# Simple mean trajectory (ordinal variable)

6 messages
Open this post in threaded view
|
Report Content as Inappropriate

## Simple mean trajectory (ordinal variable)

 Hello. I have 5 measurement points, my dependent variable is ordinal (0 - 3), and I want to visualize my data. I'm pretty new to R. What I want is to find out whether people with different baseline covariates have different trajectories, so I want a plot with the means trajectory of my dependent variable (the individual points do not make a lot of sense in ordinal data) on each measurement point per group, e.g. females vs. males. I found different codes, but they don't work well for me. This one looks promising, though: > xyplot(phq4 ~ time, data = data, type = 'l', >       panel=function(...){ >         panel.xyplot(...) >         panel.loess(...,fun=mean,horizontal=FALSE,col='red',lwd=3) >       } >       ) Works and gives me the mean trajectory (I think), but also the individual trajectories (so I'd like to get rid of them). Also, I would need a way to build 2 trajectories in 2 graphs ("group=gender" only gives 1 mean trajectory), + standard deviations or something similar that makes sense as a measure of variance. Thanks -T         [[alternative HTML version deleted]] ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|
Report Content as Inappropriate

## Re: Simple mean trajectory (ordinal variable)

 On Jun 28, 2012, at 1:50 PM, Eiko Fried wrote: > Hello. > > I have 5 measurement points, my dependent variable is ordinal (0 -   > 3), and > I want to visualize my data. I'm pretty new to R. > What I want is to find out whether people with different baseline > covariates have different trajectories, so I want a plot with the   > means > trajectory of my dependent variable (the individual points do not   > make a > lot of sense in ordinal data) on each measurement point per group,   > e.g. > females vs. males. > > I found different codes, but they don't work well for me. This one   > looks > promising, though: > >> xyplot(phq4 ~ time, data = data, type = 'l', >>      panel=function(...){ >>        panel.xyplot(...) If you do not want to plot the points then you should drop the call to   xyplot(...) >>        panel.loess(...,fun=mean,horizontal=FALSE,col='red',lwd=3) >>      } >>      ) > > Works and gives me the mean trajectory (I think), but also the   > individual > trajectories (so I'd like to get rid of them). Also, I would need a   > way to > build 2 trajectories in 2 graphs ("group=gender" only gives 1 mean > trajectory), + standard deviations or something similar that makes   > sense as > a measure of variance. > > Thanks > -T > > [[alternative HTML version deleted]] > > ______________________________________________ > [hidden email] 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. David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|
Report Content as Inappropriate

## Re: Simple mean trajectory (ordinal variable)

 David - I didn't see a fun= argument to panel.loess Frank David Winsemius wrote On Jun 28, 2012, at 1:50 PM, Eiko Fried wrote: > Hello. > > I have 5 measurement points, my dependent variable is ordinal (0 -   > 3), and > I want to visualize my data. I'm pretty new to R. > What I want is to find out whether people with different baseline > covariates have different trajectories, so I want a plot with the   > means > trajectory of my dependent variable (the individual points do not   > make a > lot of sense in ordinal data) on each measurement point per group,   > e.g. > females vs. males. > > I found different codes, but they don't work well for me. This one   > looks > promising, though: > >> xyplot(phq4 ~ time, data = data, type = 'l', >>      panel=function(...){ >>        panel.xyplot(...) If you do not want to plot the points then you should drop the call to   xyplot(...) >>        panel.loess(...,fun=mean,horizontal=FALSE,col='red',lwd=3) >>      } >>      ) > > Works and gives me the mean trajectory (I think), but also the   > individual > trajectories (so I'd like to get rid of them). Also, I would need a   > way to > build 2 trajectories in 2 graphs ("group=gender" only gives 1 mean > trajectory), + standard deviations or something similar that makes   > sense as > a measure of variance. > > Thanks > -T > > [[alternative HTML version deleted]] > > ______________________________________________ > [hidden email] 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. David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code. Frank Harrell Department of Biostatistics, Vanderbilt University
Open this post in threaded view
|
Report Content as Inappropriate

## Re: Simple mean trajectory (ordinal variable)

 On Jun 29, 2012, at 9:29 AM, Frank Harrell wrote: > David - I didn't see a fun= argument to panel.loess > Frank I imagine that argument was just being thrown away. I wasn't paying   any attention for the request for plotting means ... only addressing   the request to get rid of the points. I suppose one could have used panel.xyplot to plot the means, but the   OP did not include a sample dataset, and I have gotten rather   selective about what sorts of datasets I will build on the fly when   posters fail to supply them. -- David. > > David Winsemius wrote >> >> On Jun 28, 2012, at 1:50 PM, Eiko Fried wrote: >> >>> Hello. >>> >>> I have 5 measurement points, my dependent variable is ordinal (0 - >>> 3), and >>> I want to visualize my data. I'm pretty new to R. >>> What I want is to find out whether people with different baseline >>> covariates have different trajectories, so I want a plot with the >>> means >>> trajectory of my dependent variable (the individual points do not >>> make a >>> lot of sense in ordinal data) on each measurement point per group, >>> e.g. >>> females vs. males. >>> >>> I found different codes, but they don't work well for me. This one >>> looks >>> promising, though: >>> >>>> xyplot(phq4 ~ time, data = data, type = 'l', >>>>     panel=function(...){ >>>>       panel.xyplot(...) >> >> If you do not want to plot the points then you should drop the call   >> to >> xyplot(...) >> >>>>       panel.loess(...,fun=mean,horizontal=FALSE,col='red',lwd=3) >>>>     } >>>>     ) >>> >>> Works and gives me the mean trajectory (I think), but also the >>> individual >>> trajectories (so I'd like to get rid of them). Also, I would need a >>> way to >>> build 2 trajectories in 2 graphs ("group=gender" only gives 1 mean >>> trajectory), + standard deviations or something similar that makes >>> sense as >>> a measure of variance. >>> >>> Thanks >>> -T >>> David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|
Report Content as Inappropriate

## Re: Simple mean trajectory (ordinal variable)

 I'm sorry, but I wasn't aware that I should attach data (and can't, because I must not disclose them). Thanks for helping me get rid of the individual points, I'm now trying to get standard errors and - more importantly - parallel lines for different values of a variable, e.g. history of depression YES=line1 , NO=line2. Adding group=variable, in the xyplot argument doesn't have any effect. Sorry, I really did read through the xyplot document and the help, and googled this problem, but found no solution. -T