Filter Library

Camera

Interface Physics

ToolStringPrefix.cpp

/*
 * ToolStringPrefix.cpp - format a number with a prefix.
 *
 * This file is part of the Camera Filter Library.
 * Computer Aided Measurement Environment for Realtime Atomic imaging (Camera)
 *
 * Copyright (C) 2004, Leiden Probe Microscopy.
 * Copyright (C) 2004, Universiteit Leiden.
 *
 * Authors: Martin J. Moene (original)
 *
 * $Id: ToolStringPrefix.cpp 213 2005-06-13 10:48:33Z moene $
 */

/*
 * Inspired on:
 * Simple CString Extension, By Marc Clifton
 * http://www.codeproject.com/string/cstringex.asp
 */

#include "stdafx.h"                     // for common (pre-compiled) headers
//#include <cfl/stdafx.h>                 // for common (pre-compiled) headers
#include "cfl/ToolStringPrefix.h"       // header file

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

#ifndef dim
   #define dim(a) (sizeof(a)/sizeof(*(a)))
#endif

/**
 * format number like 1.23 m.
 */

CStringPrefix::CStringPrefix( double value, const char* format /* = "%.3lg" */ )
{
   struct Table
   {
      double divisor; char* postfix;
   }
   table[] =
   {
      { 1e0  ,  "", },  // -
      { 1e-3 , "m", },  // milli
      { 1e+3 , "k", },  // kilo
      { 1e-6 , "u", },  // micro
      { 1e+6 , "M", },  // mega
      { 1e-9 , "n", },  // nano
      { 1e+9 , "G", },  // giga
      { 1e-12, "p", },  // pico
      { 1e+12, "T", },  // tera
      { 1e-15, "f", },  // femto
      { 1e+15, "P", },  // peta
      { 1e-18, "a", },  // atto
      { 1e+18, "E", },  // exa
      { 1e-21, "z", },  // zepto
      { 1e+21, "Z", },  // zeta
      { 1e-24, "y", },  // yocto
      { 1e+24, "Y", },  // yotta
   };

   CString number;
   number.Format( format, value );

   for ( Table* p = table; p < table + dim(table); ++p )
   {
      double x = value / p->divisor;

      if ( 1 <= x && x < 1000 )
      {
         number.Format( format, x );
         number += p->postfix;
         break;
      }
   }

   CString::operator=( number );
}

/*------------------------------------------------------------------------
 * UNIT TEST
 *------------------------------------------------------------------------
 *
 * Build: prompt>cl -GX -nologo -MT -DBUILD_UNITTEST StringPrefix.cpp
 */

#ifdef BUILD_UNITTEST

#include <iostream>                     // for std::cout

typedef const char* charCptr;           ///< convenience type

/**
 * test driver.
 */

int main()
{
   double list[] =
   {
      1.23456e-66,
      1.23456e-16,
      1.23456e-15,
      1.23456e-14,
      1.23456e-13,
      1.23456e-12,
      1.23456e-11,
      1.23456e-10,
      1.23456e-9,
      1.23456e-8,
      1.23456e-7,
      1.23456e-6,
      1.23456e-5,
      1.23456e-4,
      1.23456e-3,
      1.23456e-2,
      1.23456e-1,
      1.23456e-0,
      1.23456e+1,
      1.23456e+2,
      1.23456e+3,
      1.23456e+4,
      1.23456e+5,
      1.23456e+6,
      1.23456e+7,
      1.23456e+8,
      1.23456e+9,
      1.23456e+10,
      1.23456e+11,
      1.23456e+13,
      1.23456e+14,
      1.23456e+15,
      1.23456e+16,
      1.23456e+66,
   };

   for ( double* p = list; p < list + dim(list); ++p )
   {
      std::cout << *p << " : " << charCptr( CStringPrefix( *p, "%.3lg " ) ) << std::endl;
   }

   return 0;
}

#endif // BUILD_UNITTEST

/*
 * end of file
 */

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