From: Gabor Grothendieck <ggrothendieck_at_gmail.com>

Date: Fri 22 Jul 2005 - 23:15:29 EST

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 Received on Fri Jul 22 23:19:45 2005

Date: Fri 22 Jul 2005 - 23:15:29 EST

Try as.expression(bquote(...whatever...))

On 7/22/05, Dan Bolser <dmb@mrc-dunn.cam.ac.uk> wrote:

> On Thu, 21 Jul 2005, Marc Schwartz (via MN) wrote:

*>
**> >[Note: the initial posts have been re-arranged to attempt to maintain
**> >the flow from top to bottom]
**> >
**> >> >Dan Bolser writes:
**> >> > >
**> >> > > I would like to annotate my plot with a little box containing the slope,
**> >> > > intercept and R^2 of a lm on the data.
**> >> > >
**> >> > > I would like it to look like...
**> >> > >
**> >> > > +----------------------------+
**> >> > > | Slope : 3.45 +- 0.34 |
**> >> > > | Intercept : -10.43 +- 1.42 |
**> >> > > | R^2 : 0.78 |
**> >> > > +----------------------------+
**> >> > >
**> >> > > However I can't make anything this neat, and I can't find out how to
**> >> > > combine this with symbols for R^2 / +- (plus minus).
**> >> > >
**> >> > > Below is my best attempt (which is franky quite pour). Can anyone
**> >> > > improve on the below?
**> >> > >
**> >> > > Specifically,
**> >> > >
**> >> > > aligned text and numbers,
**> >> > > aligned decimal places,
**> >> > > symbol for R^2 in the text (expression(R^2) seems to fail with
**> >> > > 'paste') and +-
**> >> > >
**> >> > >
**> >> > >
**> >> > > Cheers,
**> >> > > Dan.
**> >> > >
**> >> > >
**> >> > > dat.lm <- lm(dat$AVG_CH_PAIRS ~ dat$CHAINS)
**> >> > >
**> >> > > abline(coef(dat.lm),lty=2,lwd=1.5)
**> >> > >
**> >> > >
**> >> > > dat.lm.sum <- summary(dat.lm)
**> >> > > dat.lm.sum
**> >> > >
**> >> > > attributes(dat.lm.sum)
**> >> > >
**> >> > > my.text.1 <-
**> >> > > paste("Slope : ", round(dat.lm.sum$coefficients[2],2),
**> >> > > "+/-", round(dat.lm.sum$coefficients[4],2))
**> >> > >
**> >> > > my.text.2 <-
**> >> > > paste("Intercept : ", round(dat.lm.sum$coefficients[1],2),
**> >> > > "+/-", round(dat.lm.sum$coefficients[3],2))
**> >> > >
**> >> > > my.text.3 <-
**> >> > > paste("R^2 : ", round(dat.lm.sum$r.squared,2))
**> >> > >
**> >> > > my.text.1
**> >> > > my.text.2
**> >> > > my.text.3
**> >> > >
**> >> > >
**> >> > > ## Add legend
**> >> > > text(x=3,
**> >> > > y=300,
**> >> > > paste(my.text.1,
**> >> > > my.text.2,
**> >> > > my.text.3,
**> >> > > sep="\n"),
**> >> > > adj=c(0,0),
**> >> > > cex=1
**> >
**> >
**> >> On Thu, 21 Jul 2005, Christoph Buser wrote:
**> >>
**> >> >Dear Dan
**> >> >
**> >> >I can only help you with your third problem, expression and
**> >> >paste. You can use:
**> >> >
**> >> >plot(1:5,1:5, type = "n")
**> >> >text(2,4,expression(paste("Slope : ", 3.45%+-%0.34, sep = "")), pos = 4)
**> >> >text(2,3.8,expression(paste("Intercept : ", -10.43%+-%1.42)), pos = 4)
**> >> >text(2,3.6,expression(paste(R^2,": ", "0.78", sep = "")), pos = 4)
**> >
**> >> >I do not have an elegant solution for the alignment.
**> >
**> >
**> >On Thu, 2005-07-21 at 19:55 +0100, Dan Bolser wrote:
**> >> Cheers for this.
**> >>
**> >> I was trying to get it to work, but the problem is that I need to replace
**> >> the values above with variables, from the following code...
**> >>
**> >>
**> >> dat.lm <- lm(dat$AVG_CH_PAIRS ~ dat$CHAINS)
**> >> dat.lm.sum <- summary(dat.lm)
**> >>
**> >> my.slope.1 <- round(dat.lm.sum$coefficients[2],2)
**> >> my.slope.2 <- round(dat.lm.sum$coefficients[4],2)
**> >>
**> >> my.inter.1 <- round(dat.lm.sum$coefficients[1],2)
**> >> my.inter.2 <- round(dat.lm.sum$coefficients[3],2)
**> >>
**> >> my.Rsqua.1 <- round(dat.lm.sum$r.squared,2)
**> >>
**> >>
**> >> Anything I try results in either the words 'paste("Slope:", my.slope.1,
**> >> %+-%my.slope.2,sep="")' being written to the plot, or just
**> >> 'my.slope.1+-my.slope2' (where the +- is correctly written).
**> >>
**> >> I want to script it up and write all three lines to the plot with
**> >> 'sep="\n"', rather than deciding three different heights.
**> >
**> >
**> >> Thanks very much for what you gave, its a good start for me to figure out
**> >> how I am supposed to be telling R what to do!
**> >>
**> >> Any way to just get fixed width fonts with text? (for the alignment
**> >> problem)
**> >
**> >
**> >Dan,
**> >
**> >Here is one approach. It may not be the best, but it gets the job done.
**> >You can certainly take this and encapsulate it in a function to automate
**> >the text/box placement and to pass values as arguments.
**> >
**> >A couple of quick concepts:
**> >
**> >1. As far as I know, plotmath cannot do multiple lines, so each line in
**> >your box needs to be done separately.
**> >
**> >2. The horizontal alignment is a bit problematic when using expression()
**> >or bquote() since I don't believe that multiple spaces are honored as
**> >such after parsing. Thus I break up each component (label, ":" and
**> >values) into separate text() calls. The labels are left justified.
**> >
**> >3. The alignment for the numeric values are done with right
**> >justification. So, as long as you use a consistent number of decimals in
**> >the value outputs (2 here), you should be OK. This means you might need
**> >to use formatC() or sprintf() to control the numeric output values on
**> >either side of the +/- sign.
**> >
**> >4. In the variable replacement, note the use of substitute() and the
**> >list of x and y arguments as replacement values in the expressions.
**> >
**> >
**> >
**> ># Set your values
**> >my.slope.1 <- 3.45
**> >my.slope.2 <- 0.34
**> >
**> >my.inter.1 <- -10.43
**> >my.inter.2 <- 1.42
**> >
**> >my.Rsqua <- 0.78
**> >
**> >
**> ># Create the initial plot as per Christoph's post
**> >plot(1:5, 1:5, type = "n")
**> >
**> >
**> >#-------------------------------------
**> ># Do the Slope
**> >#-------------------------------------
**> >
**> >text(1, 4.5, "Slope", pos = 4)
**> >text(2, 4.5, ":")
**> >text(3, 4.5, substitute(x %+-% y,
**> > list(x = my.slope.1,
**> > y = my.slope.2)),
**> > pos = 2)
**> >
**> >
**> >#-------------------------------------
**> ># Do the Intercept
**> >#-------------------------------------
**> >
**> >text(1, 4.25, "Intercept", pos = 4)
**> >text(2, 4.25, ":")
**> >text(3, 4.25, substitute(x %+-% y,
**> > list(x = my.inter.1,
**> > y = my.inter.2)),
**> > pos = 2)
**> >
**> >
**> >#-------------------------------------
**> ># Do R^2
**> >#-------------------------------------
**> >
**> >text(1, 4.0, expression(R^2), pos = 4)
**> >text(2, 4.0, ":")
**> >text(3, 4.0, substitute(x, list(x = my.Rsqua)),
**> > pos = 2)
**> >
**> >
**> >#-------------------------------------
**> ># Do the Box
**> >#-------------------------------------
**> >
**> >rect(1, 3.75, 3, 4.75)
**> >
**> >
**> >You can adjust the x,y coordinates for the various text elements as you
**> >may require and can also calculate them based upon the xlim, ylim of
**> >your actual plot. You can also modify the 'cex' argument to text() for
**> >adjusting the sizes of the fonts in use.
**>
**>
**> I have been trying many different combinations of the suggestions so
**> far...
**>
**> bquote, substitute, expression, paste, etc.
**>
**> Also I was trying to use the 'expression' part of the 'legend' function to
**> make thing easier (make new lines, make columns, make rectangles)...
**>
**> So far all in vain.
**>
**> I am sure a fairly neat solution is possible using 'legend' and
**> 'expression', but I cant get a legend which contains a variable
**> substituted value *and* a special symbol.
**>
**> Can anyone show me an example of this simple step, and then I can try to
**> build on that.
**>
**>
**> Thanks all for suggestions, its one of those 'it seems so easy' problems
**> (for me).
**>
**> P.S. Whats with the documentation for bquote?
**>
**>
**>
**> >BTW, to use a monospaced font, you can set par(family = "mono").
**> >See ?par for more information.
**> >
**> >HTH,
**> >
**> >Marc Schwartz
**> >
**> >
**>
**> ______________________________________________
**> 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
*

>

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 Received on Fri Jul 22 23:19:45 2005

*
This archive was generated by hypermail 2.1.8
: Fri 03 Mar 2006 - 03:33:55 EST
*