Re: [R] Polar graph of time and tide On 5/2/07, Jim Lemon  wrote: > Alan E. Davis wrote: > > I have been trying to visualize times of lowest tides, month by month. > >  I have tide predictions with times either in unix time or a text > > format, and heights in feet or meters.  I had been able to derive the > > clock times of each prediction.   I would now like to graph this data > > with points showing heights as "r" and times as "theta", from 0000 to > > 2355.  There is a seasonal component: I am interested in displaying > > times of lowest tides in particular. > > > > I am sure this is so simple as to burden those on the list; I however > > have spent two evenings trying to figure out how to use polar.plot, > > and I'm not sure that's the best way to do this.  May I request some > > advice?  The docs with polar.plot are not complete, I fear. > > > > Thank you, begging for your indulgence, > > > Hi Alan, > Earl Glynn's advice is spot-on if you are trying to map tides onto the > diurnal cycle. However, I get the impression that you want an annual > cycle. If this is the case, it is probably best to go to the underlying > function, radial.plot. Here is an example with some imaginary tides. > > lowtide<-sin(seq(1:12)+sin(seq(1,24,by=2)/10)) > lowtide<-rescale(lowtide,c(0,2355)) > month.abbr<-c("jan","Feb","Mar","Apr","May","Jun", >  "Jul","Aug","Sep","Oct","Nov","Dec") > radial.plot(lowtide,labels=month.abbr,rp.type="s") Note that month.abb is built into R so one could eliminate the month.abbr<- line and write: radial.plot(lowtide, labels = month.abb, rp.type = "s") ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.