[mlpack-git] master: Make the Mahalanobis distance a true metric by default. (8a87c23)

[gitdub at big.cc.gt.atl.ga.us]

Repository : https://github.com/mlpack/mlpack

On branch  : master
Link       : https://github.com/mlpack/mlpack/compare/904762495c039e345beba14c1142fd719b3bd50e...f94823c800ad6f7266995c700b1b630d5ffdcf40

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commit 8a87c23ce000200fba777f378ad599a0d5243a75
Author: Ryan Curtin <ryan at ratml.org>
Date:   Fri Oct 31 20:59:56 2014 +0000

    Make the Mahalanobis distance a true metric by default.


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8a87c23ce000200fba777f378ad599a0d5243a75
 src/mlpack/core/metrics/mahalanobis_distance.hpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mlpack/core/metrics/mahalanobis_distance.hpp b/src/mlpack/core/metrics/mahalanobis_distance.hpp
index 99b4249..23518dd 100644
--- a/src/mlpack/core/metrics/mahalanobis_distance.hpp
+++ b/src/mlpack/core/metrics/mahalanobis_distance.hpp
@@ -40,9 +40,11 @@ namespace metric {
  * which is faster to evaluate.
  *
  * @tparam TakeRoot If true, takes the root of the output.  It is slightly
- *   faster to leave this at the default of false.
+ *   faster to leave this at the default of false, but this means the metric may
+ *   not satisfy the triangle inequality and may not be usable for methods that
+ *   expect a true metric.
  */
-template<bool TakeRoot = false>
+template<bool TakeRoot = true>
 class MahalanobisDistance
 {
  public: