From 317e27d2287fbabb336d4b7d4d127d557d012811 Mon Sep 17 00:00:00 2001
From: Boris Stefanovic <owldev@bluewin.ch>
Date: Wed, 8 Jun 2022 00:52:07 +0200
Subject: [PATCH] ADD: check random centers are not already in set
---
src/cluster.c | 4 +--
src/kmeans.c | 87 +++++++++++++++++++++++++++++++++++++++++++++------
src/kmeans.h | 10 +++---
3 files changed, 86 insertions(+), 15 deletions(-)
diff --git a/src/cluster.c b/src/cluster.c
index f1b2c27..bfb7149 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -45,8 +45,8 @@ void cluster_add_point_fpt(cluster_fpt_t* cluster, vector_fpt_t* point) {
void cluster_update_center_int(cluster_int_t* cluster) {
vector_destroy_int(cluster->center);
- cluster->center = vector_create_int(cluster->points->head->point->dim);
list_points_node_int_t* node = cluster->points->head;
+ cluster->center = vector_create_int(node->point->dim);
while (node != NULL) {
vector_add_inplace_int(cluster->center, *(node->point));
node = node->next;
@@ -56,8 +56,8 @@ void cluster_update_center_int(cluster_int_t* cluster) {
void cluster_update_center_fpt(cluster_fpt_t* cluster) {
vector_destroy_fpt(cluster->center);
- cluster->center = vector_create_fpt(cluster->points->head->point->dim);
list_points_node_fpt_t* node = cluster->points->head;
+ cluster->center = vector_create_fpt(node->point->dim);
while (node != NULL) {
vector_add_inplace_fpt(cluster->center, *(node->point));
node = node->next;
diff --git a/src/kmeans.c b/src/kmeans.c
index 7ee9705..a8b6df1 100644
--- a/src/kmeans.c
+++ b/src/kmeans.c
@@ -2,13 +2,14 @@
cluster_int_t** kmeans_init_clusters_int(const vector_int_t** points, const size_t point_count, const size_t nclusters) {
+ // check args and init
if (NULL == points || point_count < 2 || nclusters < 2) return NULL;
cluster_int_t** clusters = calloc(nclusters, sizeof(vector_int_t*));
if (NULL == clusters) return NULL;
// determine range in which we are working
vector_int_t* min = vector_copy_int(points[0]);
vector_int_t* max = vector_copy_int(points[0]);
- for (size_t i = 0; i < point_count; ++i) {
+ for (size_t i = 1; i < point_count; ++i) {
for (size_t p = 0; p < max->dim; ++p) {
const int_t value = points[i]->data[p];
if (value < min->data[p]) min->data[p] = value;
@@ -18,21 +19,89 @@ cluster_int_t** kmeans_init_clusters_int(const vector_int_t** points, const size
// until we have enough centers
for (size_t i = 0; i < nclusters; ++i) {
vector_int_t* center = vector_create_int(max->dim);
- for (size_t p = 0; p < center->dim; ++p) {
- center->data[p] = rand_int_range(min->data[p], max->data[p]);
+ bool valid = false;
+ while (!valid) {
+ // initialise center values randomly, within the "polygon" of our set of points
+ for (size_t p = 0; p < center->dim; ++p) {
+ center->data[p] = rand_int_range(min->data[p], max->data[p] + 1);
+ }
+ // check center is not already in clusters, although probability is extremely low...
+ for (size_t k = 0; k < i; ++k) {
+ vector_int_t* kth_center = clusters[k]->center;
+ bool neq = false;
+ for (size_t p = 0; p < center->dim; ++p) {
+ if (center->data[p] != kth_center->data[p]) {
+ neq = true;
+ break;
+ }
+ }
+ if (neq) {
+ valid = true;
+ }
+ }
+ }
+ clusters[i]->center = center;
+ }
+ return clusters;
+}
+
+cluster_fpt_t** kmeans_init_clusters_fpt(const vector_fpt_t** points, const size_t point_count, const size_t nclusters) {
+ // check args and init
+ if (NULL == points || point_count < 2 || nclusters < 2) return NULL;
+ cluster_fpt_t** clusters = calloc(nclusters, sizeof(vector_fpt_t*));
+ if (NULL == clusters) return NULL;
+ // determine range in which we are working
+ vector_fpt_t* min = vector_copy_fpt(points[0]);
+ vector_fpt_t* max = vector_copy_fpt(points[0]);
+ for (size_t i = 1; i < point_count; ++i) {
+ for (size_t p = 0; p < max->dim; ++p) {
+ const fpt_t value = points[i]->data[p];
+ if (value < min->data[p]) min->data[p] = value;
+ if (value > max->data[p]) max->data[p] = value;
+ }
+ }
+ // until we have enough centers
+ for (size_t i = 0; i < nclusters; ++i) {
+ vector_fpt_t* center = vector_create_fpt(max->dim);
+ bool valid = false;
+ while (!valid) {
+ // initialise center values randomly, within the "polygon" of our set of points
+ for (size_t p = 0; p < center->dim; ++p) {
+ center->data[p] = rand_double_range(min->data[p], max->data[p]);
+ }
+ // check center is not already in clusters, although probability is extremely low...
+ for (size_t k = 0; k < i; ++k) {
+ vector_fpt_t* kth_center = clusters[k]->center;
+ bool neq = false;
+ for (size_t p = 0; p < center->dim; ++p) {
+ if (center->data[p] != kth_center->data[p]) {
+ neq = true;
+ break;
+ }
+ }
+ if (neq) {
+ valid = true;
+ }
+ }
}
- // TODO: maybe check center is not already in clusters, although probability is extremely low...
clusters[i]->center = center;
}
return clusters;
}
-void kmeans_int(
- vector_int_t** points, const size_t point_count,
- cluster_int_t** clusters, const size_t nb_clusters,
- fpt_t (* distance_function)(const vector_int_t*, const vector_int_t*)) {
+void kmeans_int(vector_int_t** points, const size_t point_count, cluster_int_t** clusters, const size_t nb_clusters, fpt_t (* distance_function)(const vector_int_t*, const vector_int_t*)) {
//TODO
bool changed = true;
- while (changed) {}
+ while (changed) {
+ changed = false;
+ }
+}
+
+void kmeans_fpt(vector_fpt_t** points, const size_t point_count, cluster_fpt_t** clusters, const size_t nb_clusters, fpt_t (* distance_function)(const vector_fpt_t*, const vector_fpt_t*)) {
+ //TODO
+ bool changed = true;
+ while (changed) {
+ changed = false;
+ }
}
diff --git a/src/kmeans.h b/src/kmeans.h
index 34a83c8..3d29bc6 100644
--- a/src/kmeans.h
+++ b/src/kmeans.h
@@ -7,10 +7,12 @@
cluster_int_t** kmeans_init_clusters_int(const vector_int_t** points, const size_t point_count, const size_t nclusters);
-void kmeans_int(
- vector_int_t** points, const size_t point_count,
- cluster_int_t** clusters, const size_t nb_clusters,
- fpt_t (* distance_function)(const vector_int_t*, const vector_int_t*));
+cluster_fpt_t** kmeans_init_clusters_fpt(const vector_fpt_t** points, const size_t point_count, const size_t nclusters);
+
+
+void kmeans_int(vector_int_t** points, const size_t point_count, cluster_int_t** clusters, const size_t nb_clusters, fpt_t (* distance_function)(const vector_int_t*, const vector_int_t*));
+
+void kmeans_fpt(vector_fpt_t** points, const size_t point_count, cluster_fpt_t** clusters, const size_t nb_clusters, fpt_t (* distance_function)(const vector_fpt_t*, const vector_fpt_t*));
#endif //PROG_KMEANS_KMEANS_H
--
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