[Boost-commit] svn:boost r66765 - trunk/libs/math/example

Subject: [Boost-commit] svn:boost r66765 - trunk/libs/math/example
From: pbristow_at_[hidden]
Date: 2010-11-26 05:23:24

Author: pbristow
Date: 2010-11-26 05:23:23 EST (Fri, 26 Nov 2010)
New Revision: 66765
URL: http://svn.boost.org/trac/boost/changeset/66765

Log:
Removed diagnostic output for gcc.
Text files modified: 
   trunk/libs/math/example/inverse_chi_squared_example.cpp |    91 ++++++++------------------------------- 
   1 files changed, 20 insertions(+), 71 deletions(-)

Modified: trunk/libs/math/example/inverse_chi_squared_example.cpp
==============================================================================
--- trunk/libs/math/example/inverse_chi_squared_example.cpp	(original)
+++ trunk/libs/math/example/inverse_chi_squared_example.cpp	2010-11-26 05:23:23 EST (Fri, 26 Nov 2010)
@@ -63,13 +63,12 @@
 RealType naive_pdf4(RealType df, RealType scale, RealType x)
 { // Formula from http://mathworld.wolfram.com/InverseChi-SquaredDistribution.html
   // Weisstein, Eric W. "Inverse Chi-Squared Distribution." From MathWorld--A Wolfram Web Resource.
-
   // *Scaled* version, definition 3, df aka nu, scale aka sigma^2
   // using tgamma for simplicity as a check.
    using namespace std; // For ADL of std functions.
    using boost::math::tgamma;
-   RealType nu = df; // Wolfram greek symbols.
-   RealType xi = scale;
+   RealType nu = df; // Wolfram uses greek symbols nu,
+   RealType xi = scale; // and xi.
    RealType result = 
      pow(2, -nu/2) *  exp(- (nu * xi)/(2 * x)) * pow(x, -1-nu/2) * pow((nu * xi), nu/2) 
      / tgamma(nu/2);
@@ -81,9 +80,11 @@
 
   cout << "Example (basic) using Inverse chi squared distribution. " << endl;
 
-  cout.precision(std::numeric_limits<double>::max_digits10); // 
+  // TODO find a more practial/useful example.  Suggestions welcome?
+
   int i = std::numeric_limits<double>::max_digits10;
   cout << "Show all potentially significant decimal digits std::numeric_limits<double>::max_digits10 = " << i << endl; 
+  cout.precision(std::numeric_limits<double>::max_digits10); // 
 
   inverse_chi_squared ichsqdef; // All defaults  - not very useful!
   cout << "default df = " << ichsqdef.degrees_of_freedom()
@@ -100,8 +101,8 @@
   {
     cout.precision(3);
     double nu = 5.;
-    double scale1 = 1./ nu; // 1st definition sigma^2 = 1/df;
-    double scale2 = 1.; // 2nd definition sigma^2 = 1
+    //double scale1 = 1./ nu; // 1st definition sigma^2 = 1/df;
+    //double scale2 = 1.; // 2nd definition sigma^2 = 1
     inverse_chi_squared ichsq(nu, 1/nu); // Not scaled
     inverse_chi_squared sichsq(nu, 1/nu); // scaled
 
@@ -109,18 +110,19 @@
 
     int width = 8;
 
-    cout << " x      pdf(inchsq)    pdf1   pdf2 pdf(scaled)   pdf      pdf    cdf" << endl;
+    cout << "     x        pdf      pdf1   pdf2  pdf(scaled)    pdf       pdf      cdf     cdf" << endl;
     for (double x = 0.0; x < 1.; x += 0.1)
     {
       cout 
-        << setw(width) << x << ' ' << setw(width) << pdf(ichsq, x) // unscaled
-        << ' ' << setw(width) << naive_pdf1(nu, 1/nu, x) // Wiki def 1 unscaled matches graph 
-        << ' ' << setw(width) << naive_pdf2(nu, scale2, x) // scale = 1 - 2nd definition.
+        << setw(width) << x 
+        << ' ' << setw(width) << pdf(ichsq, x) // unscaled
+        << ' ' << setw(width) << naive_pdf1(nu,  x) // Wiki def 1 unscaled matches graph 
+        << ' ' << setw(width) << naive_pdf2(nu,  x) // scale = 1 - 2nd definition.
         << ' ' << setw(width) << naive_pdf3(nu, 1/nu, x) // scaled 
         << ' ' << setw(width) << naive_pdf4(nu, 1/nu, x) // scaled 
         << ' ' << setw(width) << pdf(sichsq, x)  // scaled
         << ' ' << setw(width) << cdf(sichsq, x)  // scaled
-        << ' ' << setw(width) << cdf(ichsq, x) 
+        << ' ' << setw(width) << cdf(ichsq, x)  // unscaled
        << endl;
     }
   }
@@ -128,8 +130,8 @@
   cout.precision(std::numeric_limits<double>::max_digits10);
 
   inverse_chi_squared ichisq(2., 0.5);
-
-  cout << cdf(ichisq, 1.) << endl;
+  cout << "pdf(ichisq, 1.) = " << pdf(ichisq, 1.) << endl;
+  cout << "cdf(ichisq, 1.) = " << cdf(ichisq, 1.) << endl;
 
   return 0;
 }  // int main()
@@ -137,13 +139,13 @@
 /*
 
 Output is:
-  Example (basic) using Inverse chi squared distribution. 
+ Example (basic) using Inverse chi squared distribution. 
   Show all potentially significant decimal digits std::numeric_limits<double>::max_digits10 = 17
   default df = 1, default scale = 1
   default df = 4, default scale = 0.25
   default df = 3, default scale = 2
   nu = 5, scale = 0.2
-   x      pdf(inchsq)    pdf1   pdf2 pdf(scaled)   pdf      pdf    cdf
+       x        pdf      pdf1   pdf2  pdf(scaled)    pdf       pdf      cdf     cdf
          0        0    -1.#J    -1.#J    -1.#J    -1.#J        0        0        0
        0.1     2.83     2.83 3.26e-007     2.83     2.83     2.83   0.0752   0.0752
        0.2     3.05     3.05  0.00774     3.05     3.05     3.05    0.416    0.416
@@ -155,61 +157,8 @@
        0.8    0.155    0.155    0.713    0.155    0.155    0.155     0.94     0.94
        0.9     0.11     0.11    0.668     0.11     0.11     0.11    0.953    0.953
          1   0.0807   0.0807     0.61   0.0807   0.0807   0.0807    0.963    0.963
+  pdf(ichisq, 1.) = 0.30326532985631671
+  cdf(ichisq, 1.) = 0.60653065971263365
 
-*/
-
-
-/*  Parked temporary.
- double df = 5.;
-  double x = 0.2;
-  // Construction using default RealType double, and default shape and scale..
-  inverse_chi_squared_distribution<> my_inverse_chi_squared(df); // (nu)
-
-  cout << "my_inverse_chi_squared.degrees_of_freedom() = " << my_inverse_chi_squared.degrees_of_freedom() << endl;
-  cout << "x = " << x << ", pdf = " << pdf(my_inverse_chi_squared, x)
-     << ", cdf = " << cdf(my_inverse_chi_squared, x)
-    << endl;
-
-  // Construct using typedef and default shape and scale parameters.
- 
-  // Example of providing an 'out of domain' or 'bad' parameter,
-  // here a degrees of freedom = 2, for which mean is not defined.
-  // Try block is essential to catch the exception message.
-  // (Uses the default policy which is to throw on all errors).
-  try
-  {
-    inverse_chi_squared ic2(2);
-    cout << "degrees of freedom(ic2) = " << ic2.degrees_of_freedom() << endl;
 
-    cout << "mean(ic2) = " << mean(ic2) << endl;
-  }
-  catch(const std::exception& e)
-  { // Always useful to include try & catch blocks because default policies 
-    // are to throw exceptions on arguments that cause errors like underflow, overflow. 
-    // Lacking try & catch blocks, the program will abort without a message below,
-    // which may give some helpful clues as to the cause of the exception.
-    std::cout <<
-      "\n""Message from thrown exception was:\n   " << e.what() << std::endl;
-  }
-
-  // Example of providing an 'out of domain' or 'bad' parameter,
-  // here a degrees of freedom < 0, for which mean is not defined.
-  // Try block is essential to catch the exception message.
-  // (Uses the default policy which is to throw on all errors).
-  try
-  {
-     inverse_chi_squared icm1(-1);
-
-  }
-  catch(const std::exception& e)
-  { // Always useful to include try & catch blocks because default policies 
-    // are to throw exceptions on arguments that cause errors like underflow, overflow. 
-    // Lacking try & catch blocks, the program will abort without a message below,
-    // which may give some helpful clues as to the cause of the exception.
-    std::cout <<
-      "\n""Message from thrown exception was:\n   " << e.what() << std::endl;
-    //   Message from thrown exception was:
-    // Error in function boost::math::variance(const inverse_gamma_distribution<double>&):
-    // Shape parameter is 1.8999999999999999, but must be > 2!
-  }
-  */
\ No newline at end of file
+*/
\ No newline at end of file