[GRASS-dev] ascii export and import, large file problem

[Jerry Nelson]

To provide more info, 

The 'after' info
|   Rows:         21048

|   Columns:      17067

|   Total Cells:  359226216

|        Projection: UTM (zone 37)

|            N: 1989570.65127245    S: -516147.35893555   Res: 119.047796

|            E: 1868393.2390198    W: -163395.4953122   Res: 119.047796

|   Range of data:    min = 0.000000  max = 557.001038


The 'before' info
|   Rows:         21048   
|   Columns:      17067

|   Total Cells:  359226216

|        Projection: UTM (zone 37)

|            N: 1989664.48241023    S: -516147.35893555   Res: 119.05225396

|            E: 1868393.2316229    W: -163395.4953122   Res: 119.04779557

|   Range of data:    min = 0.000000  max = 557.001038

-----Original Message-----
From: Glynn Clements [mailto:glynn at gclements.plus.com] 
Sent: Thursday, April 12, 2007 9:43 AM
To: Jerry Nelson
Cc: 'grass-dev'
Subject: Re: [GRASS-dev] ascii export and import, large file problem


Jerry Nelson wrote:

> I'm using grass6.3 updated today so the large file support for the ascii
> commands is included. I export a file using r.out.arc and then read it
back
> in using r.in.arc. The attached jpg shows the original raster on the
right.
> The screen on the left is the original raster minus the exported and
> imported version. The bottom two thirds or so of the left raster is zero,
as
> it should be, but the top 1/3 has a bunch of small values (range is - to
> +2.9).

My first guess is that the export->import process is changing the
vertical extent of the map slightly, so the calculation in the upper
portion of the map is using cells which are off by one row.

What does r.info say about the bounds of the two maps?

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