tcql / astro-turf

CLI for applying turf functions to streaming data

astro-turf

allows you to run turf functions on streaming line delimited json

specifying methods

use --method

astro --method=bboxPolygon

accepted method names are any turf module

methods that take additional parameters

If you want to call a method that requires other parameters, for example, buffer, use --args. $ is a standin for the streaming line input. Note that the value of --args must be quoted if it contains strings or objects.

cat polygons.json | astro --method=buffer --args='$,10,"miles"'

splitting feature collections

If the input contains feature collections, they can be split so that each feature is processed separately using --splitCollections. This is useful when piping the input from another task that outputs feature collections (like turf-random does)

echo '[-122.8,37.2,-121.7,37.9]' | \
  astro --method=random --args='"point",1000,{"bbox":$}' | \
  astro --splitCollections --method=buffer --args='$,100,"miles"'

parallel processing (experimental)

Processing can be done in parallel, using one worker per CPU core via the -P flag. Unless you are doing especially heavy operations (such as complex unions, large merges, etc) this is not advised, because the cost of sending messages between processes usually outweighs the benefit of processing in parallel.