Commands

The fio-planet packages adds three commands to the fio CLI from the Fiona package: filter, map, and reduce.

Note

fio-planet's filter command shadows, or overrides, Fiona's own fio filter.

fio-filter

For each feature read from stdin, fio-filter evaluates a pipeline of one or more steps described using methods from the Shapely library in Lisp-like expressions. If the pipeline expression evaluates to True, the feature passes through the filter. Otherwise the feature does not pass.

For example, this pipeline expression

$ fio cat zip+https://s3.amazonaws.com/fiona-testing/coutwildrnp.zip \
| fio filter '< (distance g (Point -109.0 38.5)) 100'

lets through all features that are less than 100 meters from the given point and filters out all other features.

fio-map

For each feature read from stdin, fio-map applies a transformation pipeline and writes a copy of the feature, containing the modified geometry, to stdout. For example, polygonal features can be roughly "cleaned" by using a buffer g 0 pipeline.

$ fio cat zip+https://s3.amazonaws.com/fiona-testing/coutwildrnp.zip \
| fio map 'buffer g 0'

fio-reduce

Given a sequence of GeoJSON features (RS-delimited or not) on stdin this prints a single value using a provided transformation pipeline. The set of geometries of the input features in the context of these expressions is named "c".

For example, the pipeline expression

$ fio cat zip+https://s3.amazonaws.com/fiona-testing/coutwildrnp.zip \
| fio reduce 'unary_union c'

dissolves the geometries of input features.