mtext                package:graphics                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 alignment. If 'adj' is not a finite value (the
          default), the value of '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
     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.)

     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.

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:

     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)

