Created
March 11, 2020 12:04
-
-
Save apaszke/fef347c22472c12f0cfb9da17e8241eb to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import time | |
import numpy as np | |
segments = np.ones((100000, 12, 3)) | |
M = np.ones((4, 4)) | |
def _proj_transform_vectors(vecs, M): | |
is_masked = isinstance(vecs, np.ma.MaskedArray) | |
if is_masked: | |
mask = vecs.mask | |
vecs_pad = np.empty((vecs.shape[0] + 1,) + vecs.shape[1:]) | |
vecs_pad[:-1] = vecs | |
vecs_pad[-1] = 1 | |
product = np.dot(M, vecs_pad) | |
result = product[:3] / product[3] | |
if is_masked: | |
return np.ma.array(result, mask=mask) | |
else: | |
return result | |
def baseline(): | |
num_faces, num_face_vertices, _ = segments.shape | |
vecs = segments.reshape(-1, 3).T | |
_, _, pzs = pvecs = _proj_transform_vectors(vecs, M) | |
del vecs # To avoid typos with pvecs | |
psegments = pvecs.T.reshape(segments.shape) | |
assert psegments.shape == (num_faces, num_face_vertices, 3) | |
epilogue(psegments) | |
def _proj_transform_vectors_new(vecs, M): | |
is_masked = isinstance(vecs, np.ma.MaskedArray) | |
if is_masked: | |
mask = vecs.mask | |
vecs_pad = np.empty(vecs.shape[:-1] + (vecs.shape[-1] + 1,)) | |
vecs_pad[..., :-1] = vecs | |
vecs_pad[..., -1] = 1 | |
product = vecs_pad @ M.T | |
result = product[..., :3] / product[..., 3:] | |
if is_masked: | |
return np.ma.array(result, mask=mask) | |
else: | |
return result | |
def new(): | |
psegments = _proj_transform_vectors_new(segments, M) | |
epilogue(psegments) | |
def epilogue(psegments): | |
face_z = np.mean(psegments[..., 2], axis=-1) | |
if isinstance(face_z, np.ma.MaskedArray): | |
# NOTE: Unpacking .data is safe here, because every face has to contain | |
# a valid vertex. | |
face_z = face_z.data | |
face_order = np.argsort(face_z, axis=-1)[::-1] | |
np.min(psegments[..., 2]) | |
from timeit import timeit | |
N = 25 | |
new_t = timeit(new, number=N) / N * 1000 | |
baseline_t = timeit(baseline, number=N) / N * 1000 | |
print('New:\t\t{: .2f}ms'.format(new_t)) | |
print('Baseline:\t{: .2f}ms'.format(baseline_t)) | |
print('Diff:\t\t{: .2f}ms'.format(baseline_t - new_t)) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment