Operations and joins

GeoDataFrames supplies spatial tables, geometry-column metadata, and I/O. It does not define a second geometry-operation system. Geometry values implement GeoInterface, and GeometryOps.jl provides predicates and geometry operations for those values. Use the geometry-operations guide for a table workflow and the GeometryOps documentation for the supported operation set and its assumptions.

Spatial joins combine that geometry work with tabular join semantics. FlexiJoins.jl composes a GeometryOps predicate into a join condition and returns the matching rows. GeoDataFrames has no GeoPandas-style sjoin method; use FlexiJoins and choose the join shape that fits the rows to retain. The spatial-joins guide shows that composition and its candidate filtering.

This separation keeps table handling, geometric logic, and join policy independent. Before operations or joins that compare coordinates, make both tables use the appropriate CRS; see reproject data.