QGIS Scipy Clustering
This plugin implements point custering in scipy and add a label integer field to the feature class for the clustered data. Both hierarchical and k-means clustering are implemented.
This is a Procesing plugin (actuvated automatically) and can be found in the processing toolbox.
Please note that there are memory limitations in hierarchical clustering - the space required to create the clusters is O(n^2), which means that larger datasets will run out of memory fast. As such there is a plugin setting in the Processing options that sets the upper limit of points to process, by default set at 10,000. K-means is much more forgiving in terms of memory, so the limit is not enforced in those algorithms.
All credit to the scipy team for the original implementation of the cluster algorithms.
Jones E, Oliphant E, Peterson P, et al. SciPy: Open Source Scientific Tools for Python, 2001-, http://www.scipy.org/ [Online].
seagull by Lane F. Kinkade from the Noun Project https://thenounproject.com/term/seagull/166081