stats.h

#ifndef _STATS_LIB_
#define _STATS_LIB_

#include "linear_congruential_random_generator.h"
#include <limits.h>
#include <math.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#define STATS_SUCCESS 0
#define STATS_NOT_ENOUGH_POINTS 1
#define STATS_VARIANCE_IS_NULL 2

#ifndef EPISLON
#define EPSILON 0.01
#endif

#ifndef REAL_NUMBER
#define REAL_NUMBER float
#endif

#ifndef MAX_REAL_NUMBER
#define MAX_REAL_NUMBER __FLT_MAX__
#endif

#ifndef MIN_REAL_NUMBER
#define MIN_REAL_NUMBER (-(MAX_REAL_NUMBER)-1)
#endif

#ifndef INTEGER
#define INTEGER unsigned int
#endif

typedef REAL_NUMBER real_number;
typedef INTEGER vec_size;

#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
  real_number max;
  real_number min;
  real_number mean;
  real_number absAverageDeviation;
  real_number standardDeviation;
  real_number variance;
  real_number skewness;
  real_number kurtosis; // The formula for the excess kurtosis was used
} DataSummary;

// Simple analysis of data
real_number maxOfArray(real_number* array, vec_size size);
real_number minOfArray(real_number* array, vec_size size);
real_number mean(real_number* array, vec_size size);
real_number variance(real_number* array, vec_size size);
real_number standardDeviation(real_number* array, vec_size size);
real_number absAverageDeviation(real_number* array, vec_size size);
real_number covariance(real_number* x, real_number* y, vec_size size);
vec_size analyzeData(real_number* array, vec_size size, DataSummary* moments);

// Fitting curves
void simpleLinearRegression(real_number* x, real_number* y, vec_size size,
                            real_number* a, real_number* b);

// Clustering
void kmeans(real_number* data, vec_size size, vec_size dimensions,
            vec_size nbClusters, real_number* centroids,
            vec_size* assignations);

#ifdef __cplusplus
}
#endif

#endif