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TxqSciNumberFormat.h

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//---------------------------------------------------------------------------
//
// File:    TxqSciNumberFormat.h
//
// Purpose:  a class for producing a string from a double
//
// Version: $Id: TxqSciNumberFormat.h,v 1.6 2001/10/12 18:51:23 kgl Exp $
//
// This class name comes from Ronan's Jplot package.
//
//---------------------------------------------------------------------------

#ifndef TXQ_SCINUMBERFORMAT_H
#define TXQ_SCINUMBERFORMAT_H

// system includes
// #include <cstdio>
#include <vector>

// Txq includes
#include "TxqSciNumberPattern.h"
#include "TxqFloatingDecimal.h"

// Qt includes
#include <qstring.h>

class TxqSciNumberFormat
{

public:

    TxqSciNumberFormat(TxqSciNumberPattern p)
    {
       pattern = p;
    }

   ~TxqSciNumberFormat(){}

    QString format(double d) {

    //
    // local copies of FloatingDecimal values
    // and needed variables
    //
       int nDigits           = pattern.numPreDecimal +
                                pattern.numPostDecimal;
                                // pattern.numExp;
                                
       TxqFloatingDecimal fd(d, nDigits);

       bool isNegative       = fd.isNegative();
       bool isExceptional    = fd.isExceptional();
       int decExponent       = fd.getExponent();
           std::vector<QString> digits;
    //
    // local copies of pattern variables
    //
       int numPreDecDigits  = pattern.numPreDecimal;
       int numPostDecDigits = pattern.numPostDecimal;
       int numExpDigits     = pattern.numExp;

       int expAdjust = numPreDecDigits-1;

    // 
    // get the number of digits into the digit array
    //
           int i;
       for (i=0; i<nDigits; i++)  {
           QString tmpDigit;
           digits.push_back(tmpDigit.sprintf("%d",fd.getDigit()));
       }
          
    // formatted value will go in result char[]
    // make pletty of room for number of digits plus special characters
       QString result;

    // i keeps count of where we are in result array
    // negative value, push a minus sign on
       if (isNegative)
       {
           result = '-';
           i = 1;
       }

     // NaN or infinite - treat as speical case
       if (isExceptional)
       {
          // cerr << "TxqSciNumberFormat::Number is too big or too small " << endl;
       }

       else
       {
           int exp = decExponent;
           int c;
           for (c = 0; c < numPreDecDigits; c++)
           {
              if (c < nDigits) result += digits[c] ;
              else result += '0';
              // result += (c < nDigits) ? digits[c] : '0';
           }

           // adjust exponential
           // exp -= numPreDecDigits;
           int sign = fd.getExponentSign();
           if (expAdjust != 0) {
              exp -= expAdjust;
              int esign = 0;
              if ( (exp < 1.0) && (exp!= 0) ) esign = -1;
              if (sign != esign) sign = esign;
           }

           // insert decimal point
           result += '.';
           i++;

           // copy format.post bytes from digits[format.pre] to result[i]
           for (c = 0; c < numPostDecDigits; c++)
           {
              int srcIndex = numPreDecDigits + c;
              i++;
              if (srcIndex < nDigits) result += digits[srcIndex];
              else  result += '0';
              // result += (srcIndex < nDigits) ? digits[srcIndex] : '0';
              // result += (srcIndex < nDigits) ? digits[srcIndex] : '0';
           }

           // insert exponential sign
           result += 'E';
           i++;

           // insert +/- sign for exponential
           // result += (fd.getExponentSign() < 0) ? '-' : '+';
           // result += (fd.getExponentSign() == -1 ) ? '-' : '+';
           result += (sign == -1 ) ? '-' : '+';
           i++;

           // force exponent to be positive
           exp = abs(exp);

           // exponent has 1, 2, or 3, digits
           if (exp <= 9)
           {
              if (numExpDigits >= 3) {
                  result += '0';
                  i++;
              }
              if (numExpDigits >= 2) {
                  result += '0';
                  i++;
              }
              result += (char)(exp + '0');
              i++;
           }
           else if (exp <= 99)
           {
              if (numExpDigits >= 3) {
                  result += '0';
                  i++;
              }
              result  += (char)(exp/10 + '0' );
              i++;
              result  += (char)(exp%10 + '0' );
              i++;
           }
           else
           {
              result += (char)(exp/100 + '0');
              i++;
              exp %= 100;
              result += (char)(exp/10 + '0');
              i++;
              result += (char)(exp%10 + '0' );
              i++;
           }
       }

       return result;

    }

private:

    TxqSciNumberPattern pattern;
};
#endif

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