[GRASS-user] r.proj error

[Hamish]

gary wrote:

> Well 14 hours later, my r.proj bombed.

I'm not surprised!

> Unfortunately, I don't have an email account set up for root. Any
> ideas on why this bombed?

why are you running GRASS as root? That's probably not a very good idea.

FWIW, in GRASS 6.1 r.proj has been changed to be run as a normal module,
i.e. no email; has 0-100% progress meter.


> BTW, is there some easy way to keep the projected resolution from 
> exceeding the input resolution? Given the nearest neighbor algorithm, 
> there is nothing to be gain by interpolation (I assume).

Remember it will likely be slighlty rotated and stretched as well.

> Output:
> Cols:   90240 (90240)
> Rows:   201058 (201058)
     ^^^^^^^
> North: 4224601.960000 (4224601.960000)
> South: 4023544.200000 (4023544.200000)
> West:  513581.640000 (513581.640000)
> East:  603821.510000 (603821.510000)
> ew-res: 0.999999
> ns-res: 0.999999


90240 x 201058 = 18 billion cells, at least 72 gig of data. ouch.

set the target resolution a bit lower,

> Input:
> Cols:   3608 (3608)
> Rows:   6546 (6546)
...
> ew-res: 0.000278
> ns-res: 0.000278


0.000278 deg lat * 1852m/naut mi. * 60 naut mi./degree = 30.9m

( *cos(lat) for longitude )

in target location:
g.region res=30 -a


> Allocating memory and reading input map...  100%
> Projecting... WARNING: error writing null row 190379
> ERROR: error writing output map
> You have new mail in /var/spool/mail/root
..
> Unfortunately, I don't have an email account set up for root.

maybe your computer is one step ahead of you, try:

less /var/spool/mail/root



you may also try 'r.proj -n'  (similar to 'i.rectify -c'?)



Hamish