Raster¶

Description¶

Calculate hypsometric curves for features of polygon layer and save them as CSV file for further processing.

Parameters¶

DEM to analyze [raster]

DEM to use for calculating altitudes.

Boundary layer [vector: polygon]

Polygonal vector layer with boundaries of areas used to calculate hypsometric curves.

Step [number]

Distance between curves.

Default: 100.0

Use % of area instead of absolute value [boolean]

Write area percentage to “Area” field of the CSV file instead of absolute area value.

Default: False

Outputs¶

Output directory [directory]

Directory where output will be saved. For each feature from input vector layer CSV file with area and altitude values will be created.

File name consists of prefix hystogram_ followed by layer name and feature ID.

Console usage¶

processing.runalg('qgis:hypsometriccurves', input_dem, boundary_layer, step, use_percentage, output_directory)

See also¶

Description¶

Calculates basic statistics of the raster layer.

Parameters¶

Input layer [raster]

Raster to analyze.

Outputs¶

Statistics [html]

Analysis results in HTML format.

Minimum value [number]

Minimum cell value.

Maximum value [number]

Maximum cell value.

Sum [number]

Sum of all cells values.

Mean value [number]

Mean cell value.

valid cells count [number]

Number of cells with data.

No-data cells count [number]

Number of NODATA cells.

Standard deviation [number]

Standard deviation of cells values.

Console usage¶

processing.runalg('qgis:rasterlayerstatistics', input, output_html_file)

See also¶

Description¶

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

Following values calculated for each zone:

• minimum

• maksimum

• 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¶