pddp2means: Init commit

On branch pddp2means
Changes to be committed:
	new file:   README
	new file:   data/40k.csv
	new file:   src/pddp_2means.c
	new file:   src/pddp_2means.h

pddp2means/README

+/***********************************************************************************************
+*cr                                       University of Patras, Greece
+*cr                                   Copyright (c) 2015 University of Patras
+*cr                                           All rights reserved
+*cr
+*cr                                           Developed by: HPClab 
+*cr                               Computer Engineering and Informatics Department
+*cr                                           University of Patras
+*cr
+***********************************************************************************************/
+
+Usage: 
+```
+#./pddp_2means <input_file> <output_file> <clusters>
+./pddp_2means ../data/40k.csv pddp_2means.out 19
+```

pddp2means/src/pddp_2means.h

+#include <omp.h>
+#include <math.h>
+#include <float.h>
+#include <stdio.h>
+#include <alloca.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+
+/*
+ * Each line of the input data file must be less than this value.
+ */
+#define BUFFER_SIZE			(1024*1024)
+
+/*
+ * Define the alignment in bytes that is required for optimal vectorization
+ */
+#define ALIGNMENT			64
+
+#define TWO_MEANS_TOLERANCE		1.0e-4
+#define TWO_MEANS_MAX_ITERATIONS	50
+#define POWER_ITERATION_TOLERANCE	1.0e-8
+#define POWER_ITERATION_MAX_ITERATIONS	5000
+
+//#define DEBUG	1
+
+#if defined(DEBUG)
+#define DBG(format, ...)	printf(format, __VA_ARGS__)
+#else
+#define DBG(format, ...)
+#endif
+
+struct node {
+	unsigned long	*indices;	/* Number of data_points in the cluster			(data_points) */
+	double		*centroid;	/* The mean vector for the cluster			(attributes)  */
+	struct node	*leftchild;
+	struct node	*rightchild;
+	struct node	*sibling;
+	double		scat;		/* Total scatter value for the cluster		*/
+	unsigned long	num_of_indices;	/* Number of elements in vector 'indices'	*/
+	unsigned long	keep_in_tree;
+	unsigned long	is_splittable;
+};
+
+typedef struct node	Node;
+
+/*******************************************************************************/
+
+#pragma offload_attribute (push,target(mic))
+
+void print_elapsed_time(struct timeval start, struct timeval end, char *msg);
+Node *allocate_node(unsigned long data_points);
+void init_node(Node *node, Node *sibling, double *M, unsigned long data_points, unsigned long *indices, double *centroid, unsigned long attributes, unsigned long padded_attributes, unsigned long threads);
+void process_node(Node *node, double *M, unsigned long attributes, unsigned long padded_attributes, unsigned long current_level, unsigned long max_level);
+double calc_scatter(Node *node, double *M, unsigned long attributes, unsigned long padded_attributes, unsigned long threads);
+void vector_2_means(Node *node, double *M, double *v, unsigned long attributes, unsigned long padded_attributes, unsigned long **l_indices, unsigned long **r_indices, double **l_centroid, double **r_centroid, unsigned long *l_data_points, unsigned long *r_data_points, unsigned long threads);
+void power_iteration(Node *node, double *M, unsigned long attributes, unsigned long padded_attributes, double **v, unsigned long threads);
+void reset_nodes_to_keep(Node *node);
+void keep_all_nodes(Node *node);
+void find_max_scatter_value(Node *node, Node **K);
+unsigned long find_nodes_to_keep(Node *node, unsigned long clusters);
+double max_cluster_diameter(Node *node, double *M, unsigned long attributes, unsigned long padded_attributes);
+void find_all_leaves(Node *node, Node **cluster_nodes, unsigned long *cluster_num);
+void find_all_splittable_leaves(Node *node, Node **cluster_nodes, unsigned long *cluster_num);
+double min_cluster_distance(Node *node, unsigned long clusters, unsigned long attributes);
+void post_order_traversal(Node *node, unsigned long *indices, unsigned long *cluster);
+void assign_cluster_numbers(Node *node, unsigned long *result, unsigned long data_points);
+
+#pragma offload_attribute (pop)
+
+void write_results(unsigned long *result, unsigned long data_points, char *filename);
+
+/*******************************************************************************/
+