Trac #20342: Method for the rate of a linear code.

The "rate" of a linear code is `k/n` where `k` is the dimension and `n`
the length of the code. This is fundamental number that all coding
theorists use. This should be available for any linear code in Sage.

Note that it should be implemented on the class `AbstractLinearCode` to
be available to both `LinearCode` and specific families of codes such as
`GeneralizedReedSolomonCode`.

URL: https://trac.sagemath.org/20342
Reported by: jsrn
Ticket author(s): David Lucas
Reviewer(s): Daniel Augot

Author: Release Manager

src/sage/coding/linear_code.py

@@ -2772,6 +2772,21 @@ def relative_distance(self):
         """
         return self.minimum_distance() / self.length()
 
+
+    def rate(self):
+        r"""
+        Return the ratio of the number of information symbols to
+        the code length.
+
+        EXAMPLES::
+
+            sage: C = codes.HammingCode(GF(2), 3)
+            sage: C.rate()
+            4/7
+        """
+        return self.dimension() / self.length()
+
+
     def redundancy_matrix(self):
         r"""
         Returns the non-identity columns of a systematic generator matrix for