similar to: Simple extraction of level,x,y from contourLines()

Hi Folks, I have been using contour() to produce some contour plots (of a spatially-smooted density produced by kde2d()), with very satisfactory results. I now want access to the coordinates of the points on the contours, and it would seem that contour() does not return a value, so there is nothing from which these could be extracted. However, apparently contourLines() does, and it seems to be

Greetings all! I'm wanting to plot contours of a function, and I don't want to evaluate it at a dense grid of points (i.e. I don't want a huge array of values). Say I have a vector of x-values such as x <- 0.1*c(1:10), and the same for y <- 0.1*(0:10). I then evaluate a 10*10 matrix z of values of z = f(x,y). so I can then do CL <- contourLines(x,y,z) and get a list of

I want to use contourLines() to get contour line coordinate vectors, but I don't want to make a plot. However contourLines() insists on opening a graphics device. Is there a way tell it not to do this? > version platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status Patched major 2 minor 1.0 year 2005 month 04 day 20 language R

Hello, I have searched for documentation on the function contourLines's algorithm but cannot find a thing. I am about to submit a paper to a journal but cannot yet do so because I need to provide some reference for this function. Does anyone know what algorithm is used for this function? Thanks, Derek Lacoursiere -- View this message in context:

To everyone, Is there a way to extract coordinates or an equation from a "straight" contour line? Thanks. Cheers Julius Tesoro

Hello, Is it possible to draw level lines on the surface of a bivariate function? In the following example, to draw surface and levels lines for a multivariate normal law, I use persp, trans3d, contourLines and lines, but if the lines are correctly drawn, some parts of them are, of course, visible even if they are drawn on a non visible "face". Any suggestion to avoid this problem

Hello everybody, I search a function which returns the contour of map with levels like contourLines, but I would like this function return the border of the map too, because the function contourLines cannot consider the corner of the map and it is not adapted to fill polygon after that. Thanks in advance Pierre Bruyer

Greetings, All! I want to draw contour lines in red, using contour(), but also have the contour labels (for the level-values) in black so that they will stand out against a coloured background already generated using filled.contour() (the background shades from green at low levels of "risk" to red at high levels). In any case, contour labels in red are already somewhat inconspicuous

I have a list of polygons generated by the contourLines() command (each object of the list is a list in itself with two objects: a vector of x values, and a vector of y values for each vertex). I wish to convert that list into a gpc.poly object of multiple contours. How do I do this? gpclib apparently has no method of coercing lists into the gpc.poly object type. As well, when I have a

I am using contour to draw contour lines onto a photo (jpeg) of a leaf on a white background. I have two problems: 1) The contour gets plotted at right angles to the jpeg image. I guess this is a problem of referencing the start and end points of the image matrix but I can't see how to over come this other than loading in a second image that has been rotated 90 degrees and plotting the

Hi Folks, I'd be grateful for good suggestions about the following. I'm plotting a family of (X,Y) curves (for different levels of another variable, Z): say 6 curves in all but could be more or less -- it's a rather variables situation. I'd like to label each curve with the value of Z that it corresponds to. The problem is that the layout (shapes, spacings, ranges of X over

Considering the R function/plot shown below, I wonder whether it is possible to do the following changes: (1) Change the color of each point to be picked from list of colors according to its z-value. (The range should be from blue (z=0) to red (z=1).) The grid should then be omitted. [I have seen "terrain.colors", but don't know how to use it for this purpose.] (2) Add two lines to

Hello List! I asked this before (with no solution), but maybe this time... I'm trying to project a surface to the XY under a 3d cloud using lattice. I can project contour lines following the code for fig 13.7 in Deepayan Sarkar's "Lattice, Multivariate Data Visualization with R", but it fails when I try to "color them in" using panel.levelplot. ?utilities.3d says there

I am currently trying to use R to construct a regression model to explain output based on temperature. I have combined my output and temp data into a notepad file. there is no problem with loading the data into R. > data.df output temp 1 850 17 2 849 17 3 905 17 4 925 17 5 1043 19 6 1104 20 7 1097 18 8 979 19 9 926 18 10 1133 18 ~~ ~~ 240 1124

Requisite info: R version 2.11.1 (2010-05-31) running on a 64 bit HP Windows 7 machine. Greetings, R-ians: I have used contour() for several years. Now I would like to extract from a contour plot the x, y coordinates of a contour z=constant. This seems as though it would be straight-forward but I''ve been unsuccessful in my searches of CRAN. Can anyone provide a hint?

Hello list, I'm new to R and I have a problem :-) Below is what my data file that looks like. I tried to import and contour this data by doing this: cv_data <- read.table("cv_data.csv",sep=",",header=TRUE) attach(cv_data) contour(x,y,z) I get the error "Error in contour.default(x,y,z) : increasing 'x', and 'y' values expected" I

Hi Folks, I'm probably overlooking some small point, but can't see it. Trying the "Local trend surfaces" example from p.437 of MASS (3rd edn) by V&R, all goes well until the line contour(topo.mar$x, topo.mar$y, topo.lo$fit, levels=seq(700,1000,25), xlab="fi t", ylab="") which produces the response: Error in contour.default(topo.mar$x,

Full_Name: Dominik Heide Version: 2.3.1 OS: Linux (Suse 9.3) Submission from: (NULL) (134.76.220.200) The contour functions has sommewhere (I think in .../main/plot3d.c) a maximum number of line segments that is set using a define. The contour line in my data too long for this and therefore not correct analysed (I get the message 'contour(): circular/long seglist -- bug.report()!').

Hi Folks, I'd be grateful for some views on the following. When I say "plot y against x" I mean that y is on the vertical axis and x is on the horizontal axis. I acquired this usage so long ago that I can no longer remember how I acquired it, and therefore can not cite my "authority" for my usage. There can also be an implication that y is a function of x (or y is a

Hi Folks, I'm contemplating using locator() to digitise external graphics. To set context, I would be using X11 display on Linux. To pre-empt the obvious comment: I've found on the R site the suggestion to use the 'pixmap' package. I've tried this, and it works; but it involves building a big R object (the internal pixmap representation), and this chokes my somewhat puny