I wanted to annotate some points on lines, above and below the lines.
I thought the easiest way would be to use text() and two pos values.
However I found when the text was rotated the space and alignment
between the point and the text did not remain constant. The following
code illustrates the problem:
x <- c(0,10.)
y <- c(0,10.)
offset <- 3
centre <- 5
plot(x,y, xlim=range(x), ylim=range(y),type="n",
xlab="",ylab="",
main="",xaxt="n",yaxt="n")
for (i in (seq(0, 340, by=45)) )
{
px <- centre + cos((i*pi)/180) * offset
py <- centre + sin((i*pi)/180) * offset
text(px, py,
labels=substitute(that%->%phantom(1),list(that=i)), pos=1,
col="blue",
cex=0.7, srt=i)
text(px, py,
labels=substitute(that%<-%phantom(1),list(that=i)), pos=3,
col="blue",cex=0.7,srt=i)
lines(px, py, type="p", col="black") #just for reference
}
What have I done wrong?
In addition, on my screen, the arrow symbols do not rotate at all
although they do on the pdf image.
(R version 1.71, MacOS X 10.2.6)
Many thanks.
Paul
Dr. P. B. Pynsent,
Research and Teaching Centre,
Royal Orthopaedic Hospital,
Birmingham, B31 2AP, U.K.
On Tue, 29 Jul 2003, p.b.pynsent wrote:> I wanted to annotate some points on lines, above and below the lines. > I thought the easiest way would be to use text() and two pos values. > However I found when the text was rotated the space and alignment > between the point and the text did not remain constant. The following > code illustrates the problem:You are rotating the text about its centre, but pos is not in the rotated frame, as I read it, so why should this be rotation-invariant? Try> plot(1:10, type="n") > text(5,5, "a bit of text") > text(5,5, "a bit of text", pos=1) > text(5,5, "a bit of text", pos=1, srt=45)to see the effect of pos and srt. You go down then rotate, not rotate and then go down.> x <- c(0,10.) > y <- c(0,10.) > offset <- 3 > centre <- 5 > plot(x,y, xlim=range(x), ylim=range(y),type="n", xlab="",ylab="", > main="",xaxt="n",yaxt="n") > for (i in (seq(0, 340, by=45)) ) > { > px <- centre + cos((i*pi)/180) * offset > py <- centre + sin((i*pi)/180) * offset > text(px, py, > labels=substitute(that%->%phantom(1),list(that=i)), pos=1, col="blue", > cex=0.7, srt=i) > text(px, py, > labels=substitute(that%<-%phantom(1),list(that=i)), pos=3, > col="blue",cex=0.7,srt=i) > lines(px, py, type="p", col="black") #just for reference > } > What have I done wrong? > In addition, on my screen, the arrow symbols do not rotate at all > although they do on the pdf image. > (R version 1.71, MacOS X 10.2.6)*WHICH* Mac port of R? There are two! The lack of rotation is a limitation of the (unspecified) graphics device of your (unspecified) port, whichever it is: it works on Linux and Windows, for example, so I would expect this to work on an X11 device on the Darwin port. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
Dear Prof Ripley, Many thanks for this response. I do not understand how your example addresses my problem. Basically what concerns me is the relationship between pos=1 and pos=3 upon rotation, if I take your example and modify it slightly to be at srt=180 I would expect to get an inverted view of srt=0. This is not the case, the spacing between the two lines of text becomes so different that at 180 degrees the text now fits within the non rotated text. At intermediate values the text remains aligned to the vertical of the plot rather than to the angle of rotation and so becomes offset. What I had hoped for was what I get with srt=0, rotated as whole so it looked the same but was just rotated to the specified angle. plot(1:10, type="n") text(5,5, "a bit of text", pos=1) text(5,5, "a bit of text", pos=3) text(5,5, "a bit of text", pos=1, srt=180) text(5,5, "a bit of text", pos=3, srt=180) Paul On Tuesday, July 29, 2003, at 11:26 am, Prof Brian Ripley wrote:> On Tue, 29 Jul 2003, p.b.pynsent wrote: > >> I wanted to annotate some points on lines, above and below the lines. >> I thought the easiest way would be to use text() and two pos values. >> However I found when the text was rotated the space and alignment >> between the point and the text did not remain constant. The following >> code illustrates the problem: > > You are rotating the text about its centre, but pos is not in the > rotated frame, as I read it, so why should this be rotation-invariant? > > Try > >> plot(1:10, type="n") >> text(5,5, "a bit of text") >> text(5,5, "a bit of text", pos=1) >> text(5,5, "a bit of text", pos=1, srt=45) > > to see the effect of pos and srt. You go down then rotate, not rotate > and > then go down. > >> x <- c(0,10.) >> y <- c(0,10.) >> offset <- 3 >> centre <- 5 >> plot(x,y, xlim=range(x), ylim=range(y),type="n", xlab="",ylab="", >> main="",xaxt="n",yaxt="n") >> for (i in (seq(0, 340, by=45)) ) >> { >> px <- centre + cos((i*pi)/180) * offset >> py <- centre + sin((i*pi)/180) * offset >> text(px, py, >> labels=substitute(that%->%phantom(1),list(that=i)), pos=1, >> col="blue", >> cex=0.7, srt=i) >> text(px, py, >> labels=substitute(that%<-%phantom(1),list(that=i)), pos=3, >> col="blue",cex=0.7,srt=i) >> lines(px, py, type="p", col="black") #just for reference >> } >> What have I done wrong? >> In addition, on my screen, the arrow symbols do not rotate at all >> although they do on the pdf image. >> (R version 1.71, MacOS X 10.2.6) > > *WHICH* Mac port of R? There are two! > > The lack of rotation is a limitation of the (unspecified) graphics > device > of your (unspecified) port, whichever it is: it works on Linux and > Windows, for example, so I would expect this to work on an X11 device > on > the Darwin port. >Yes this is ambiguous,sorry. Not the Darwin port.> -- > Brian D. Ripley, ripley at stats.ox.ac.uk > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 > >
On Tue, 29 Jul 2003, p.b.pynsent wrote:> Dear Prof Ripley, > Many thanks for this response. I do not understand how your example > addresses my problem. Basically what concerns me is the relationship > between pos=1 and pos=3 upon rotation, if I take your example and > modify it slightly to be at srt=180 I would expect to get an inverted > view of srt=0. > This is not the case, the spacing between the two lines of text becomes > so different that at 180 degrees the text now fits within the non > rotated text. At intermediate values the text remains aligned to the > vertical of the plot rather than to the angle of rotation and so > becomes offset. > > What I had hoped for was what I get with srt=0, rotated as whole so it > looked the same but was just rotated to the specified angle.But you got what is documented, and my example addessed that.> > plot(1:10, type="n") > text(5,5, "a bit of text", pos=1) > text(5,5, "a bit of text", pos=3) > text(5,5, "a bit of text", pos=1, srt=180) > text(5,5, "a bit of text", pos=3, srt=180) > > Paul > > On Tuesday, July 29, 2003, at 11:26 am, Prof Brian Ripley wrote: > > > On Tue, 29 Jul 2003, p.b.pynsent wrote: > > > >> I wanted to annotate some points on lines, above and below the lines. > >> I thought the easiest way would be to use text() and two pos values. > >> However I found when the text was rotated the space and alignment > >> between the point and the text did not remain constant. The following > >> code illustrates the problem: > > > > You are rotating the text about its centre, but pos is not in the > > rotated frame, as I read it, so why should this be rotation-invariant? > > > > Try > > > >> plot(1:10, type="n") > >> text(5,5, "a bit of text") > >> text(5,5, "a bit of text", pos=1) > >> text(5,5, "a bit of text", pos=1, srt=45) > > > > to see the effect of pos and srt. You go down then rotate, not rotate > > and > > then go down. > > > >> x <- c(0,10.) > >> y <- c(0,10.) > >> offset <- 3 > >> centre <- 5 > >> plot(x,y, xlim=range(x), ylim=range(y),type="n", xlab="",ylab="", > >> main="",xaxt="n",yaxt="n") > >> for (i in (seq(0, 340, by=45)) ) > >> { > >> px <- centre + cos((i*pi)/180) * offset > >> py <- centre + sin((i*pi)/180) * offset > >> text(px, py, > >> labels=substitute(that%->%phantom(1),list(that=i)), pos=1, > >> col="blue", > >> cex=0.7, srt=i) > >> text(px, py, > >> labels=substitute(that%<-%phantom(1),list(that=i)), pos=3, > >> col="blue",cex=0.7,srt=i) > >> lines(px, py, type="p", col="black") #just for reference > >> } > >> What have I done wrong? > >> In addition, on my screen, the arrow symbols do not rotate at all > >> although they do on the pdf image. > >> (R version 1.71, MacOS X 10.2.6) > > > > *WHICH* Mac port of R? There are two! > > > > The lack of rotation is a limitation of the (unspecified) graphics > > device > > of your (unspecified) port, whichever it is: it works on Linux and > > Windows, for example, so I would expect this to work on an X11 device > > on > > the Darwin port. > > > Yes this is ambiguous,sorry. Not the Darwin port. > > -- > > Brian D. Ripley, ripley at stats.ox.ac.uk > > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > > University of Oxford, Tel: +44 1865 272861 (self) > > 1 South Parks Road, +44 1865 272866 (PA) > > Oxford OX1 3TG, UK Fax: +44 1865 272595 > > > > > >-- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
On Tuesday, July 29, 2003, at 01:04 pm, Prof Brian Ripley wrote:>>>> What have I done wrong? >>>> In addition, on my screen, the arrow symbols do not rotate at all >>>> although they do on the pdf image. >>>> (R version 1.71, MacOS X 10.2.6) >>> >>> *WHICH* Mac port of R? There are two! >>> >>> The lack of rotation is a limitation of the (unspecified) graphics >>> device >>> of your (unspecified) port, whichever it is: it works on Linux and >>> Windows, for example, so I would expect this to work on an X11 device >>> on >>> the Darwin port. >>> >> Yes this is ambiguous,sorry. Not the Darwin port. >I have now tested the Darwin and OS X versions on my Apple. As you predicted, the arrows are correctly rotated on the X11 screen so this is some error on the OS X port. Dr. P. B. Pynsent, Research and Teaching Centre, Royal Orthopaedic Hospital, Birmingham, B31 2AP, U.K.