Deck 18: Cross-Cutting Trip-Ups

What's the single most common Points-related mistake?

Forgetting .compute() before treating it like a pandas DataFrame.

True or false: setting a transformation on an element immediately changes its stored pixel/point data.

False → it's metadata only, applied at render/query/transform() time.

What should you check before moving or deleting an original .zarr folder you cropped data from?

Whether the cropped object is "self-contained" (is_self_contained())

Can a coordinate transformation be specified directly between two elements?

No → only ever between an element and a coordinate system.

If you carefully style shapes in napari before saving them to SpatialData, is that styling preserved?

No → only the geometry is saved, not fill color, line width, etc.

Is it safe to assume datashader is always the faster rendering backend?

No → for points, current benchmarks show no clear benefit, and for shapes/polygons the crossover point is in the low hundreds of objects, not universal.