source: orange/docs/widgets/rst/regression/regressiontree.rst @ 11050:e3c4699ca155

Revision 11050:e3c4699ca155, 2.0 KB checked in by Miha Stajdohar <miha.stajdohar@…>, 16 months ago (diff)

Widget docs From HTML to Sphinx.

Line 
1.. _Regression Tree:
2
3Regression Tree Learner
4=======================
5
6.. image:: ../icons/RegressionTree.png
7
8Regression Tree Learner
9
10Signals
11-------
12
13Inputs:
14   - Examples (ExampleTable)
15      A table with training examples
16
17
18Outputs:
19   - Learner
20      The classification tree learning algorithm with settings as specified in the dialog.
21   - Regression Tree
22      Trained classifier (a subtype of Classifier)
23
24
25Signal :code:`Regression Tree` sends data only if the learning data (signal :code:`Examples` is present.
26
27Description
28-----------
29
30This widget constructs a regression tree learning algorithm. As all widgets for classification and regression, this widget provides a learner and classifier/regressor on the output. Learner is a learning algorithm with settings as specified by the user. It can be fed into widgets for testing learners, for instance :code:`Test Learners`.
31
32.. image:: images/RegressionTree.png
33   :alt: Regression Tree Widget
34
35Learner can be given a name under which it will appear in, say, :code:`Test Learners`. The default name is "Regression Tree".
36
37If :code:`Binarization` is checked, the values of multivalued attributes are split into two groups (based on the statistics in the particular node) to yield a binary tree. Binarization gets rid of the usual measures' bias towards attributes with more values and is generally recommended.
38
39The widget can be instructed to prune the tree during induction by setting :obj:`Do not split nodes with less instances than`. For pruning after induction, there is pruning with m-estimate of error.
40
41After changing one or more settings, you need to push :obj:`Apply`, which will put the new learner on the output and, if the training examples are given, construct a new classifier and output it as well.
42
43Examples
44--------
45
46There are two typical uses of this widget. First, you may want to induce the model and check what it looks like with the schema below.
47
48.. image:: images/RegressionTree-Schema.png
49
50The second schema checks the accuracy of the algorithm.
51
52.. image:: images/RegressionTree-Schema2.png
Note: See TracBrowser for help on using the repository browser.