This illustrates why you really do not want percents... (I never quite understand why people do want them - I can understand raw counts wheh used in teaching as a precursor to the concept of a density, but percentages is an odd in-between sort of thing.)
Anyways, the scaling factor is the bin width (you figure out whether to multiply or divide, I get it wrong every second time), possibly multiplied by 100%. A pragmatic way out would seem to be switch out dnorm with dnorm_scaled <- function(...) scale*dnorm(...) in the call to panel.mathdensity. -Peter D On 05 May 2014, at 22:23 , jimdare <james.d...@es.govt.nz> wrote: > Hello, > > This may seem like a simple problem, but it's frustrating me immensely. I'm > trying to overlay a normal curve (dnorm) on top of a histogram using the > code below. This works find when the type = "density", but the person for > whom I'm making the plot wants the y axis in percent of total rather than > density. When I change type to "percent", I get the histogram scale I'm > after, but the dnorm plot is greatly reduced. How could I scale the density > plot to the percent of total axis. Alternatively, perhaps there is a way to > add density to a secondary y axis? > > Thanks in advance for your help. > > Jimdare > > > plot<-histogram(~rdf[,j]|Year,nint=20, data=rdf,main = i,strip = > my.strip,xlab = j, > type = "percent",layout=c(2,1), > panel=function(x, ...) { > panel.histogram(x, ...) > > panel.mathdensity(dmath=dnorm, col="black", > # Add na.rm = TRUE to mean() and sd() > args=list(mean=mean(x, na.rm = TRUE), > sd=sd(x, na.rm = TRUE)), ...) > }) > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Lattice-Histogram-with-Normal-Curve-Y-axis-as-percentages-tp4690000.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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.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.