.. _VectorDimensionalityReduction: 

VectorDimensionalityReduction
=============================





Performs dimensionality reduction of the input vector data according to a model file.

Description
-----------

This application performs a vector data dimensionality reduction based on a model file produced by the :ref:`TrainDimensionalityReduction` application.



Parameters
----------

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**Name of the input vector data** :code:`-in vectorfile` *Mandatory* |br|
The input vector data to reduce.

**Statistics file** :code:`-instat filename [dtype]` |br|
An XML file containing mean and standard deviation to center and reduce samples before dimensionality reduction (produced by ComputeImagesStatistics application).

**Model file** :code:`-model filename [dtype]` *Mandatory* |br|
A model file (produced by the TrainDimensionalityReduction application,

**Output vector data file containing the reduced vector** :code:`-out filename [dtype]` |br|
Output vector data file storing sample values (OGR format). If not given, the input vector data file is used. In overwrite mode, the original features will be lost.

**Input features to use for reduction** :code:`-feat string1 string2...` |br|
List of field names in the input vector data used as features for reduction.

**Output feature** :code:`-featout [prefix|list]` *Default value: prefix* |br|
Naming of output features

* **Prefix** |br| Use a name prefix

* **List** |br| Use a list with all names



Prefix options
^^^^^^^^^^^^^^

**Feature name prefix** :code:`-featout.prefix.name string` *Default value: reduced_* |br|
Name prefix for output features. This prefix is followed by the numeric index of each output feature.

List options
^^^^^^^^^^^^

**Feature name list** :code:`-featout.list.names string1 string2...` *Mandatory* |br|
List of field names for the output features which result from the reduction.



------------

**Principal component dimension** :code:`-pcadim int` |br|
This optional parameter can be set to reduce the number of eignevectors used in the PCA model file. This parameter can't be used for other models

**Writing mode** :code:`-mode [overwrite|update]` *Default value: overwrite* |br|
This parameter determines if the output file is overwritten or updated [overwrite/update]. If an output file name is given, the original file is copied before creating the new features.

* **Overwrite** |br| Overwrite mode

* **Update** |br| Update mode





Examples
--------

From the command-line:

.. code-block:: bash

    otbcli_VectorDimensionalityReduction -in vectorData.shp -instat meanVar.xml -model model.txt -out vectorDataOut.shp -feat perimeter area width


From Python:

.. code-block:: python

	import otbApplication

	app = otbApplication.Registry.CreateApplication("VectorDimensionalityReduction")

	app.SetParameterString("in", "vectorData.shp")
	app.SetParameterString("instat", "meanVar.xml")
	app.SetParameterString("model", "model.txt")
	app.SetParameterString("out", "vectorDataOut.shp")
	app.SetParameterStringList("feat", ['perimeter', 'area', 'width'])

	app.ExecuteAndWriteOutput()





See also
--------

| :ref:`TrainDimensionalityReduction`