On Dec 10, 2010, at 10:25 AM, Simon Kiss wrote:
Dear colleagues,
i found a line or two of code in the help archives from Uwe Ligges
about creating slanted x-labels for a barplot and it works well for
my purposes (code below). However, I was hoping someone could
explain to me precisely what the code is doing.
I'm aware it's invoking the text command, and I know the first ttwo
arguments to text are x and y co-ordinates. I'm also aware that
par("usr")[3] is grabbing the third element of the vector of
plotting co-ordinates.
More accurately the limits of the plot area in plot dimensions.
But I tried replacing par("usr")[3] with just "0" and that didn't
work; all the labels got bunched up on the left.
That was the "y" argument, not the rotation argument. (Which means I
am surprised that it bunched things to the side ... and for me it did
nothing at all... same graphic.) It is the srt argument that controls
the angle.
Is it necessary to create a new object via "barplot"
That gives you appropriate positions for the labels in plot coordinate
terms and the xpd argument allows these locations to be used outside
the plot area.
and then quote that in the x,y coordinates of text?
What do you mean by "then quote it in the x,y,coordinates"? I don't
see any quotes. You could of course just look at the plot area and
supply your own locations. You would need to figure out what the
unlabeled x-axis scale really was, but that too is documented.
--
David.
Like I said, the code works great, but I'm trying to actually
understand the rationale behind the elements so I can apply it in
future.
Yours, Simon Kiss
#Reproducible Code
mydat<-data.frame(countries=c("Canada", "Denmark", "Framce", "United
Kingdom", "Germany", "Australia", "New Zealand", "Switzerland",
"Belgium", "Netherlands"), stories_total=c(429, 25,
239, 99, 100, 96, 18, 21, 0, 6), avg=c(4.165048544, 6.25,
6.459459459, 0.908256881, 1.923076923, 1.103448276, 1.058823529,
1.615384615, 0, 0.107142857), steps=c(2, 2, 2, 0,1, 1, 1, 0,0,0),
newspapers=c(103, 4, 37, 109, 52, 87, 17, 13, 10, 56))
mydat.sort1<-mydat[order(-mydat$avg), ]
myplot<-barplot(mydat.sort1$avg, col=c("black", "black", "black",
"grey", "white", "grey", "grey", "white", "white", "white"),
ylim=c(0,7), main="Regulatory Action On Bisphenol A By Newspaper
Coverage")
col.vec=c("black", "grey", "white")
legend("topright", col=col.vec, fill=c("black", "grey", "white"),
legend=c("Meaningful Ban", "Recommendations To Withdraw", "No
Legislative Action"))
labels=mydat.sort1$countries
#These lines create the labels
text(myplot, par("usr")[3], labels=labels, srt=35, offset=1, adj=1,
xpd=TRUE)
axis(2)
par("usr")[3]
*********************************
Simon J. Kiss, PhD
Assistant Professor, Wilfrid Laurier University
73 George Street
Brantford, Ontario, Canada
N3T 2C9
Cell: +1 519 761 7606
______________________________________________
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.
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
