Using numpy arrays as images

[tjtuom]

I get an exception when using numpy arrays as images with the Image component. I get my image from opencv imread. I guess the problem is that it is trying to compare the arrays when deciding whether to render or not.

Traceback (most recent call last): File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/base_components.py", line 255, in _mouse_release self._mouse_clicked(ev) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/base_components.py", line 260, in _mouse_clicked self._on_click(ev) File "/Users/tjtuom/Code/takomo/annotate/annote_edifice.py", line 56, in <lambda> *[Label(text=f, on_click=lambda ev, f=f: self.on_click(f)) for f in self.props.files] File "/Users/tjtuom/Code/takomo/annotate/annote_edifice.py", line 52, in on_click self.props.on_image_selected(f) File "/Users/tjtuom/Code/takomo/annotate/annote_edifice.py", line 117, in on_image_selected self.current_image = path.join(IMAGE_DIR, f) File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/contextlib.py", line 124, in __exit__ next(self.gen) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/_component.py", line 373, in render_changes self.set_state(**changes_context) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/_component.py", line 408, in set_state raise e File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/_component.py", line 404, in set_state self._controller._request_rerender([self], kwargs) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/app.py", line 178, in _request_rerender render_result = self._render_engine._request_rerender(components) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 431, in _request_rerender commands = self._gen_commands(widget_trees, render_context) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 413, in _gen_commands commands.extend(widget_tree.gen_qt_commands(render_context)) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 75, in gen_qt_commands rendered = child.gen_qt_commands(render_context) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 75, in gen_qt_commands rendered = child.gen_qt_commands(render_context) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 75, in gen_qt_commands rendered = child.gen_qt_commands(render_context) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 82, in gen_qt_commands new_props = PropsDict({k: v for k, v in self.component.props._items if k not in old_props or _try_neq(old_props[k], v)}) File "/Users/tjtuom/Code/takomo/experiments/venv/lib/python3.9/site-packages/edifice/engine.py", line 82, in <dictcomp> new_props = PropsDict({k: v for k, v in self.component.props._items if k not in old_props or _try_neq(old_props[k], v)}) ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

[tjtuom]

So the problem is the or in new_props = PropsDict({k: v for k, v in self.component.props._items if k not in old_props or _try_neq(old_props[k], v)}). When comparing numpy arrays_try_neg returns another array instead of a boolean which causes the or operator to produce a value error.

>>> import numpy as np
>>> a = np.array([1, 2, 3])
>>> b = np.array([1,2, 3])

>>> a != b
array([False, False, False])

>>> a or b
Traceback (most recent call last):
File "", line 1, in
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

I solved it with:
def _try_neq(a, b): try: if isinstance(a, np.ndarray) and isinstance(b, np.ndarray): return not np.array_equal(a, b) else: return a != b except: return a is not b

[fding]

Thanks for the fix! I'll patch it in when I get back from vacation.