Grid data wrapper

##Grid data wrapper (grid)

This wrapper loads ESRI grid files (ASCII).

Parameters:

• directory local directory to search for files
• file-mask regular expression used for finding files in the local folder. The first group should contains the timestamp
• _extension _file extension
• time-format time format for the timestamp
• _rate _update rate

Example:

<address wrapper="grid">
   <predicate key="directory">.</predicate>
   <predicate key="extension">dem</predicate>
   <predicate key="file-mask">^(\d{14}).dem</predicate>
   <predicate key="time-format">yyyyMMddHHmmss</predicate>
   <predicate key="rate">3600000</predicate>   <!-- in milliseconds -->
</address>
<query>SELECT * FROM wrapper</query>

In the output structure:

<output-structure>
   <field name="ncols" type="int"/>
   <field name="nrows" type="int"/>
   <field name="xllcorner" type="double"/>
   <field name="yllcorner" type="double"/>
   <field name="cellsize" type="double"/>
   <field name="nodata_value" type="double"/>
   <field name="grid" type="binary"/>
</output-structure>

Input file:

ncols         4
nrows         6
xllcorner     0.0
yllcorner     0.0
cellsize      50.0
NODATA_value  -9999
-9999 -9999 5 2
-9999 20 100 36
3 8 35 10
32 42 50 6
88 75 27 9
13 5 1 -9999

See also: http://en.wikipedia.org/wiki/ESRI_grid