Source code for nngt.core.spatial_graph

# -*- coding: utf-8 -*-
# SPDX-FileCopyrightText: 2015-2023 Tanguy Fardet
# SPDX-License-Identifier: GPL-3.0-or-later
# nngt/core/

""" SpatialGraph class for spatial graph generation and management """

import numpy as np

import nngt
from nngt.lib import InvalidArgument, nonstring_container

from .connections import Connections
from .graph import Graph

# ------------ #
# SpatialGraph #
# ------------ #

[docs]class SpatialGraph(Graph): """ The detailed class that inherits from :class:`~nngt.Graph` and implements additional properties to describe spatial graphs (i.e. graph where the structure is embedded in space. """ #-------------------------------------------------------------------------# # Class properties __num_graphs = 0 __max_id = 0 #-------------------------------------------------------------------------# # Constructor, destructor, attributes def __init__(self, nodes=0, name="SpatialGraph", weighted=True, directed=True, copy_graph=None, shape=None, positions=None, **kwargs): ''' Initialize SpatialClass instance. .. versionchanged: 2.4 Move `from_graph` to `copy_graph` to reflect changes in Graph. Parameters ---------- nodes : int, optional (default: 0) Number of nodes in the graph. name : string, optional (default: "Graph") The name of this :class:`Graph` instance. weighted : bool, optional (default: True) Whether the graph edges have weight properties. directed : bool, optional (default: True) Whether the graph is directed or undirected. shape : :class:`~nngt.geometry.Shape`, optional (default: None) Shape of the neurons' environment (None leads to a square of side 1 cm) positions : :class:`numpy.array` (N, 2), optional (default: None) Positions of the neurons; if not specified and `nodes` is not 0, then neurons will be reparted at random inside the :class:`~nngt.geometry.Shape` object of the instance. **kwargs : keyword arguments for :class:`~nngt.Graph` or :class:`~nngt.geometry.Shape` if no shape was given. Returns ------- self : :class:`~nggt.SpatialGraph` ''' self.__id = self.__class__.__max_id self.__class__.__num_graphs += 1 self.__class__.__max_id += 1 self._shape = None self._pos = None super().__init__(nodes, name=name, weighted=weighted, directed=directed, copy_graph=copy_graph, **kwargs) self._init_spatial_properties(shape, positions, **kwargs) def __del__(self): if hasattr(self, '_shape'): if self._shape is not None: self._shape._parent = None self._shape = None super().__del__() self.__class__.__num_graphs -= 1 @property def shape(self): ''' The environment's spatial structure. ''' return self._shape #-------------------------------------------------------------------------# # Init tool def _init_spatial_properties(self, shape, positions=None, **kwargs): ''' Create the positions of the neurons from the graph `shape` attribute and computes the connections distances. ''' positions = None if positions is None else np.asarray(positions) self.new_edge_attribute('distance', 'double') if positions is not None and len(positions) != self.node_nb(): raise InvalidArgument("Wrong number of neurons in `positions`.") if shape is not None: shape.set_parent(self) self._shape = shape else: if positions is None or not np.any(positions): if 'height' in kwargs and 'width' in kwargs: self._shape = nngt.geometry.Shape.rectangle( kwargs['height'], kwargs['width'], parent=self) elif 'radius' in kwargs: self._shape = nngt.geometry.Shape.disk( kwargs['radius'], parent=self) elif 'radii' in kwargs: self._shape = nngt.geometry.Shape.ellipse( kwargs['radii'], parent=self) elif 'polygon' in kwargs: self._shape = nngt.geometry.Shape.from_polygon( kwargs['polygon'], min_x=kwargs.get('min_x', -5000.), max_x=kwargs.get('max_x', 5000.), unit=kwargs.get('unit', 'um'), parent=self) else: raise RuntimeError('SpatialGraph needs a `shape` or ' 'keywords arguments to build one, or ' 'at least `positions` so it can create ' 'a square containing them') else: minx, maxx = np.min(positions[:, 0]), np.max(positions[:, 0]) miny, maxy = np.min(positions[:, 1]), np.max(positions[:, 1]) height, width = 1.01*(maxy - miny), 1.01*(maxx - minx) centroid = (0.5*(maxx + minx), 0.5*(maxy + miny)) self._shape = nngt.geometry.Shape.rectangle( height, width, centroid=centroid, parent=self) b_rnd_pos = True if not self.node_nb() or positions is None else False self._pos = self._shape.seed_neurons() if b_rnd_pos else positions Connections.distances(self) #-------------------------------------------------------------------------# # Positions
[docs] def get_positions(self, nodes=None): ''' Returns a copy of the nodes' positions as a (N, 2) array. Parameters ---------- nodes : int or array-like, optional (default: all nodes) List of the nodes for which the position should be returned. ''' if nodes is not None: if nonstring_container(nodes): # numpy slicing does not work with everything nodes = np.asarray(nodes) return np.array(self._pos[nodes]) else: return self._pos[nodes] return np.array(self._pos)
[docs] def set_positions(self, positions, nodes=None): ''' Set the nodes' positions as a (N, 2) array. Parameters ---------- positions : array-like List of positions, of shape (N, 2). nodes : int or array-like, optional (default: all nodes) List of the nodes for which the position should be set. ''' if nodes is not None: self._pos[nodes] = positions else: if len(positions) != self.node_nb(): raise ValueError("One position per node is required.") self._pos = np.array(positions)