add chunkerfit to guide

Author: askhamwhat

chunkie/guide/guide_chunkers.m

@@ -126,3 +126,52 @@
 
 saveas(figure(6),"guide_chunkers_interior.png");
 
+%%
+% START CHUNKERFIT
+
+% Sample a smooth curve at random points
+rng(0)
+n = 20;
+tt = sort(2*pi*rand(n,1));
+r = chnk.curves.bymode(tt, [2 0.5 0.2 0.7]);
+
+% can pass cparams and pref structures, as in
+% chunkerfunc, via the opts structure
+% asking for splitting can be more efficient, dependent on
+% desired tolerance
+
+% first asking for lower precision from chunkerfunc
+opts = [];
+opts.ifclosed = true;
+opts.cparams = [];
+opts.cparams.eps = 1e-3;
+opts.pref = [];
+opts.pref.k = 16;
+chnkr = chunkerfit(r, opts);
+
+% automatically creates a chunker between each node
+opts.splitatpoints = true;
+chnkrsp = chunkerfit(r, opts);
+
+% then asking for more precision from chunkerfunc
+opts.cparams.eps = 1e-9;
+opts.splitatpoints = false;
+chnkr2 = chunkerfit(r, opts);
+
+% automatically creates a chunker between each node
+opts.splitatpoints = true;
+chnkrsp2 = chunkerfit(r, opts);
+
+figure(7)
+clf
+tiledlayout(2,2,"TileSpacing","compact");
+nexttile; plot(chnkr,'k-x'); title(sprintf("nch = %d, eps=1e-3",chnkr.nch));
+hold on; plot(r(1,:),r(2,:),'bd');
+nexttile; plot(chnkrsp,'k-x'); title(sprintf("nch = %d, eps=1e-3\n (splitting)",chnkrsp.nch));
+hold on; plot(r(1,:),r(2,:),'bd');
+nexttile; plot(chnkr2,'k-x'); title(sprintf("nch = %d, eps=1e-9",chnkr2.nch));
+hold on; plot(r(1,:),r(2,:),'bd');
+nexttile; plot(chnkrsp2,'k-x'); title(sprintf("nch = %d, eps=1e-9\n (splitting)",chnkrsp2.nch));
+hold on; plot(r(1,:),r(2,:),'bd');
+% END CHUNKERFIT
+saveas(figure(7),"guide_chunkers_chunkerfit.png");

chunkie/guide/guide_chunkers_chunkerfit.png

@@ -68,6 +68,21 @@ parameterized curves:
 
 |pic1|  |pic2|
 
+For a given set of points, a spline curve can be fit to them and
+discretized as a chunker using `chunkerfit`:
+
+.. include:: ../../chunkie/guide/guide_chunkers.m
+   :literal:
+   :code: matlab
+   :start-after: % START CHUNKERFIT
+   :end-before: % END CHUNKERFIT
+
+.. image:: ../../chunkie/guide/guide_chunkers_chunkerfit.png
+   :width: 500px
+   :alt: circle chunker
+   :align: center
+
+
 Given a set of vertices, a rounded polygon can be defined:
 
 .. include:: ../../chunkie/guide/guide_chunkers.m
@@ -81,6 +96,8 @@ Given a set of vertices, a rounded polygon can be defined:
    :alt: circle chunker
    :align: center
 
+	   
+
 
 Working with Chunkers
 ----------------------