Included support for rational numbers

1 files changed, 129 insertions, 0 deletions

diff --git a/rational.py b/rational.py
new file mode 100644
index 0000000..0a5571a
--- /dev/null
+++ b/rational.py
@@ -0,0 +1,129 @@
+# rational.py, rational number class Reinier Heeres <reinier@heeres.eu>
+#
+# This program 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 2 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+# Change log:
+#    2007-07-03: rwh, first version
+
+import types
+
+import logging
+_logger = logging.getLogger('Rational')
+
+from gettext import gettext as _
+
+class Rational:
+
+    def __init__(self, n=None, d=None):
+        self.n = 0
+        self.d = 0
+
+        if n is not None:
+            self.set(n, d)
+
+    def set(self, n, d=None):
+        if d is not None:
+            self.n = long(n)
+            self.d = long(d)
+        elif type(n) is types.TupleType or type(n) is types.ListType:
+            self.n = long(rval[0])
+            self.d = long(rval[1])
+        elif type(n) == types.StringType:
+            return
+
+        self._simplify()
+
+    def __str__(self):
+        if self.d == 1 or self.d == 0:
+            return "%d" % (self.n)
+        else:
+            return "%d/%d" % (self.n, self.d)
+           
+    def __float__(self):
+        return float(self.n) / float(self.d)
+
+    def gcd(self, a, b):
+        if b == 0:
+            return a
+        else:
+            return self.gcd(b, a % b)
+
+    def _simplify(self):
+        if self.d == 0:
+            return
+
+        if self.n == self.d:
+            self.n = long(1)
+            self.d = long(1)
+        else:
+            gcd = self.gcd(self.n, self.d)
+            self.n /= gcd
+            self.d /= gcd
+
+    def __add__(self, rval):
+        if isinstance(rval, Rational):
+            ret = Rational(self.n * rval.d + self.d * rval.n, self.d * rval.d)
+        elif type(rval) is types.IntType or type(rval) is types.LongType:
+            ret = Rational(self.n + self.d * rval, self.d)
+        else:
+            ret = float(self) + rval
+        return ret
+
+    def __radd__(self, lval):
+        return self.__add__(lval)
+
+    def __sub__(self, rval):
+        if isinstance(rval, Rational):
+            ret = Rational(self.n * rval.d - self.d * rval.n, self.d * rval.d)
+        elif type(rval) is types.IntType or type(rval) is types.LongType:
+            ret = Rational(self.n - self.d * rval, self.d)
+        else:
+            ret = float(self) - rval
+        return ret
+
+    def __rsub__(self, lval):
+        return self.__sub__(lval)
+
+    def __mul__(self, rval):
+        if isinstance(rval, Rational):
+            ret = Rational(self.n * rval.n, self.d * rval.d)
+        elif type(rval) is types.IntType or type(rval) is types.LongType:
+            ret = Rational(self.n * rval, self.d)
+        else:
+            ret = float(self) * rval
+        return ret
+
+    def __rmul__(self, lval):
+        return self.__mul__(lval)
+
+    def __div__(self, rval):
+        if isinstance(rval, Rational):
+            ret = Rational(self.d * rval.d, self.n * rval.n)
+        elif type(rval) is types.IntType or type(rval) is types.LongType:
+            ret = Rational(self.n, self.d * rval)
+        else:
+            ret = float(self) / rval
+        return ret
+
+    def __rdiv__(self, lval):
+        return self.__div__(lval)
+
+    def __neg__(self):
+        self.n = -self.n
+
+    def __abs__(self):
+        self.n = abs(self.n)
+        self.d = abs(self.d)
+