similar to: Unable to understand strptime() behaviour

Displaying 20 results from an estimated 6000 matches similar to: "Unable to understand strptime() behaviour"

2004 Mar 29
2
Confidence Intervals for slopes
Hi, I'm trying to get confidence intervals to slopes from a linear model and I can't figure out how to get at them. As a cut 'n' paste example: ################# # dummy dataset - regression data for 3 treatments, each treatment with different (normal) variance x <- rep(1:10, length=30) y <- 10 - (rep(c(0.2,0.5,0.8), each=10)*x)+c(rnorm(10, sd=0.1), rnorm(10,
2004 Feb 14
2
converting data to date format
Dear all, I import my data from a csv-file containing one row with date-entries. How can I tell R to treat this data as dates? I've tried to bring it in character-format (as.charachter()) followed by as.POSIXlt() but I get an error message, that the character string is not in a standard unambiguous format, although the date is of format yyyy-mm-dd (what is standard format according to R
2004 May 24
2
Month names
This is how I get the month names from within R: > mon <- rep(strptime("01/01/1952", format = "%d/%m/%Y"), 12) > mon$mon <- mon$mon + 0:11 > mnam <- months(mon, abbreviate = F) > mnam [1] "januar" "februar" "marts" "april" "maj" "juni" "juli" "august"
2005 Apr 19
2
Odd diagnostic plots in mixed-effects models
Dear R community, In the excellent nlme package the default diagnostic plot graphs the innermost residuals against innermost fitted values. I recently fit a mixed-effects model in which there was a very clear positive linear trend in this plot. I inferred that this trend occurred because my fixed effect was a two-level factor, and my random effect was a 12-level factor. The negative residuals
2004 Nov 10
1
List seems to drop empty levels of factors when containin g them
I don't get the same result, do you have a package loaded that would change the default behavior (such as Hmisc)? > list(grp.1) [[1]] [1] 1 2 Levels: 1 2 > list(grp.1[mask]) [[1]] [1] 1 Levels: 1 2 > library(Hmisc) <<snip>> > list(grp.1[mask]) [[1]] [1] 1 Levels: 1 --Matt > version _ platform i386-pc-mingw32 arch i386 os
2002 Jul 18
3
Oddity with names
Hi all, I'm using R 1.5.1 on Windows 2000. The following snippet of code doesn't seem to do anything - no error is reported, and there is no name change. names(myFrame[,c(1:3)]) <- c("name1", "name2", "name3") This code however works nicely: names(myFrame)[c(1:3)] <- c("name1", "name2", "name3") Can anyone suggest why
2003 Mar 08
2
Looking for non-central F quantile
Greetings all, I'm trying to figure out how to calculate the inverse CDF (i.e. a quantile) for a non-central F distribution. I could put together a quick numerical solver routine using the CDF, but I wonder if there's a function that I've missed that would be more efficient? Thank-you, Andrew Andrew Robinson Ph: 208 885 7115 Department of Forest Resources Fa: 208 885
2004 Mar 23
2
Coefficients and standard errors in lme
Hello, I have been searching for ways to obtain these for combinations of fixed factors and levels other than the 'baseline' group (contrasts coded all 0's) from a mixed-effects model in lme. I've modelled the continuous variable y as a function of a continuous covariate x, and fixed factors A, B, and C. The fixed factors have two levels each and I'd like to know whether
2004 Sep 21
2
Bootstrap ICC estimate with nested data
I would appreciate some thoughts on using the bootstrap functions in the library "bootstrap" to estimate confidence intervals of ICC values calculated in lme. In lme, the ICC is calculated as tau/(tau+sigma-squared). So, for instance the ICC in the following example is 0.116: > tmod<-lme(CINISMO~1,random=~1|IDGRUP,data=TDAT) > VarCorr(tmod) IDGRUP = pdLogChol(1)
2004 Mar 10
3
converting lists got by tapply to dataframes
I have two lists: xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) ) xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site , FUN=function(z)yield[z])) I can convert xa to a dataframe easily with: as.data.frame(xa) But if i try the same with xb I get: as.data.frame(xb) Error in as.data.frame.default(xb) : can't coerce array into a data.frame What
2004 Mar 26
8
stop() vs. error() ?
Why does stop("we are done") print "Error in eval.with.vis(expr, envir, enclos) :" ? It would seem to me that a plain stop() is not an error, and that it would make more sense to have an error() function that is different from a stop(). Is there a rationale here that I am missing? sincerely, /iaw
2004 Dec 13
2
Farmating printed Numbers and Text
Hello, is there any function to print (using "cat" or "print" etc.) a table of values row per row in a exact order, even if the value has 3 digit and in the next row eg. 5 digits? This means I want to print a number with 3 digits with 2 spaces in front and a number with 4 digits only with one space in front. regards Andreas
2002 Jul 07
2
R on Sharp Zaurus 5500?
Hello, has anyone tried to get R running on a Sharp Zaurus 5500? Andrew Andrew Robinson Phone: 208-885-7115 Department of Forest Resources Fax: 208-885-6226 University of Idaho E: andrewr at uidaho.edu Po Box 441133 WWW: http://www.uidaho.edu/~andrewr Moscow, ID 83843 and: http://www.biometrics.uidaho.edu/ No statement above
2004 May 06
3
strptime
Delving into the murky world of dates and times I found this: dates <- c("02/27/92", "02/27/92", "01/14/92", "02/28/92", "02/01/92") > times <- c("23:03:20", "22:29:56", "01:03:30", "18:21:03", "16:56:26") > x <- paste(dates, times) > z <- strptime(x, "%m/%d/%y
2002 May 06
1
Load Data
Dear R Users What's the easiest way to load an excel data file to R? Thanks Rick --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.351 / Virus Database: 197 - Release Date: 19/4/2002 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read
2004 Jan 03
1
R doesn't run on g4 iBook with Panther
I have a 12" G4 iBook with the latest os (Panther) with the recent updates. When I start R by double clicking, it expands for a fraction of a second and then, nothing happens. There is mention in the readme about using something called "i-install" to uninstall a mistakenly installed library, but I do not know how to do this. Any help would be appreciated. Thanks, Martin
2004 Oct 04
1
Could anyone tell me how to extract pvalue from "lm" fitting?
Dear R people, I have a naive question: after fitting "lm" to a data, I can't extract the pvalue corresponding to a specific covariate in a direct way. Could anyone give me a hint? Thank you very much. Frank
2005 Jan 04
1
Histogram
I have data on a single variable LOGT. It has about 300,000 observations. I am trying to make a Histogram out of this data set. Following is my effort. Could anyone help me to solve this error. > hist(x) Error in hist.default(x) : `x' must be numeric > class(x) [1] "data.frame" > is.object(x) [1] TRUE > is.vector(x) [1] FALSE > is.numeric(x) [1] FALSE >
2005 Jun 15
2
Plotting second axes outside xyplot
Hi all, I'm trying to find a way to get xyplot to produce a second set of axes outside the right hand side of the graph. This is my progress so far: EE <- equal.count(ethanol$E, number=9, overlap=1/4) xyplot(NOx ~ C | EE, data = ethanol, prepanel = function(x, y) prepanel.loess(x, y, span = 1), xlab = "Compression Ratio", ylab = "NOx (micrograms/J)",
2004 Oct 03
1
help working with persp plot function
Hi, I don't understand why this is not working. Help is appreciated. I need to plot the following as a surface, but persp returns an error. tpcp_xy[1:10,] X_COORD Y_COORD TPCP 1 465459.7 175924.1 0.85 2 466145.8 324017.3 2.30 3 467720.2 372143.1 1.56 4 470293.2 348064.8 2.87 5 476566.9 205501.8 0.94 6 477774.9 142561.0 1.31 7 479207.0 162919.6 3.04 8 480890.8 290641.3 2.20 9