**********************************
Základní statistiky rastrových dat
**********************************

Vyzkoušejme na mapách :file:`geology` a :file:`elevation.dem` následující
moduly. Zobrazte si nápovědu pomocí parametru ``--help``, vykoušejte
různé parametry a přepínače. [#f1]_ 

.. image:: ../../images/geology.png

==============================================
Příklad spustění příkazu v grafickém prostředí
==============================================

.. image:: ../../images/r_univar_geology.png

=================
:command:`r.info` 
=================

Vypíše základní informace o uživatelem vybrané rastrové mapě.::

        GRASS> r.info geology

        +----------------------------------------------------------------------------+
        | Layer:    geology                        Date: Mon May  4 10:00:14 1987 :  |
        | Mapset:   PERMANENT                      Login of Creator: grass           |
        | Location: spearfish60                                                      |
        | DataBase: /home/jachym/grassdata                                           |
        | Title:    Geology ( geology )                                              |
        | Timestamp: none                                                            |
        |----------------------------------------------------------------------------|
        |                                                                            |
        |   Type of Map:  cell                 Number of Categories: 9               |
        |   Data Type:    CELL                                                       |
        |   Rows:         140                                                        |
        |   Columns:      190                                                        |
        |   Total Cells:  26600                                                      |
        |        Projection: UTM (zone 13)                                           |
        |            N:    4928000    S:    4914000   Res:   100                     |
        |            E:     609000    W:     590000   Res:   100                     |
        |   Range of data:    min = 1  max = 9                                       |
        |                                                                            |
        |   Data Source:                                                             |
        |    Cell file produced by EROS Data Center                                  |
        |                                                                            |
        |                                                                            |
        |   Data Description:                                                        |
        |    Shows the geology for the map area                                      |
        |                                                                            |
        |   Comments:                                                                |
        |                                                                            |
        |                                                                            |
        +----------------------------------------------------------------------------+

============================
:command:`r.category` [#f2]_
============================
Vytiskne hodnoty kategorií a štítky spojené s uživatelem zadanou rastrovou mapou.::

        GRASS> r.category geology

        1	metamorphic
        2	transition
        3	igneous
        4	sandstone
        5	limestone
        6	shale
        7	sandy shale
        8	claysand
        9	sand


==================
:command:`r.stats` 
==================
Vytvoří statistiku ploch pro rastrové mapy. (celkový rozsah a počet buněk)::

        GRASS> r.stats -ac geology

        1 10523700.000000 11693
        2 127800.000000 142
        3 32880600.000000 36534
        4 67463100.000000 74959
        5 55219500.000000 61355
        6 41780700.000000 46423
        7 10139400.000000 11266
        8 13081500.000000 14535
        9 32904900.000000 36561
        * 8055000.000000 8950

===================
:command:`r.report` 
===================
Vypíše správu pro rastrovou mapu nebo několik map.::

        GRASS> r.report geology units=me

        +-----------------------------------------------------------------------------+
        |                         RASTER MAP CATEGORY REPORT                          |
        |LOCATION: spearfish60                                Wed Feb 11 21:30:34 2009|
        |-----------------------------------------------------------------------------|
        |          north: 4928010    east: 609000                                     |
        |REGION    south: 4913700    west: 589980                                     |
        |          res:        30    res:      30                                     |
        |-----------------------------------------------------------------------------|
        |MASK:none                                                                    |
        |-----------------------------------------------------------------------------|
        |MAP: Geology (geology in PERMANENT)                                          |
        |-----------------------------------------------------------------------------|
        |                      Category Information                       |     square|
        |#|description                                                    |     meters|
        |-----------------------------------------------------------------------------|
        |1|metamorphic. . . . . . . . . . . . . . . . . . . . . . . . . . | 10,523,700|
        |2|transition . . . . . . . . . . . . . . . . . . . . . . . . . . |    127,800|
        |3|igneous. . . . . . . . . . . . . . . . . . . . . . . . . . . . | 32,880,600|
        |4|sandstone. . . . . . . . . . . . . . . . . . . . . . . . . . . | 67,463,100|
        |5|limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . | 55,219,500|
        |6|shale. . . . . . . . . . . . . . . . . . . . . . . . . . . . . | 41,780,700|
        |7|sandy shale. . . . . . . . . . . . . . . . . . . . . . . . . . | 10,139,400|
        |8|claysand . . . . . . . . . . . . . . . . . . . . . . . . . . . | 13,081,500|
        |9|sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | 32,904,900|
        |*|no data. . . . . . . . . . . . . . . . . . . . . . . . . . . . |  8,055,000|
        |-----------------------------------------------------------------------------|
        |TOTAL                                                            |272,176,200|
        +-----------------------------------------------------------------------------+

===================
:command:`r.univar` 
===================
Vypíše základní statistiku pro rastrovou mapu.::

        GRASS> r.univar -e erode.index

        total null and non-null cells: 302418
        total null cells: 42955

        Of the non-null cells:
        ----------------------
        n: 259463
        minimum: 1
        maximum: 12
        range: 11
        mean: 4.19528
        mean of absolute values: 4.19528
        standard deviation: 1.4046
        variance: 1.97291
        variation coefficient: 33.4806 %
        sum: 1088519
        1st quartile: 4
        median (odd number of cells): 4
        3rd quartile: 4
        90th percentile: 5


.. [#f1] :command:`d.mon x0; d.rast geology`, neboli zobrazte si rastrovou mapu :file:`geology`
.. [#f2] :command:`r.cats` byl ve verzi 6.4  nahrazen příkazem :command:`r.category`