Added example with 1MM entries and a 50 dimension key

Author: sdeming

examples/test3.c

@@ -0,0 +1,103 @@
+/*! gcc -std=c89 -pedantic -Wall -g -o test2 test2.c libkdtree.a -lm */
+/* Extended test program, contributed by David Underhill */
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <time.h>
+#include "kdtree.h"
+
+#define DEF_NUM_PTS 1000000
+
+/* returns the distance squared between two dims-dimensional double arrays */
+static double dist_sq( double *a1, double *a2, int dims );
+
+/* get a random double between -10 and 10 */
+static double rd( void );
+
+/* generate an array of random values for dimensions */
+static void generate_dims(int num, double *nums);
+
+int main(int argc, char **argv) {
+  int i, num_pts = DEF_NUM_PTS;
+  void *ptree;
+  char *data, *pch;
+  struct kdres *presults;
+  double pos[50], dist;
+  double pt[50];
+  double nums[50];
+  double radius = 40;
+
+  for (i=0; i<50; ++i) {
+    pt[i] = rd();
+  }
+
+  if(!(data = malloc(num_pts))) {
+    perror("malloc failed");
+    return 1;
+  }
+
+  srand( time(0) );
+  
+  /* create a k-d tree for 50-dimensional points */
+  ptree = kd_create(50);
+  
+  /* add some random nodes to the tree (assert nodes are successfully inserted) */
+  printf("Seeding %d entries of %d dimensions...\n", num_pts, 50);
+  for( i=0; i<num_pts; ++i ) {
+    data[i] = 'a' + i;
+    generate_dims(50, nums);
+    assert( 0 == kd_insert( ptree, nums, &data[i] ) );
+  }
+
+  /* find points closest to the origin and within distance radius */
+  printf("Searching in radius of %1.02f...\n", radius);
+  presults = kd_nearest_range( ptree, pt, radius );
+
+  /* print out all the points found in results */
+  printf( "found %d results:\n", kd_res_size(presults) );
+
+  while( !kd_res_end( presults ) ) {
+    /* get the data and position of the current result item */
+    pch = (char*)kd_res_item( presults, pos );
+    
+    /* compute the distance of the current result from the pt */
+    dist = sqrt( dist_sq( pt, pos, 50 ) );
+
+    /* print out the retrieved data */
+    //printf( "node at (%.3f, %.3f, %.3f) is %.3f away and has data=%c\n", 
+	//    pos[0], pos[1], pos[2], dist, *pch );
+
+    /* go to the next entry */
+    kd_res_next( presults );
+  }
+
+  /* free our tree, results set, and other allocated memory */
+  free( data );
+  kd_res_free( presults );
+  kd_free( ptree );
+
+  return 0;
+}
+
+static double dist_sq( double *a1, double *a2, int dims ) {
+  double dist_sq = 0, diff;
+  while( --dims >= 0 ) {
+    diff = (a1[dims] - a2[dims]);
+    dist_sq += diff*diff;
+  }
+  return dist_sq;
+}
+
+static double rd( void ) {
+  return (double)rand()/RAND_MAX * 20.0 - 10.0;
+}
+
+static void generate_dims(int num, double *nums)
+{
+  int i = 0;
+  for (i=0; i<50; ++i) {
+    nums[i] = rd();
+  }
+}