Technical facts

Operating system(s) or programming environment(s)

Lubuntu 15.04 (vivid)

IDE(s):

Qt Creator 3.1.1

Project type:

Console application

C++ standard:

C++98

Compiler(s):

G++ 4.9.2

Libraries used:

STL: GNU ISO C++ Library, version 4.9.2

Qt project file: ./CppCalculateSqrt/CppCalculateSqrt.pro


include(../../ConsoleApplication.pri) #Or use the code below

# QT += core

# QT += gui

# greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

# CONFIG   += console

# CONFIG   -= app_bundle

# TEMPLATE = app

# CONFIG(release, debug|release) {

#   DEFINES += NDEBUG NTRACE_BILDERBIKKEL

# }

# QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++

# unix {

#   QMAKE_CXXFLAGS += -Werror

# }



include(../../Libraries/Boost.pri) #Or use the code below

# win32 {

#   INCLUDEPATH += \

#     ../../Libraries/boost_1_54_0

# }



SOURCES += main.cpp

./CppCalculateSqrt/main.cpp


#include <cmath>

#include <iomanip>

#include <iostream>



#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#include <boost/units/unit.hpp>

#include <boost/units/systems/si.hpp>

#include <boost/units/io.hpp>

#pragma GCC diagnostic pop





template <class T> T CalculateSqrt(const T& x);



///Simple approximation algorithm to calculate the square root,

///instead of using std::sqrt

template <>

double CalculateSqrt(const double& x)

{

  assert(x >= 0.0);

  if (x == 0.0) return 0.0;

  const int precision = 6;

  double y = 0.5*x;

  for (int i=0; i!=precision; ++i)

  {

    y+=(x/y);

    y*=0.5;

  }

  return y;

}



template <>

boost::units::quantity<boost::units::si::length> CalculateSqrt(

  const boost::units::quantity<boost::units::si::length>& x)

{

  return CalculateSqrt(x.value()) * boost::units::si::meter;

}







int main()

{

  std::cout << std::setprecision(35) << std::fixed;

  for (int i=0; i!=10; ++i)

  {

    const double x = static_cast<double>(i);

    std::cout << std::sqrt(x) << '\t' << CalculateSqrt(x) << '\n';

  }

  std::cout << '\n';

  for (int i=0; i!=10; ++i)

  {

    const boost::units::quantity<boost::units::si::length> x

      = static_cast<double>(i) * boost::units::si::meter;

    std::cout << std::sqrt(x.value()) << '\t' << CalculateSqrt(x) << '\n';

  }

}



/* Screen output:



0.00000000000000000000000000000000000   0.00000000000000000000000000000000000

1.00000000000000000000000000000000000   1.00000000000000000000000000000000000

1.41421356237309514547462185873882845   1.41421356237309514547462185873882845

1.73205080756887719317660412343684584   1.73205080756887719317660412343684584

2.00000000000000000000000000000000000   2.00000000000000000000000000000000000

2.23606797749978980505147774238139391   2.23606797749978980505147774238139391

2.44948974278317788133563226438127458   2.44948974278317788133563226438127458

2.64575131106459071617109657381661236   2.64575131106459071617109657381661236

2.82842712474619029094924371747765690   2.82842712474619029094924371747765690

3.00000000000000000000000000000000000   3.00000000000000000000000000000000000



0.00000000000000000000000000000000000   0.00000000000000000000000000000000000 m

1.00000000000000000000000000000000000   1.00000000000000000000000000000000000 m

1.41421356237309514547462185873882845   1.41421356237309514547462185873882845 m

1.73205080756887719317660412343684584   1.73205080756887719317660412343684584 m

2.00000000000000000000000000000000000   2.00000000000000000000000000000000000 m

2.23606797749978980505147774238139391   2.23606797749978980505147774238139391 m

2.44948974278317788133563226438127458   2.44948974278317788133563226438127458 m

2.64575131106459071617109657381661236   2.64575131106459071617109657381661236 m

2.82842712474619029094924371747765690   2.82842712474619029094924371747765690 m

3.00000000000000000000000000000000000   3.00000000000000000000000000000000000 m

Press <RETURN> to close this window...



*/

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(C++) CalculateSqrt

Technical facts

Qt project file: ./CppCalculateSqrt/CppCalculateSqrt.pro

./CppCalculateSqrt/main.cpp