fix floating-point computation in create_cluster_tree

Author: PierreMarchand20

CHANGELOG.md

@@ -41,6 +41,7 @@ All notable changes to this project will be documented in this file.
 - Fix bug in task-based HLU, PR#81 thanks to @ABoisneault.
 - Fix `number_of_generated_coefficient` computation.
 - Fix overflow in `get_distributed_hmatrix_information`.
+- Fix float-point computation issue in `create_cluster_tree`.
 
 ## [1.0.2] - 2026-02-14
 

include/htool/clustering/tree_builder/tree_builder.hpp

@@ -125,7 +125,12 @@ Cluster<T> ClusterTreeBuilder<T>::create_cluster_tree(int number_of_points, int
     } else {
         partition_type = Simple;
         if (size_partition >= number_of_children) {
-            depth_of_partition                    = static_cast<int>(floor(log(size_partition) / log(number_of_children)));
+            depth_of_partition = 0;
+            int tmp            = size_partition;
+            while (tmp >= number_of_children) {
+                tmp /= number_of_children;
+                depth_of_partition++;
+            }
             number_of_children_on_partition_level = number_of_children;
             if (size_partition != std::pow(number_of_children, depth_of_partition)) {
                 Logger::get_instance().log(LogLevel::WARNING, "The given size for the partition is not a power of the number of children in the cluster tree.");