Distance matrix Measure distances between two point layers, and output results as a) Square distance matrix, b) Linear distance matrix, or c) Summary of distances. Can limit distances to the k nearest features. icons/gis/matrix.png Analysis Tools Inputs, parameters, and additional information to be added Sum line lengths Calculate the total sum of line lengths for each polygon of a polygon vector layer. icons/gis/sum_lines.png Analysis Tools Inputs, parameters, and additional information to be added Points in polygon Count the number of points that occur in each polygon of an input polygon vector layer. icons/gis/sum_points.png Analysis Tools Inputs, parameters, and additional information to be added Basic statistics Compute basic statistics (mean, std dev, N, sum, CV) on an input field. icons/gis/basic_statistics.png Analysis Tools Inputs, parameters, and additional information to be added List unique values List all unique values in an input vector layer field. icons/gis/unique.png Geometry Tools Inputs, parameters, and additional information to be added Nearest neighbour analysis Compute nearest neighbour statistics to assess the level of clustering in a point vector layer. icons/gis/neighbour.png Analysis Tools Inputs, parameters, and additional information to be added Mean coordinate(s) Compute either the normal or weighted mean center of an entire vector layer, or multiple features based on a unique ID field. icons/gis/mean.png Analysis Tools Inputs, parameters, and additional information to be added Line intersection Locate intersections between lines, and output results as a point shapefile. Useful for locating road or stream intersections, ignores line intersections with length > 0. icons/gis/intersections.png Analysis Tools Inputs, parameters, and additional information to be added Random selection Randomly select n number of features, or n percentage of features from an input vector layer. icons/gis/random_selection.png Sampling Tools Inputs, parameters, and additional information to be added Random selection within subsets Randomly select features wihtin subsets of a vector layer based on a unique ID field. icons/gis/sub_selection.png Sampling Tools Inputs, parameters, and additional information to be added Random points Generate pseudo-random points over a given input layer (raster or vector) and export them as a point shapefile. icons/gis/random_points.png Sampling Tools Inputs, parameters, and additional information to be added Regular points Generate a regular grid of points over a specified region and export them as a point shapefile. icons/gis/regular_points.png Sampling Tools Inputs, parameters, and additional information to be added Vector grid Generate a line or polygon vector grid based on user specified grid spacing. icons/gis/vector_grid.png Sampling Tools Inputs, parameters, and additional information to be added Select by location Select features based on their location relative to another layer to form a new selection, or add or subtract from the current selection. icons/gis/select_location.png Sampling Tools Inputs, parameters, and additional information to be added Convex hulls Create minimum convex hull(s) (polygons) for an entire input layer, or based on a unique ID field. icons/gis/convex_hull.png Geoprocessing Tools Inputs, parameters, and additional information to be added Buffer(s) Create buffer(s) around features based on specified distance, or distance field. icons/gis/buffer.png Geoprocessing Tools Inputs, parameters, and additional information to be added Intersect Overlay vector layers such that output contains those areas where both layers intersect. icons/gis/intersect.png Geoprocessing Tools Inputs, parameters, and additional information to be added Union Overlay vector layers such that output contains all intersecting and non-intersecting areas of input layers. icons/gis/union.png Geoprocessing Tools Inputs, parameters, and additional information to be added Symetrical difference Overlay vector layers such that output contains those areas of the input and difference layers that do not intersect. icons/gis/sym_difference.png Geoprocessing Tools Inputs, parameters, and additional information to be added Clip Overlay vector layers such that output contains those areas of the input layer that intersect the clip layer. icons/gis/clip.png Geoprocessing Tools Inputs, parameters, and additional information to be added Difference Overlay vector layers such that output contains those areas of the input layer that do not intersect the clip layer. icons/gis/difference.png Geoprocessing Tools Inputs, parameters, and additional information to be added Dissolve Merge features based on input field. All features with indentical input values are combined to form one single feature. icons/gis/dissolve.png Geoprocessing Tools Inputs, parameters, and additional information to be added Check geometry validity Check polygon geometries for self-intersections, closed-holes and polygons, and correct node ordering. icons/gis/check_geometry.png Geometry Tools Inputs, parameters, and additional information to be added Export/Add geometry values Add vector layer geometry info to point (XCOORD, YCOORD), line (LENGTH), or polygon (AREA, PERIMETER) layer. icons/gis/export_geometry.png Geometry Tools Inputs, parameters, and additional information to be added Polygon centroids Calculate the true centroids, or 'center of mass' for each polygon in an input polygon layer. icons/gis/centroids.png Geometry Tools The centroid of a convex polygon will always lie inside the polygon, however many non-convex polygons may have a centroid that is outside the polygon itself. The centroid of a ring polygon, for example, will lie in the polygons's central void. Delaunay triangulation Generate a Delaunay triangulation as a polygon vector layer from a set of input points. icons/gis/centroids.png Geometry Tools The Delaunay triangulation for a set of points in the plane is a triangulation such that no point is inside the circumcircle of any triangle in the triangulation. The Delaunay triangulation of a discrete point set corresponds to the dual graph of the Voronoi tessellation of the same point set. Simplify geometries Simplify (generalise) line or polygon vector layers using (a modified) Douglas-Peucker algorithm. icons/gis/simplify.png Geometry Tools The purpose of the Douglas-Peucker algorithm is to find a line (or polygon) not too dissimilar but that has fewer points than the given input line (or polygon). The algorithm defines 'too dissimilar' based on the maximum distance between the original curve and the smoothed curve (tolerance). The smoothed line consists of a subset of the points that defined the original line. Multipart to singleparts Convert multipart features to multiple singlepart features. Creates simple polygons and lines. icons/gis/multi_to_single.png Geometry Tools Inputs, parameters, and additional information to be added Singleparts to multipart Merge multiple features to a single multipart feature based on a unique ID field. icons/gis/single_to_multi.png Geometry Tools Inputs, parameters, and additional information to be added Polygons to lines Convert polygon features to line features. Multipart polygons are converted to multiple singlepart lines. icons/gis/to_lines.png Geometry Tools Inputs, parameters, and additional information to be added Extract nodes Extract nodes from line and polygon vector layers and output them as points. icons/gis/extract_nodes.png Geometry Tools Inputs, parameters, and additional information to be added Export to new projection Based on input CRS, project features to new CRS and export as new shapefile. icons/gis/export_projection.png Data Management Tools Inputs, parameters, and additional information to be added Define current projection Specify the CRS for shapefiles whose CRS has not been defined. icons/gis/define_projection.png Data Management Tools Inputs, parameters, and additional information to be added Join attributes Join additional attributes to vector layer attribute table and output results to a new shapefile. Additional attributes can be from a vector layer or stand-alone dbf table. icons/gis/join_attributes.png Data Management Tools Inputs, parameters, and additional information to be added Join attributes by location Join additional attributes to vector layer based on spatial relationship. Attributes from one vector layer are appended to the attribute table of another layer and exported as a shapefile icons/gis/join_location.png Data Management Tools Inputs, parameters, and additional information to be added Vector split Split input vector layer into multiple separate vector layers based on input field. icons/gis/split_layer.png Geoprocessing Tools Inputs, parameters, and additional information to be added