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diff --git a/xs/src/qhull/html/qh-optp.htm b/xs/src/qhull/html/qh-optp.htm new file mode 100644 index 000000000..9c6df90f5 --- /dev/null +++ b/xs/src/qhull/html/qh-optp.htm @@ -0,0 +1,253 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> +<html> + +<head> +<title>Qhull print options (P)</title> +</head> + +<body> +<!-- Navigation links --> +<p><b>Up:</b> <a href="http://www.qhull.org">Home page</a> for Qhull<br> +<b>Up:</b> <a href="index.htm#TOC">Qhull manual</a>: Table of Contents<br> +<b>To:</b> <a href="qh-quick.htm#programs">Programs</a> +• <a href="qh-quick.htm#options">Options</a> +• <a href="qh-opto.htm#output">Output</a> +• <a href="qh-optf.htm#format">Formats</a> +• <a href="qh-optg.htm#geomview">Geomview</a> +• <a href="qh-optp.htm#print">Print</a> +• <a href="qh-optq.htm#qhull">Qhull</a> +• <a href="qh-optc.htm#prec">Precision</a> +• <a href="qh-optt.htm#trace">Trace</a> +• <a href="../src/libqhull_r/index.htm">Functions</a></p> + +<hr> +<!-- Main text of document --> +<h1><a +href="http://www.geom.uiuc.edu/graphics/pix/Special_Topics/Computational_Geometry/delaunay.html"><img +src="qh--dt.gif" alt="[delaunay]" align="middle" width="100" +height="100"></a> Qhull print options (P)</h1> + +This section lists the print options for Qhull. These options are +indicated by 'P' followed by a letter. See +<a href="qh-opto.htm#output">Output</a>, <a href="qh-optg.htm#geomview">Geomview</a>, +and <a href="qh-optf.htm#format">Format</a> for other output options. + + +<p><b>Copyright © 1995-2015 C.B. Barber</b></p> + +<hr> + +<p><a href="index.htm#TOC">»</a> <a href="qh-quick.htm#programs">Programs</a> +<a name="format">•</a> <a href="qh-quick.htm#options">Options</a> +• <a href="qh-opto.htm#output">Output</a> +• <a href="qh-optf.htm#format">Formats</a> +• <a href="qh-optg.htm#geomview">Geomview</a> +• <a href="qh-optp.htm#print">Print</a> +• <a href="qh-optq.htm#qhull">Qhull</a> +• <a href="qh-optc.htm#prec">Precision</a> +• <a href="qh-optt.htm#trace">Trace</a> +• <a href="../src/libqhull_r/index.htm">Functions</a></p> + +<h2>Print options</h2> +<blockquote> +<dl compact> + <dt> </dt> + <dd><b>General</b></dd> + <dt><a href="#Pp">Pp</a></dt> + <dd>do not report precision problems </dd> + <dt><a href="#Po">Po</a></dt> + <dd>force output despite precision problems</dd> + <dt><a href="#Po2">Po</a></dt> + <dd>if error, output neighborhood of facet</dd> + <dt> </dt> + <dt> </dt> + <dd><b>Select</b></dd> + <dt><a href="#Pdk">Pdk:n</a></dt> + <dd>print facets with normal[k] >= n (default 0.0)</dd> + <dt><a href="#PDk">PDk:n</a></dt> + <dd>print facets with normal[k] <= n </dd> + <dt><a href="#PFn">PFn</a></dt> + <dd>print facets whose area is at least n</dd> + <dt><a href="#Pg">Pg</a></dt> + <dd>print good facets only (needs '<a href="qh-optq.htm#QGn">QGn</a>' + or '<a href="qh-optq.htm#QVn">QVn </a>')</dd> + <dt><a href="#PMn">PMn</a></dt> + <dd>print n facets with most merges</dd> + <dt><a href="#PAn">PAn</a></dt> + <dd>print n largest facets by area</dd> + <dt><a href="#PG">PG</a></dt> + <dd>print neighbors of good facets</dd> +</dl> +</blockquote> +<hr> + +<h3><a href="#print">»</a><a name="PAn">PAn - keep n largest +facets by area</a></h3> + +<p>The <i>n</i> largest facets are marked good for printing. This +may be useful for <a href="qh-impre.htm#approximate">approximating +a hull</a>. Unless '<a href="#PG">PG</a>' is set, '<a href="#Pg">Pg</a>' +is automatically set. </p> + +<h3><a href="#print">»</a><a name="Pdk">Pdk:n - print facet if +normal[k] >= n </a></h3> + +<p>For a given output, print only those facets with <i>normal[k] >= n</i> +and <i>drop</i> the others. For example, 'Pd0:0.5' prints facets with <i>normal[0] +>= 0.5 </i>. The default value of <i>n</i> is zero. For +example in 3-d, 'Pd0d1d2' prints facets in the positive octant. +<p> +If no facets match, the closest facet is returned.</p> +<p> +On Windows 95, do not combine multiple options. A 'd' is considered +part of a number. For example, use 'Pd0:0.5 Pd1:0.5' instead of +'Pd0:0.5d1:0.5'. + +<h3><a href="#print">»</a><a name="PDk">PDk:n - print facet if +normal[k] <= n</a></h3> + +<p>For a given output, print only those facets with <i>normal[k] <= n</i> +and <i>drop</i> the others. +For example, 'PD0:0.5' prints facets with <i>normal[0] +<= 0.5 </i>. The default value of <i>n</i> is zero. For +example in 3-d, 'PD0D1D2' displays facets in the negative octant. +<p> +If no facets match, the closest facet is returned.</p> + +<p>In 2-d, 'd G PD2' displays the Delaunay triangulation instead +of the corresponding paraboloid. </p> + +<p>Be careful of placing 'Dk' or 'dk' immediately after a real +number. Some compilers treat the 'D' as a double precision +exponent. </p> + +<h3><a href="#print">»</a><a name="PFn">PFn - keep facets whose +area is at least n</a></h3> + +<p>The facets with area at least <i>n</i> are marked good for +printing. This may be useful for <a +href="qh-impre.htm#approximate">approximating a hull</a>. Unless +'<a href="#PG">PG</a>' is set, '<a href="#Pg">Pg</a>' is +automatically set. </p> + +<h3><a href="#print">»</a><a name="Pg">Pg - print good facets </a></h3> + +<p>Qhull can mark facets as "good". This is used to</p> + +<ul> + <li>mark the lower convex hull for Delaunay triangulations + and Voronoi diagrams</li> + <li>mark the facets that are visible from a point (the '<a + href="qh-optq.htm#QGn">QGn </a>' option)</li> + <li>mark the facets that contain a point (the '<a + href="qh-optq.htm#QVn">QVn</a>' option).</li> + <li>indicate facets with a large enough area (options '<a + href="#PAn">PAn</a>' and '<a href="#PFn">PFn</a>')</li> +</ul> + +<p>Option '<a href="#Pg">Pg</a>' only prints good facets that +also meet '<a href="#Pdk">Pdk</a>' and '<a href="#PDk">PDk</a>' +options. It is automatically set for options '<a href="#PAn">PAn</a>', +'<a href="#PFn">PFn </a>', '<a href="qh-optq.htm#QGn">QGn</a>', +and '<a href="qh-optq.htm#QVn">QVn</a>'.</p> + +<h3><a href="#print">»</a><a name="PG">PG - print neighbors of +good facets</a></h3> + +<p>Option 'PG' can be used with or without option '<a href="#Pg">Pg</a>' +to print the neighbors of good facets. For example, options '<a +href="qh-optq.htm#QGn">QGn</a>' and '<a href="qh-optq.htm#QVn">QVn</a>' +print the horizon facets for point <i>n. </i></p> + +<h3><a href="#print">»</a><a name="PMn">PMn - keep n facets with +most merges</a></h3> + +<p>The n facets with the most merges are marked good for +printing. This may be useful for <a +href="qh-impre.htm#approximate">approximating a hull</a>. Unless +'<a href="#PG">PG</a>' is set, '<a href="#Pg">Pg</a>' is +automatically set. </p> + +<p>Use option '<a href="qh-optf.htm#Fm">Fm</a>' to print merges +per facet. + +<h3><a href="#print">»</a><a name="Po">Po - force output despite +precision problems</a></h3> + +<p>Use options 'Po' and '<a href="qh-optq.htm#Q0">Q0</a>' if you +can not merge facets, triangulate the output ('<a href="qh-optq.htm#Qt">Qt</a>'), +or joggle the input (<a href="qh-optq.htm#QJn">QJ</a>). + +<p>Option 'Po' can not force output when +duplicate ridges or duplicate facets occur. It may produce +erroneous results. For these reasons, merged facets, joggled input, or <a +href="qh-impre.htm#exact">exact arithmetic</a> are better.</p> + +<p>If you need a simplicial Delaunay triangulation, use +joggled input '<a href="qh-optq.htm#QJn">QJ</a>' or triangulated +output '<a +href="qh-optf.htm#Ft">Ft</a>'. + +<p>Option 'Po' may be used without '<a href="qh-optq.htm#Q0">Q0</a>' +to remove some steps from Qhull or to output the neighborhood of +an error.</p> + +<p>Option 'Po' may be used with option '<a href="qh-optq.htm#Q5">Q5</a>') +to skip qh_check_maxout (i.e., do not determine the maximum outside distance). +This can save a significant amount of time. + +<p>If option 'Po' is used,</p> + +<ul> + <li>most precision errors allow Qhull to continue. </li> + <li>verify ('<a href="qh-optt.htm#Tv">Tv</a>') does not check + coplanar points.</li> + <li>points are not partitioned into flipped facets and a + flipped facet is always visible to a point. This may + delete flipped facets from the output. </li> +</ul> + +<h3><a href="#print">»</a><a name="Po2">Po - if error, output +neighborhood of facet</a></h3> + +<p>If an error occurs before the completion of Qhull and tracing +is not active, 'Po' outputs a neighborhood of the erroneous +facets (if any). It uses the current output options.</p> + +<p>See '<a href="qh-optp.htm#Po">Po</a>' - force output despite +precision problems. + +<h3><a href="#print">»</a><a name="Pp">Pp - do not report +precision problems </a></h3> + +<p>With option 'Pp', Qhull does not print statistics about +precision problems, and it removes some of the warnings. It +removes the narrow hull warning.</p> + +<!-- Navigation links --> +<hr> + +<p><b>Up:</b> <a href="http://www.qhull.org">Home page</a> for Qhull<br> +<b>Up:</b> <a href="index.htm#TOC">Qhull manual</a>: Table of Contents<br> +<b>To:</b> <a href="qh-quick.htm#programs">Programs</a> +• <a href="qh-quick.htm#options">Options</a> +• <a href="qh-opto.htm#output">Output</a> +• <a href="qh-optf.htm#format">Formats</a> +• <a href="qh-optg.htm#geomview">Geomview</a> +• <a href="qh-optp.htm#print">Print</a> +• <a href="qh-optq.htm#qhull">Qhull</a> +• <a href="qh-optc.htm#prec">Precision</a> +• <a href="qh-optt.htm#trace">Trace</a> +• <a href="../src/libqhull_r/index.htm">Functions</a></p> +<!-- GC common information --> +<hr> + +<p><a href="http://www.geom.uiuc.edu/"><img src="qh--geom.gif" +align="middle" width="40" height="40"></a><i>The Geometry Center +Home Page </i></p> + +<p>Comments to: <a href=mailto:qhull@qhull.org>qhull@qhull.org</a> +</a><br> +Created: Sept. 25, 1995 --- <!-- hhmts start --> Last modified: see top <!-- hhmts end --> </p> +</body> +</html> |