GRASS to ARC grid projection differences

GRASS GRASS user
1

hello,

does anyone know why there would be a large difference
between the region specified for a grass raster file
and the x and y min/max when it is converted to an
arc grid? see eg./details below:

GRASS: (utm) ARC: (utm)

ncols 129
nrow 249
n 3957930 xmax 3954330
s 3950460 xmin 3950460
e 369040 ymax 372640
w 365170 ymin 365170
cellsize 30m cell 30m

thanks...alynne.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
& Alynne Bayard (alynne@cast.uark.edu) &
& Research Assistant - Tree-Ring Laboratory &
& Ancient Cross Timbers Project &
& Department of Geosciences, Ozark Hall #113 &
& University of Arkansas &
& Fayetteville, AR 72701 &
& tel: (501) 575-4277 ; fax: (501) 575-3177 &
& (xtimber) http://www.uark.edu/xtimber/ &
& {me= http://www.cast.uark.edu/~alynne\} &
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2

Alynne,
It appears your x and y have been transposed - y max is equivalent to
north, y min is equivalent to south, etc. You'll find that the
difference between y max and y min is equal to 249 * 30, as is should
be, but the starting coordinate is wrong (it's the west coordinate!).

Best regards,
  -Malcolm Williamson

Alynne Bayard wrote:

hello,

does anyone know why there would be a large difference
between the region specified for a grass raster file
and the x and y min/max when it is converted to an
arc grid? see eg./details below:

GRASS: (utm) ARC: (utm)

ncols 129
nrow 249
n 3957930 xmax 3954330
s 3950460 xmin 3950460
e 369040 ymax 372640
w 365170 ymin 365170
cellsize 30m cell 30m

thanks...alynne.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
& Alynne Bayard (alynne@cast.uark.edu) &
& Research Assistant - Tree-Ring Laboratory &
& Ancient Cross Timbers Project &
& Department of Geosciences, Ozark Hall #113 &
& University of Arkansas &
& Fayetteville, AR 72701 &
& tel: (501) 575-4277 ; fax: (501) 575-3177 &
& (xtimber) http://www.uark.edu/xtimber/ &
& {me= http://www.cast.uark.edu/~alynne\} &
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

3

thanks for everyones' responses...the error was made by
the typists, not the software...ab.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
& Alynne Bayard (alynne@cast.uark.edu) &
& Research Assistant - Tree-Ring Laboratory &
& Ancient Cross Timbers Project &
& Department of Geosciences, Ozark Hall #113 &
& University of Arkansas &
& Fayetteville, AR 72701 &
& tel: (501) 575-4277 ; fax: (501) 575-3177 &
& (xtimber) http://www.uark.edu/xtimber/ &
& {me= http://www.cast.uark.edu/~alynne\} &
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