search for: skiada

...very carefully, but it seems to me that he following lines should return "1" at the end: x<-1:4 names(x) <- c("","a","b","c") x[""] Instead, they return NA. Could anyone provide an explanation for this behavior? Thanks, Haris Skiadas Department of Mathematics and Computer Science Hanover College

Greetings, I have a problem that I am sure is very straightforward, but I just can't wrap my head around it. I've read the help pages on text, plotmath, expression, substitute, but somehow I can't find the answer to this simple question. Basically consider the following example: plot( NULL, xlim = c(0,2), ylim = c(0,2) ) expressions <- expression( -infinity, infinity )

...xt to each other, to develop a feeling for what histograms might correspond to what boxplots. Is there perhaps some reason why I should avoid showing those graphs to them like that, that I am not aware of? Or just a reason why I haven't seen them combined like this much? TIA Charilaos Skiadas Department of Mathematics Hanover College P.O.Box 108 Hanover, IN 47243

...t.factor work (I keep getting a "could not find function plot.factor" error). Anyway, just wondered whether there is some page somewhere that discusses these little differences here and there, as I am sure there will be a number of other problems such as these along the way. Haris Skiadas Department of Mathematics and Computer Science Hanover College

...0 1 0 2 0 1 1 1 1 2 2 1 Or something along those lines. Then I would like to convert this to a LaTeX table, in the obvious sort of way. I couldn't find an answer with a quick look through the documentation. Are these two things already done, before I try to roll my own? Haris Skiadas Department of Mathematics and Computer Science Hanover College

I am getting some unexpected results from some functions of igraph and it is possible that I am misinterpreting the vertex numbers. Eg., the max betweenness measure seems to be from a vertex that is not connected to a single other vertex. Below if my code snippet: require(igraph) my.graph <- graph.adjacency(adjmatrix = my.adj.matrix, mode=c("undirected")) most.between.vert <-

I'm trying to do a linear regression between the columns of matrices. In example below I want to regress column 1 of matrix xdat with column1 of ydat and do a separate regression between the column 2s of each matrix. But the output I get seems to give correct slopes but incorrect intercepts and another set of slopes with value NA. How do I do this correctly? I'm after the slope and

...utside of academia, or in general any other resources that talk about R as a practical alternative to the other non-free statistical packages. Perhaps some statistics, or particular examples of use? Any links would be greatly appreciated. Thanks for any thoughts/input into this. Charilaos Skiadas Department of Mathematics Hanover College P.O.Box 108 Hanover, IN 47243

Dear R-Help, I'm new to R and struggling with weighting data when I run regression. I've tried to use search to solve my problem but haven't found anything helpful so far. I (successfully) import data from SPSS (15) and try to run a linear regression on a subset of my data file where WEIGHT is the name of my weighting variable (numeric), e.g.: library(foreign)

...ntext, no ... to look in > plotw2(df, las=1, xaxs="i") > plotw2(df, xlim=c(0,4)) I was guessing this might be related to some sort of argument matching, but I don't see why xaxs doesn't cause a problem in that case. So I am somewhat puzzled. Thanks in advance. Haris Skiadas Department of Mathematics and Computer Science Hanover College

I have a data frame named "database" with panel data, a little piece of which looks like this: Symbol Name Trial Factor1 Factor2 External 1 548140 A 1 -3.87 -0.32 0.01 2 547400 B 1 12.11 -0.68 0.40 3 547173 C 1

...ould start from the evaluation environment that eval created, and hence would locate the a=5 value. But this is clearly not what happens. Anyway, hope someone will correct me where I'm wrong, and explain to me what I am doing wrong, and ideally how to diagnose such things. Thanks, Haris Skiadas Department of Mathematics and Computer Science Hanover College

Hi, I'm looking for some way to pick up the numbers which are contained and buried in a long character. For example, outtree.new="(((B:1204.25,E:1204.25):7581.11,F:8785.36):8353.85,C:17139.21);" num.char =

Hi, Below I have a function mlogl_k, later it's called with "nlm" . __BEGIN__ vsamples<- c(14.7, 18.8, 14, 15.9, 9.7, 12.8) mlogl_k <- function( k_func, x_func, theta_func, samp) { tot_mll <- 0 for (comp in 1:k_func) { curr_mll <- (- sum(dgamma(samp, shape = x_func, scale=theta_func, log = TRUE))) tot_mll <- tot_mll + curr_mll }

Several people have given great advice on how to successfully use X11 on Mac to so we can use the dvi previewer to view latex() output from Hmisc. Now after a version upgrade of X11 and X11sdk we are getting lots of crashes. I noticed a Mac dvi previewer with an executable stored as /Applications/TeX/TeXShop.app/Contents/MacOS/TeXShop Can we bypass X11 problems and point Hmisc to this

...eates the new menu and an item in it. The problem seems to arise when I try to create a submenu in a menu I have just created. Any thoughts how to accomplish this, or rather what am I doing wrong? Should this go to R-SIG-GUI instead? Or is there another list more appropriate? Thanks, Haris Skiadas Department of Mathematics and Computer Science Hanover College

...tate I would say. Anyway the reason of the message is that I have prepared a small screencast showing how R and Sweave look and feel like in TextMate, prompted by a thread in the MacOSX TeX mailing list. I thought it might be of interest to some people here also, so here is the link: http://skiadas.dcostanet.net/afterthought/2007/02/21/r-and-sweave-in- textmate/ It's not much, and the sound is not all that great, but it mostly shows how things feel like. Hoping this is not too off topic... Haris Skiadas Department of Mathematics and Computer Science Hanover College PS: Yes, it is...

I would like to get rid of the row numbers using xtable and latex. The commands d = cbind(1:10,rep(1:2,5)) ans = xtable(d) latex(ans) gives output containing \begin{tabular}{rrr} \hline & 1 & 2 \\ \hline 1 & 1.00 & 1.00 \\ 2 & 2.00 & 2.00 \\ 3 & 3.00 & 1.00 \\ 4 & 4.00 & 2.00 \\ 5 & 5.00 & 1.00 \\ 6 & 6.00 &

...cle the smaller one (whichever one it is) until they have the same length. I was wondering if there is a anything better than something like: x<-1:3 y<-1:10 x<-rep(x,length=max(x,y)) y<-rep(y,length=max(x,y)) or some variant of that using if to avoid the two calls to rep. Haris Skiadas Department of Mathematics and Computer Science Hanover College

hello all sorry for the following "none" R related question. does anyone know of a reference to calculate the following identity: |I + ABC| where I is an identity matrix and A, B,C may not have to be square matrices? you help will be greatly appreciated. H. V. Henderson; S. R. Searle SIAM Review, Vol. 23, No. 1. (Jan., 1981), pp. 53-60. provides a result to