McCauley's new site format proposal

Rod Paterson rgp%abba at haw.oz.au
Tue Apr 5 21:27:52 EDT 1994


>I have been looking at the new site record format proposal by Darrell
>McCauley/Bernard Engel. Looks like a big leap forward. There is however
>one problem in handling string attributes and since I'm not able to
>attend the Reston Conference I'll bring this up here: Strings can not
>contain whitespace. Extending the example on page 3, 2nd paragraph:
>
>	#56 @clay %5.6
>	#54 @"blue" clay %5.4
>	#62 @Rosebloom silt loam, frequently flooded %6.2
>	#49 @Rosebloom silt loam, ponded %4.9
>Unless I'm very mistaken G_new_get_site() will return an error status on
>records 2,3,4,5  because it sees the wrong number of string fields; 2, 5,
>4 and 3 respectively. My suggestion is to indicate strings by enclosing
>them between double quote characters:
>
>	#56 "clay" %5.6
>	#54 "\"blue\" clay" %5.4
>	#62 "Rosebloom silt loam, frequently flooded" %6.2
>	#49 "Rosebloom silt loam, ponded" %4.9
>	#55 "Memphis silt loam" %5.5
>
>This mechanism is much used in our daily software like cc, shells
>(including the celebrated tclsh), troff, scripts for r.binfer etc. etc.
>
>Raymond

I agree.I think it is essential that strings are able to contain
white space.

I also think it would be a good idea to incorporate a header in 
the site file that names what each Z or string variable is and
what the units are if relevant.If there are many Z fields
in a site file how will the user remember which field is which.

It would be nice from a user's point of view to be able to select site
variables by name rather than position when running r.surf.tps or
other surface interpolation procedures.
Consider the geochemist who may have 20 element variables in his site
file.

If it is considered unpalatable to have a header in the site file itself
then an alternative could be to have a separate header file as is done for 
vector and raster data sets.This header could also contain details of data
format as well as variable names and units. ie.self describing

Sorry for getting into this so late but from a user's perspective
these are important issues.

Rod Paterson
Aberfoyle Resources Ltd
Phone: 61-3-8822226
Fax:   61-3-8131086
Email: rgp at aberfoyle.oz.au




More information about the grass-dev mailing list