http://wiki.r-project.org/rwiki/ 2008-07-26T19:17:38+01:00 http://wiki.r-project.org/rwiki/ http://wiki.r-project.org/rwiki/lib/images/favicon.ico text/html 2008-07-26T19:17:12+01:00 Tony Plate (tplate@acm.org) http://wiki.r-project.org/rwiki/doku.php?id=getting-started:installation:debian&do=diff1217092632 There is a mailing list “R Special Interest Group for Debian ports of R” R-SIG-Debian, where you can find, and should ask or discuss about Debian specific stuff related to R. Quantian, a Knoppix / Debian variant tailored to numerical and... text/html 2008-07-24T13:37:59+01:00 Anne Ghisla (a.ghisla@studenti.uninsubria.it) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:when_to_use&do=diff1216899479 What belongs here is a description of the class of problems for which R spatial is a solution and a gentle hint about how to define the class of problems for which a GIS is a better solution. R Spatial Can R can analyse spatial data, see CRAN Spa... text/html 2008-07-21T13:49:02+01:00 Bjarke Christensen (bjarke.christensen@sydbank.dk) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:overlapping&do=diff1216640942 Via Adrian Baddeley on R-sig-geo: library(spatstat) X <- crossing.psp(as.psp(W), S) X$n > 0 # returns TRUE if the line segment crosses any of the edges of the # rectangle. The command as.psp(W) converts the edges of the... text/html 2008-07-21T11:15:10+01:00 Bjarke Christensen (bjarke.christensen@sydbank.dk) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:distances&do=diff1216631710 The function spDistsN1() from the maptools package returns a vector of distances between a matrix of 2D points and a single 2D point, using Euclidean or Great Circle distance (WGS84 ellipsoid) methods. An example: library(maptools) data(meuse) coor... text/html 2008-07-20T23:25:57+01:00 baptiste (ba208@ex.ac.uk) http://wiki.r-project.org/rwiki/doku.php?id=tips:graphics-misc:ggplot2theme_inbase&do=diff1216589157 This possibly pointless exercise aims at reproducing the default theme of ggplot2 graphs with base graphics. It could be useful to obtain a consistent style in a document comprising both types of graphs. library(ggplot2)   graphics.off... text/html 2008-07-17T14:25:08+01:00 Dimitris Rizopoulos (dimitris.rizopoulos@med.kuleuven.be) http://wiki.r-project.org/rwiki/doku.php?id=packages:cran:ltm&do=diff1216297508 This package provides a flexible framework for Item Response Theory analyses for dichotomous and polytomous data under a Marginal Maximum Likelihood approach. The fitting algorithms provide valid inferences under Missing At Random missing data mecha... text/html 2008-07-17T14:19:52+01:00 Dimitris Rizopoulos (dimitris.rizopoulos@med.kuleuven.be) http://wiki.r-project.org/rwiki/doku.php?id=packages:cran:jm&do=diff1216297192 This package fits shared parameter models for the joint modelling of normal longitudinal responses and event times under a maximum likelihood approach. Various options for the survival model and optimization/integration algorithms are provided. De... text/html 2008-07-14T03:27:12+01:00 Ben Goodrich (bgokGM@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=packages:cran:fair&do=diff1215998832 FAiR is a package to enhance the ability to conduct Factor Analysis in R and provides some functionality that is not found in any other R package or other statistical program. FAiR implements a new way to estimate the factor analysis model called se... text/html 2008-07-13T13:16:37+01:00 Christophe Genolini (genolini@u-paris10.fr) http://wiki.r-project.org/rwiki/doku.php?id=tips:classes-s4&do=diff1215947797 The main reference is still ‘The Green Book’, i.e. John Chambers (1998) “Programming with Data”. Further, the following two help pages (and the ones they link to) should be used for reference: help(Methods) -- but use R ver... text/html 2008-07-05T02:04:20+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:stats-spatial:sampling&do=diff1215216260 Your first port of call should be spsample() in the sp package. This can sample points randomly, regularly or in other ways, from a variety of shapes. If you have your sample of points, and want to find data from the polygons which the points fall ... text/html 2008-07-05T01:59:30+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:merging&do=diff1215215970 You can use either the rbind() methods defined in sp, or the spRbind() methods defined in maptools. One caveat is that your two objects need to have non-overlapping sets of IDs. To ensure this happens, use spChFIDs from maptools.... text/html 2008-07-05T01:27:28+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:stats-spatial&do=diff1215214048 R has quite a lot of capability for spatial statistics, although (like spatial statistics itself) it is scattered through a variety of packages. Start with the spatial task view on CRAN. For spatial data import, export and manipulation, see spatial... text/html 2008-07-05T01:09:27+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data&do=diff1215212967 Spatial data When to use R spatial Overview of R spatial packages Getting spatial data into and out of R Converting between spatial data formats within R Subsetting spatial data Combining spatial data Measuring distances Finding nearby objec... text/html 2008-07-03T16:14:11+01:00 Paul Hiemstra (p.hiemstra@geo.uu.nl) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:spatial_data_visualization&do=diff1215094451 One of the harder topics in R is visualization. Visualizing spatial data is no exception. This page discusses topics related to spatial data visualization in R. When running the example code it is assumed that the sp package is loaded. When referri... text/html 2008-07-01T20:09:13+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:import_export&do=diff1214935753 Your first port of call should probably be the rgdal package. If that doesn’t work, check the table below. Import and export spatial data into and from sp classes The sp package provides S4 classes for representing spatial data such as poi... text/html 2008-07-01T16:08:32+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:subsetting&do=diff1214921312 If your data is in sp format, you can use [] as normal. Normally this will be useful if you have, e.g. a SpatialPolygonsDataFrame with some data attached: library(sp) # say we have a countries object with a field "country.name" G8 ... text/html 2008-07-01T16:07:20+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:packages&do=diff1214921240 Dealing with spatial data, you will need to do one or more of the following: get data into R clean, subset and explore the data run statistical analyses (maybe) export data back out from R There are many spatial data packages on CRAN. This ta... text/html 2008-07-01T14:29:35+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:spatial-data:conversion&do=diff1214915375 — David Hugh-Jones 2008/07/01 Internal R formats for spatial data There is not (yet!) one canonical way to represent spatial data in R. The main formats are as follows: Formats used by the sp package (SpatialPoints,SpatialLines,SpatialPo... text/html 2008-07-01T11:14:35+01:00 David Hugh-Jones (davidhughjones@gmail.com) http://wiki.r-project.org/rwiki/doku.php?id=tips:tips&do=diff1214903675 A collection of short pages with R code examples (”snippets”) 1)... For those who migrate Paul Johnson’s Rtips, please, update the Rtips status page. Data Input-output aggregate_values export_table import_table ms_windows pd... text/html 2008-06-30T14:29:25+01:00 Ben Bolker (bolker@zoo.ufl.edu) http://wiki.r-project.org/rwiki/doku.php?id=getting-started:translations:mathematica2r&do=diff1214828965 Mathematica (from Wolfram Software) is a widely used commercial software package/language that was initially developed to do symbolic computation and graphics (similar to Maxima, Maple, or Yacas) but also has a very broad range of numerical capabili...