mtext
Write Text into the Margins of a Plot
Text is written in one of the four margins of the current figure region or one of the outer margins of the device region.
- Keywords
- aplot
Usage
mtext(text, side = 3, line = 0, outer = FALSE, at = NA,
adj = NA, padj = NA, cex = NA, col = NA, font = NA, …)Arguments
- text
a character or expression vector specifying the text to be written. Other objects are coerced by
as.graphicsAnnot.- side
on which side of the plot (1=bottom, 2=left, 3=top, 4=right).
- line
on which MARgin line, starting at 0 counting outwards.
- outer
use outer margins if available.
- at
give location of each string in user coordinates. If the component of
atcorresponding to a particular text item is not a finite value (the default), the location will be determined byadj.- adj
adjustment for each string in reading direction. For strings parallel to the axes,
adj = 0means left or bottom alignment, andadj = 1means right or top alignment.If
adjis not a finite value (the default), the value ofpar("las")determines the adjustment. For strings plotted parallel to the axis the default is to centre the string.- padj
adjustment for each string perpendicular to the reading direction (which is controlled by
adj). For strings parallel to the axes,padj = 0means right or top alignment, andpadj = 1means left or bottom alignment.If
padjis not a finite value (the default), the value ofpar("las")determines the adjustment. For strings plotted perpendicular to the axis the default is to centre the string.- cex
character expansion factor.
NULLandNAare equivalent to1.0. This is an absolute measure, not scaled bypar("cex")or by settingpar("mfrow")orpar("mfcol"). Can be a vector.- col
color to use. Can be a vector.
NAvalues (the default) mean usepar("col").- font
font for text. Can be a vector.
NAvalues (the default) mean usepar("font").- …
Further graphical parameters (see
par), includingfamily,lasandxpd. (The latter defaults to the figure region unlessouter = TRUE, otherwise the device region. It can only be increased.)
Details
The user coordinates in the outer margins always range from zero to one, and are not affected by the user coordinates in the figure region(s) --- R differs here from other implementations of S.
All of the named arguments can be vectors, and recycling will take place to plot as many strings as the longest of the vector arguments.
Note that a vector adj has a different meaning from
text. adj = 0.5 will centre the string, but for
outer = TRUE on the device region rather than the plot region.
Parameter las will determine the orientation of the string(s).
For strings plotted perpendicular to the axis the default justification
is to place the end of the string nearest the axis on the specified
line. (Note that this differs from S, which uses srt if
at is supplied and las if it is not. Parameter
srt is ignored in R.)
Note that if the text is to be plotted perpendicular to the axis,
adj determines the justification of the string and the
position along the axis unless at is specified.
Graphics parameter "ylbias" (see par) determines
how the text baseline is placed relative to the nominal line.
Side Effects
The given text is written onto the current plot.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
See Also
title, text, plot,
par;
plotmath for details on mathematical annotation.
Examples
library(graphics)
plot(1:10, (-4:5)^2, main = "Parabola Points", xlab = "xlab")
mtext("10 of them")
for(s in 1:4)
mtext(paste("mtext(..., line= -1, {side, col, font} = ", s,
", cex = ", (1+s)/2, ")"), line = -1,
side = s, col = s, font = s, cex = (1+s)/2)
mtext("mtext(..., line= -2)", line = -2)
mtext("mtext(..., line= -2, adj = 0)", line = -2, adj = 0)
##--- log axis :
plot(1:10, exp(1:10), log = "y", main = "log =\"y\"", xlab = "xlab")
for(s in 1:4) mtext(paste("mtext(...,side=", s ,")"), side = s)