Printing the first point

Exercise

This exercise uses PDAL to print information from the first point. Issue the following command in your OSGeo4W Shell.

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pdal info c:/Users/hobu/PDAL/exercises/info/interesting.las -p 0

Here’s a summary of what’s going on with that command invocation

  1. pdal: The pdal application :)
  2. info: We want to run info on the data. All commands are run by the pdal application.
  3. c:/Users/hobu/PDAL/exercises/info/interesting.las: The file we are running the command on. PDAL will be able to identify this file is an ASPRS LAS file from the extension, .las, but not every file type is easily identified. You can use a pipeline to override which reader PDAL will use to open the file.
  4. -p 0: -p corresponds to “print a point”, and 0 means to print the first one (computer people count from 0).
../../../_images/info-interesting-single-point.png

Notes

  1. PDAL uses JSON as the exchange format when printing information from info. JSON is a structured, human-readable format that is much simpler than its XML cousin.
  2. You can use the writers.text writer to output point attributes to CSV format for other processing.
  3. Output help information on the command line by issuing the --help option
  4. A common query with pdal info is --all, which will print all header, metadata, and statistics about a file.