Me@2: /*
Me@2:  *  Copyright 2010 OpenSourceStewardshipFoundation.org
Me@2:  *  Licensed under GNU General Public License version 2
Me@2:  *
Me@2:  * Author: seanhalle@yahoo.com
Me@2:  *
Me@2:  */
Me@4: #include <stdio.h>
Me@2: #include "Histogram.h"
Me@2: 
Me@2: /*This Histogram Abstract Data Type has a number of bins, the starting
Me@2:  * value, and the width of each bin, as a float, all chosen at creation.
Me@2:  *
Me@2:  *One creates a Histogram instance using the makeFloatHistogram function, then
Me@2:  * updates it with the addToFloatHist function, and prints it out with the
Me@2:  * printFloatHist function.
Me@2:  *
Me@2:  *Note, the bin width is an integer, so the end of the range is adjusted
Me@2:  * accordingly.  Use the bin-width to calculate the bin boundaries.
Me@2:  */
Me@2: 
Me@2: 
Me@2: FloatHist *
Me@2: makeFloatHistogram( int32 numBins, float32 startOfRange, float32 binWidth )
Me@2:  {
Me@2:    FloatHist *hist;
Me@2:    int i;
Me@2: 
Me@3:    hist = VMS__malloc( sizeof(FloatHist) );
Me@3:    hist->bins = VMS__malloc( numBins * sizeof(int) );
Me@2: 
Me@2:    hist->numBins      = numBins;
Me@2:    hist->binWidth     = binWidth;
Me@2:    hist->endOfRange   = startOfRange + hist->binWidth * numBins;
Me@2:    hist->startOfRange = startOfRange;
Me@2: 
Me@2:    for( i = 0; i < hist->numBins; i++ )
Me@2:     {
Me@2:       hist->bins[ i ] = 0;
Me@2:     }
Me@2: 
Me@2:    return hist;
Me@2:  }
Me@2: 
Me@2: 
Me@2: /*All values higher than or equal to a bin's start value and less than the
Me@2:  * start value of the next higher are put into that bin.
Me@2:  */
Me@2: void
Me@2: addToFloatHist( float32 value, FloatHist *hist )
Me@2:  {
Me@2:    int binIdx;
Me@2: 
Me@2:    if( value < hist->startOfRange )
Me@2:     { binIdx = 0;
Me@2:     }
Me@2:    else if( value > hist->endOfRange )
Me@2:     { binIdx = hist->numBins - 1;
Me@2:     }
Me@2:    else
Me@2:     {    //truncate so bin holds:   binStartVal =< values < nextBinStartVal
Me@2:       binIdx = (int32)((value - hist->startOfRange) / hist->binWidth);
Me@2:     }
Me@2: 
Me@2:    hist->bins[ binIdx ] += 1;
Me@2:  }
Me@2: 
Me@2: void
Me@2: printFloatHist( FloatHist *hist )
Me@2:  {
Me@2:    int32   binIdx, i, numBars, maxHeight;
Me@2:    float32 barValue, binStart, binEnd;
Me@2: 
Me@2:    maxHeight = 0;
Me@2:    for( i = 0; i < hist->numBins; i++ )
Me@2:     {
Me@2:       if( maxHeight < hist->bins[ i ] ) maxHeight = hist->bins[ i ];
Me@2:     }
Me@2:    barValue = maxHeight / 40;  //40 spaces across page for tallest bin
Me@2: 
Me@2:    printf("histogram: \n");
Me@2:    if( barValue == 0 ) printf("error printing histogram\n");
Me@2:    for( binIdx = 0; binIdx < hist->numBins; binIdx++ )
Me@2:     {
Me@2:       binStart = hist->startOfRange + hist->binWidth * binIdx;
Me@2:       binEnd = binStart + hist->binWidth;
Me@2:       printf("bin range: %3f - %3f", binStart, binEnd );
Me@2: 
Me@2:       numBars = hist->bins[ binIdx ] / barValue;
Me@2:          //print one bin, height of bar is num dashes across page
Me@2:       for( i = 0; i < numBars; i++ )
Me@2:        {
Me@2:          printf("-");
Me@2:        }
Me@2:       printf("\n");
Me@2:     }
Me@2:  }
Me@2: 
Me@3: 
Me@3: void
Me@4: freeFloatHist( FloatHist *hist )
Me@3:  {
Me@3:    VMS__free( hist->bins );
Me@3:    VMS__free( hist );
Me@3:  }