## NAME

sites.occur - Description of the site occurrence report produced by s.menu.

## DESCRIPTION

This is a discussion of the site occurrence report produced by s.menu.

## SAMPLE OUTPUT

                                 SITE OCCURRENCE REPORT
                            Yakima Firing Center, Washington

    Location:  yakima
    Mapset:    sample
    Site List: arch_erosion - archeology (34 sites)

    Analysis Region:
                        north: 5199975.00
       west:  692975.00                       east:  737975.00
                        south: 5154975.00

    ============================================================================

    Layer: arch_survey          Archeologic Survey Areas (arch_survey)

    cells in analysis region:     810000
    sites in analysis region:         34

                                                                         degrees
                                 cells     %    expected actual   chi      of
    Site Characteristics         cover   cover   sites    sites  square  freedom
    --------------------        ------- ------- -------- ------ -------- -------
    (  0) No data                764310                      11

    (  1) Hartmann,phase 1        25821    56.5     19.2      6    9.088     1
    (  2) Hartmann,phase 2        11032    24.1      8.2     14    4.084     1
    (  3) Wapora,phase 3           8837    19.3      6.6      3    1.945     1
                                ------- ------- -------- ------ -------- -------
          Totals                  45690   100.0     34.0     23   15.117     2

    ============================================================================

## EXPLANATION

The "Site Occurrence Report" provides aggregate site information organized by raster map layers.

The report header contains the following information:

Location
  GRASS database location (e.g., yakima),
Mapset
  GRASS mapset (e.g., sample)
Analysis Region
  the rectangular area in which the analysis was run, reflecting the current geographic settings of the user's mapset.
Site List
  name and description of the site list used for the report and the number of sites in the list. See manual entry for s.menu for more discussion about these site lists.

The rest of the report is divided into reports for each raster map layers specified by the user. In this SAMPLE OUTPUT, only one map layer (arch_survey) was specified.

Certain information heads up each of these reports:

layer
  identifies the raster map layer along with the map layer TITLE.
cells in analysis region
  the size of the analysis region (in cells).
sites in analysis region
  the number of sites in the analysis region.

For each map layer category which occurs in a cell falling within the boundaries of the analysis region, as well as totals for the map layer as a whole, various statistics are presented:

Site Characteristics
  These are the numbers (i.e., values) and names (i.e., descriptions) for each category (i.e., characteristic) which occurs in the map layer.
cells cover
  the number of cells in the analysis region having the category value (i.e., site characteristic).
% cover
  the predominance of the category within the analysis region.
expected sites
  the number of sites in the analysis region which would be expected to be observed having the category value if all sites were evenly distributed by in the region.
actual sites
  the number of sites in the analysis region which were occurred in cells having the category value.
chi square
  gives the user a statistical test of the hypothesis that 'site distribution is dependent on environmental factors'. For this hypothesis to be true, the chi-square test must fail since we are calculating expected sites according to the hypothesis that 'sites are randomly distributed'.
degrees of freedom
  Number of degrees of freedom for the chi-square test. Each category value will have 1 degree of freedom, and can be tested alone. The entire map layer will have 1 less degree of freedom than the number of categories.

## NOTE

Category zero (0) throughout GRASS represents "no data". Therefore, it is reported, but not included in the totals or in the computation of the chi-square statistics.

## SEE ALSO

s.db.rim
s.in.ascii
s.menu
s.out.ascii
s.surf.idw
sites.S
sites.format
sites.report

Last changed: $Date: 2002/01/25 05:45:35 $