Files
mp-units/example/box_example.cpp
Andy Little 024f5a9c83 change const order
move in,ft,fathom,ft2,ft3,mph from us to international namespace
TODO distinguish units with different names for same values
2020-01-12 21:34:36 +01:00

126 lines
3.3 KiB
C++

#include <units/physical/si/acceleration.h>
#include <units/physical/si/length.h>
#include <units/physical/si/volume.h>
#include <units/physical/si/time.h>
#include <units/physical/si/force.h>
#include <units/physical/si/mass.h>
#include <units/physical/si/density.h>
#include <cassert>
namespace{
namespace length{
template <typename Rep = double>
using m = units::si::length<units::si::metre,Rep>;
template <typename Rep = double>
using mm = units::si::length<units::si::millimetre,Rep>;
}
namespace acceleration{
template <typename Rep = double>
using mps2 = units::si::acceleration<units::si::metre_per_second_sq,Rep>;
template <typename Rep = double>
constexpr mps2<> g{static_cast<Rep>(9.80665)};
}
namespace force{
template <typename Rep = double>
using N = units::si::force<units::si::newton,Rep>;
}
namespace mass {
template <typename Rep = double>
using kg = units::si::mass<units::si::kilogram,Rep>;
}
namespace density {
template <typename Rep = double>
using kgpm3 = units::si::density<units::si::kilogram_per_metre_cub,Rep>;
}
namespace volume {
template <typename Rep = double>
using m3 = units::si::volume<units::si::cubic_metre,Rep>;
}
}
struct Box{
Box(const length::m<> & l,
const length::m<> & w,
const length::m<> & h
): length{l},width{w},height{h}{}
force::N<> filled_weight()const
{
const volume::m3<> volume
= length * width * height;
const mass::kg<> mass = contents.density * volume;
return mass * acceleration::g<>;
}
length::m<> fill_level(const mass::kg<> & measured_mass)const
{
return height
* (measured_mass * acceleration::g<>) / filled_weight();
}
volume::m3<> spare_capacity(const mass::kg<> & measured_mass)const
{
return (height - fill_level(measured_mass)) * width * length;
}
struct contents{
contents():density{air_density}{}
density::kgpm3<> density;
}contents;
void set_contents_density(const density::kgpm3<> & density_in)
{
assert( density_in > air_density );
contents.density = density_in;
}
static constexpr density::kgpm3<> air_density{1.225};
length::m<> length;
length::m<> width;
length::m<> height;
};
#include <iostream>
using namespace units::si::literals;
int main()
{
auto box = Box{1000.0mm, 500.0mm, 200.0mm};
box.set_contents_density(1000.0kgpm3);
auto fill_time = 200.0s; // time since starting fill
auto measured_mass = 20.0kg; // measured mass at fill_time
std::cout << "mpusz/units box example...\n";
std::cout << "fill height at " << fill_time << " = "
<< box.fill_level(measured_mass) << "( " << (box.fill_level(measured_mass)/ box.height)*100 << "% full)\n";
std::cout << "spare_capacity at " << fill_time << " = "
<< box.spare_capacity(measured_mass) <<'\n';
std::cout << "input flow rate after " << fill_time
<< " = " << measured_mass / fill_time <<'\n';
std::cout << "float rise rate = "
<< box.fill_level(measured_mass) / fill_time <<'\n';
auto fill_time_left
= (box.height / box.fill_level(measured_mass) - 1) * fill_time ;
std::cout << "box full E.T.A. at current flow rate = " << fill_time_left <<'\n';
}