Sites format

[David Gerdes]

This is the 3rd time I have written this message.  The grass.user news list
kept dropping it for some reason.  Hopefully this will make it.

This is in response to the messages about the GRASS sites format.

The original format was:

<easting>|<northing>|<description>

where <description> is an alpha string

Then to allow sites to be converted to raster files, an alternative 
format was added:

<easting>|<northing>|#num <description>

where num is an integer which would be used as the cell value in the
raster map.  Note that num MUST be integer. (until GRASS supports 
floating point...)


When we developed s.surf.tps, I misinterpreted this format and thought
that num could be float as well.  This led to the situation we have
now.  s.surf.tps currently requires an improperly formatted sites file.
i.e. <easting>|<northing>|#float   We intend on fixing this in a
future release of s.surf.tps. s.surf.idw will also need to be modified
slightly it seems.

What we will probably do is to change s.surf.tps to accept either of the
'official' formats above, and require that the float data be at the 
beginning of the <description> field, and then provide a command line
flag to support the format that it currently uses, for backwards 
compatibility.

This optional flag could be added to any other site programs to allow
for compatibility (with the understanding that it is not a proper format)
with s.surf.tps.

My apologies for the problems this has created.
-- 
  David Gerdes
  US Army Construction Engineering Research Lab
  Spatial Analysis & Systems Team
  dpgerdes at zorro.cecer.army.mil