Adding upstream version 1.0.2.upstream/1.0.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 140 insertions, 0 deletions

diff --git a/src/2geom/choose.h b/src/2geom/choose.h
new file mode 100644
index 0000000..64ce76f
--- /dev/null
+++ b/src/2geom/choose.h
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+/**
+ * \file
+ * \brief Calculation of binomial cefficients
+ *//*
+ * Copyright 2006 Nathan Hurst <njh@mail.csse.monash.edu.au>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ */
+
+#ifndef LIB2GEOM_SEEN_CHOOSE_H
+#define LIB2GEOM_SEEN_CHOOSE_H
+
+#include <vector>
+
+namespace Geom {
+
+// XXX: Can we keep only the left terms easily?
+// this would more than halve the array
+// row index becomes n2 = n/2, row2 = n2*(n2+1)/2, row = row2*2+(n&1)?n2:0
+// we could also leave off the ones
+
+template <typename T>
+T choose(unsigned n, unsigned k) {
+    static std::vector<T> pascals_triangle;
+    static unsigned rows_done = 0;
+    // indexing is (0,0,), (1,0), (1,1), (2, 0)...
+    // to get (i, j) i*(i+1)/2 + j
+    if(/*k < 0 ||*/ k > n) return 0;
+    if(rows_done <= n) {// we haven't got there yet
+        if(rows_done == 0) {
+            pascals_triangle.push_back(1);
+            rows_done = 1;
+        }
+        while(rows_done <= n) {
+            unsigned p = pascals_triangle.size() - rows_done;
+            pascals_triangle.push_back(1);
+            for(unsigned i = 0; i < rows_done-1; i++) {
+                pascals_triangle.push_back(pascals_triangle[p]
+                                           + pascals_triangle[p+1]);
+		p++;
+            }
+            pascals_triangle.push_back(1);
+            rows_done ++;
+        }
+    }
+    unsigned row = (n*(n+1))/2;
+    return pascals_triangle[row+k];
+}
+
+// Is it faster to store them or compute them on demand?
+/*template <typename T>
+T choose(unsigned n, unsigned k) {
+	T r = 1;
+	for(unsigned i = 1; i <= k; i++)
+		r = (r*(n-k+i))/i;
+	return r;
+	}*/
+
+
+
+template <typename ValueType>
+class BinomialCoefficient
+{
+  public:
+    typedef ValueType value_type;
+    typedef std::vector<value_type> container_type;
+
+    BinomialCoefficient(unsigned int _n)
+        : n(_n), m(n >> 1)
+    {
+        coefficients.reserve(m+1);
+        coefficients.push_back(1);
+        int h = m + 1;
+        value_type bct = 1;
+        for (int i = 1; i < h; ++i)
+        {
+            bct *= (n-i+1);
+            bct /= i;
+            coefficients.push_back(bct);
+        }
+    }
+
+    unsigned int size() const
+    {
+        return degree() +1;
+    }
+
+    unsigned int degree() const
+    {
+        return n;
+    }
+
+    value_type operator[] (unsigned int k) const
+    {
+        if (k > m)  k = n - k;
+        return coefficients[k];
+    }
+
+  private:
+    const int n;
+    const unsigned int m;
+    container_type coefficients;
+};
+
+} // end namespace Geom
+
+#endif // LIB2GEOM_SEEN_CHOOSE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :