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lrtest.cpp

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#include <assert.h>
#include <stdio.h>


#include <lregress.h>

using namespace std;




void init_data( vector<lregress::point> &data )
{
  static double X[] = { 55.77,
                        55.05,
                        54.27,
                        50.63,
                        49.86,

                        53.04,
                        51.33,
                        56.70,
                        55.07,
                        55.76,
               
                        54.40,
                        55.39,
                        57.49,
                        57.56,
                        58.76,
               
                        59.32,
                        57.21,
                        68.55,
                        65.04,
                        66.98,

                        63.69,
                        58.34 };

  static double Y[] = { 83.9,
                        66.4,
                        73.1,
                        66.7,
                        30.1,
               
                        36.2,
                        22.8,
                        66.5,
                        37.0,
                        58.0,

                        71.9,
                        83.1,
                        66.2,
                        72.3,
                        65.8,

                        123.5,
                        116.8,
                        160.1,
                        158.2,
                        152.2,

                        134.8,
                        87.3 };

  const size_t N = sizeof( X ) / sizeof( double );
  assert( N == (sizeof( Y ) / sizeof(double)) );

  size_t i;
  for (i = 0; i < N; i++) {
    lregress::point p( X[i], Y[i] );
    data.push_back( lregress::point( p ) );
  }
} // init_data


main()
{
  lregress lr;
  lregress::lineInfo info;

  vector<lregress::point> data;
  init_data( data );
  const size_t N = data.size();

  size_t i;
  // print out the points
  for (i = 0; i < N; i++) {
    // printf("%7.4f  %7.4f\n", data[i].x(), data[i].y() );
  }

  lr.lr( data, info );

  printf("b (slope) = %7.4f, a (intercept) = %7.4f\n", 
         info.slope(), 
         info.intercept()
         );
  printf(" slopeErr = %7.4f, stddev = %7.4f, corr = %7.4f\n",
         info.slopeErr(), info.stddev(), info.corr() );

  double yPrime;
  for (i = 0; i < N; i++) {
    yPrime = info.intercept() + (info.slope() * data[i].x());
    // printf("%7.4f  %7.4f\n", data[i].x(), yPrime );
  }

} // main

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