search for: skiada

Displaying 20 results from an estimated 126 matches for "skiada".

Did you mean: skiadas
2007 Nov 07
3
Indexing, and using an empty string as a name
...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
2007 Feb 04
4
Reading expressions from character vectors
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 )
2007 Jan 14
4
Controlling size of boxplot when it is added in a plot
...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
2007 Mar 01
2
R code for "Statistical Models in S" ?
...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
2007 Feb 22
1
Cross-tabulations next to each other
...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
2008 Mar 05
4
vertex labels in igraph from adjacency matrix
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 <-
2008 Jun 07
2
Using lm with a matrix?
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
2006 Nov 08
6
Making a case for using R in Academia
...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
2008 Mar 10
3
Weighting data when running regressions
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)
2008 Mar 09
1
Calling plot with a formula, from within a function, using ..., and xlim
...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
2007 Dec 17
3
Cannot grasp how to apply "by" here...
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
2007 Dec 22
2
Understanding eval
...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
2008 Jun 12
2
numbers as part of long character
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 =
2008 May 23
2
About Passing Arguments to Function
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 }
2008 Feb 29
8
Running LaTeX dvi previewer on MacOS X
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
2007 Nov 01
1
Rcmdr Plugin and menus.txt
...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
2007 Feb 22
0
[MacOSX] Screencast for R and Sweave on TextMate
...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...
2007 Mar 01
4
question about xtable and Hmisc
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 &
2007 Oct 19
1
Manual recycling of vectors?
...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
2008 Jan 22
1
R: determinants and inverses
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