<?xml version="1.0" encoding="utf-8" ?> <!-- for emacs: -*- coding: utf-8 -*- --> <!-- Apache may like this line in the file .htaccess: AddCharset utf-8 .html --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN" "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg-flat.dtd" > <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> <head><title>koszul(Matrix) -- the Koszul complex</title> <link rel="stylesheet" type="text/css" href="../../../../Macaulay2/Style/doc.css"/> </head> <body> <table class="buttons"> <tr> <td><div><a href="_koszul_lp__Z__Z_cm__Matrix_rp.html">next</a> | <a href="_koszul.html">previous</a> | <a href="_koszul_lp__Z__Z_cm__Matrix_rp.html">forward</a> | <a href="_koszul.html">backward</a> | up | <a href="index.html">top</a> | <a href="master.html">index</a> | <a href="toc.html">toc</a> | <a href="http://www.math.uiuc.edu/Macaulay2/">Macaulay2 web site</a></div> </td> </tr> </table> <hr/> <div><h1>koszul(Matrix) -- the Koszul complex</h1> <div class="single"><h2>Synopsis</h2> <ul><li><div class="list"><dl class="element"><dt class="heading">Usage: </dt><dd class="value"><div><tt>g = koszul f</tt></div> </dd></dl> </div> </li> <li><span>Function: <a href="_koszul.html" title="Koszul complex or specific matrix in the Koszul complex">koszul</a></span></li> <li><div class="single">Inputs:<ul><li><span><tt>f</tt>, <span>a <a href="___Matrix.html">matrix</a></span>, a <tt>1</tt> by <tt>n</tt> matrix</span></li> </ul> </div> </li> <li><div class="single">Outputs:<ul><li><span><tt>g</tt>, <span>a <a href="___Chain__Complex.html">chain complex</a></span>, the Koszul complex of the matrix <tt>f</tt></span></li> </ul> </div> </li> </ul> </div> <div class="single"><h2>Description</h2> <div><table class="examples"><tr><td><pre>i1 : R = QQ[x_1..x_4];</pre> </td></tr> <tr><td><pre>i2 : f = matrix{{x_1..x_4}} o2 = | x_1 x_2 x_3 x_4 | 1 4 o2 : Matrix R <--- R</pre> </td></tr> <tr><td><pre>i3 : C = koszul f 1 4 6 4 1 o3 = R <-- R <-- R <-- R <-- R 0 1 2 3 4 o3 : ChainComplex</pre> </td></tr> <tr><td><pre>i4 : C.dd^2 1 6 o4 = 0 : R <----- R : 2 0 4 4 1 : R <----- R : 3 0 6 1 2 : R <----- R : 4 0 o4 : ChainComplexMap</pre> </td></tr> </table> </div> </div> <div class="single"><h2>See also</h2> <ul><li><span><a href="_eagon__Northcott_lp__Matrix_rp.html" title="Eagon-Northcott complex of a matrix of linear forms">eagonNorthcott</a> -- Eagon-Northcott complex of a matrix of linear forms</span></li> </ul> </div> </div> </body> </html>