Displaying 20 results from an estimated 4000 matches similar to: "OT: model diagnostics in the published literature"
2011 Aug 30
3
having trouble extracting week from chron object
Running R 2.13.1 on Windows XP.
I would like to get week of the year (1-52) for each date.
library(chron)
dts <- dates(c("02/27/92", "02/27/92", "01/14/92","02/28/92", "02/01/92"))
dts
dts.chron <- as.chron(dts)
dts.chron
class(dts.chron)
# all of these component extractions work:
months(dts.chron)
weekdays(dts.chron)
years(dts.chron)
2012 Apr 18
6
introducing R to high school students
I participate peripherally on a listserve for middle- and high-school
science teachers. Sometimes questions about graphing or data analysis
come up. I never miss an opportunity to advocate for R. However, the
teachers are often skeptical that their students would be able to
issue commands or write a little code; they think it would be too
difficult. Perhaps this stems from the Microsoft- and
2011 Mar 22
2
adding vertical segments to an xyplot in lattice
I have a dataframe that looks like this:
> str(chr)
'data.frame': 84 obs. of 7 variables:
$ county: Factor w/ 3 levels "Broome","Nassau",..: 3 3 3 3 3 3 3 3 3 3 ...
$ item : Factor w/ 28 levels "Access to healthy foods",..: 21 19 20
18 16 3 2 6 17 8 ...
$ value : num 8644 15 3.5 3.9 7.7 ...
$ low : num 7897 9 2.5 2.6 7 ...
$ high : num 9390
2009 Apr 20
4
automatic exploration of all possible loglinear models?
Is there a way to automate fitting and assessing loglinear models for
several nominal variables . . . something akin to step or drop1 or add1
for linear or logistic regression?
Thanks.
--Chris
--
Christopher W. Ryan, MD
SUNY Upstate Medical University Clinical Campus at Binghamton
40 Arch Street, Johnson City, NY 13790
cryanatbinghamtondotedu
"If you want to build a ship, don't drum
2009 Jul 01
0
xemacs and ess: keyboard shortcut for sending line to R
running R 2.9.1 on Windows XP. Formerly used Tinn-R but it has been
acting strangely lately and I haven't been able to fix it, so I am
trying to learn ESS.
I have Xemacs 21.4.19. I have ESS configured, I think, as per John Fox:
An Introduction to ESS + XEmacs for Windows Users of R
John Fox
McMaster University
Revised: 5 February 2006
2010 Mar 10
1
trouble calculating rates--sometimes the denominator is missing
Every day I get a csv file containing the names of the 64 schools in our
county, the number of students sent home ill, and the number of students
absent (plus lots of other variables). The file is cumulative since fall
of 2009. It is in "long" format: one line per school per day.
Each line is also supposed to contain the total number of students
enrolled in the school. That number
2008 Jun 26
2
stuck on making a line graph across time, with 4 categories
I can't seem to find just what I'm looking for in R help, Everitt and
Hothorn HSAUR, Murrell's book, or the R graphics gallery at
http://addictedtor.free.fr/graphiques/. Probably not looking
efficiently, but anyway,
If my data look like this:
> head(data)
cat startyear studentid
1 other 2001 12
2 UHS 2001 17
3 Lourdes 2001 10
4
2007 Jul 13
3
THANK YOU: Updating R version
Based on the feedback received, I did the following:
a) moved my lib sub-directory from the existing installed R version to
c:\myRLib
b) installed the updated R version
c) created .Renviron file in the home directory (C:\R-2.5.1) with the line
R_LIBS=c:/myRLib
d) used .libPaths() command to confirm that the new R installation was
recognizing the myRLib sub-directory
e) deleted my old R
2008 Jul 14
2
question about a small "for" loop
R 2.5.1 on WinXP
I'm trying to create new variables in a dataframe called jaw, as powers
of jaw$age up to the sixth power, and name them
jaw$age.(--the digit corresponding to the power--)
Obviously none of these work (silly for me to try, I suppose):
for (i in 2:6) {
jaw$age.'i' <- jaw$age^i
}
for (i in 2:6) {
jaw$age.i <- jaw$age^i
}
for (i in 2:6) {
2002 Mar 08
1
Random data with correlation
Hello all.
First of all, I have only been using are a short time and I'm not an
expert in statistics either.
I have the following problem. I'm working with measurements of physical
samples, each measurement has about 4000 variables. I have 33 of those
samples. From those 400 variables I deduced through non-statiscal means
that I needed about 200 of them. I read those into a data.frame
2010 Oct 15
1
multiple car scatterplots on one graph
R version 2.11.1 on WinXP
How do I get 3 scatterplots with marginal boxplots (from the
car package) onto a single plot?
I have a data frame called bank
> dim(bank)
[1] 46 5
head(bank)
x1 x2 x3 x4 pop
1 -0.45 -0.41 1.09 0.45 0
2 -0.56 -0.31 1.51 0.16 0
3 0.06 0.02 1.01 0.40 0
4 -0.07 -0.09 1.45 0.26 0
5 -0.10 -0.09 1.56 0.67 0
6 -0.14 -0.07 0.71 0.28 0
2009 Jan 27
2
using Sweave with a master file that has several iputted .tex files
Suppose I have a Master.Rnw file that looks something like this:
\documentclass[12pt]{mypaper}
\usepackage[margin=1in]{geometry}
\usepackage{setspace}
\usepackage{url}
\usepackage{indentfirst}
\usepackage{fancyhdr}
\usepackage{Sweave}
\pagestyle{fancy}
\lhead{sonographic rectal diameter and ADHD}
\rhead{ }
\usepackage{abbrevs}
%\usepackage{natbib}
%\usepackage{apacite}
2010 Oct 22
1
trouble with \textless in Hmisc latex() on a drop1 object
Yes, it's homework . . . delete now if desired . . . but I think it is an
interesting problem.
Running R 2.11.1, LaTeX on WinXP, via Sweave.
A drop1() object from a glm() produces, as part of its output, a string that
looks like this:
<none>
The trouble I run into is that running latex() on a drop1() object from
glm() produces a string that looks like this in the generated .tex
2008 Oct 30
1
trying to figure out reorder.factor in gdata
I'm trying to make a factor with levels for day of week, appear as
Monday-Sunday, rather than alphabetically. I'm using reorder.factor
from gdata package, but obviously not using it properly. What am I
doing wrong? Thanks.
>data <- read.table("DataEarly2008.txt", sep=" ", header=T, as.is=1:2)
>str(data)
'data.frame': 7953 obs. of 9 variables:
$
2009 Jan 21
1
trouble converting an array to a dataframe
I start with a dataframe called xrays. It contains scores on films from
each of two radiologists. It is in "long" format. I used the reshape
package to melt a data frame and then cast it into "wide" format, one
line for each patient (identified by redlognumb) with scores from both
radiologists for a given patient on the same line.
I named the result of the casting xrays.data.
2007 Nov 29
1
extracting items from R objects and using them in \Sexpr with Sweave--problem with $
Running R 2.5.1 on WinXP with Tinn-R, and using Sweave via MikTex.
I am having trouble with the code below:
-------------------------------------------------------
<<lowerCI95>>=
lowerCI95713 <- t.test(data713, alternative="greater")
lowerCI95713.bound <- lowerCI95713$conf.int[1]
@
Thus a lower 95\% confidence bound on the mean octane concentration is
2009 Jun 30
4
conditional coloring of output text in console or in GUI
suppose I have some logical vector
x <- as.logical(c(0,0,0,1,0,0,1,1,0))
x
How would I make the words TRUE appear on the screen in a different
color from the words FALSE?
Thanks.
--Chris
--
Christopher W. Ryan, MD
SUNY Upstate Medical University Clinical Campus at Binghamton
40 Arch Street, Johnson City, NY 13790
cryanatbinghamtondotedu
"If you want to build a ship, don't drum
2001 Feb 07
2
Literature needed
Howdy!
Could somebody point me to some good introductory readings about data
mining and descriptive data analysis? I'm a psychologist and a couple
of times I realized that some things just don't appear in
psychological literature, e.g. I've never seen a box plot anywhere in
psych journals so I'm not familiar with them. The R help function is
great when it comes to explaining
2009 Jan 30
1
problem using identify() after plot()
I can't seem to use the point-and-click identify() function properly.
I'm running R 2.5.1 (I know, I need to get around to upgrading) under
Win XP. The problem is, when I click on a point on the graph, I get an
error, "no point within 0.25 inches." But in some areas, I can click
where there is no visible point anywhere close, and an identify() label
will pop up. The troublesome
2013 Jan 02
0
follow up on teaching R to high school students
Some of you may recall that a few months ago I solicited advice and
opinions on both R-help and R-sig-teaching about an "introduction to R"
workshop I intended to present to a class of high school students
enrolled in a 3-year longitudinal science research class. Much lively
discussion ensued. Well, I did the workshop on 8 November, and thought
I'd give some follow-up as to how it