GNU Info

(groff)Fractional Type Sizes

---

Prev: Changing Type Sizes Up: Sizes

---

Enter node , (file) or (file)node

Fractional Type Sizes
---------------------

   A "scaled point" is equal to 1/SIZESCALE points, where SIZESCALE is
specified in the `DESC' file (1 by default).  There is a new scale
indicator `z' which has the effect of multiplying by SIZESCALE.
Requests and escape sequences in `gtroff' interpret arguments that
represent a point size as being in units of scaled points, but they
evaluate each such argument using a default scale indicator of `z'.
Arguments treated in this way are the argument to the `ps' request, the
third argument to the `cs' request, the second and fourth arguments to
the `tkf' request, the argument to the `\H' escape sequence, and those
variants of the `\s' escape sequence that take a numeric expression as
their argument (see below).

   For example, suppose SIZESCALE is 1000; then a scaled point is
equivalent to a millipoint; the request `.ps 10.25' is equivalent to
`.ps 10.25z' and thus sets the point size to 10250 scaled points, which
is equal to 10.25 points.

   `gtroff' disallows the use of the `z' scale indicator in instances
where it would make no sense, such as a numeric expression whose
default scale indicator was neither `u' nor `z'.  Similarly it would
make no sense to use a scaling indicator other than `z' or `u' in a
numeric expression whose default scale indicator was `z', and so
`gtroff' disallows this as well.

   There is also new scale indicator `s' which multiplies by the number
of units in a scaled point.  So, for example, `\n[.ps]s' is equal to
`1m'.  Be sure not to confuse the `s' and `z' scale indicators.

 - Register: \n[.ps]
     A read-only number register returning the point size in scaled
     points.

     `.ps' is associated with the current environment (Note:
     Environments).

 - Register: \n[.psr]
 - Register: \n[.sr]
     The last-requested point size in scaled points is contained in the
     `.psr' read-only number register.  The last requested point size
     in points as a decimal fraction can be found in `.sr'.  This is a
     string-valued read-only number register.

     Note that the requested point sizes are device-independent, whereas
     the values returned by the `.ps' and `.s' registers are not.  For
     example, if a point size of 11pt is requested for a DVI device,
     10.95pt are actually used (as specified in the `DESC' file).

     Both registers are associated with the current environment (Note:
     Environments).

   The `\s' escape has the following syntax for working with fractional
type sizes:

`\s[N]'
`\s'N''
     Set the point size to N scaled points; N is a numeric expression
     with a default scale indicator of `z'.

`\s[+N]'
`\s[-N]'
`\s+[N]'
`\s-[N]'
`\s'+N''
`\s'-N''
`\s+'N''
`\s-'N''
     Increase or or decrease the point size by N scaled points; N is a
     numeric expression with a default scale indicator of `z'.

   Note: Font Files.