cbasedann/preprocessing.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "preprocessing.h"

Feature *init_feature(float value)
{
    Feature *feature = (Feature*)malloc(sizeof(Feature));
    feature->value = value;
    feature->next_feature = NULL;

    return feature;
}

OneHotLabel *init_onehotlabel(float value)
{
    OneHotLabel *hot = (OneHotLabel*)malloc(sizeof(OneHotLabel));
    hot->value = value;
    hot->next = NULL;
    
    return hot;
}

Sample *init_sample()
{
    Sample *sample = (Sample*)malloc(sizeof(Sample));
    sample->first_feature = NULL;
    sample->first_hot = NULL;
    sample->next_sample = NULL;
    sample->t = TRAIN;

    return sample;
}

Data *init_data()
{
    Data *data = (Data*)malloc(sizeof(Data));
    data->first_sample = NULL;
    data->last_sample = NULL;
    data->size = 0;

    return data;
}

void add_sample_to_data(Data *data, Sample *sample)
{
    if(data->size == 0)
    {
        data->first_sample = sample;
        data->last_sample = sample;
        data->size++;
    }else
    {
        data->last_sample->next_sample = sample;
        data->last_sample = sample;
        data->size++;
    }
}

void destroy_sample(Sample *sample)
{
    Feature *temp1;
    while (sample->first_feature != NULL)
    {
        temp1 = sample->first_feature;
        sample->first_feature = sample->first_feature->next_feature;
        free(temp1);
    }
    OneHotLabel *temp2;
    while (sample->first_hot != NULL)
    {
        temp2 = sample->first_hot;
        sample->first_hot = sample->first_hot->next;
        free(temp2);
    }
    free(sample);
}

void destroy_data(Data *data)
{
    Sample *temp;
    while (data->first_sample != NULL)
    {
        temp = data->first_sample;
        data->first_sample = data->first_sample->next_sample;
        destroy_sample(temp);
    }
    free(data);
}

Data *csv_to_samples(char *path_to_csv, int n_features, char *features_separator, float train_percent, char *apply_onthot_encode, int n_classes)
{
    Data *data = init_data();
    FILE *file = fopen(path_to_csv, "r");
    char line[100], *dup;
    char *token;
    int features_count;
    if(file != NULL)
    {
        while(fgets(line, 100, file) != NULL)
        {
            Sample *current_sample = init_sample();
            Feature *temp_last_feature;
            features_count = n_features;
            dup = strtok(line, "\n"); //extracting line content without '\n'
            token = strtok(dup, features_separator);
            while(token != NULL)
            {
                if(features_count > 0) //first put features into current sample
                {
                    if(current_sample->first_feature == NULL)
                    {
                        current_sample->first_feature = init_feature( atof(token) );
                        temp_last_feature = current_sample->first_feature;
                    }else
                    {
                        temp_last_feature->next_feature = init_feature( atof(token) );
                        temp_last_feature = temp_last_feature->next_feature;
                    }
                    features_count--;
                }else //put label into current sample
                {
                    if(strcmp(apply_onthot_encode, "yes") == 0)
                    {
                        OneHotLabel *temp_last_hotlabel;
                        int i;
                        for(i=0 ; i<n_classes ; i++)
                        {
                            if(current_sample->first_hot == NULL)
                            {
                                current_sample->first_hot = init_onehotlabel(0.0);
                                temp_last_hotlabel = current_sample->first_hot;
                            }else
                            {
                                temp_last_hotlabel->next = init_onehotlabel(0.0);
                                temp_last_hotlabel = temp_last_hotlabel->next;
                            }
                            if((float)i == atof(token) )
                            {
                                temp_last_hotlabel->value = 1.0;
                            }
                        }
                    }else //when not applying one hot encoding, first_hot is directly equal to label
                    {
                        current_sample->first_hot = init_onehotlabel( atof(token) );
                    }
                }
                token = strtok(NULL, features_separator);
            }
            add_sample_to_data(data, current_sample);
        }
        Sample *current_sample = data->first_sample;
        int number_of_train_samples = ((float)data->size*train_percent) / 100.0; //calculate number of training samples based on provided percentage
        while(number_of_train_samples > 0)
        {
            current_sample = current_sample->next_sample;
            number_of_train_samples--;
        }
        while(current_sample != NULL)
        {
            current_sample->t = TEST;
            current_sample = current_sample->next_sample;
        }
        fclose(file);
    }else
    {
        printf("Unable to open the file\n");
        exit(-1);
    }
    return data;
}

void print_data(const Data *data)
{
    Sample *current_sample = data->first_sample;
    Feature *temp_feature;
    OneHotLabel *temp_hotlabel;
    printf("#=============================================#\n");
    if(current_sample != NULL)
    {
        int count = 1;
        while(current_sample != NULL)
        {
            printf("Sample %d : ", count);
            if(current_sample->t == TRAIN)
            {
                printf("TR\n");
            }else if(current_sample->t == TEST)
            {
                printf("TE\n");
            }else
            {
                printf("VA\n");
            }
            temp_feature = current_sample->first_feature;
            while(temp_feature != NULL)
            {
                printf("%f ", temp_feature->value);
                temp_feature = temp_feature->next_feature;
            }
            temp_hotlabel = current_sample->first_hot;
            printf(">##> ");
            while(temp_hotlabel != NULL)
            {
                printf("%f ", temp_hotlabel->value);
                temp_hotlabel = temp_hotlabel->next;
            }
            current_sample = current_sample->next_sample;
            if(current_sample != NULL)
            {
                printf("\n#---------------------------------------------#\n");
            }else
            {
                printf("\n");
            }
            count++;
        }
    }else
    {
        printf("Nothing to print : empty data !!!\n");
    }
    printf("#=============================================#\n");
}