[R] Problems plotting and regression w.r.t. date data type on x axis
Hello, probably a newbie question, but i didnt find any information on plotting/regressing w.r.t. a date data type. My trials were unfruitful. Can anyone help ? Thanks in advance! Here is my interaction with R: tabelle date number date2 1 2009-01-1 1673 2009-01-01 2 2009-12-1 2111 2009-12-01 3 2010-7-1 2487 2010-07-01 4 2013-2-1 4301 2013-02-01 regression.punkte-lm(tabelle$number ~ tabelle$date2) Fehler in model.frame.default(formula = tabelle$number ~ tabelle$date2, : ungültiger Typ (list) für die Variable 'tabelle$date2' regression.punkte-lm(tabelle$number ~ tabelle$date) plot(tabelle$date2,tabelle$number, pch=19, xlab=date of retrieval, ylab=number of animals) ***R DRAWS THIS*** regression.punkte Call: lm(formula = tabelle$number ~ tabelle$date) Coefficients: (Intercept) tabelle$date2009-12-1 tabelle$date2010-7-1 1673 438 814 tabelle$date2013-2-1 2628 abline(regression.punkte, lwd=2) ***R DOES NOT DRAW LINE*** Warnmeldung: In abline(regression.punkte, lwd = 2) : nutze nur die ersten beiden von 4 Regressionskoeffizienten summary(regression.punkte) Call: lm(formula = tabelle$number ~ tabelle$date) Residuals: ALL 4 residuals are 0: no residual degrees of freedom! Coefficients: Estimate Std. Error t value Pr(|t|) (Intercept) 1673 NA NA NA tabelle$date2009-12-1 438 NA NA NA tabelle$date2010-7-1 814 NA NA NA tabelle$date2013-2-1 2628 NA NA NA Residual standard error: NaN on 0 degrees of freedom Multiple R-squared: 1, Adjusted R-squared: NaN F-statistic: NaN on 3 and 0 DF, p-value: NA -- View this message in context: http://r.789695.n4.nabble.com/Problems-plotting-and-regression-w-r-t-date-data-type-on-x-axis-tp4658518.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problems plotting and regression w.r.t. date data type on x axis
Hi most probably your dates are not what you expect. Eg. they look like a date but they are not treated as date. You can check yourself by str(tabelle) which will result probably in factor, numeric, factor. You need to change variables date and date2 into Date class. ?strptime or ?as.Date date and date2 seems to be same but usually you shall use the same variables for plotting and for model to get correct regression line. Regards Petr -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- project.org] On Behalf Of Kategoricus Sent: Thursday, February 14, 2013 10:10 AM To: r-help@r-project.org Subject: [R] Problems plotting and regression w.r.t. date data type on x axis Hello, probably a newbie question, but i didnt find any information on plotting/regressing w.r.t. a date data type. My trials were unfruitful. Can anyone help ? Thanks in advance! Here is my interaction with R: tabelle date number date2 1 2009-01-1 1673 2009-01-01 2 2009-12-1 2111 2009-12-01 3 2010-7-1 2487 2010-07-01 4 2013-2-1 4301 2013-02-01 regression.punkte-lm(tabelle$number ~ tabelle$date2) Fehler in model.frame.default(formula = tabelle$number ~ tabelle$date2, : ungültiger Typ (list) für die Variable 'tabelle$date2' regression.punkte-lm(tabelle$number ~ tabelle$date) plot(tabelle$date2,tabelle$number, pch=19, xlab=date of retrieval, ylab=number of animals) ***R DRAWS THIS*** regression.punkte Call: lm(formula = tabelle$number ~ tabelle$date) Coefficients: (Intercept) tabelle$date2009-12-1 tabelle$date2010-7-1 1673 438 814 tabelle$date2013-2-1 2628 abline(regression.punkte, lwd=2) ***R DOES NOT DRAW LINE*** Warnmeldung: In abline(regression.punkte, lwd = 2) : nutze nur die ersten beiden von 4 Regressionskoeffizienten summary(regression.punkte) Call: lm(formula = tabelle$number ~ tabelle$date) Residuals: ALL 4 residuals are 0: no residual degrees of freedom! Coefficients: Estimate Std. Error t value Pr(|t|) (Intercept) 1673 NA NA NA tabelle$date2009-12-1 438 NA NA NA tabelle$date2010-7-1 814 NA NA NA tabelle$date2013-2-1 2628 NA NA NA Residual standard error: NaN on 0 degrees of freedom Multiple R- squared: 1, Adjusted R-squared: NaN F-statistic: NaN on 3 and 0 DF, p-value: NA -- View this message in context: http://r.789695.n4.nabble.com/Problems- plotting-and-regression-w-r-t-date-data-type-on-x-axis-tp4658518.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting- guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problems plotting and regression w.r.t. date data type on x axis
On Feb 14, 2013, at 1:10 AM, Kategoricus wrote: Hello, probably a newbie question, but i didnt find any information on plotting/regressing w.r.t. a date data type. My trials were unfruitful. Can anyone help ? Thanks in advance! Here is my interaction with R: tabelle date number date2 1 2009-01-1 1673 2009-01-01 2 2009-12-1 2111 2009-12-01 3 2010-7-1 2487 2010-07-01 4 2013-2-1 4301 2013-02-01 regression.punkte-lm(tabelle$number ~ tabelle$date2) Fehler in model.frame.default(formula = tabelle$number ~ tabelle $date2, : ungültiger Typ (list) für die Variable 'tabelle$date2' I'm guessing that you used as.POSIXlt to create that date2 variable. POSIXlt classed variables are lists and as such create all sorts of problems for functions that are expecting atomic vectors. If I'm right, you will ahve better chances of success by converting to POSIXct class. tabelle - read.table(text=date number date2 + 1 2009-01-1 1673 2009-01-01 + 2 2009-12-1 2111 2009-12-01 + 3 2010-7-1 2487 2010-07-01 + 4 2013-2-1 4301 2013-02-01, header=TRUE, stringsAsFactors=FALSE) tabelle$date2 - as.POSIXlt(tabelle$date2) regression.punkte-lm(tabelle$number ~ tabelle$date2) Error in model.frame.default(formula = tabelle$number ~ tabelle $date2, : invalid type (list) for variable 'tabelle$date2' tabelle$date2 - as.POSIXct(tabelle$date2) regression.punkte-lm(tabelle$number ~ tabelle$date2) regression.punkte Call: lm(formula = tabelle$number ~ tabelle$date2) Coefficients: (Intercept) tabelle$date2 -2.405e+04 2.082e-05 regression.punkte-lm(tabelle$number ~ tabelle$date) plot(tabelle$date2,tabelle$number, pch=19, xlab=date of retrieval, ylab=number of animals) ***R DRAWS THIS*** regression.punkte Call: lm(formula = tabelle$number ~ tabelle$date) Coefficients: (Intercept) tabelle$date2009-12-1 tabelle$date2010-7-1 1673 438 814 tabelle$date2013-2-1 2628 abline(regression.punkte, lwd=2) ***R DOES NOT DRAW LINE*** Warnmeldung: In abline(regression.punkte, lwd = 2) : nutze nur die ersten beiden von 4 Regressionskoeffizienten summary(regression.punkte) Call: lm(formula = tabelle$number ~ tabelle$date) Residuals: ALL 4 residuals are 0: no residual degrees of freedom! Coefficients: Estimate Std. Error t value Pr(|t|) (Intercept) 1673 NA NA NA tabelle$date2009-12-1 438 NA NA NA tabelle$date2010-7-1 814 NA NA NA tabelle$date2013-2-1 2628 NA NA NA Residual standard error: NaN on 0 degrees of freedom Multiple R-squared: 1, Adjusted R-squared: NaN F-statistic: NaN on 3 and 0 DF, p-value: NA David Winsemius, MD Alameda, CA, USA __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problems plotting and regression w.r.t. date data type on x axis
Hello Petr! thanks a lot for your help. The plot command plots well, but the abline returns without error and does nothing. str(tabelle) 'data.frame': 4 obs. of 3 variables: $ date : Factor w/ 4 levels 2009-01-1,2009-12-1,..: 1 2 3 4 $ number: int 1673 2111 2487 4301 $ date2 : POSIXlt, format: 2009-01-01 2009-12-01 ... plot(tabelle$date2,tabelle$number, pch=19, xlab=date of retrieval, ylab=number of animals) regression.punkte-lm(tabelle$number ~ as.Date(tabelle$date)) regression.punkte Call: lm(formula = tabelle$number ~ as.Date(tabelle$date)) Coefficients: (Intercept) as.Date(tabelle$date) -24046.326 1.799 abline(regression.punkte, lwd=2) -- View this message in context: http://r.789695.n4.nabble.com/Problems-plotting-and-regression-w-r-t-date-data-type-on-x-axis-tp4658518p4658529.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problems plotting and regression w.r.t. date data type on x axis
as.POSIXct() works fine (finally!) Thanks a lot DavidPetr for your help! -- View this message in context: http://r.789695.n4.nabble.com/Problems-plotting-and-regression-w-r-t-date-data-type-on-x-axis-tp4658518p4658537.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problems plotting and regression w.r.t. date data type on x axis
Hi -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- project.org] On Behalf Of Kategoricus Sent: Thursday, February 14, 2013 12:25 PM To: r-help@r-project.org Subject: Re: [R] Problems plotting and regression w.r.t. date data type on x axis Hello Petr! thanks a lot for your help. The plot command plots well, but the abline returns without error and does nothing. str(tabelle) 'data.frame': 4 obs. of 3 variables: $ date : Factor w/ 4 levels 2009-01-1,2009-12-1,..: 1 2 3 4 $ number: int 1673 2111 2487 4301 $ date2 : POSIXlt, format: 2009-01- 01 2009-12-01 ... As expected date is factor, number is numeric and date2 is POSIXlt format. plot(tabelle$date2,tabelle$number, pch=19, xlab=date of retrieval, ylab=number of animals) regression.punkte-lm(tabelle$number ~ as.Date(tabelle$date)) regression.punkte Here you are plotting number against POSIX date2. Call: lm(formula = tabelle$number ~ as.Date(tabelle$date)) Here you use date probably converted by as.Date. Why you do not use lm(number ~ date2, data = tabelle) which is usual form of model formula. Try also change date2 by as.POSIXct. Regards Petr Coefficients: (Intercept) as.Date(tabelle$date) -24046.326 1.799 abline(regression.punkte, lwd=2) -- View this message in context: http://r.789695.n4.nabble.com/Problems- plotting-and-regression-w-r-t-date-data-type-on-x-axis- tp4658518p4658529.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting- guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
