|updatedisclaimer|

.. comment out this Section (by putting '|updatedisclaimer|' on top) if file is not uptodate with release

.. _ftools:

fTools Plugin
=============

The goal of the fTools Python plugin is to provide a one-stop resource for many
common vector-based GIS tasks, without the need for additional software,
libraries, or complex work-arounds. It provides a growing suite of spatial data
management and analysis functions that are both fast and functional.

fTools is now automatically installed and enabled in new versions of |qg|, and
as with all plugins, it can be disabled and enabled using the Plugin Manager
(see :ref:`managing_plugins`). When enabled, the fTools plugin adds a
:menuselection:`Vector` menu to |qg|, providing functions ranging from Analysis
and Research Tools to Geometry and Geoprocessing Tools, as well as several useful
Data Management Tools.

.. _`ftools_function`:

.. index::
   single:Analysis tools

.. _table_ftools_1:

Analysis tools
..............
+---------------------+-----------------+--------------------------------------+
| **Icon**            | **Tool**        | **Purpose**                          |
+=====================+=================+======================================+
| |matrix|            | 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.              |
+---------------------+-----------------+--------------------------------------+
| |sum_lines|         | Sum line length | Calculate the total sum of line      |
|                     |                 | lengths for each polygon of a polygon|
|                     |                 | vector layer.                        |
+---------------------+-----------------+--------------------------------------+
| |sum_points|        | Points in       | Count the number of points that occur|
|                     | polygon         | in each polygon of an input polygon  |
|                     |                 | vector layer.                        |
+---------------------+-----------------+--------------------------------------+
| |unique|            | List unique     | List all unique values in an input   |
|                     | values          | vector layer field.                  |
+---------------------+-----------------+--------------------------------------+
| |basic_statistics|  | Basic statistics| Compute basic statistics (mean, std  |
|                     |                 | dev, N, sum, CV) on an input field.  |
+---------------------+-----------------+--------------------------------------+
| |neighbor|          | Nearest         | Compute nearest neighbor statistics  |
|                     | neighbor        | to assess the level of clustering in |
|                     | analysis        | a point vector layer.                |
+---------------------+-----------------+--------------------------------------+
| |mean|              | Mean            | Compute either the normal or         |
|                     | coordinate(s)   | weighted mean center of an entire    |
|                     |                 | vector layer, or multiple features   |
|                     |                 | based on a unique ID field.          |
+---------------------+-----------------+--------------------------------------+
| |intersections|     | Line            | Locate intersections between lines,  |
|                     | intersections   | and output results as a point        |
|                     |                 | shapefile.  Useful for locating road |
|                     |                 | or stream intersections, ignores     |
|                     |                 | line intersections with length > 0.  |
+---------------------+-----------------+--------------------------------------+

Table Ftools 1: fTools Analysis tools

.. index::
   single:Research tools


Research tools
..............
+---------------------+-----------------+--------------------------------------+
| **Icon**            | **Tool**        | **Purpose**                          |
+=====================+=================+======================================+
| |random_selection|  | Random selection| Randomly select n number of features,|
|                     |                 | or n percentage of features.         |
+---------------------+-----------------+--------------------------------------+
| |sub_selection|     | Random selection| Randomly select features within      |
|                     | within subsets  | subsets based on a unique ID field.  |
+---------------------+-----------------+--------------------------------------+
| |random_points|     | Random points   | Generate pseudo-random points over a |
|                     |                 | given input layer.                   |
+---------------------+-----------------+--------------------------------------+
| |regular_points|    | Regular points  | Generate a regular grid of points    |
|                     |                 | over a specified region and export   |
|                     |                 | them as a point shapefile.           |
+---------------------+-----------------+--------------------------------------+
| |vector_grid|       | Vector grid     | Generate a line or polygon grid      |
|                     |                 | based on user-specified grid spacing.|
+---------------------+-----------------+--------------------------------------+
| |select_location|   | Select by       | Select features based on their       |
|                     | location        | location relative to another layer   |
|                     |                 | to form a new selection, or add or   |
|                     |                 | subtract from the current selection. |
+---------------------+-----------------+--------------------------------------+
| |layer_extent|      | Polygon from    | Create a single rectangular          |
|                     | layer extent    | polygon layer from the extent of an  |
|                     |                 | input raster or vector layer.        |
+---------------------+-----------------+--------------------------------------+

Table Ftools 2: fTools Research tools

Geoprocessing tools
...................
+---------------------+-----------------+--------------------------------------+
| **Icon**            | **Tool**        | **Purpose**                          |
+=====================+=================+======================================+
| |convex_hull|       | Convex hull(s)  | Create minimum convex hull(s) for an |
|                     |                 | input layer, or based on an ID field.|
+---------------------+-----------------+--------------------------------------+
| |buffer|            | Buffer(s)       | Create buffer(s) around features     |
|                     |                 | based on distance, or distance field.|
+---------------------+-----------------+--------------------------------------+
| |intersect|         | Intersect       | Overlay layers such that output      |
|                     |                 | contains areas where both layers     |
|                     |                 | intersect.                           |
+---------------------+-----------------+--------------------------------------+
| |union|             | Union           | Overlay layers such that output      |
|                     |                 | contains intersecting and            |
|                     |                 | non-intersecting areas.              |
+---------------------+-----------------+--------------------------------------+
| |sym_difference|    | Symmetrical     | Overlay layers such that output      |
|                     | difference      | contains those areas of the input    |
|                     |                 | and difference layers that do not    |
|                     |                 | intersect.                           |
+---------------------+-----------------+--------------------------------------+
| |clip|              | Clip            | Overlay layers such that output      |
|                     |                 | contains areas that intersect the    |
|                     |                 | clip layer.                          |
+---------------------+-----------------+--------------------------------------+
| |difference|        | Difference      | Overlay layers such that output      |
|                     |                 | contains areas not intersecting the  |
|                     |                 | clip layer.                          |
+---------------------+-----------------+--------------------------------------+
| |dissolve|          | Dissolve        | Merge features based on input field. |
|                     |                 | All features with identical input    |
|                     |                 | values are combined to form one      |
|                     |                 | single feature.                      |
+---------------------+-----------------+--------------------------------------+
| |eliminate|         | Eliminate sliver| Merges selected features with the    |
|                     | polygons        | neighbouring polygon with the        |
|                     |                 | largest area or largest common       |
|                     |                 | boundary.                            |
+---------------------+-----------------+--------------------------------------+

Table Ftools 3: fTools Geoprocessing tools

Geometry tools
..............
+---------------------+-----------------+--------------------------------------+
| **Icon**            | **Tool**        | **Purpose**                          |
+=====================+=================+======================================+
| |check_geometry|    | Check geometry  | Check polygons for intersections,    |
|                     | validity        | closed holes, and fix node ordering. |
|                     |                 | You can choose the engine used by the|
|                     |                 | in the options dialog, digitizing tab|
|                     |                 | Change the Validate geometries value.| 
|                     |                 | There is two engines: QGIS and GEOS  |
|                     |                 | which have pretty different          |
|                     |                 | behaviour. Another tools exists which|
|                     |                 | shows different result as well:      |
|                     |                 | Topology Checker plugin and 'must not|
|                     |                 | have invalid geometries' rule.       |
+---------------------+-----------------+--------------------------------------+
| |export_geometry|   | Export/Add      | Add vector layer geometry info to    |
|                     | geometry columns| point (XCOORD, YCOORD), line         |
|                     |                 | (LENGTH), or polygon (AREA,          |
|                     |                 | PERIMETER) layer.                    |
+---------------------+-----------------+--------------------------------------+
| |centroids|         | Polygon         | Calculate the true centroids for     |
|                     | centroids       | each polygon in an input polygon     |
|                     |                 | layer.                               |
+---------------------+-----------------+--------------------------------------+
| |delaunay|          | Delaunay        | Calculate and output (as polygons)   |
|                     | triangulation   | the Delaunay triangulation of an     |
|                     |                 | input point vector layer.            |
+---------------------+-----------------+--------------------------------------+
|                     | Voronoi polygons| Calculate Voronoi polygons of an     |
|                     |                 | input point vector layer.            |
+---------------------+-----------------+--------------------------------------+
| |simplify|          | Simplify        | Generalize lines or polygons with a  |
|                     | geometry        | modified Douglas-Peucker algorithm.  |
+---------------------+-----------------+--------------------------------------+
|                     | Densify         | Densify lines or polygons by adding  |
|                     | geometry        | vertices.                            |
+---------------------+-----------------+--------------------------------------+
| |multi_to_single|   | Multipart to    | Convert multipart features to        |
|                     | singleparts     | multiple singlepart features.        |
|                     |                 | Creates simple polygons and lines.   |
+---------------------+-----------------+--------------------------------------+
| |single_to_multi|   | Singleparts to  | Merge multiple features to a single  |
|                     | multipart       | multipart feature based on a unique  |
|                     |                 | ID field.                            |
+---------------------+-----------------+--------------------------------------+
| |to_lines|          | Polygons to     | Convert polygons to lines, multipart |
|                     | lines           | polygons to multiple singlepart      |
|                     |                 | lines.                               |
+---------------------+-----------------+--------------------------------------+
| |to_lines|          | Lines to        | Convert lines to polygons, multipart |
|                     | polygons        | lines to multiple singlepart         |
|                     |                 | polygons.                            |
+---------------------+-----------------+--------------------------------------+
| |extract_nodes|     | Extract nodes   | Extract nodes from line and polygon  |
|                     |                 | layers and output them as points.    |
+---------------------+-----------------+--------------------------------------+

Table Ftools 4: fTools Geometry tools

.. note::

   The *Simplify geometry* tool can be used to remove duplicate nodes in line and
   polygon geometries. Just set the *Simplify tolerance* parameter to 0 and this
   will do the trick.

.. _table_ftools_5:

Data management tools
.....................
+---------------------+-----------------+--------------------------------------+
| **Icon**            | **Tool**        | **Purpose**                          |
+=====================+=================+======================================+
| |define_projection| | Define current  | Specify the CRS for shapefiles whose |
|                     | projection      | CRS has not been defined.            |
+---------------------+-----------------+--------------------------------------+
| |join_location|     | Join attributes | Join additional attributes to vector |
|                     | by location     | layer based on spatial relationship. |
|                     |                 | Attributes from one vector layer are |
|                     |                 | appended to the attribute table of   |
|                     |                 | another layer and exported as a      |
|                     |                 | shapefile.                           |
+---------------------+-----------------+--------------------------------------+
| |split_layer|       | Split vector    | Split input layer into multiple      |
|                     | layer           | separate layers based on input field.|
+---------------------+-----------------+--------------------------------------+
| |merge_shapes|      | Merge shapefiles| Merge several shapefiles within a    |
|                     | to one          | folder into a new shapefile based on |
|                     |                 | the layer type (point, line, area).  |
+---------------------+-----------------+--------------------------------------+
|                     | Create spatial  | Create a spatial index for OGR-      |
|                     | index           | supported formats.                   |
+---------------------+-----------------+--------------------------------------+

Table Ftools 5: fTools Data management tools