[GRASSLIST:3344] RE: r.le.pixel

[William L. Baker]

Hi David,

I'm the author of r.le.pixel.

r.le.pixel will leave a null row and
column when you use a 3x3 window because
the window starts centered over row 2 and
column 2.  No value is defined for row 1 and
column 1, since that pixel would not have the
full 9 pixels.  The larger the window, the
larger the null area along the edge. If you
feel that a calculation should be done even
though the windows would not be complete,
you could add rows or columns as needed outside
the image.  Not sure how to do this in GRASS,
but it could probably be done.

Bill Baker

-----Original Message-----
From: David Nogues [mailto:dnogues at ipe.csic.es]
Sent: Monday, March 18, 2002 4:57 AM
To: grass list
Subject: [GRASSLIST:3342] r.le.pixel


Hello all,

When Im working with r.le.pixel module in moving window mode, the result
image (example: a shannonn index with a 3x3 window) shows null value in
the pixels located in the first and last column and row. If the window
is 10x10, eastern, souhthern, northern and western four columns appears
with null value.

I've tried a lot of differents ways (mask, no mask, changing region,
etc..) and i can't get the correct result image. Anything can help me?



--
David Nogués Bravo
Instituto Pirenaico de Ecología
Consejo Superior de Investigaciones Científicas
Campus de Aula Dei
Av. Montañana, 1005
Apartado 202
50080 ZARAGOZA, ESPAÑA
Tlfno: 976716034