source: orange/docs/reference/rst/Orange.data.formats.rst @ 9524:c806ca0fa3a9

Revision 9524:c806ca0fa3a9, 1.7 KB checked in by janezd <janez.demsar@…>, 2 years ago (diff)

Added documentation about multiple classes

Line 
1.. py:currentmodule:: Orange.data
2
3=======================
4Loading and saving data
5=======================
6
7Tab-delimited format
8====================
9Orange prefers to open data files in its native, tab-delimited format. This format allows us to specify type of features
10and optional flags along with the feature names, which can ofter result in shorter loading times. This additional data
11is provided in a form of a 3-line header. First line contains feature names, followed by type of features and optional
12flags in that order.
13
14Example of iris dataset in tab-delimited format (:download:`iris.tab <code/iris.tab>`)
15
16.. literalinclude:: code/iris.tab
17   :lines: 1-7
18
19Feature types
20-------------
21 * discrete (or d) - imported as Orange.data.variable.Discrete
22 * continuous (or c) - imported as Orange.data.variable.Continuous
23 * string - imported as Orange.data.variable.String
24 * basket - used for storing sparse data. More on basket formats in a dedicated section.
25
26Optional flags
27--------------
28 * ignore (or i) - feature will not be imported
29 * class (or c) - feature will be imported as class variable. Only one feature can be marked as class.
30 * multiclass - feature is one of multiple classes. Data can have both, multiple classes and an ordinary class.
31 * meta (or m) - feature will be imported as a meta attribute.
32 * -dc
33
34
35Other supported data formats
36============================
37Orange can import data from csv or tab delimited files where the first line contains attribute names followed by
38lines containing data. For such files, orange tries to guess the type of features and treats the right-most
39column as the class variable. If feature types are known in advance, special orange tab format should be used.
Note: See TracBrowser for help on using the repository browser.