On 15-Aug-07 10:15:13, Nick Chorley wrote: >>[...] >> Now create a histogram template (any silly old data will do): >> >> H1 <- hist(c(1,2)) >> >> Next, attach your variables to it: >> >> H1$breaks <- brkpts >> H1$counts <- counts >> >> and you have your histogram in R. Also, you can use the data >> in the variables 'brkpts', 'counts' to feed into any other >> procedure which can acept data in this form. > > > This is precisely what I wanted to do, except I didn't realise > that you could assign to the variables in the histogram object > like this. > Normally when constructing the histogram, I'd use hist(x, prob=T) > to plot the probability density against x, but obviously if you're > just assigning values to the variables in the object, you can't do > that. I tried putting "prob=T" in the call to hist when making the > dummy object, but that didn't help.
Followup: The histogram object I constructed in the example from my previous reply contains the following: H1 $breaks [1] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 [12] 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 $counts [1] 3 6 3 7 7 8 19 10 16 12 16 12 13 12 11 13 11 7 3 6 $intensities [1] 0.9999992 1.0000000 $density [1] 0.9999992 1.0000000 $mids [1] 1.25 1.75 $xname [1] "c(1, 2)" $equidist [1] TRUE All these things are calculated when hist() is called for raw data. The "$breaks" and "$counts" are what I assigned to it with H1$breaks <- brkpts H1$counts <- counts "$intensities", "$density", "$mids", "$xname" and "$equidist" are what was set up by the initial call H1 <- hist(c(0,1)) Previously, I used "plot(H1)" to illustrate that the above assignments put the breakpoints and the counts into the histogram object. For a more thorough approach, you need to use plot.histogram() instead. Here you can, in fact, set the "prob=TRUE" condition in the plot by setting "freq=FALSE" in t call to plot.histogram(). But then it will look at "$density" for the values to plot. So you if you want the density plot, you would need to calculate this for yourself. E.g. H1$density <- counts/sum(counts) plot.histogram(H1,freq=FALSE) And so on ... there are many relevant details in the help pages ?hist and ?plot.histogram Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 15-Aug-07 Time: 11:53:14 ------------------------------ XFMail ------------------------------ ______________________________________________ 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.
