Hypertext Help with LaTeX
Lengths
A length is a measure of distance. Many LaTeX commands take a length
as an argument.
A length of one inch is specified by typing 1in or, to specify
the same length using metric units, by typing 2.54cm.
Units
LaTeX knows about the following common units.
- in - inches
- mm - millimeters
- cm - centimeters
- pt - points (about 1/72 inch)
- em - approximately the width of an "M"
in the current font
- ex - approximately the height of an "x"
in the current font
And the following less common units
- pc - pica (12pt/pc)
- bp - big pt (72bp/in)
- dd - didôt (1157dd=1238pt)
- cc - cîcero (12dd/cc)
- sp - scaled point (65536sp/pt)
Lengths may also be negative, for example, -1.5em.
Note that the number 0 by itself is not a length;
it must be specified as 0in or 0pt, for example.
A length may also be specified by a length command. An example
is \parindent
whose value specifies the current width of the indentation
which begins paragraphs. Multiples of such length commands may be specified,
for example by writing 2.5\parindent or -0.1\parindent.
Some length commands are
- \parindent - normal paragraph indentation
- \baselineskip -
normal vertical distance between lines in a paragraph
- \parskip -
the extra vertical space between
paragraphs
- \textwidth -
the width of text on the page
- \linewidth -
width of a line in the local
environment
- \textheight - the height of text on the page
- \unitlength - units of
lenght in Picture Environment
All length commands are robust and should not be preceded
by a \protect command.
Most lengths have a fixed value. However, LaTeX also allows for "rubber"
lengths; these have a natural length plus a degree of elasticity. For
example, the \fill length command has a natural length of zero
but is infinitely stretchable, so that a space of width \fill will
try to stretch as much as possible. Multiplying a rubber length by a fixed
factor destroys its elasticity: 0.5\fill becomes a rigid length
with a value of zero.
Setting values for length commands
The following LaTeX commands define and manipulate the value of length
commands
Commands that add space
- Horizontal space
- Vertical Space
Back to LaTeX Table of Contents
Revised: Sheldon Green, 23 Oct 1995.