[GRASS5] readsites() TODO list...

[Eric G . Miller]

On Thu, Sep 21, 2000 at 10:07:56AM -0500, Bill Brown - staff wrote:
[snip] 
> I think your G_readxyzsites would be quite useful.  I'd still like to
> see "cat" added as an attribute, though.  G_writexyzsites might be good
> too.  I think these would be more useful to the programmer because it 
> hides all the messy Site structure stuff. For G_writexyzsites, if "cat"
> is selected, you could default to writing a double cat or add another
> RASTER_MAP_TYPE parameter which would be ignored if string or floating
> point attribute are chosen.

I see no problem adding support for the cat value.  I could add the
RASTER_MAP_TYPE thingy too.  I must say, I'm a little confused by the
use of floating point cat values.  I always thought of a 'cat' as a
category which implies an integral value (even if it represents a range
of floats).  I don't understand how a floating point cat makes sense for
a site file either.  But, this is probably another matter...

> >int    type,    /* 0 = Z-dim, 1 = double, 2 = string */
> >	
> >--- This is the attribute type. By "Z-dim", I mean any of the n-dims
> >--- in the Site file spec. Double, is double attribute, string is
> >--- string attribute.  Yes, an enum or #define's are in order.
> 
> Z-dim is still confusing to me.  Maybe I'm just being dense.  So is
> Z-dim 1 the same as easting and Z-dim 2 the same as northing?  If so,
> let's just call it "dim" - if not, "n-dim" might be better.  When I

Okay, to my mind, every dimension after the easting and northing is a 
z-dim up to the cat or label or ... I don't think well in more than 3d!
Call it a limit of perceptual reality.  Anyway, I can call it just 'dim'
or 'ndim' to be consistent with the Site struct.  To me, a 'dim' could
be in any spatial direction, but since the easting and northing are
already accounted for ... you're left with the z-axis (discounting time,
and other n-dimensional geometries).  I don't see using those 'dims' for
anything other than the Z-axis -- there are double attributes already to
represent other things not defining the geometry.

[snip]

> >Anyway, shall I look at writing a generalized G_readsites() (and maybe
> >G_writesites() ?) using the standard Site struct?  I'm ambivalent.
> >
> 
> Me too.  I'd consider these "convenience" functions. 

Well, we'll let that rest for awhile.  I was going to look at some
parsing problems with s.in.ascii anyway.  I may not have time to do
anything for a week or so, going out of town...


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