similar to: having trouble extracting week from chron object

Hello All: I am trying to generate a sequence of dates using library(chron). Using the following code, I got most of what I want, dts <- seq.dates("01/02/1998", "01/10/2001", by="day") dts <- dts[!is.weekend(dts)] a sequence of weekdays only (no weekend dates), with first observation appearing as 01/02/98 and the last 01/10/01. But I would

Hi, I am trying to count weekday of the month using R. For example, 1/4/2001 is the 4th weekday of Jan, and 1/5/2001 is the 5th weekday of the month, and 1/8/2001 is the 6th weekday of the month, etc. I get as far as extracting the weekdays from a sequence of dates (see below). But I have not yet figured out a fast way of counting without using a For Loop. Does anyone know how to do such counting

Hello dear useRs and wizaRds, I encountered the following problem using the hist() method for the 'times' classes from package 'chron'. You should be able to recreate it using the code: library(chron) # pasted from chron help file (?chron) dts <- dates(c("02/27/92", "02/27/92", "01/14/92", "02/28/92", "02/01/92")) class(dts)

Hello, today I've updated on the newest R-Version. But sadly a function I needed didnt want to work: The input is e.g. days(as.Date("21-07-2005","%d-%m-%y")) the error is: Fehler in Math.Date(dts): floor nicht definiert f??r Date Objekte (Error in Math.Date(dts): floor not defined for date objects) Same for year. Only months gives me the correct output. In Version

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

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

Dear all I use aggregate with variables of type numeric and dates. For type numeric functions, such as sum() are very fast, but similar simple functions, such as min() are much slower for the variables of type 'dates'. The difference gets bigger the larger the 'id' var is - but see this sample code: dts <- dates(c("02/27/92", "02/27/92",

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

Hello, I have a dataset which has fields giving both calendar date and weekday. I know better functions are now available, but I am still using chron because of the is.holiday() function and a homemade (even Heath Robinson would be ashamed) is.daylight() function. As a check for typos in the data input, I checked that the dates matched the weekdays. I'm getting some confusing results

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

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

I know that this is correct: library(chron) x = dates("01-03-04", format="d-m-y", out.format="day mon year") print(x) It gives me the string "01 Mar 2004" which is correct. I also know that I can say: print(day.of.week(3,1,2004)) in which case he says 1, for today is monday. My question is: How do I combine these two!? :-) I have a

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) {

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

note: whole function is below- I am sure I am doing something silly. when I use it like USGS(input="precipitation") it is choking on the precip.1 <- subset(DF, precipitation!="NA") b <- ddply(precip.1$precipitation, .(precip.1$gauge_name), cumsum) DF.precip <- precip.1 DF.precip$precipitation <- b$.data part, but runs fine outside of the function: days=7

There seems no default setting for tck, causing problems for plot.times() > library(chron) > dts <- dates(c("02/27/92", "02/27/92", "01/14/92", + "02/28/92", "02/01/92")) > y<-chron(dts,out.format=c("dmy","h:m:s")) > y [1] 270292 270292 140192 280292 010292 > plot(y,1:5) Error in axis(n, at =

I'm getting warnings when I plot a zoo object: > dts <- chron(rep("2007-09-10", 5), paste("00:0", 0:4, ":00", sep=""), c("y-m-d", "h:m:s")) > dat.zoo <- zoo(1:5, dts) > plot(dat.zoo) Warning messages: 1: In v[[perm[1]]] : partial match of 'm' to 'month' 2: In v[[perm[2]]] : partial match of 'd'

Hi, I am using aggregate() to add up groups of data according to year and month. It seems that the function aggregate() automatically sorts the levels of factors of the grouping elements, even if the order of the levels of factors is supplied. I am wondering if this is a bug, or if I missed something important. Below is an example that shows what I mean. Does anyone know if this is just the way

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}

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.