BoxPlot

The BoxPlot is a plot operator that computes a box plot over

• a selection of numerical columns of a single vector dataset, or
• multiple raster datasets.

Thereby, the operator considers all data in the given query rectangle.

The boxes of the plot span the 1st and 3rd quartile and highlight the median. The whiskers indicate the minimum and maximum values of the corresponding attribute or raster.

Errors

The operator returns an error in the following cases.

• Vector data: The attribute for one of the given columnNames is not numeric.
• Vector data: The attribute for one of the given columnNames does not exist.
• Raster data: The length of the columnNames parameter does not match the number of input rasters.

Notes

If your dataset contains infinite or NAN values, they are ignored for the computation. Moreover, if your dataset contains more than 10.000values (which is likely for rasters), the median and quartiles are estimated using the P^2 algorithm described in:

R. Jain and I. Chlamtac, The P^2 algorithm for dynamic calculation of quantiles and histograms without storing observations, Communications of the ACM, Volume 28 (October), Number 10, 1985, p. 1076-1085. https://www.cse.wustl.edu/~jain/papers/ftp/psqr.pdf

Parameters

Name	Type	Description	Examples
columnNames	array	## Vector Data The names of the attributes to generate boxes for. ## Raster Data Optional: An alias for each input source. The operator will automatically name the boxes Raster-1, Raster-2, … if this parameter is empty. If aliases are given, the number of aliases must match the number of input rasters. Otherwise an error is returned.	["temperature","humidity"] ["A","B"]

Sources

Name	Type	Description
source	MultipleRasterOrSingleVectorOperator	It is either a set of RasterOperator or a single VectorOperator

Examples

{
    "type": "BoxPlot",
    "params": {
        "columnNames": ["x", "y"]
    },
    "sources": {
        "source": {
            "type": "OgrSource",
            "params": {
                "data": "ndvi"
            }
        }
    }
}

{
    "type": "BoxPlot",
    "params": {
        "columnNames": ["A", "B"]
    },
    "sources": {
        "source": [
            {
                "type": "GdalSource",
                "params": {
                    "data": "ndvi"
                }
            },
            {
                "type": "GdalSource",
                "params": {
                    "data": "temperature"
                }
            }
        ]
    }
}