[GRASS-dev] Re: [GRASS-user] low radiance values after i.atcor and i.topo.corr

Glynn Clements glynn at gclements.plus.com
Thu Jun 19 06:12:53 EDT 2008


Nikos Alexandris wrote:

> > I have committed these changes (splitting the cluster code off to a
> > separate library, and changing it to use DCELL instead of CELL) to the
> > SVN trunk.
> > 
> > I would appreciate it if someone who understands i.cluster could test
> > the current version.
> 
> I've compiled and run it yesterday. How can I tell that the changes are
> effective? Should i.cluster NOT work before the changes with FP maps?

Well, the most important point is the absence of regressions, i.e. 
anything which used to work should continue to work.

Beyond that, the old i.cluster (and underlying library code) only
handled integer values, so any FP maps were rounded to integers.

If you take an existing set of maps and scale down the values to the
point that rounding will introduce significant error, you should see a
significant difference between the old and new versions (i.e. the new
version should continue to work, the old one will produce bogus
results).

-- 
Glynn Clements <glynn at gclements.plus.com>


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