Displaying 20 results from an estimated 2000 matches similar to: "is a sequence of dates consecutive, without gaps?"
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
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
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) {
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
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}
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.
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
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:
$
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
2007 Jul 11
0
installing, removing, upgrading, and downgrading packages
I'm very new to R, trying to learn it. I started with R 2.4, but I have
since upgraded to 2.5.0, on WindowsXP. I understand that 2.5.1 is now
available.
Last night in the course of things I loaded libraries "coin" and
"survival". I received warning messages that they had been built under
version 2.5.1. However, as far as I could tell, they worked OK. But
this brought
2007 Sep 17
0
color schemes in Tinn-R
A question for anyone using Tinn-R: I find that using the default color
scheme with the white background on my laptop hard on the ole' eyes. I
see the drop-down menus leading to the ability to change the colors of
individual components (numbers, commmands, strings, etc, and the
background for each of those.) I can play around with background colors
and foreground colors. However, I'm
2008 Jul 24
0
OT: course in research administration
I'm currently enrolled in the distance education masters degree program
in statistics at Texas A&M University. I'm hoping the program will help
me develop skills useful in advancing my primary care research
endeavors. Having a great time so far, learning a lot.
I have one semester in which to take a non-statistical elective. What
I'd like to learn in that semester is some of
2009 Jan 23
0
high values of my response variable get chopped off of lattice dotplots
I am trying the following lattice graphics code:
> library(lattice)
> attach(junk)
> summary(junk)
mean.barr variable value
Min. : 3.50 item15 :15 Min. :0.0000
1st Qu.: 9.50 item14 :14 1st Qu.:0.0000
Median :11.00 item16 :14 Median :0.0000
Mean :11.64 item1 : 0 Mean :0.6744
3rd Qu.:16.00 item2 : 0 3rd Qu.:1.0000
Max. :20.00 item3 :
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
2007 Jul 22
1
summary of linear fixed effects model is different than the HSAUR book
Running R 2.5.1 and a newly downloaded lme4 package on WinXP
I'm trying to work my way through Everitt and Hothorn's "Handbook of
Statistical Analyses Using R," c 2006. (No, it's not homework.)
Chapter 10 discusses linear mixed effects models for longitudinal data.
I've called my long data frame BtheB.long
Here's the model from the book, which I run.
lmer1 <-
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
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
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
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)
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