Re: [R] subsetting with by() or other function??
Fair enough. To clarify what I'm trying to achieve I've pasted below a small piece of the larger data frame with the hierarchical structure of factors POPULATION and LOCID and the ascending order of YEARS and the variable DBC that I would like to transform to another variable that is a lag of the previous years DBC (call it LAG1DBC) within LOCID within POPULATION. The desired outcome is shown in the second example data set pasted below the first. The setup is desired for doing some 1st order autoregressive analyses (not in the time series library). Any examples I've tried doing using by() only seem to work for outputing results not creating new variables in an existing data frame. I suspect that people do similar types of hierarchical subgroup data manipulations all the time in R (I know how to do these easily in SYSTAT), so I'm sure I'm missing some obvious, simple trick. My search of the R newslist archives and various other R documentation has not yielded any solutions yet. Suggestions are graciously welcomed. LOCID POPULATION YEARDBC 1 algb-1 A 1992 0.70451575 2 algb-1 A 1993 0.59506851 3 algb-1 A 1997 0.84837544 4 algb-1 A 1998 0.50283182 5 algb-1 A 2000 0.91242707 6 algb-2 A 1992 0.09747155 7 algb-2 A 1993 0.84772253 8 algb-2 A 1997 0.43974081 9 algb-2 A 1998 0.83108544 10 algb-2 A 2000 0.22291192 11 algb-3 A 1992 0.44234175 12 algb-3 A 1993 0.54089534 5680 taylr-73 B 2001 0.43918082 5681 taylr-73 B 2002 0.34694427 5682 taylr-73 B 2003 3.35619190 5683 taylr-73 B 2004 0.71575815 5684 taylr-73 B 2005 0.42038506 5685 taylr-74 B 1992 3.88410354 5686 taylr-74 B 1993 3.32472557 5687 taylr-74 B 1994 3.29861501 5688 taylr-74 B 1996 0.48153827 5689 taylr-74 B 1997 3.63570636 5690 taylr-74 B 1998 1.94630194 LOCID POPULATION YEARDBC LAG1DBC 1 algb-1 A 1992 0.70451575 NA 2 algb-1 A 1993 0.59506851 0.70451575 3 algb-1 A 1997 0.84837544 0.59506851 4 algb-1 A 1998 0.50283182 0.84837544 5 algb-1 A 2000 0.91242707 0.50283182 6 algb-2 A 1992 0.09747155 NA 7 algb-2 A 1993 0.84772253 0.09747155 8 algb-2 A 1997 0.43974081 0.84772253 9 algb-2 A 1998 0.83108544 0.43974081 10 algb-2 A 2000 0.22291192 0.83108544 11 algb-3 A 1992 0.44234175 NA 12 algb-3 A 1993 0.54089534 0.44234175 5680 taylr-73 B 2001 0.43918082 NA 5681 taylr-73 B 2002 0.34694427 0.43918082 5682 taylr-73 B 2003 3.35619190 0.34694427 5683 taylr-73 B 2004 0.71575815 3.35619190 5684 taylr-73 B 2005 0.42038506 0.71575815 5685 taylr-74 B 1992 3.88410354 NA 5686 taylr-74 B 1993 3.32472557 3.88410354 5687 taylr-74 B 1994 3.29861501 3.32472557 5688 taylr-74 B 1996 0.48153827 3.29861501 5689 taylr-74 B 1997 3.63570636 0.48153827 5690 taylr-74 B 1998 1.94630194 3.63570636 Brian Brian S. Cade U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort Collins, CO 80526-8818 email: [EMAIL PROTECTED] tel: 970 226-9326 Florence Combes [EMAIL PROTECTED] 10/13/2005 05:34 AM To Brian S Cade [EMAIL PROTECTED] cc Subject Re: [R] subsetting with by() or other function?? maybe an example of the data you have and the data you want could be helpful for the people of the list to understand, and so to be able to help you ? best regards, Florence. On 10/12/05, Brian S Cade [EMAIL PROTECTED] wrote: I think I must be missing something obvious, but I'm having trouble getting a data transformation to work on groupings of data within a data frame (csss3) as defined by 2 factors (population, locid). The data are sorted by year within locid within population and I want to lag another variable (dbc), i.e, shift them down by 1 row replacing the first row with NA, within groups defined by locid nested within population. I thought I could do something using by(csss3,list(locid, population), function) but don't seem to be having any success. Any suggestions?? Brian Brian S. Cade U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort Collins, CO 80526-8818 email: [EMAIL PROTECTED] tel: 970 226-9326 [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] subsetting with by() or other function??
Dimitris: Thank you for the suggestion but I get an error just as when I did similar commands using by(), The error given is Error in $-.data.frame(`*tmp*`, LAGDBC, value = tapply(csss3lagm81$DBC, : replacement has 1089 rows, data has 8314 So I'm not sure what the problem is - why does the transformed tmp only have 1089 rows instead of 8314 like the full data frame? Brian Brian S. Cade U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort Collins, CO 80526-8818 email: [EMAIL PROTECTED] tel: 970 226-9326 Dimitris Rizopoulos [EMAIL PROTECTED] 10/13/2005 10:04 AM To Brian S Cade [EMAIL PROTECTED] cc Subject Re: [R] subsetting with by() or other function?? I think this should be something like: dat$LAG1DBC - tapply(dat$DBC, dat$LOCID, function(x) c(NA, x[-length(x)])) I hope it helps. Best, Dimitris Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://www.med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm - Original Message - From: Brian S Cade [EMAIL PROTECTED] To: Florence Combes [EMAIL PROTECTED]; r-help@stat.math.ethz.ch Sent: Thursday, October 13, 2005 5:48 PM Subject: Re: [R] subsetting with by() or other function?? Fair enough. To clarify what I'm trying to achieve I've pasted below a small piece of the larger data frame with the hierarchical structure of factors POPULATION and LOCID and the ascending order of YEARS and the variable DBC that I would like to transform to another variable that is a lag of the previous years DBC (call it LAG1DBC) within LOCID within POPULATION. The desired outcome is shown in the second example data set pasted below the first. The setup is desired for doing some 1st order autoregressive analyses (not in the time series library). Any examples I've tried doing using by() only seem to work for outputing results not creating new variables in an existing data frame. I suspect that people do similar types of hierarchical subgroup data manipulations all the time in R (I know how to do these easily in SYSTAT), so I'm sure I'm missing some obvious, simple trick. My search of the R newslist archives and various other R documentation has not yielded any solutions yet. Suggestions are graciously welcomed. LOCID POPULATION YEARDBC 1 algb-1 A 1992 0.70451575 2 algb-1 A 1993 0.59506851 3 algb-1 A 1997 0.84837544 4 algb-1 A 1998 0.50283182 5 algb-1 A 2000 0.91242707 6 algb-2 A 1992 0.09747155 7 algb-2 A 1993 0.84772253 8 algb-2 A 1997 0.43974081 9 algb-2 A 1998 0.83108544 10 algb-2 A 2000 0.22291192 11 algb-3 A 1992 0.44234175 12 algb-3 A 1993 0.54089534 5680 taylr-73 B 2001 0.43918082 5681 taylr-73 B 2002 0.34694427 5682 taylr-73 B 2003 3.35619190 5683 taylr-73 B 2004 0.71575815 5684 taylr-73 B 2005 0.42038506 5685 taylr-74 B 1992 3.88410354 5686 taylr-74 B 1993 3.32472557 5687 taylr-74 B 1994 3.29861501 5688 taylr-74 B 1996 0.48153827 5689 taylr-74 B 1997 3.63570636 5690 taylr-74 B 1998 1.94630194 LOCID POPULATION YEARDBC 1 algb-1 A 1992 0.70451575 NA 2 algb-1 A 1993 0.59506851 0.70451575 3 algb-1 A 1997 0.84837544 0.59506851 4 algb-1 A 1998 0.50283182 0.84837544 5 algb-1 A 2000 0.91242707 0.50283182 6 algb-2 A 1992 0.09747155 NA 7 algb-2 A 1993 0.84772253 0.09747155 8 algb-2 A 1997 0.43974081 0.84772253 9 algb-2 A 1998 0.83108544 0.43974081 10 algb-2 A 2000 0.22291192 0.83108544 11 algb-3 A 1992 0.44234175 NA 12 algb-3 A 1993 0.54089534 0.44234175 5680 taylr-73 B 2001 0.43918082 NA 5681 taylr-73 B 2002 0.34694427 0.43918082 5682 taylr-73 B 2003 3.35619190 0.34694427 5683 taylr-73 B 2004 0.71575815 3.35619190 5684 taylr-73 B 2005 0.42038506 0.71575815 5685 taylr-74 B 1992 3.88410354 NA 5686 taylr-74 B 1993 3.32472557 3.88410354 5687 taylr-74 B 1994 3.29861501 3.32472557 5688 taylr-74 B 1996 0.48153827 3.29861501 5689 taylr-74 B 1997 3.63570636 0.48153827 5690 taylr-74 B 1998 1.94630194 3.63570636 Brian Brian S. Cade U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort
