similar to: matrix indices

Displaying 20 results from an estimated 3000 matches similar to: "matrix indices"

2010 Aug 17
4
replacing values in a vector
Dear helpRs Does anyone have an elegant way of doing the following: For a given numeric vector, e.g. vec <- c(3,2,6,4,7) Create a series of vectors where all but 1 of the values are replaced by 0's, e.g. vec.a <- c(3,0,0,0,0) vec.b <- c(0,2,0,0,0) vec.c <- c(0,0,6,0,0) vec.d <- c(0,0,0,4,0) vec.e <- c(0,0,0,0,7) I have looked at `replace', but can't think of a
1999 Dec 21
2
generating a sequence
Hi everyone I'm trying to generate a vector of the form a <- c(1,2,3,4,1,2,3,1,2,1) where n = 5 in a general way, where n can be any positive integer. I've run out of ideas. Does anyone have any suggestions? Thanks Karen Karen Kotschy Centre for Water in the Environment University of the Witwatersrand Johannesburg Tel: 011 716-2218
1999 Dec 21
2
generating a sequence
Hi everyone I'm trying to generate a vector of the form a <- c(1,2,3,4,1,2,3,1,2,1) where n = 5 in a general way, where n can be any positive integer. I've run out of ideas. Does anyone have any suggestions? Thanks Karen Karen Kotschy Centre for Water in the Environment University of the Witwatersrand Johannesburg Tel: 011 716-2218
2005 Jun 28
2
enhanced MDS
Hi again Sorry, in looking again at sammon and isoMDS I see that they seem to do exactly what I want, except that they are non-metric, which means, as I understand it, that they relate the rank orders of the variables rather than the actual distances. Could I use these non-metric MDS packages even if my distances are metric? Thanks Karen -- Karen Kotschy Centre for Water in the Environment
1999 May 19
1
R and ArcView
Does anyone know if an R plug-in exists for the GIS package ArcView running under Windows98 or NT? I know such a plug-in is available for S-PLUS. Thanks Karen Kotschy Centre for Water in the Environment Department of Botany University of the Witwatersrand Johannesburg South Africa Tel : +2911 716-2218 Postal address: P/Bag 3 P.O Wits 2050 South Africa
2005 Jul 12
3
adding a factor column based on levels of another factor
Hi R users Does anyone out there have a better/quicker way of adding a factor column to a data frame based on levels of another factor? I have a (large) data frame consisting of records for individual plants, each represented by a unique ID number. The species of each plant is indicated in the column "species", which is a factor column with many different levels (species). There are
1999 Nov 25
0
desperate!
Dear R community I sent a message out a while ago asking for help with multiple comparison tests for ANOVA's, but haven't had any response yet. I'm sending a final desperate plea. If I can't get this done in R I'm going to have to redo a whole lot of stuff in a commercial package, which I'm REALLY not keen to do! My problem is how to implement these tests in R. Below
1999 Aug 26
1
moving R objects
Another question: Is it possible to move R objects from one directory to another without copying the whole .RData and .Rhistory files? (I'm running under Linux) Thanks Karen Kotschy Centre for Water in the Environment University of the Witwatersrand Johannesburg Tel: 011 716-2218 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read
1999 Aug 26
1
error bars on barplots
Hello again I'm trying to put error bars onto a barplot. I've tried something that Bill Simpson suggested a while ago, ie: x<-c(1,2,3,4,5) y<-c(1.1, 2.3, 3.0, 3.9, 5.1) ucl<-c(1.3, 2.4, 3.5, 4.1, 5.3) lcl<-c(.9, 1.8, 2.7, 3.8, 5.0) plot(x,y, ylim=range(c(lcl,ucl))) arrows(x,ucl,x,lcl,length=.05,angle=90,code=3) #or segments(x,ucl,x,lcl) but I can't get it to work on a
2005 Jun 24
1
Mahalanobis distances
Dear R community Have just recently got back into R after a long break and have been amazed at how much it has grown, and how active the list is! Thank you so much to all those who contribute to this amazing project. My question: I am trying to calculate Mahalanobis distances for a matrix called "fgmatrix" >dim(fgmatrix) [1] 76 15 >fg.cov <- cov.wt(fgmatrix)
2005 Jun 28
1
enhanced multidimensional scaling?
Dear R list Would anyone be able to tell me whether it is possible to do "enhanced multidimensional scaling" (enhanced MDS) in R? In other words, something that goes beyond "cmdscale" by iteratively improving the fit between observed dissimilarities and inter-object distances, using the KYST algorithm (Kruskal, 1964). I have found several implementations of non-metric MDS
1999 Nov 17
0
help with multiple comparisons
Dear R users I have a question which is only partly related to R, but I'm sending it to this list in the hope that someone with a better statistical background than mine will be kind enough to help me. It concerns multiple comparison testing in ANOVA. I know this subject has been raised before on this list, and I have looked through the relevant messages and read the article in
2000 Jan 04
0
multiple comparison function
Hi I asked a while ago about multiple comparison tests for use with multi--way ANOVAs. Thanks to all those who replied and gave me some ideas and functions. What I ended up doing was writing my own function for Tukey's HSD test (ref: Zar's Biostatistics pg 186-190), as this was the procedure I could best understand. I've included my function here for those who may be interested.
2012 Jun 03
1
Multiple imputation, multinomial response & random effects
Dear R-group, Could somebody recommend a package that can deal with a multinomial response variable (choice of breeding tactic in mice, which has four unordered levels), multiply-imputed data (generated using the Amelia package) and two non-nested random effects: individual identity (133 individuals made up to four choices each) and year (for which there are six levels and sample size varies
2012 Nov 08
2
Controlling R fonts through LaTeX
Dear help list Does anybody know if it is possible to somehow tell R to let LaTeX handle the fonts for postscript plots produced by R? It is for a thesis and I have MANY figures. These are created by R scripts dynamically as the document is compiled, using the Make system. I see that I can `manually' specify the font family each time I call the postscript device, but I am looking for a
2011 Jul 26
0
How do you report lmer results?
Dear R-Gurus I am a PhD student from South Africa working on chimpanzee behaviour. I am looking at patterns of shade utilization and am using generalized linear mixed models to examine the effects of various factors on whether chimpanzees choose to spend time in the sun or shade. I realise that the lme4 package and the outputs of the lmer functions have been discussed ad nauseum but I have been
2005 Jun 28
2
function for cumulative occurrence of elements
Hello, I have a data set with 9700 records, and 7 parameters. The data were collected for a survey of forest communities. Sample plots (1009) and species (139) are included in this data set. I need to determine how species are accumulated as new plots are considered. Basically, I want to develop a species area curve. I've included the first 20 records from the data set. Point
2012 May 26
2
Assessing interaction effects in GLMMs
Dear R gurus I am running a GLMM that looks at whether chimpanzees spend time in shade more than sun (response variable 'y': used cbind() on counts in the sun and shade) based on the time of day (Time) and the availability of shade (Tertile). I've included some random factors too which are the chimpanzee in question (Individual) and where they are in a given area (Zone). There are
2011 Aug 17
2
Getting vastly different results when running GLMs
Dear R gurus I am analysing data from a study of behaviour and shade utilization of chimpanzees. I am using GLMs in R (version 2.13.0) to test whether shade/sun utilization is predicted by behaviour observed. I am thus interested in whether an interaction of behaviour (as a predictor) and presence in the sun/shade (also predictor) predicts the counts I have for the respective categories. I have
2010 Aug 17
3
Sweave
Dear R users, I am using Sweave. I would like to use the width option for the graphics : \begin{figure}[h!] \centering \includegraphics[width=0.7\textwidth]{x} \end{figure} How do I get this ? Thank you very much, Randall [[alternative HTML version deleted]]