I want to plot maximum and minimum water temperatures on the same axes and
thought I had the correct syntax:
watertemp <- read.table("../../data/hydro/water-temp.dat", header =
TRUE, sep =",")
watertemp$sampdate <- as.Date(as.character(watertemp$sampdate))
watertempsum <- summary(watertemp)
print(watertempsum)
maxwatemp <- xyplot(maxtemp ~ sampdate, data=watertemp, col="red",
type="h", main="USGS Foss Gauge Water Temperatures,
1974-1981", ylab="Temperature (C)", xlab="Date",
scales=list(tck=c(1,0)))
minwatemp <- xyplot(mintemp ~ sampdate, data=watertemp, col="blue",
type="h")
plot(maxwatemp)
par(new=TRUE)
plot(minwatemp)
However, R plots only minwatemp and displays this:
Warning message:
In par(new = TRUE) : calling par(new=TRUE) with no plot
Despite my searching for the reason I don't see what syntax error I made.
The two questions I ask of you:
1. Where have I gone wrong in this script?
2. With 2,492 daily observations in the source file (including 242 NAs for
maxtemp and 243 NAs for mintemp), what would be a more appropriate plot to
show both sets of data?
Thanks in advance,
Rich
Instead of trying to mix lattice and base functions, you might try using the formula: maxtemp+mintemp ~ sampdate And then: col= c(?red?, ?blue?) Sent from my iPhone, so make sure those quotes are ordinary double quotes. ? David> On Sep 27, 2019, at 6:27 AM, Rich Shepard <rshepard at appl-ecosys.com> wrote: > > I want to plot maximum and minimum water temperatures on the same axes and > thought I had the correct syntax: > > watertemp <- read.table("../../data/hydro/water-temp.dat", header = TRUE, sep =",") > watertemp$sampdate <- as.Date(as.character(watertemp$sampdate)) > watertempsum <- summary(watertemp) > print(watertempsum) > maxwatemp <- xyplot(maxtemp ~ sampdate, data=watertemp, col="red", type="h", main="USGS Foss Gauge Water Temperatures, 1974-1981", ylab="Temperature (C)", xlab="Date", scales=list(tck=c(1,0))) > minwatemp <- xyplot(mintemp ~ sampdate, data=watertemp, col="blue", type="h") > plot(maxwatemp) > par(new=TRUE) > plot(minwatemp) > > However, R plots only minwatemp and displays this: > Warning message: > In par(new = TRUE) : calling par(new=TRUE) with no plot > > Despite my searching for the reason I don't see what syntax error I made. > The two questions I ask of you: > > 1. Where have I gone wrong in this script? > > 2. With 2,492 daily observations in the source file (including 242 NAs for > maxtemp and 243 NAs for mintemp), what would be a more appropriate plot to > show both sets of data? > > Thanks in advance, > > Rich > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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.
On 27/09/19 10:27 AM, Rich Shepard wrote:> I want to plot maximum and minimum water temperatures on the same axes and > thought I had the correct syntax: > > watertemp <- read.table("../../data/hydro/water-temp.dat", header = > TRUE, sep =",") > watertemp$sampdate <- as.Date(as.character(watertemp$sampdate)) > watertempsum <- summary(watertemp) > print(watertempsum) > maxwatemp <- xyplot(maxtemp ~ sampdate, data=watertemp, col="red", > type="h", main="USGS Foss Gauge Water Temperatures, 1974-1981", > ylab="Temperature (C)", xlab="Date", scales=list(tck=c(1,0))) > minwatemp <- xyplot(mintemp ~ sampdate, data=watertemp, col="blue", > type="h") > plot(maxwatemp) > par(new=TRUE) > plot(minwatemp) > > However, R plots only minwatemp and displays this: > Warning message: > In par(new = TRUE) : calling par(new=TRUE) with no plot > > Despite my searching for the reason I don't see what syntax error I made. > The two questions I ask of you: > > 1. Where have I gone wrong in this script? > > 2. With 2,492 daily observations in the source file (including 242 NAs for > maxtemp and 243 NAs for mintemp), what would be a more appropriate plot to > show both sets of data?You are using xyplot() from the lattice package (which you did not mention). Your par(new=TRUE) syntax would probably work with base R graphics (although it would be suboptimal; one would normally use points() to add a second graph on the same figure). I would hazard that it won't work at all with lattice graphics. Moreover you seem to be trying to mix lattice graphics and base R graphics in a higgledy-piggledy fashion: first you call xyplot() and then you call plot(). To do what you want with lattice graphics I think you need to learn about and apply *panels* --- in particular panel.points(). Using panels appropriately is a bit tricky, I find, and requires some study. You may better off using base R graphics, unless there are considerations which demand the use of lattice. Something like this, maybe: plot(maxtemp ~ sampdate, data=watertemp, type="h", col="red", <annotation arguments>) points(maxtemp ~ sampdate, data=watertemp, type="h",col="blue") (Not tested since your example is not reproducible.) cheers, Rolf Turner -- Honorary Research Fellow Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
On 27/09/19 11:08 AM, David Winsemius wrote:> Instead of trying to mix lattice and base functions, you might try using the formula: > > maxtemp+mintemp ~ sampdate > > And then: col= c(?red?, ?blue?) > > Sent from my iPhone, so make sure those quotes are ordinary double quotes.Ah-ha! I've learned something about lattice that I had not previously taken on board. Thanks David! cheers, Rolf -- Honorary Research Fellow Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
On Fri, 27 Sep 2019, David Winsemius wrote:> Instead of trying to mix lattice and base functions, you might try using > the formula: > > maxtemp+mintemp ~ sampdate > > And then: col= c(?red?, ?blue?)David, I certainly will. I've not needed R for projects for many months and when I looked through previous scripts and the lattice book I failed to find what I needed. So what I tried was a solution to a different but similar issue on stackexchange. Many thanks, Rich
On Fri, 27 Sep 2019, Rolf Turner wrote:> You may better off using base R graphics, unless there are considerations > which demand the use of lattice. Something like this, maybe: > > plot(maxtemp ~ sampdate, data=watertemp, type="h", col="red", > <annotation arguments>) > points(maxtemp ~ sampdate, data=watertemp, type="h",col="blue")Rolf, Thanks very much. Regards, Rich