Escape sequences in text

The routines which draw text all allow you to include escape sequeces in the text to be plotted. These are character sequences which are are interpreted as instructions to change font, draw superscripts and subscripts, draw non-ASCII (e.g., Greek letters) etc. All escape sequences start with a double backslash character (\\).

The following escape sequences are defined:

\\u: move up to the superscript position (ended with \d)
\\d: move down to subscript position (ended with \\u)
\\b: backspace (to allow overprinting)
\\\\: backslash
\\+: toggle overline mode
\\-: toggle underline mode
\\gx: Greek letter corresponding to Roman letter x (see below)
\\fn: switch to normal font
\\fr: switch to Roman font
\\fi: switch to italic font
\\fs: switch to script font
\\(nnn): Hershey character nnn (1 to 4 decimal digits)

Sections of text can have an underline or overline appended. For example, the string

$\displaystyle \overline{{S}}$ ( $\displaystyle \underline{{freq}}$ )

is obtained by specifying "\\+S\\+(\\-freq\\-)".

Greek letters are obtained by \\g followed by a Roman letter. Table $[*]$ shows how these letters map into Greek characters.

Table: Roman characters corresponding to Greek characters

Roman

Greek

Roman

Greek

Roman

Greek

Roman

Greek