Hi all, I'm having two small problems and was wondering if you could help me out. Problem 1: When I use pch to place a symbol onto a plot it seems to place the point a little off the exact location. I have read the help file for this which says to use "." as the plotting character, which will then produce centered points but I am unclear as to how to do this. Problem 2: How do I get R to draw a curve through a number of data points rather than a straight line. From the description of the functions scatter.smooth and loess.smooth, I think they are what I'm looking for, but when I try to run them in R Version 1.1.0, it returns the following error Error in sdgraph() : couldn't find function "scatter.smooth" Your help as always is greatly appreciated Margaret Riordan -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Wed, 9 Aug 2000, Margaret Riordan wrote:> Hi all, > I'm having two small problems and was wondering if you could help me > out. > > Problem 1: > When I use pch to place a symbol onto a plot it seems to place the point > a little off the exact location. I have read the help file for this > which says to use "." as the plotting character, which will then produce > centered points but I am unclear as to how to do this.pch="." But we have tried hard to get the symbols in the right places, so which R version and which graphics device is this? e.g. plot(1:10, 1:10, type="n") abline(v=1:10);abline(h=1:10) for(i in 1:10) for(j in 1:10) points(i, j, pch = ".") is correct (to 0.5 pixel) on my system) and so is for(i in 1:10) for(j in 1:10) points(i, j, pch = 16) (yes, I do know how to vectorize this!)> Problem 2: How do I get R to draw a curve through a number of data > points rather than a straight line. From the description of the > functions scatter.smooth and loess.smooth, I think they are what I'm > looking for, > but when I try to run them in R Version 1.1.0, it returns the following > error > Error in sdgraph() : couldn't find function "scatter.smooth"They are in library modreg. You should not have got help on them in 1.1.0 without doing library(modreg) first. However, they fit a smooth curve through a scatter plot, not through the data points themselves (smoothing, not interpolation). There are many other possibilities, and I would tend to prefer smooth.spline (also in modreg) as it automatically chooses the degree of smoothing. Then there are regression splines, running lines smoothers (supsmu), kernel smoothers, .... V&R3 and its on-line statistical complements have a catalogue and comparisons. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Wed, 9 Aug 2000, Margaret Riordan wrote:> Problem 1: > When I use pch to place a symbol onto a plot it seems to place the point > a little off the exact location. I have read the help file for this > which says to use "." as the plotting character, which will then produce > centered points but I am unclear as to how to do this.plot(rnorm(100),rnorm(100),pch=".")> Problem 2: How do I get R to draw a curve through a number of data > points rather than a straight line. From the description of the > functions scatter.smooth and loess.smooth, I think they are what I'm > looking for, > but when I try to run them in R Version 1.1.0, it returns the following > error > Error in sdgraph() : couldn't find function "scatter.smooth"it's in library(modreg) ... Peter ** To YOU I'm an atheist; to God, I'm the Loyal Opposition. Woody Allen ** P.Malewski Tel.: 0531 500965 Maschplatz 8 Email: P.Malewski at tu-bs.de ************************38114 Braunschweig******************************** -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._