[Boost-commit] svn:boost r78723 - in trunk: boost/math/distributions libs/math/test

Subject: [Boost-commit] svn:boost r78723 - in trunk: boost/math/distributions libs/math/test
From: john_at_[hidden]
Date: 2012-05-28 12:27:00

Author: johnmaddock
Date: 2012-05-28 12:27:00 EDT (Mon, 28 May 2012)
New Revision: 78723
URL: http://svn.boost.org/trac/boost/changeset/78723

Log:
Tighten Weibull distro tests.
Fix corner cases in Weibull distro.
Fixes #6939.
Fixes #6938.
Text files modified: 
   trunk/boost/math/distributions/weibull.hpp |    16 ++++++++++++----                        
   trunk/libs/math/test/test_weibull.cpp      |    13 +++++++++++--                           
   2 files changed, 23 insertions(+), 6 deletions(-)

Modified: trunk/boost/math/distributions/weibull.hpp
==============================================================================
--- trunk/boost/math/distributions/weibull.hpp	(original)
+++ trunk/boost/math/distributions/weibull.hpp	2012-05-28 12:27:00 EDT (Mon, 28 May 2012)
@@ -28,7 +28,7 @@
       RealType shape,
       RealType* result, const Policy& pol)
 {
-   if((shape < 0) || !(boost::math::isfinite)(shape))
+   if((shape <= 0) || !(boost::math::isfinite)(shape))
    {
       *result = policies::raise_domain_error<RealType>(
          function,
@@ -133,11 +133,19 @@
       return result;
 
    if(x == 0)
-   { // Special case, but x == min, pdf = 1 for shape = 1,
-      return 0;
+   {
+      if(shape == 1)
+      {
+         return 1 / scale;
+      }
+      if(shape > 1)
+      {
+         return 0;
+      }
+      return policies::raise_overflow_error<RealType>(function, 0, Policy());
    }
    result = exp(-pow(x / scale, shape));
-   result *= pow(x / scale, shape) * shape / x;
+   result *= pow(x / scale, shape - 1) * shape / scale;
 
    return result;
 }

Modified: trunk/libs/math/test/test_weibull.cpp
==============================================================================
--- trunk/libs/math/test/test_weibull.cpp	(original)
+++ trunk/libs/math/test/test_weibull.cpp	2012-05-28 12:27:00 EDT (Mon, 28 May 2012)
@@ -311,22 +311,31 @@
    //
    // Special cases:
    //
-   BOOST_CHECK(pdf(dist, 0) == 0);
    BOOST_CHECK(cdf(dist, 0) == 0);
    BOOST_CHECK(cdf(complement(dist, 0)) == 1);
    BOOST_CHECK(quantile(dist, 0) == 0);
    BOOST_CHECK(quantile(complement(dist, 1)) == 0);
 
+   BOOST_CHECK_EQUAL(pdf(weibull_distribution<RealType>(1, 1), 0), 1);
+
    //
    // Error checks:
    //
-   BOOST_CHECK_THROW(weibull_distribution<RealType>(0, -1), std::domain_error);
+   BOOST_CHECK_THROW(weibull_distribution<RealType>(1, -1), std::domain_error);
    BOOST_CHECK_THROW(weibull_distribution<RealType>(-1, 1), std::domain_error);
+   BOOST_CHECK_THROW(weibull_distribution<RealType>(1, 0), std::domain_error);
+   BOOST_CHECK_THROW(weibull_distribution<RealType>(0, 1), std::domain_error);
    BOOST_CHECK_THROW(pdf(dist, -1), std::domain_error);
    BOOST_CHECK_THROW(cdf(dist, -1), std::domain_error);
    BOOST_CHECK_THROW(cdf(complement(dist, -1)), std::domain_error);
    BOOST_CHECK_THROW(quantile(dist, 1), std::overflow_error);
    BOOST_CHECK_THROW(quantile(complement(dist, 0)), std::overflow_error);
+   BOOST_CHECK_THROW(quantile(dist, -1), std::domain_error);
+   BOOST_CHECK_THROW(quantile(complement(dist, -1)), std::domain_error);
+
+   BOOST_CHECK_EQUAL(pdf(dist, 0), exp(-pow(RealType(0) / RealType(3), RealType(2))) * pow(RealType(0), RealType(1)) * RealType(2) / RealType(3));
+   BOOST_CHECK_EQUAL(pdf(weibull_distribution<RealType>(1, 3), 0), exp(-pow(RealType(0) / RealType(3), RealType(1))) * pow(RealType(0), RealType(0)) * RealType(1) / RealType(3));
+   BOOST_CHECK_THROW(pdf(weibull_distribution<RealType>(0.5, 3), 0), std::overflow_error);
 
 } // template <class RealType>void test_spots(RealType)