Possible issue with the sort call in get_shapely_from_sets_of_point function about dvh-analytics

[cutright]

Good catch. I think the decimal precision with a str call may be an issue in some cases though (i.e., trailing zeros)?

I think the simplest fix is to remove the sets_of_points_keys all together, and then sort all_z_values before the thickness calculation.

DVH-Analytics/dvha/tools/roi_formatter.py

Lines 253 to 261 in a168cf6

	sets_of_points_keys = list(sets_of_points)
	sets_of_points_keys.sort()
	all_z_values = [round(float(z), 2) for z in sets_of_points_keys]
	thicknesses = np.abs(np.diff(all_z_values))
	if len(thicknesses):
	thicknesses = np.append(thicknesses, np.min(thicknesses))
	else:
	thicknesses = np.array([MIN_SLICE_THICKNESS])

So remove lines 253-254 and change line 256 to this:

all_z_values = sorted([round(float(z), 2) for z in sets_of_points])

That said, the code feels sloppy to me, I'll probably clean it up a bit before pushing.

I only found one use of this thickness calculation in DVHA (surface area), and even there it only used the minimum value. Thankfully, this is a pretty minimal impact to DVHA users.

DVH-Analytics/dvha/tools/roi_geometry.py

Lines 221 to 228 in a168cf6

	shapely_roi = get_shapely_from_sets_of_points(sets_of_points)
	slice_count = len(shapely_roi["z"])
	area = 0.0
	polygon = shapely_roi["polygon"]
	z = shapely_roi["z"]
	thickness = min(shapely_roi["thickness"])

[cutright]

I only did one test import so far. All surface area calculations were identical except for my external ROI, which was way off.

I still think this can be done more concisely, but at least this avoids calling index based on type-converted values.

DVH-Analytics/dvha/tools/roi_formatter.py

Lines 253 to 275 in 29a5fa3

	roi_slices = {"z": [], "thickness": [], "polygon": []}
	sets_of_points_keys = list(sets_of_points) # lock in for-loop order
	z_values = list(map(float, sets_of_points_keys))
	# Get the thickness of each slice
	order = get_sorted_indices(z_values)
	thickness = np.abs(np.diff([z_values[i] for i in order]))
	if len(thickness):
	thickness = np.append(thickness, np.min(thickness))
	else:
	thickness = np.array([MIN_SLICE_THICKNESS])
	for i, z in enumerate(sets_of_points_keys):
	polygon = points_to_shapely_polygon(sets_of_points[z])
	if polygon:
	if tolerance is not None:
	polygon = polygon.simplify(tolerance, preserve_topology)
	roi_slices["z"].append(round(float(z), 2))
	roi_slices["thickness"].append(thickness[order[i]])
	roi_slices["polygon"].append(polygon)
	return roi_slices