1 files changed, 66 insertions, 0 deletions
diff --git a/src/jtutil/fuzzy.cc b/src/jtutil/fuzzy.cc
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+++ b/src/jtutil/fuzzy.cc
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+// fuzzy.cc -- template for fuzzy comparisons et al on floating point values
+// $Id$
+//
+// fuzzy::tolerance - comparison tolerance
+// fuzzy::EQ
+// fuzzy::is_integer
+// fuzzy::floor
+// fuzzy::ceiling
+//
+// *** instantiations of fuzzy template for <float> and <double>
+//
+
+#include "stdc.h"
+#include "util++.hh"
+
+//*****************************************************************************
+
+template <class fpt>
+bool fuzzy<fpt>::EQ(fpt x, fpt y)
+{
+fpt max_abs = jtutil::max(jtutil::abs(x), jtutil::abs(y));
+fpt epsilon = jtutil::max(tolerance, tolerance*max_abs);
+
+return jtutil::abs<fpt>(x-y) <= epsilon;
+}
+
+//*****************************************************************************
+
+template <class fpt>
+bool fuzzy<fpt>::is_integer(fpt x)
+{
+int i = round<fpt>::to_integer(x);
+return EQ(x, fpt(i));
+}
+
+//*****************************************************************************
+
+template <class fpt>
+int fuzzy<fpt>::floor(fpt x)
+{
+return fuzzy<fpt>::is_integer(x)
+       ? round<fpt>::to_integer(x)
+       : round<fpt>::floor(x);
+}
+
+//*****************************************************************************
+
+template <class fpt>
+int fuzzy<fpt>::ceiling(fpt x)
+{
+return fuzzy<fpt>::is_integer(x)
+       ? round<fpt>::to_integer(x)
+       : round<fpt>::ceiling(x);
+}
+
+//*****************************************************************************
+// *** instantiations of fuzzy template for <float> and <double>
+//*****************************************************************************
+
+// instantiation for <float>
+template class fuzzy<float>;
+float fuzzy<float>::tolerance = 1.0e-5;		// about 100 * FLT_EPSILON
+
+// instantiations for <double>
+template class fuzzy<double>;
+double fuzzy<double>::tolerance = 1.0e-12;	// about 1e4 * DBL_EPSILON