| """ | |
| Internal debugging utilities, that are not expected to be used in the rest of | |
| the codebase. | |
| WARNING: Code in this module may change without prior notice! | |
| """ | |
| from io import StringIO | |
| from pathlib import Path | |
| import subprocess | |
| from matplotlib.transforms import TransformNode | |
| def graphviz_dump_transform(transform, dest, *, highlight=None): | |
| """ | |
| Generate a graphical representation of the transform tree for *transform* | |
| using the :program:`dot` program (which this function depends on). The | |
| output format (png, dot, etc.) is determined from the suffix of *dest*. | |
| Parameters | |
| ---------- | |
| transform : `~matplotlib.transform.Transform` | |
| The represented transform. | |
| dest : str | |
| Output filename. The extension must be one of the formats supported | |
| by :program:`dot`, e.g. png, svg, dot, ... | |
| (see https://www.graphviz.org/doc/info/output.html). | |
| highlight : list of `~matplotlib.transform.Transform` or None | |
| The transforms in the tree to be drawn in bold. | |
| If *None*, *transform* is highlighted. | |
| """ | |
| if highlight is None: | |
| highlight = [transform] | |
| seen = set() | |
| def recurse(root, buf): | |
| if id(root) in seen: | |
| return | |
| seen.add(id(root)) | |
| props = {} | |
| label = type(root).__name__ | |
| if root._invalid: | |
| label = f'[{label}]' | |
| if root in highlight: | |
| props['style'] = 'bold' | |
| props['shape'] = 'box' | |
| props['label'] = '"%s"' % label | |
| props = ' '.join(map('{0[0]}={0[1]}'.format, props.items())) | |
| buf.write(f'{id(root)} [{props}];\n') | |
| for key, val in vars(root).items(): | |
| if isinstance(val, TransformNode) and id(root) in val._parents: | |
| buf.write(f'"{id(root)}" -> "{id(val)}" ' | |
| f'[label="{key}", fontsize=10];\n') | |
| recurse(val, buf) | |
| buf = StringIO() | |
| buf.write('digraph G {\n') | |
| recurse(transform, buf) | |
| buf.write('}\n') | |
| subprocess.run( | |
| ['dot', '-T', Path(dest).suffix[1:], '-o', dest], | |
| input=buf.getvalue().encode('utf-8'), check=True) | |