new2_1.html

Delaunay三角形的网格剖分程序

<TITLE>COG 2.1: Comparison with version 2.0</TITLE>

<H1>Differences between COG 2.1 and COG 2.0</H1>

<H2>New Management of Coordinate Transformations</H2>

 <P>The main difference is the new management of coordinate
transformations.  They have been completely redesigned.  Affine
transformations are no longer implemented as separate coordinate
transformations which may be composed with others, like in

<PRE>
 c2 = new wzYZSwitch(c1);
</PRE>

 <P>Instead, they are now standard methods for all coordinate
transformations:

<PRE>
 c1-&gt;switchYZ();
</PRE>

 <P>This is supposed to give some time economy in a typical
application where almost every non-linear transformation will be
composed with some affine transformations.

 <P>We have also made coordinate transformations a class derived from
general (non-invertible) maps.  Once the affine transformations have
different syntax for different dimension, we have made them derived
classes of dimension-dependent classes <B>wz1Dmap, wz2Dmap,
wz3Dmap</B>.  Therefore, we have no longer a common base class
<B>wzCoordinates</B>, which should be replaced by <B>wzMap</B>

<H2>Commands "run" and "use" renamed</H2>

 <P>It has been criticized that the names "run" and "use" for the perl
commands I have used to extract test code from documentation, link and
run it corrupts the general namespace.

 <P>Therefore, these commands have been renamed:

 <UL>
 <LI> <B>cog</B> extracts, links and runs the test code;
 <LI> <B>cogrun</B> also looks if the library is up to date, and
renames the old <B>run</B>;
 <LI> <B>coguse</B> extracts the code from documentation, and renames
the old <B>use</B>;
 </UL>