[GRASS5] s.proj site header

Helena hmitaso at unity.ncsu.edu
Sat Sep 29 21:24:54 EDT 2001


"Eric G. Miller" wrote:

> On Fri, 28 Sep 2001 19:08:56 -0500, Helena <hmitaso at unity.ncsu.edu> wrote:
>
> [snip]
> > >A new implementation seen in s.in.shape is there, but commented.
> > what do you mean by this?
> >
> > >The time stamp facility does not appear to work at present.
> > I found this in manual for s.in.shape - does this mean that the time
> > stamp
> > associated with the shape file is not imported?
>
> If you figure out how to use the sites timestamp interface (or if
> it works), let me know.  When I've mucked with sites programs, I
> could never get anything useful to happen.  I'm not sure if the
> documentation is just poor, or if there's a real bug in the
> implementation.  I never spent much time trying to figure it
> out, as most the sites modules I've worked on never supported
> that header to begin with (I was trying to add it).

most of the header is really just for users convenience (so that you know
what
is in your data set) so it is mostly s.info that is using it. In s.surf.rst
we read the
header and write the time stamp to the resulting rasters - this is important
for
working with spatio-temporal data (and in fact almost all the data that I
have
been recently working with are spatiotemporal, including such previously
considered static layers like digital elevation models), so that one could
manage
the data as time series, create animations, and do all kinds of
spatiotemporal analysis for which
we still don't have any functionality in GRASS but hopefully we will get
there.
So at this point all that is there regarding the time stamp is that the
temporal
info can be stored with each data layer and can be transfered automatically
to the result created based on this data layer (I believe (hope) that there
are quite a few
modules that read and write the time stamp quietly). It would be
really nice (and probably not too difficult) to have an option with d.rast,
d.sites..., nviz,
to display the time stamp.

So to conclude this, time stamp is just another capability (along
with g3d) that we started to support modeling and simulations, but which has
never
been really finished or even fully used, but you should be able to add it to
your file,
read it and write it to the resulting file. I don't think that there are any
problems with it, as
my problems turned out to be my mistakes (embarassingly I did not read the
description
of the sites header properly),

Helena

>
>
> --
> Eric G. Miller <egm2 at jps.net>
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