distributions.cpp

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#include "distributions.h"
#include "insertShape.h"
#include <float.h>
#include <cmath>
#include <cstdlib>
#include <iostream>

/*
    The Distributions class was created specifically for 
    easy use of a customized exponential distribution 
    which allows users to specify the min and max limit 
    which the distribution function can return. 
    (exponentail distribution function truncated on both sides)
    
    The Distributions class was created keeping in mind 
    other distributions may be needed later. 

    Currently, exponential distribution is the only 
    distribution contained in the Distributions class.
*/

/***********************************************************/
/******************* Constructor ***************************/
Distributions::Distributions(std::mt19937_64 &_generator, std::vector<Shape> &shapeFamilies) {
    // Maximum double less than 1.0
    // (0.9999... before being recognized as 1)
    maxInput = getMaxDecimalForDouble();

    // Init exponential dist class
    expDist = new ExpDist(maxInput, _generator);

    // User input check and exp dist init 
    checkDistributionUserInput(shapeFamilies);
}

/***********************************************************/
/******************  Get Max Digits  ***********************/
int Distributions::getMaxDigits() {
    // log(2) / log (10) = 0.301029995663982
    return std::floor(DBL_MANT_DIG * 0.30102999566398) + 2;
}


/***********************************************************/
/************** Get Max Number Less Than 1.0  **************/
double Distributions::getMaxDecimalForDouble() {
    char temp[32];
    int length = getMaxDigits();
 
    temp[0] = '.';
    for (int i = 1; i < length; i++) {
        temp[i] = '9';
    }
    temp[length] = '\0'; // Add NULL char

    double returnVal = atof(temp);
    return returnVal;
}

/********************************************************************************/
/*** Initialize and  Error Check On User Input for Exponendtail Distribution  ***/
void Distributions::checkDistributionUserInput(std::vector<Shape> &shapeFamilies) {

    for (unsigned int i = 0; i < shapeFamilies.size(); i++) {
        switch (shapeFamilies[i].distributionType) {
            double input;

            case 1: // Lognormal

                break;

            case 2: // Truncated power-law

                break;

            case 3: // Exponential

                // Check exponential minimum value        
                input = expDist->computeInput(shapeFamilies[i].expMin, shapeFamilies[i].expLambda);
                if (input >= 1) {
                    std::cout << "\n\nWARNING: The defined minimum value, " << shapeFamilies[i].expMin
                              << ", for " << shapeType(shapeFamilies[i])
                              << " family " << getFamilyNumber(i, shapeFamilies[i].shapeFamily)
                              << " will not be able to be produced by the exponential distribution due to precision issues.\n";

                    std::cout << "The minimum value is too large. The largest value the distribution can "
                              << "produce with current parameters is "
                              << expDist->getMaxValue(shapeFamilies[i].expLambda) << "\n";

                    std::cout << "Please adjust the minimum value, or the mean, and try again.\n";
                    exit(1);
                }
                else {
                    shapeFamilies[i].minDistInput = input;
                }

                // Check exponential maximum value
                input = expDist->computeInput(shapeFamilies[i].expMax, shapeFamilies[i].expLambda);

                if (input >= 1) {
                    std::cout << "\n\nWARNING: The defined maximum value, " << shapeFamilies[i].expMax << ", for "
                              << shapeType(shapeFamilies[i]) << " family " << getFamilyNumber(i, shapeFamilies[i].shapeFamily)
                              << " will not be able to be produced by the exponential distribution due to precision issues.\n";

                    std::cout << "The largest value the distribution can produce with current parameters is "
                              << expDist->getMaxValue(shapeFamilies[i].expLambda) << "\n";

                    std::cout << "Press Enter to automatically adjust this exponential maximum value to "
                              << expDist->getMaxValue(shapeFamilies[i].expLambda) << " (q to Quit)\n";

                    // Prompt user to press enter to continue or q to quit
                    quitOrContinue();
                    double max  = expDist->getMaxValue(shapeFamilies[i].expLambda);
                    //check that the max is not less or equal to the min
                    if (max <= shapeFamilies[i].expMin) {
                        std::cout << "ERROR: The maximum exponetnial distribution radius possible for " << shapeType(shapeFamilies[i])
                                  << " family " << getFamilyNumber(i, shapeFamilies[i].shapeFamily)
                                  << " is less than or equal to the minimum exponential distribution radius.\n";
                        std::cout << "Please adjust the exponential distribution parameters in " << shapeType(shapeFamilies[i])
                                  << " family " << getFamilyNumber(i, shapeFamilies[i].shapeFamily) << "\n";
                        exit(1);
                    }
                }

                shapeFamilies[i].maxDistInput = input;

                break; // End case 3
        }
    }
}


/******************************************************/
/*************** Quit or Continue *********************/
void Distributions::quitOrContinue() {
    char str[256];

    do {
        // Get input
        std::cin.get(str, 256);
        std::cin.clear();
        std::cin.ignore();

        if ((str[0] == 'q' && str[1] == '\0') || (str[0] == 'Q' && str[1] == '\0')) {
            exit(1);
        }

        if (str[0] != 0) {
            std::cout << "Invalid input.\n";
        }

    } while (str[0] != 0);
}

/******************************************************/
Distributions::~Distributions() {
    delete expDist;
}