[R] significant results with KW but not in post-hoc test

Dear all, I did a Kruskall-Wallis test for a comparison of a variable of interest between 10 sites and I get a significant result (p=0.0019). however, when I perform a post-hoc test using kruskalmc from the pgirmess package, I get no difference between any of the paired comparisons. I cannot find

Re: [R] Sampling a matrix with different probability distributions

g) L. Snow Ph.D. > Statistical Data Center > Intermountain Healthcare > greg.s...@imail.org > 801.408.8111 > > >> -Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- >> project.org] On Behalf Of Silvia Lomascolo >> Sent

[R] Sampling a matrix with different probability distributions

I need to sample a matrix according to different distributions, instead of just randomly. Here is some code that will hopefully clarify what I need: I have a matrix M of 1287 interactions between species in rows and species in columns, according to their abundance: pla<- c(10, 9, 6, 5, 3) #abun

Re: [R] How do I sample "cases" within a matrix?

Thank you! This seems to work!!! Silvia. Charles C. Berry wrote: > > > See below > > On Wed, 29 Apr 2009, Silvia Lomascolo wrote: > >> >> Hi R community, >> I am trying to obtain a sample from a matrix but sample(my.matrix) >> doesn&#x

Re: [R] How do I sample "cases" within a matrix?

> > On my computer it seems to work... hope this really help, this time ! > Regards. Olivier > > > > > Silvia Lomascolo wrote: >> >> Hi R community, >> I am trying to obtain a sample from a matrix but sample(my.matrix) >> doesn't do what I need. I h

[R] How do I sample "cases" within a matrix?

Hi R community, I am trying to obtain a sample from a matrix but sample(my.matrix) doesn't do what I need. I have a matrix of 1287 interactions between the species in columns and the species in rows and I want to obtain a smaller matrix with say, 800 interactions, that may or may not have the same

[R] How do I sample "cases" within a matrix?

Hi R community, I am trying to obtain a sample from a matrix but sample(my.matrix) doesn't do what I need. I have a matrix of 1287 interactions between the species in columns and the species in rows and I want to obtain a smaller matrix with say, 800 interactions, that may or may not have the same

Re: [R] Novice question about getting data into R

> refdata = > read.table("K:\\MerchantData\\RiskModel\\refund_distribution.csv", header > = TRUE) Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : line 1 did not have 42 elements > refdata = > read.table("K:\\MerchantData\\RiskModel\\refund_distribution.csv") Error

[R] plotting other axes for PCA

Hi R-community, I am doing a PCA and I need plots for different combinations of axes (e.g., PC1 vs PC3, and PC2 vs PC3) with the arrows indicating the loadings of each variables. What I need is exactly what I get using biplot (pca.object) but for other axes. I have plotted PC2 and 3 using the sc

[R] PCA error: svd(x, nu=0) infinite or missing values

Hi, I am trying to do a PCA on my data but I keep getting the error message svd(x, nu=0) infinite or missing values >From the messages posted on the subject, I understand that the NAs in my data might be the problem, but I thought na.omit would take care of that. Less than 5% of my cells are mi

Re: [R] linking Tinn-R to a new R version

ROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Silvia Lomascolo > Sent: Friday, October 26, 2007 2:31 PM > To: r-help@r-project.org > Subject: [R] linking Tinn-R to a new R version > > > Hi all, > Can anyone please tell me how to start R from Tinn-R's "Toogl

[R] linking Tinn-R to a new R version

Hi all, Can anyone please tell me how to start R from Tinn-R's "Toogle start/close Rgui" button, after I've updated to a new version of R? It seems like Tinn-R keeps looking for the previous version of R. I have updated R twice already since I started using Tinn-R and I haven't been able to make t

[R] error in sample ()

I am trying to get a random matrix based on an original matrix called disperser.mx, with dimensions 30x73 When I write the following code: >scramble = sample (disperser.mx) >newmat = matrix(scramble, nrow=30) I get the following warning message and a very weird matrix with 30 rows but only 3 co

[R] help with stepclass (klaR)

I use Windows, R version 2.5.1 When I try to run stepclass (klaR) I get an error message/warning saying: 1: error(s) in modeling/prediction step in: cv.rate(vars = c(model, tryvar), data = data, grouping = grouping, ... Actually, I look 16 warnings of this type. Can anyone tell me what this

[R] error in manova

I work with Windows, R 2.4.1. I'm a beginner with R! After doing a Discriminant Function Analysis, I am trying to run manova to get a measure of significance of my lda results. I want to predict groups 1 through 4 using 78 variables (bad group/var ratio, I know, but I'm just exploring the possib

Re: [R] Non-metric multidimensional scaling

>Error in isoMDS(Gquad.dist) : zero or negative distance between objects >179 and 180. >How can I handle this, is it valid to add 0.5 to every element in the >distance matrix or is someother alternative more appropriate? This means that your objects 179 and 180 are identical so just remove one