[boost] Looking for a simple example of instantiating normal_distribution from the random library correctly

From: Kuntz, David A (david.a.kuntz_at_[hidden])
Date: 2004-08-03 12:43:47

> 	I am instantiating normal_distribution  from the random library
> incorrectly and looking for a simple example of how to do it
> correctly.
> 
> 	I compiled, built and ran random_test.cpp and can see when I
> step through the normal_distribution () operator that _r1 and _r2 have
> values < 1.
> 
> 	Here are the relevant excerpts from my incorrect attempt at
> instantiation and calling the () operator:
> 
> 	typedef boost::mt19937 base_generator_type;
> 
> 	boost::uint32_t x = 42u;
> 	Ideal4045EsmModel::base_generator_type base_generator(x);
> 
> 	double randomDrawResult;
> 	    
> 	boost::normal_distribution<double> boostNormalRand;
> 
> 	boostNormalRand.reset();
> 
> 	randomDrawResult = boostNormalRand(base_generator);  
> 
> 	This compiles, builds, and runs, but when I step through the
> normal_distribution () operator, _r1 and _r2 have very large positive
> values, resulting in  an attempt to take the log of a negative number
> and an Indefinite value being returned.
> 
> 	I am a relatively inexperienced C++ developer. I have built and
> stepped through random_test.cpp
> (http://www.boost.org/libs/random/random_test.cpp) and can see that
> its gets correct results, but I found it quite difficult to follow. Is
> there anyone out there who could show me a simpler way?
> 
> 	Thanks,
> 
> 	Dave
> 
> 
> 
>