[GRASS-dev] Re: [GRASS-user] problems using r.proj with large data set

[Glynn Clements]

Dylan Beaudette wrote:

> the output from r.proj and r.proj.seg give about 99.99% identical results. I 
> have attached the output from r.report run on the difference between the two 
> maps.

Odd. There shouldn't be *any* difference (other than the fact that
r.proj.seg will tend to produce some nulls where r.proj produces
non-null values). The difference map should have min=max=0, i.e. 
wherever both programs produce non-null values, they should be
identical.

AFAICT, there shouldn't even be any rounding-error differences; the
actual interpolation expressions are essentially identical.

Can you figure out a way to reproduce this with readily-available data
(or even synthetic data)?

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