Release 1.0.0

.github/workflows/publish.yml

@@ -112,4 +112,4 @@ jobs:
       # pinned to a commit, as this action can publish to PyPI; dependabot updates it
       - uses: pypa/gh-action-pypi-publish@dc37677b2e1c63e2034f94d8a5b11f265b73ba33  # v1.14.2
         with:
-          skip_existing: true
+          skip-existing: true

CHANGELOG.md

@@ -1,3 +1,203 @@
+1.0.0
+
+First 1.0 release: six years of production use since the first commit in 2020
+(including as a real dependency of both the Robotics Toolbox for Python and the
+Machine Vision Toolbox for Python), and this cycle's type hints, documentation,
+testing and bug-fixing pass, felt like the right point to commit to API
+stability.  This is the first release with a considered API, so it contains
+several deliberate breaking changes, listed first with how to migrate.
+
+Breaking changes (from 0.6.5)
+
+- The `UGraph`/`DGraph` constructor arguments are keyword-only.  0.6.5 accepted
+  and silently ignored a first positional argument, so `UGraph(6)` looked as
+  though it set a dimension but did nothing.  Now it is a `TypeError`: write
+  `UGraph(dim=6)`.
+- `degree` of a `DGraph` is the graph-theory degree, in plus out, so a
+  self-loop counts 2 and the degrees sum to twice the number of edges.  It used
+  to count only the edges leaving the vertex.  This changes `vertex.degree`,
+  `graph.degree()` and `graph.connectivity()`, and `graph.average_degree()` is
+  now 2E/N for both kinds of graph (it was E/N for a `DGraph`).  The previous
+  values are `vertex.out_degree`, `[v.out_degree for v in g]` and `g.ne / g.n`.
+  `laplacian()` is unchanged (out-degree minus adjacency).  Undirected graphs
+  are unchanged.
+- `graph.edges()` is a `list` in the order the edges were added.  It was the
+  graph's own `set`, with no defined order, although documented as a list.  Both
+  `graph.edges()` and `vertex.edges()` return a new list, so changing the result
+  cannot corrupt the graph.  Use `set(g.edges())` for set operations.
+- `Edge.v1` and `Edge.v2` are read-only, and so is `Vertex.label` (the graph
+  assigns it, and reading it now finds the components, where 0.6.5 gave `None`
+  until `nc` had been asked for).  Assigning an endpoint of an edge that was in a graph left the
+  graph inconsistent and the edge impossible to remove.  Give the vertices to
+  `Edge(v1, v2)` or connect the edge with `v1.connect(v2, edge=e)`.
+- Assigning `Vertex.name` renames it in the graph (so `g[new]` works) and
+  refuses a name already in use or `None`.
+- `add_vertex` raises `ValueError` for a name already used in the graph or a
+  vertex that already belongs to a graph, instead of silently shadowing it.
+  The default name `#N` is now the first free one, which could previously
+  repeat after a removal.
+- There is one vertex class, `Vertex`: a vertex has no direction of its own, the
+  graph it belongs to decides how an edge is recorded at its ends.  `UVertex`
+  and `DVertex` are deprecated names for it (below).  A vertex given to
+  `add_vertex` is no longer checked against the kind of graph, because there is
+  no kind to mismatch.  An override of the private `_attach`/`_detach` hooks
+  moves from a vertex subclass to a `UGraph`/`DGraph` subclass.
+- The abstract base class `PGraph` is now `Graph`, and `Graph` and `Vertex` are
+  exported from the package.  `Graph` is concrete: `Graph(directed=True)` is a
+  `DGraph` and `Graph()` a `UGraph`.
+- `Adjacency()` treats a non-zero diagonal element as a self-loop.
+- The `str` of an edge between vertices that are not in a graph shows `--`,
+  because there is no kind of graph to say whether it is directed.
+
+Deprecated (still work, with a `DeprecationWarning`)
+
+- `Laplacian()` is `laplacian()`: a capital initial denotes a class method that
+  builds a graph, like `Adjacency()` and `Dict()`.
+- `UVertex` and `DVertex` are `Vertex`.
+- `remove()` is `remove_vertex()` or `remove_edge()`, which say which they do.
+- The options of `plot()` are named for what they are: `vopt` is `vertex_opt`,
+  `eopt` is `edge_opt`, `text` is `labels` and `text_opt`, `colorcomponents` is
+  `color_components` and `force2d` is `force_2d`.  The positional order is
+  unchanged; giving both an old name and its new one is a `TypeError`.
+
+Added
+
+- `adjacent()` and `isadjacent()`, the graph-theory names, which have one
+  spelling.  `neighbours()`, `neighbors()` and `isneighbour()` from 0.6.5 are
+  kept as aliases, with `isneighbor()` added, and none of them warn.
+- `plot()` draws each edge once.  A directed graph has arrowheads, which
+  `arrow_opt` styles; edges that join the same pair of vertices, in either
+  direction, are arcs that bow apart; and a loop is a circle at its vertex.  In
+  0.6.5 a directed graph looked like an undirected one, parallel edges lay
+  exactly on top of each other and a loop was a line of no length.  `plot()`
+  does the same in 3D, and `highlight_edge()` follows an arc.
+- `Graph(directed=...)`, the `directed` property, and `vertex_class` and
+  `edge_class` constructor arguments, so that user subclasses of `Vertex` and
+  `Edge` are built by the graph.
+- `add_edge()` accepts an `Edge`, and `connect()` an `edge=` argument.
+- `edges_to(dest)` lists every edge from a vertex to another, so parallel edges
+  can be seen; `edgeto(dest)` is still the cheapest.
+- Directed vertices record their incoming edges: `predecessors()`,
+  `successors()`, `in_edges()`, `out_edges()`, `in_degree` and `out_degree`.
+- `export()` writes a graph as GraphViz dot, Mermaid, GraphML or ELK JSON, or as
+  an image rendered by the GraphViz executables, with the layout preserved.  The
+  `pgraph.exporters` module can be extended with `register_exporter`.
+- `validate()` reports every way in which a graph's records disagree, for tests
+  and debugging.
+- A graph can be pickled, and `copy()` works for graphs of any size.  `copy()`
+  raised `RecursionError` for a path of about 100 vertices.
+- `iscyclic()`, `remove_edge()`, `remove_vertex()` and the `dim` argument, which
+  declares that every embedded vertex has a coordinate of exactly that length.
+- Self-loops and parallel edges are supported throughout: adjacency, incidence,
+  degree and Laplacian matrices, and planning, which takes the cheapest of
+  parallel edges.
+- `SE2Metric(weight)` is the `"SE2"` metric with a weight on the angle, the
+  length that a radian is worth, so that position and orientation need not
+  count equally.  `"SE2"` is `SE2Metric()`, a weight of 1, so existing results
+  are unchanged.  It can be the metric or the heuristic of a graph and is
+  pickled with its weight.
+- Spatial queries on an embedded graph: `coordinates()` is the matrix of vertex
+  coordinates, a column per vertex; `within(box)` the vertices inside a box;
+  `near(point, radius)` those within a distance, nearest first; and
+  `subgraph(vertices)` the graph that a set of vertices induces, given as
+  vertices, names or a boolean mask, as a new graph that shares nothing with
+  the original.
+- `build_kdtree()` makes an optional k-d tree that `closest()` and `near()` use
+  for the built-in metrics, `SE2Metric` included.  It needs scipy, which is
+  imported only then and is not a dependency; and it is dropped whenever a
+  vertex is added or removed or a coordinate is assigned, so a stale one is
+  never used.
+- `validate()` also checks that coordinates are finite vectors of one length,
+  and with `embedded=True` that every vertex has one.
+
+Faster
+
+- `path_BFS`, `path_UCS` and `path_Astar` scaled badly: they searched lists with
+  `in`, and took the minimum of the whole frontier at every step.  Results and
+  the verbose output are identical.  On a random graph of 10,000 vertices and
+  30,000 edges, the mean of six random queries is 3 ms for breadth-first search
+  where 0.6.5 took 172 ms, 18 ms for uniform cost where it took 1,500 ms, and
+  13 ms for A* where it took 410 ms.
+- The components are found by a union-find over the edges, 4 ms for that graph
+  where 0.6.5 took 15 ms after a change.
+- Creating a vertex is faster: `Vertex(coord)` takes 0.35 µs where 0.6.5 took
+  1.5 µs, and `g.add_vertex(coord)` 1.7 µs where it took 2.2 µs.  Making the
+  coordinate with `np.r_` was most of the cost.
+- `import pgraph` takes 0.04 s where it took 0.6 s, and loads neither
+  matplotlib, spatialmath nor scipy: they are imported by the methods that plot
+  or build a spatial index.  A script that only builds graphs and plans paths no
+  longer pays for them.
+- `str(g)` separates thousands: `DGraph: 4,881 vertices, 8,392 edges, 14
+  components`.
+
+Fixed
+
+- `Dict()` always created undirected vertices, even for a `DGraph`; `connect()`
+  joined vertices of two different graphs, and now also validates the
+  endpoints of a supplied edge; `path_BFS`/`path_UCS`/`path_Astar` checked the
+  type of the start vertex twice and never the goal; and `distance()` and the
+  planners packed `nan` or `None` into their results for edges with no cost
+  instead of raising.
+- `nc` never returned for many directed graphs, the smallest a 4-cycle, and
+  neither did `component()`, `samecomponent()` or `plot()`, which ask for it.
+  Components of a directed graph are weakly connected, as they were meant to
+  be, and are numbered from 0 by the first vertex of each, for both kinds of
+  graph.  They are also no longer found again by every call once the graph has
+  changed.
+- `Edge.vertices()` raised `DeprecationWarning` as an exception; it now warns
+  and returns the endpoints, as `Edge.endpoints` does.
+- `incidence()` returned the wrong matrix for every graph with an edge: a loop
+  variable overwrote the vertex index, so edges were marked in the wrong rows,
+  and for a directed graph the vertex at the end of an edge was not marked at
+  all.  The columns follow `edges()`, which is now in the order the edges were
+  added, where 0.6.5 used the order of a set.
+- `remove()` crashed for every directed edge; `dotfile()` closed `sys.stdout`
+  when called with its default arguments; and several methods raised a bare
+  `AttributeError` or `TypeError` instead of a clear message for a vertex with
+  no coordinate or no graph.
+- `highlight_edge()`, and so `highlight_path()`, raised `AttributeError` for a
+  graph of three dimensions, because it drew a flat arrow in the 3D axes (0.6.5
+  drew lines), and `highlight_vertex()` put its marker at z = 0.  They draw in
+  the dimension of the axes, so a 3D graph plotted with `force_2d` is
+  highlighted in 2D.
+- Removing a vertex left its `_graph` pointing at the graph; renaming a vertex
+  left the name table stale; `g[x]` accepted any type.
+
+Known limitations
+
+- A graph whose metric is a `lambda` or a locally defined function can be copied
+  but not pickled; the built-in `"L1"`, `"L2"` and `"SE2"` and module-level
+  functions can be.
+
+Build, tests and documentation
+
+- Modern type hints and reST docstrings throughout, most with a runnable
+  example, and `mypy` is a CI check.
+- The documentation is organized by task, with the data structures explained and
+  a policy page on object lifecycle, and builds with `sphinx-pyrunblock` (which
+  replaces the unmaintained `sphinx-autorun`) and the matplotlib plot directive.
+- Python 3.9 to 3.14 are tested, the unused `scipy` dependency is dropped, and
+  PyPI publishing is automated through GitHub Releases and trusted publishing.
+  The workflow checks that the tag is the version in `pyproject.toml` and that
+  the tagged commit is on `main`, and installs the built wheel and runs a path
+  query before it uploads.
+- The documentation site is deployed with the GitHub Pages actions.  It had not
+  been updated since January 2025, because the CI pushed to a branch that Pages
+  no longer served.
+- `llms.txt` and `llms-full.txt` are published with the documentation, for AI
+  assistants: a short introduction with a quick start and common mistakes, and the
+  whole documentation as one text file.  `AGENTS.md` describes the source for
+  assistants that work on it.
+- Two notebooks in `examples/`: `roads.ipynb`, the Queensland example, and
+  `london.ipynb`, the road network of central London from OpenStreetMap as a
+  directed graph with one-way streets, planned through with A*.  There is also
+  a benchmark, `examples/benchmark.py`, and the README has its results and an
+  installation section.
+- The Queensland figure in the README shows the shortest route.  It had been
+  drawn with coordinates in metres and distances in kilometres, which made the
+  A* heuristic far too large, so the route it found, 1,759 km, was not the
+  shortest, 1,659 km.
+
 0.6.3
 
 - runs with Numpy2.x