<?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>component example</title> <link rel="stylesheet" type="text/css" href="../../../../Macaulay2/Style/doc.css"/> </head> <body> <table class="buttons"> <tr> <td><div><a href="_components.html">next</a> | <a href="___Complex__Field.html">previous</a> | <a href="_components.html">forward</a> | <a href="___Complex__Field.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>component example</h1> <div>The following simple example illustrates the use of <a href="_remove__Lowest__Dimension.html" title="remove components of lowest dimension">removeLowestDimension</a>,<a href="_top__Components.html" title="compute top dimensional component">topComponents</a>,<a href="_radical.html" title="the radical of an ideal">radical</a>, and <a href="_minimal__Primes.html" title="minimal associated primes of an ideal">minimalPrimes</a>.<table class="examples"><tr><td><pre>i1 : R = ZZ/32003[a..d];</pre> </td></tr> <tr><td><pre>i2 : I = monomialCurveIdeal(R,{1,3,4}) 3 2 2 2 3 2 o2 = ideal (b*c - a*d, c - b*d , a*c - b d, b - a c) o2 : Ideal of R</pre> </td></tr> <tr><td><pre>i3 : J = ideal(a^3,b^3,c^3-d^3) 3 3 3 3 o3 = ideal (a , b , c - d ) o3 : Ideal of R</pre> </td></tr> <tr><td><pre>i4 : I = intersect(I,J) 4 3 3 3 4 3 3 4 6 3 2 o4 = ideal (b - a d, a*b - a c, b*c - a*c d - b*c*d + a*d , c - b*c d - ------------------------------------------------------------------------ 3 3 5 5 2 3 2 3 2 4 2 4 3 3 3 3 2 3 c d + b*d , a*c - b c d - a*c d + b d , a c - a d + b d - a c*d , ------------------------------------------------------------------------ 3 3 3 3 2 3 3 2 3 2 2 3 2 3 3 2 3 2 b c - a d , a*b c - a c*d + b c*d - a*b d , a b*c - a c d + b c d - ------------------------------------------------------------------------ 2 3 3 3 3 2 4 2 3 2 a b*d , a c - a b*d , a c - a b d) o4 : Ideal of R</pre> </td></tr> <tr><td><pre>i5 : removeLowestDimension I 3 2 2 2 3 2 o5 = ideal (b*c - a*d, c - b*d , a*c - b d, b - a c) o5 : Ideal of R</pre> </td></tr> <tr><td><pre>i6 : topComponents I 3 2 2 2 3 2 o6 = ideal (b*c - a*d, c - b*d , a*c - b d, b - a c) o6 : Ideal of R</pre> </td></tr> <tr><td><pre>i7 : radical I 2 2 3 2 6 3 3 2 4 5 o7 = ideal (b*c - a*d, a*c - b d, b - a c, c - c d - b d + b*d ) o7 : Ideal of R</pre> </td></tr> <tr><td><pre>i8 : minimalPrimes I 3 2 2 2 3 2 o8 = {ideal (- b*c + a*d, - c + b*d , a*c - b d, - b + a c), ideal (- c + ------------------------------------------------------------------------ 2 2 d, b, a), ideal (c + c*d + d , b, a)} o8 : List</pre> </td></tr> </table> </div> </div> </body> </html>