Replace list(zip(...)) with np.stack(..., axis=1) (#3768)

roym899 · web-flow · commit 4d8fcad62c1e · 2023-10-10T14:42:42.000+02:00
#3625 was already mostly addressed by #3620, but used `list(zip(...))` instead of `np.stack`. The latter seems like the better approach, since it avoids splitting up the array into lots of smaller arrays. So this is replacing the `list(zip(...))` pattern with `np.stack(..., axis=1)`. Closes #3625.
diff --git a/docs/content/getting-started/logging-python.md b/docs/content/getting-started/logging-python.md
@@ -158,7 +158,7 @@ We can represent the scaffolding using a batch of 3D line strips:
 ```python
 rr.log(
     "dna/structure/scaffolding",
-    rr.LineStrips3D(list(zip(points1, points2)), colors=[128, 128, 128])
+    rr.LineStrips3D(np.stack(points1, points2, axis=1), colors=[128, 128, 128])
 )
 ```
 
diff --git a/examples/python/dna/main.py b/examples/python/dna/main.py
@@ -60,7 +60,7 @@ def log_data() -> None:
     rr.log("helix/structure/left", rr.Points3D(points1, colors=colors1, radii=0.08))
     rr.log("helix/structure/right", rr.Points3D(points2, colors=colors2, radii=0.08))
 
-    rr.log("helix/structure/scaffolding", rr.LineStrips3D(list(zip(points1, points2)), colors=[128, 128, 128]))
+    rr.log("helix/structure/scaffolding", rr.LineStrips3D(np.stack((points1, points2), axis=1), colors=[128, 128, 128]))
 
     time_offsets = np.random.rand(NUM_POINTS)
     for i in range(400):
diff --git a/rerun_py/rerun_sdk/rerun_demo/data.py b/rerun_py/rerun_sdk/rerun_demo/data.py
@@ -81,7 +81,7 @@ def build_rect_pyramid(count=20, width=100, height=100):
     y = np.linspace(0, height, count)
     widths = np.linspace(float(width) / count, width, count)
     heights = 0.8 * np.ones(count) * height / count
-    rects = np.array(list(zip(x, y, widths, heights)))
+    rects = np.stack((x, y, widths, heights), axis=1)
     colors = turbo_colormap_data[np.linspace(0, len(turbo_colormap_data) - 1, count, dtype=int)]
 
     return RectPyramid(rects, RectFormat.XCYCWH, colors)

Original file line number	Diff line number	Diff line change
`@@ -158,7 +158,7 @@ We can represent the scaffolding using a batch of 3D line strips:`
`158`	`158`	```python
`159`	`159`	`rr.log(`
`160`	`160`	`"dna/structure/scaffolding",`
`161`		`- rr.LineStrips3D(list(zip(points1, points2)), colors=[128, 128, 128])`
	`161`	`+ rr.LineStrips3D(np.stack(points1, points2, axis=1), colors=[128, 128, 128])`
`162`	`162`	`)`
`163`	`163`	```
`164`	`164`