diff options
Diffstat (limited to 'doc/groff.html.node/Measurements.html')
| -rw-r--r-- | doc/groff.html.node/Measurements.html | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/doc/groff.html.node/Measurements.html b/doc/groff.html.node/Measurements.html new file mode 100644 index 0000000..a4f1c82 --- /dev/null +++ b/doc/groff.html.node/Measurements.html @@ -0,0 +1,177 @@ +<!DOCTYPE html> +<html> +<!-- Created by GNU Texinfo 7.0.3, https://www.gnu.org/software/texinfo/ --> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> +<!-- This manual documents GNU troff version 1.23.0. + +Copyright © 1994-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A +copy of the license is included in the section entitled "GNU Free +Documentation License". --> +<title>Measurements (The GNU Troff Manual)</title> + +<meta name="description" content="Measurements (The GNU Troff Manual)"> +<meta name="keywords" content="Measurements (The GNU Troff Manual)"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta name="viewport" content="width=device-width,initial-scale=1"> + +<link href="index.html" rel="start" title="Top"> +<link href="Request-Index.html" rel="index" title="Request Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="GNU-troff-Reference.html" rel="up" title="GNU troff Reference"> +<link href="Numeric-Expressions.html" rel="next" title="Numeric Expressions"> +<link href="Text.html" rel="prev" title="Text"> +<style type="text/css"> +<!-- +a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em} +span:hover a.copiable-link {visibility: visible} +--> +</style> + + +</head> + +<body lang="en"> +<div class="section-level-extent" id="Measurements"> +<div class="nav-panel"> +<p> +Next: <a href="Numeric-Expressions.html" accesskey="n" rel="next">Numeric Expressions</a>, Previous: <a href="Text.html" accesskey="p" rel="prev">Text</a>, Up: <a href="GNU-troff-Reference.html" accesskey="u" rel="up">GNU <code class="code">troff</code> Reference</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<h3 class="section" id="Measurements-1">5.3 Measurements</h3> +<a class="index-entry-id" id="index-measurements"></a> +<a class="index-entry-id" id="index-scaling-indicator"></a> +<a class="index-entry-id" id="index-indicator_002c-scaling"></a> + +<a class="index-entry-id" id="index-units-of-measurement"></a> +<a class="index-entry-id" id="index-measurement-units"></a> +<p>The formatter sometimes requires the input of numeric parameters to +specify measurements. These are specified as integers or decimal +fractions with an optional <em class="dfn">scaling unit</em> suffixed. A scaling unit +is a letter that immediately follows the last digit of a number. Digits +after the decimal point are optional. Measurement expressions include +‘<samp class="samp">10.5p</samp>’, ‘<samp class="samp">11i</samp>’, and ‘<samp class="samp">3.c</samp>’. +</p> +<a class="index-entry-id" id="index-basic-units_002c-conversion-to"></a> +<a class="index-entry-id" id="index-units_002c-basic_002c-conversion-to"></a> +<a class="index-entry-id" id="index-conversion-to-basic-units"></a> +<p>Measurements are scaled by the scaling unit and stored internally (with +any fractional part discarded) in basic units. +<a class="index-entry-id" id="index-device-resolution_002c-obtaining-in-the-formatter"></a> +<a class="index-entry-id" id="index-resolution_002c-device_002c-obtaining-in-the-formatter"></a> +The device resolution can therefore be obtained by storing a value of +‘<samp class="samp">1i</samp>’ to a register. The only constraint on the basic unit is that +it is at least as small as any other unit. +</p> +<dl class="table"> +<dd><a class="index-entry-id" id="index-basic-scaling-unit-_0028u_0029"></a> +<a class="index-entry-id" id="index-u-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-u"></a> +<a class="index-entry-id" id="index-scaling-unit-u"></a> +</dd> +<dt><code class="code">u</code></dt> +<dd><p>Basic unit. +</p> +</dd> +<dt id='index-inch-scaling-unit-_0028i_0029'><span><code class="code">i</code><a class="copiable-link" href='#index-inch-scaling-unit-_0028i_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-i-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-i"></a> +<a class="index-entry-id" id="index-scaling-unit-i"></a> +<p>Inch; defined as 2.54 centimeters. +</p> +</dd> +<dt id='index-centimeter-scaling-unit-_0028c_0029'><span><code class="code">c</code><a class="copiable-link" href='#index-centimeter-scaling-unit-_0028c_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-c-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-c"></a> +<a class="index-entry-id" id="index-scaling-unit-c"></a> +<p>Centimeter; a centimeter is about 0.3937 inches. +</p> +</dd> +<dt id='index-point-scaling-unit-_0028p_0029'><span><code class="code">p</code><a class="copiable-link" href='#index-point-scaling-unit-_0028p_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-p-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-p"></a> +<a class="index-entry-id" id="index-scaling-unit-p"></a> +<p>Point; a typesetter’s unit used for measuring type size. +There are 72 points to an inch. +</p> +</dd> +<dt id='index-pica-scaling-unit-_0028P_0029'><span><code class="code">P</code><a class="copiable-link" href='#index-pica-scaling-unit-_0028P_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-P-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-P"></a> +<a class="index-entry-id" id="index-scaling-unit-P"></a> +<p>Pica; another typesetter’s unit. There are 6 picas to an inch and +12 points to a pica. +</p> +</dd> +<dt><code class="code">s</code></dt> +<dt><code class="code">z</code></dt> +<dd><p>See <a class="xref" href="Using-Fractional-Type-Sizes.html">Using Fractional Type Sizes</a>, for a discussion of these units. +</p> +</dd> +<dt><code class="code">f</code></dt> +<dd><p>GNU <code class="code">troff</code> defines this unit to scale decimal fractions in the +interval [0, 1] to 16-bit unsigned integers. It multiplies a quantity +by 65,536. See <a class="xref" href="Colors.html">Colors</a>, for usage. +</p></dd> +</dl> + +<p>The magnitudes of other scaling units depend on the text formatting +parameters in effect. These are useful when specifying measurements +that need to scale with the typeface or vertical spacing. +</p> +<dl class="table"> +<dt id='index-em-scaling-unit-_0028m_0029'><span><code class="code">m</code><a class="copiable-link" href='#index-em-scaling-unit-_0028m_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-m-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-m"></a> +<a class="index-entry-id" id="index-scaling-unit-m"></a> +<p>Em; an em is equal to the current type size in points. It is named thus +because it is approximately the width of the letter ‘<samp class="samp">M</samp>’. +</p> +</dd> +<dt id='index-en-scaling-unit-_0028n_0029'><span><code class="code">n</code><a class="copiable-link" href='#index-en-scaling-unit-_0028n_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-n-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-n"></a> +<a class="index-entry-id" id="index-scaling-unit-n"></a> +<p>En; an en is one-half em. +</p> +</dd> +<dt id='index-vertical-space-unit-_0028v_0029'><span><code class="code">v</code><a class="copiable-link" href='#index-vertical-space-unit-_0028v_0029'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-space_002c-vertical_002c-unit-_0028v_0029"></a> +<a class="index-entry-id" id="index-vee-scaling-unit-_0028v_0029"></a> +<a class="index-entry-id" id="index-v-scaling-unit"></a> +<a class="index-entry-id" id="index-unit_002c-scaling_002c-v"></a> +<a class="index-entry-id" id="index-scaling-unit-v"></a> +<p>Vee; recall <a class="ref" href="Page-Geometry.html">Page Geometry</a>. +</p> +</dd> +<dt id='index-M-scaling-unit'><span><code class="code">M</code><a class="copiable-link" href='#index-M-scaling-unit'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-unit_002c-scaling_002c-M"></a> +<a class="index-entry-id" id="index-scaling-unit-M"></a> +<p>Hundredth of an em. +</p></dd> +</dl> + + + +<ul class="mini-toc"> +<li><a href="Motion-Quanta.html" accesskey="1">Motion Quanta</a></li> +<li><a href="Default-Units.html" accesskey="2">Default Units</a></li> +</ul> +</div> +<hr> +<div class="nav-panel"> +<p> +Next: <a href="Numeric-Expressions.html">Numeric Expressions</a>, Previous: <a href="Text.html">Text</a>, Up: <a href="GNU-troff-Reference.html">GNU <code class="code">troff</code> Reference</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |