Ignore:
Timestamp:
06/30/20 00:34:59 (2 weeks ago)
Author:
Maciej Komosinski
Message:

Added functions to properly round floating point values to specified precision

File:
1 edited

Legend:

Unmodified
Added
Removed
  • cpp/common/nonstd_math.cpp

    r896 r970  
    11// This file is a part of Framsticks SDK.  http://www.framsticks.com/
    2 // Copyright (C) 1999-2019  Maciej Komosinski and Szymon Ulatowski.
     2// Copyright (C) 1999-2020  Maciej Komosinski and Szymon Ulatowski.
    33// See LICENSE.txt for details.
    44
    55#include "nonstd_math.h"
     6#ifdef USE_PRINTFLOAT_DRAGON4
     7#include <PrintFloat/PrintFloat.h>
     8#else
     9#include <sstream>
     10#endif
    611
    712RandomGenerator &rndGetInstance()
     
    1116}
    1217
     18int doubleToString(double x, int precision, char *buffer, int bufferlen)
     19{
     20#ifdef USE_PRINTFLOAT_DRAGON4
     21        return PrintFloat64(buffer, bufferlen, x,
     22                ((x < -1e17) || (x > 1e17) || ((x < 1e-4) && (x > -1e-4) && (x != 0.0)))
     23                ? PrintFloatFormat_Scientific : PrintFloatFormat_Positional,
     24                precision); //http://www.ryanjuckett.com/programming/printing-floating-point-numbers/
     25#else
     26        char format[10];
     27        sprintf(format, "%%.%dg", precision < 0 ? 17 : precision); //https://stackoverflow.com/questions/16839658/printf-width-specifier-to-maintain-precision-of-floating-point-value
     28        return sprintf(buffer, format, x);
     29#endif
     30}
     31
     32
     33double round(const double x, const int precision)
     34{
     35#ifdef USE_PRINTFLOAT_DRAGON4
     36        char buffer[30];
     37        doubleToString(x, precision, buffer, 30);
     38        double rounded = strtod(buffer, NULL);
     39#else
     40        std::stringstream ss;
     41        ss << std::fixed;
     42        ss.precision(precision); // set the number of places after decimal
     43        ss << x;
     44        double rounded = stod(ss.str());
     45#endif
     46        //printf("%d  %20g \t %20g\n", precision, x, rounded); //for debugging
     47        return rounded;
     48}
    1349
    1450
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