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Zonal Statistics

Description

Calculates some statistics values for pixels of input raster inside certain zones, defined as polygon layer.

Following values calculated for each zone:

  • minimum
  • maximum
  • sum
  • count
  • mean
  • standard deviation
  • number of unique values
  • range
  • variance

Parameters

Raster layer [raster]
Raster to analyze.
Raster band [number]

Number of raster band to analyze.

Default: 1

Vector layer containing zones [vector: polygon]
Layer with zones boundaries.
Output column prefix [string]

Prefix for output fields.

Default: _

Load whole raster in memory [boolean]

Determines if raster band will be loaded in memory (True) or readed by chunks (False). Useful only when disk IO or raster scanning inefficiencies are your limiting factor.

Default: True

Outputs

Output layer [vector]
The resulting layer. Basically this is same layer as zones layer with new columns containing statistics added.

Console usage

processing.runalg('qgis:zonalstatistics', input_raster, raster_band, input_vector, column_prefix, global_extent, output_layer)

See also