Rational_test Class Reference

Description

Test:

cover some aspects of working with fractional numbers.

• demonstrate some basics, as provided by boost::rational
• check for possibly dangerous values
• re-quantise a rational number

  See also

  rational.hpp

  stage::model::test::ZoomWindow_test

Definition at line 54 of file rational-test.cpp.

Private Member Functions
void	demonstrate_basics ()
virtual void	run (Arg)
void	verify_intLog2 ()
void	verify_limits ()
void	verify_requant ()

Member Function Documentation

demonstrate_basics()

void demonstrate_basics ( )

inlineprivate

Test:

demonstrate fundamental properties of rational arithmetics as provided by boost::rational

• represent rational fractions precisely
• convert to other types and then perform the division
• our typedef Rat = boost::rational<int64_t>
• our user-defined literal "_r" to simplify notation
• string conversion to reveal numerator and denominator
• automatic normalisation and reduction
• some typical fractional calculation examples.

Definition at line 79 of file rational-test.cpp.

verify_limits()

void verify_limits ( )

inlineprivate

Test:

demonstrate the limits and perils of rational fractions

• largest and smallest number representable
• numeric overflow due to normalisation
• predicates to check for possible trouble

Definition at line 110 of file rational-test.cpp.

verify_intLog2()

void verify_intLog2 ( )

inlineprivate

Test:

an optimised implementation of integer binary logarithm

• basically finds the highest bit which is set
• can be used with various integral types
• performs better than using the floating-point solution

Todo:

this test (and the implementation) belongs into some basic util header.

Definition at line 199 of file rational-test.cpp.

References util::ilog2().

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verify_requant()

void verify_requant ( )

inlineprivate

Test:

helper to re-quantise a rational fraction

• recast a number in terms of another denominator
• this introduces an error of known limited size
• and is an option to work around "poisonous" fractions

Definition at line 331 of file rational-test.cpp.

References MAX.

Inheritance diagram for Rational_test:

Collaboration diagram for Rational_test:

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The documentation for this class was generated from the following file:

• rational-test.cpp