calculated using grobWidth() and grobHeight() as opposed to simpler stringWidth() and stringHeight().

Hi everyone,I'm trying to figure out how to use gPath and the documentation is not very helpful :( I have the following plot object: plot-surrounds:: background plot.gTree.378:: background guide.gTree.355:: (background.rect.345, minor-horizontal.segments.347, minor-vertical.segments.349, major-horizontal.segments.351, major-vertical.segments.353) guide.gTree.356::

Dear list, Following a recent enquiry, I've been playing with the idea of creating a colour gradient for a polygon, using the Grid package. The idea is to draw a number of stripes of different colours, using the grid.clip function. Below is my current attempt at this, library(grid) rotate.polygon <- function(g, angle=0){ # utility function, works fine matR <- matrix(c(cos(angle),

I'm trying to create a layout with named viewports that I can use for other functions. I create the viewport tree that I want, and a list of grobs with the viewports describing where they should go. library(grid) vp <- vpTree( viewport(layout=grid.layout(2,2), name="layout"), children=vpList( viewport(layout.pos.col = 1, layout.pos.row=1, name="tl"),

Dear list, I'm trying to arrange various grid objects on a page using a frameGrob. It works fine with basic grobs (textGrob, gTree, etc.), and also with ggplot2 objects using the ggplotGrob() function. I am however stuck with lattice. As far as I understand, lattice produces a list of class trellis, which is eventually displayed using the plot.trellis method. I am not sure if/how one can

Dear all, I've tried all sorts of variations discussed in "R graphics" by Paul Murrell, but I still can't understand how to write a drawDetails method for a class derived from a gTree. Below is a minimal, dummy example where two strings are plotted in two separate viewports. I require the creation of the strings to be evaluated inside the drawDetails function because my real

Dear all, I'm trying to access and modify grobs in a ggplot2 plot. The basic idea for raw Grid objects I understand from Paul Murrell's R graphics book, or this page of examples, http://www.stat.auckland.ac.nz/~paul/grid/copygrob/copygrobs.R However I can't figure out how to apply this to a ggplot (basically I don't know how to write a syntactically correct gPath), p

Hi R list, I like the default ticks that are set up using grid.xaxis() or grid.yaxis() with no arguments. Finding good values for the 'at' argument is usually not a trivial task; the default behavior of these functions seems to work well. The problem with this strategy is that I cannot figure out how to "recover" the positions of these ticks when you do NOT specify the

I am trying to create a lattice plot and would like to later, i.e. after the plot is drawn, add a grey rectangle behind a portion of it. The following works except that the rectrangle is on top of and obscures a portion of the chart. I also tried adding col = "transparent" to the gpar list but that did not help -- I am on windows and perhaps the windows device does not support

Dear all, In an attempt to draw fill patterns in grid graphics, I have encountered a behavior of grobX that I cannot understand from the documentation. Consider this, library(grid) ## gTree g1 <- gTree(children=gList( rectGrob(0.5,0.5, width=unit(0.8,"npc"), height=unit(2,"cm")), circleGrob(r=0.3)), vp=viewport(0.5,0.5)) ##

Hi everyone I'd like to flip grobs (grid graphical objects) along an axis, e.g. flip grobs horizontally or vertically. I couldn't find any hints, neither in the documentation nor by searching the web. Does anybody know how to achieve this? Cheers /thomas

Hi All, I am trying to find out how to access the components of a ggplot plot, and I found this reply from Paul Murrel http://www.nabble.com/navigating-ggplot-viewports-tt14826352.html#a15056223. I tried it, and it works. However, I am trying to develop some functions that will do the drawing "automatically", and usually I will not know the full name of the grob that has the layout vp,

Hello! Don't quite understand how can I delete grobs and simultaneously erase graphic output they produce. I first change grob's "vp" field to null (grid.edit(gr,vp=NULL)) to erase it and then call rm(gr) (as grobs are external pointers I'm not shure what this method actually frees allocated memory). May be there is simpler method? Does garbage collector have any effect

Hello! Don't quite understand how can I delete grobs and simultaneously erase graphic output they produce. I first change grob's "vp" field to null (grid.edit(gr,vp=NULL)) to erase it and then call rm(gr) (as grobs are external pointers I'm not shure what this method actually frees allocated memory). May be there is simpler method? Does garbage collector have any effect

I recently called plot(x,y) where x was an array of POSIXct timestamps, and was pleasantly surprised that it produced a nice plot right out of the box: z <- as.POSIXct(c("2006-10-26 08:00:00 EDT","2007-10-25 12:00:00 EDT")) x <- seq(z[1],z[2],len=100) y <- 1:100 plot(x,y,type="l") The X axis had nice labels, one tick mark every other month. (Plotting on

The xyplot help page gives quite a lot of information how to use key and indicates that legend needs to be used if multiple keys are needed. However, it gives only a brief description of what the grob needs to contain to do multiple keys. I've only used the occasional grid function in panel functions, so I don't have much of a sense of how grobs are constructed. I've been unable to

Dear All, I continue trying to get several of my plotting functions to use ggplot, because I really do like the concept of the graphical objects, and working with them in the abstract. I am now trying to access the grobs to manipulate using grid. However, until now all I managed was to get the plot as a gTree object, and manipulate it as a gTree from there. The problem is that then it is no