X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fleast-squares.cc;h=9c250bea915e7590396ef1bb071ec06ddf5ab413;hb=47db9a3883d726ca53e2133a3b2298f78dd6a32e;hp=c7ca185bbfa4ea8de4763339bbaf30c65dab0edb;hpb=9f3572d98bb948c9689cd1f75401a029451fa001;p=lilypond.git

diff --git a/lily/least-squares.cc b/lily/least-squares.cc
index c7ca185bbf..9c250bea91 100644
--- a/lily/least-squares.cc
+++ b/lily/least-squares.cc
@@ -1,9 +1,20 @@
 /*
-  least-squares.cc -- implement minimise_least_squares
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 1996--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c) 1996--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  LilyPond is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "least-squares.hh"
@@ -12,38 +23,41 @@
 
 void
 minimise_least_squares (Real *coef, Real *offset,
-			vector<Offset> const &input)
+                        vector<Offset> const &input)
 {
   Real sx = 0.0;
   Real sy = 0.0;
   Real sqx = 0.0;
   Real sxy = 0.0;
 
-  for (vsize i = 0; i < input.size ();i++)
+  for (vsize i = 0; i < input.size (); i++)
     {
       Real x = input[i][X_AXIS];
       Real y = input[i][Y_AXIS];
       sx += x;
       sy += y;
       sqx += sqr (x);
-      sxy += x*y;
+      sxy += x * y;
     }
-  int N = input.size ();
+
+  int count = input.size ();
 
   *coef = 0.0;
   *offset = 0.;
 
-  Real den = (N * sqx - sqr (sx));
-  if (!N || !den)
+  Real den = (count * sqx - sqr (sx));
+  if (!count || !den)
     {
-      programming_error ("minimise_least_squares ():  Nothing to minimise");
+      programming_error ("minimise_least_squares ():  Nothing to minimise\n"
+                         "This means that vertical spacing is triggered\n"
+                         "before line breaking\n");
       *coef = 0.0;
-      *offset = N ? sy / N : 0.0;
+      *offset = count ? sy / count : 0.0;
     }
   else
     {
-      *coef = (N *sxy - sx * sy) / den;
-      *offset = (sy - (*coef) * sx) / N;
+      *coef = (count * sxy - sx * sy) / den;
+      *offset = (sy - (*coef) * sx) / count;
     }
 }