NeuroMorpho Get Persistence Vector

Get the persistence vector (Topological Morphology Descriptor, TMD) for a NeuroMorpho neuron by its numeric neuron_id. Returns a 100-coefficient shape signature plus a scaling_factor, used as a feature vector for ML clustering and classification of dendritic/neuronal morphology. Get a neuron_id from NeuroMorpho_search_neurons or NeuroMorpho_get_neuron. Example: neuron_id=1 returns scaling_factor 244.928 and a 100-element coefficients array (3276.79, 3356.89, ...).