mtext {base}

R Documentation

Write Text into the Margins of a Plot

Description

Text is written in one of the four margins of the current figure region or one of the outer margins of the device region.

Usage

mtext(text, side = 3, line = 0, outer = FALSE, at = NA,
      adj = NA, cex = NA, col = NA, font = NA, vfont = NULL, ...)

Arguments

text	one or more character strings or expressions.
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 in user-coordinates. If length(at)==0 (the default), the location will be determined by adj.
adj	adjustment for each string. For strings parallel to the axes, adj=0 means left or bottom alignment, and adj=1 means right or top aligment. If adj is not a finite value (the default), the value par("las") determines the adjustment. For strings plotted parallel to the axis the default is to centre the string.
...	Further graphical parameters (see text and par) ; currently supported are:
cex	character expansion factor (default = 1).
col	color to use.
font	font for text.
vfont	vector font for text.

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 is differing here from other implementations of S.

The arguments side, line, at, at, adj, the further graphical parameters and even outer 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 justifcation is to place the end of the string nearest the axis on the specified line.

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.

Side Effects

The given text is written onto the current plot.

See Also

title, text, plot, par; plotmath for details on mathematical annotation.

Examples

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)

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