filters.expressionstats

The filters.expressionstats stage computes counting summary for a single dimension for a given set of expressions. This is useful for summarizing dimensions that are conveniently countable.

Default Embedded Stage

This stage is enabled by default

Streamable Stage

This stage supports streaming operations

Warning

The dimension selected should be an integer, not floating point dimension. Additionally, a dimension with lots of unique values is likely to generate a many entries in the map. This may not be what you want.

Example

{
    "pipeline": [{
        "bounds": "([-10190065.06156413, -10189065.06156413], [5109498.61041016, 5110498.61041016])",
        "filename": "https://s3-us-west-2.amazonaws.com/usgs-lidar-public/IA_Eastern_1_2019/ept.json",
        "requests": "16",
        "type": "readers.ept"
    },
    {
        "type": "filters.stats"
    },
    {
        "type": "filters.expressionstats",
        "dimension":"Classification",
        "expressions":["Withheld == 1", "Keypoint == 1", "Overlap == 1", "Synthetic == 1"]
    },
    {
        "filename": "hobu-office.laz",
        "type": "writers.copc"
    }]
}

Output

{
  "dimension": "Classification",
  "statistic":
  [
    {
      "expression": "(Keypoint==1.000000)",
      "position": 0
    },
    {
      "expression": "(Overlap==1.000000)",
      "position": 1
    },
    {
      "bins":
      [
        {
          "count": 154,
          "value": 1
        }
      ],
      "expression": "(Synthetic==1.000000)",
      "position": 2
    },
    {
      "bins":
      [
        {
          "count": 313615,
          "value": 1
        },
        {
          "count": 6847,
          "value": 7
        },
        {
          "count": 4425,
          "value": 18
        }
      ],
      "expression": "(Withheld==1.000000)",
      "position": 3
    }
  ]
}

Options

dimension

The dimension on which to apply the expressions.

expressions

An array of expressions to apply.

where

An expression that limits points passed to a filter. Points that don’t pass the expression skip the stage but are available to subsequent stages in a pipeline. [Default: no filtering]

where_merge

A strategy for merging points skipped by a where option when running in standard mode. If true, the skipped points are added to the first point view returned by the skipped filter. If false, skipped points are placed in their own point view. If auto, skipped points are merged into the returned point view provided that only one point view is returned and it has the same point count as it did when the filter was run. [Default: auto]