-/*
- least-squares.cc -- implement minimise_least_squares
-
+/*
+ least-squares.cc -- implement minimise_least_squares
+
source file of the GNU LilyPond music typesetter
-
- (c) 1996--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
-
- */
+
+ (c) 1996--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
+*/
#include "least-squares.hh"
#include "warn.hh"
void
-minimise_least_squares (Real * coef, Real * offset,
- Array<Offset> const &input)
+minimise_least_squares (Real *coef, Real *offset,
+ vector<Offset> const &input)
{
Real sx = 0.0;
Real sy = 0.0;
- Real sqx =0.0;
+ Real sqx = 0.0;
Real sxy = 0.0;
- for (int i=0; i < input.size ();i++)
+ for (vsize i = 0; i < input.size ();i++)
{
- Real x=input[i][X_AXIS];
+ Real x = input[i][X_AXIS];
Real y = input[i][Y_AXIS];
sx += x;
sy += y;
sqx += sqr (x);
sxy += x*y;
}
- int N = input.size ();
- *coef =0.0;
- *offset =0.;
-
- Real den = (N*sqx - sqr (sx));
- if (!N || !den)
+ int count = input.size ();
+
+ *coef = 0.0;
+ *offset = 0.;
+
+ 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;
}
}