:orphan: .. _algs_include: ******************* Algorithms Include ******************* .. only:: html .. contents:: :local: :depth: 1 Python Code Sample ================== .. The following section is used to load python code sample in algs help .. **algorithm_code_section** .. code-block:: python import processing processing.run("algorithm_id", {parameter_dictionary}) The *algorithm id* is displayed when you hover over the algorithm in the Processing Toolbox. The *parameter dictionary* provides the parameter NAMEs and values. See :ref:`processing_console` for details on how to run processing algorithms from the Python console. .. **end_algorithm_code_section** Output Types ============ .. The following describes the different options for algorithm outputs, with variants including the "skip output" and the "append" options Directory --------- .. **directory_output_types** * Save to a Temporary Directory * Save to Directory .. **end_directory_output_types** .. **directory_output_types_skip** * Skip Output * Save to a Temporary Directory * Save to Directory .. **end_directory_output_types_skip** File ---- .. **file_output_types** * Save to a Temporary File * Save to File… .. **end_file_output_types** .. **file_output_types_skip** * Skip Output * Save to a Temporary File * Save to File… .. **end_file_output_types_skip** Layer ----- .. **layer_output_types** * Create Temporary Layer (``TEMPORARY_OUTPUT``) * Save to File… * Save to Geopackage… * Save to Database Table… The file encoding can also be changed here. .. **end_layer_output_types** .. **layer_output_types_append** * Create Temporary Layer (``TEMPORARY_OUTPUT``) * Save to File… * Save to Geopackage… * Save to Database Table… * Append to Layer… The file encoding can also be changed here. .. **end_layer_output_types_append** .. **layer_output_types_skip** * Skip Output * Create Temporary Layer (``TEMPORARY_OUTPUT``) * Save to File… * Save to Geopackage… * Save to Database Table… The file encoding can also be changed here. .. **end_layer_output_types_skip** Extent Dropdown =============== .. The following refers to the extent selector widget in the algorithms GUI .. **extent_options** Available methods are: * Calculate from layer…: uses extent of a layer loaded in the current project * Calculate from layout map…: uses extent of a :ref:`layout map item ` in the active project * Calculate from bookmark…: uses extent of a saved :ref:`bookmark ` * Use map canvas extent * Draw on canvas: click and drag a rectangle delimiting the area to take into account * Enter the coordinates as ``xmin, xmax, ymin, ymax`` .. **end_extent_options** Geometric predicates ==================== .. The following section is included in vector selection algorithms such as qgisselectbylocation, qgisextractbylocation and vector general algorithms such as qgisjoinattributesbylocation and qgisjoinbylocationsummary .. **geometric_predicates** Geometric predicates are boolean functions used to determine the spatial relation a feature has with another by comparing whether and how their geometries share a portion of space. .. figure:: /docs/user_manual/processing_algs/img/selectbylocation.png :align: center Looking for spatial relations between layers Using the figure above, we are looking for the green circles by spatially comparing them to the orange rectangle feature. Available geometric predicates are: *Intersect* Tests whether a geometry intersects another. Returns 1 (true) if the geometries spatially intersect (share any portion of space - overlap or touch) and 0 if they don’t. In the picture above, this will return circles 1, 2 and 3. *Contain* Returns 1 (true) if and only if no points of b lie in the exterior of a, and at least one point of the interior of b lies in the interior of a. In the picture, no circle is returned, but the rectangle would be if you would look for it the other way around, as it contains circle 1 completely. This is the opposite of *are within*. *Disjoint* Returns 1 (true) if the geometries do not share any portion of space (no overlap, not touching). Only circle 4 is returned. *Equal* Returns 1 (true) if and only if geometries are exactly the same. No circles will be returned. *Touch* Tests whether a geometry touches another. Returns 1 (true) if the geometries have at least one point in common, but their interiors do not intersect. Only circle 3 is returned. *Overlap* Tests whether a geometry overlaps another. Returns 1 (true) if the geometries share space, are of the same dimension, but are not completely contained by each other. Only circle 2 is returned. *Are within* Tests whether a geometry is within another. Returns 1 (true) if geometry a is completely inside geometry b. Only circle 1 is returned. *Cross* Returns 1 (true) if the supplied geometries have some, but not all, interior points in common and the actual crossing is of a lower dimension than the highest supplied geometry. For example, a line crossing a polygon will cross as a line (true). Two lines crossing will cross as a point (true). Two polygons cross as a polygon (false). In the picture, no circles will be returned. .. **end_geometric_predicates** Notes on algorithms =================== .. **warning_attributes** .. warning:: **Geometry modification only** This operation modifies only the features geometry. The attribute values of the features are **not modified**, although properties such as area or length of the features will be modified by the overlay operation. If such properties are stored as attributes, those attributes will have to be manually updated. .. **end_warning_attributes** Raster data types ================= Simplified list --------------- .. **raster_data_types_simplified** .. The following section is included in raster based algorithms such as gdalrastercalculator * 0 --- Byte (Eight bit unsigned integer (quint8)) * 1 --- Int16 (Sixteen bit signed integer (qint16)) * 2 --- UInt16 (Sixteen bit unsigned integer (quint16)) * 3 --- UInt32 (Thirty two bit unsigned integer (quint32)) * 4 --- Int32 (Thirty two bit signed integer (qint32)) * 5 --- Float32 (Thirty two bit floating point (float)) * 6 --- Float64 (Sixty four bit floating point (double)) Available options depend on the GDAL version built with QGIS (see :menuselection:`Help --> About` menu) .. **end_raster_data_types_simplified** Without user input (native) --------------------------- .. **native_raster_data_types** .. The following section is included in raster based algorithms such as qgisrasterbooleanand, qgisrasterbooleanor, qgisreclassifybylayer, qgisreclassifybytable * 0 --- Byte (Eight bit unsigned integer (quint8)) * 1 --- Int16 (Sixteen bit signed integer (qint16)) * 2 --- UInt16 (Sixteen bit unsigned integer (quint16)) * 3 --- Int32 (Thirty two bit signed integer (qint32)) * 4 --- UInt32 (Thirty two bit unsigned integer (quint32)) * 5 --- Float32 (Thirty two bit floating point (float)) * 6 --- Float64 (Sixty four bit floating point (double)) * 7 --- CInt16 (Complex Int16) * 8 --- CInt32 (Complex Int32) * 9 --- CFloat32 (Complex Float32) * 10 --- CFloat64 (Complex Float64) Available options depend on the GDAL version built with QGIS (see :menuselection:`Help --> About` menu) .. **end_native_raster_data_types** Without user input ------------------ .. **raster_data_types** .. The following section is included in raster based algorithms such as gdalrasterize, gdalmerge, gdalretile, gdalgriddatametrics, gdalgridinversedistancenearestneighbor, gdalgridinversedistance, gdalgridlinear, gdalgridaverage, gdalgridnearestneighbor, gdalproximity * 0 --- Byte (Eight bit unsigned integer (quint8)) * 1 --- Int16 (Sixteen bit signed integer (qint16)) * 2 --- UInt16 (Sixteen bit unsigned integer (quint16)) * 3 --- UInt32 (Thirty two bit unsigned integer (quint32)) * 4 --- Int32 (Thirty two bit signed integer (qint32)) * 5 --- Float32 (Thirty two bit floating point (float)) * 6 --- Float64 (Sixty four bit floating point (double)) * 7 --- CInt16 (Complex Int16) * 8 --- CInt32 (Complex Int32) * 9 --- CFloat32 (Complex Float32) * 10 --- CFloat64 (Complex Float64) Available options depend on the GDAL version built with QGIS (see :menuselection:`Help --> About` menu) .. **end_raster_data_types** With user input --------------- .. **raster_data_types_extended** .. The following section is included in raster based algorithms such as gdalwarpreproject, gdalcliprasterbyextent, gdalcliprasterbymasklayer, gdalrearrange_bands, gdaltranslate * 0 --- Use Input Layer Data Type * 1 --- Byte (Eight bit unsigned integer (quint8)) * 2 --- Int16 (Sixteen bit signed integer (qint16)) * 3 --- UInt16 (Sixteen bit unsigned integer (quint16)) * 4 --- UInt32 (Thirty two bit unsigned integer (quint32)) * 5 --- Int32 (Thirty two bit signed integer (qint32)) * 6 --- Float32 (Thirty two bit floating point (float)) * 7 --- Float64 (Sixty four bit floating point (double)) * 8 --- CInt16 (Complex Int16) * 9 --- CInt32 (Complex Int32) * 10 --- CFloat32 (Complex Float32) * 11 --- CFloat64 (Complex Float64) Available options depend on the GDAL version built with QGIS (see :menuselection:`Help --> About` menu) .. **end_raster_data_types_extended**