#2854: results in winGRASS7 32bit vs 64bit: should they be identical?
-------------------------+---------------------------------
Reporter: hellik | Owner: grass-dev@…
Type: defect | Status: new
Priority: normal | Milestone: 7.0.3
Component: Raster | Version: svn-releasebranch70
Keywords: | CPU: x86-64
Platform: MSWindows 7 |
-------------------------+---------------------------------
taken from the dev ML [1]:
{{{
>>Like this you check if the difference is very small and below the
>>acceptable threshold.
>>In C, we use GRASS_EPSILON for these comparisons.
>
> now done with GRASS_EPSILON 1.0e-15
>
> r.mapcalc expression=difftestepsilon = if( abs( accum32bit at accumtest
-
> accum64bit at accumtest) <= 1.0e-15, 1 , 100 )
>
> attached a screenshot of this map
>
> accum_diff_wingrass32bitvs64bit.png
> <http://osgeo-
org.1560.x6.nabble.com/file/n5243286/accum_diff_wingrass32bitvs64bit.png>
Mhh..
Can you open a ticket with all relevant bits + the difference
screenshot along with a legend and "r.univar -e" output?
}}}
tested with the NC sample data set on the same 64bit- win7 box running
32bit and 64bit winGRASS binaries.
{{{
GRASS version: 7.0.3RC1
GRASS SVN Revision: 67443
Build Date: 2015-12-31
Build Platform: i386-w64-mingw32
GDAL/OGR: 1.11.3
PROJ.4: 4.9.2
GEOS: 3.5.0
SQLite: 3.7.17
Python: 2.7.4
wxPython: 2.8.12.1
Platform: Windows-7-6.1.7601-SP1 (OSGeo4W)
g.region -p -a raster=elevation@PERMANENT align=elevation@PERMANENT
projection: 99 (Lambert Conformal Conic)
zone: 0
datum: nad83
ellipsoid: a=6378137 es=0.006694380022900787
north: 228500
south: 215000
west: 630000
east: 645000
nsres: 10
ewres: 10
rows: 1350
cols: 1500
cells: 2025000
r.watershed elevation=elevation@PERMANENT accumulation=accum_wg32bit
SECTION 1a (of 4): Initiating Memory.
SECTION 1b (of 4): Determining Offmap Flow.
SECTION 2: A* Search.
SECTION 3a: Accumulating Surface Flow with MFD.
SECTION 3b: Adjusting drainage directions.
SECTION 4: Closing Maps.
(Thu Jan 07 11:30:02 2016) Command finished (40 sec)
r.univar -e map=accum_wg32bit@watershedtest
total null and non-null cells: 2025000
total null cells: 0
Of the non-null cells:
----------------------
n: 2025000
minimum: -638533
maximum: 330838
range: 969371
mean: -262.231
mean of absolute values: 685.177
standard deviation: 13021.3
variance: 1.69554e+008
variation coefficient: -4965.58 %
sum: -531016814.625176
1st quartile: 2.03496
median (even number of cells): 4.11548
3rd quartile: 9.49
90th percentile: 34.8313
(Thu Jan 07 11:31:41 2016) Command finished (17 sec)
}}}
{{{
System Info
GRASS version: 7.0.3RC1
GRASS SVN Revision: 67443
Build Date: 2015-12-31
Build Platform: x86_64-w64-mingw32
GDAL/OGR: 1.11.3
PROJ.4: 4.9.2
GEOS: 3.5.0
SQLite: 3.7.17
Python: 2.7.5
wxPython: 2.8.12.1
Platform: Windows-7-6.1.7601-SP1 (OSGeo4W)
g.region -p
projection: 99 (Lambert Conformal Conic)
zone: 0
datum: nad83
ellipsoid: a=6378137 es=0.006694380022900787
north: 228500
south: 215000
west: 630000
east: 645000
nsres: 10
ewres: 10
rows: 1350
cols: 1500
cells: 2025000
r.watershed elevation=elevation@PERMANENT accumulation=accum_wg64bit
SECTION 1a (of 4): Initiating Memory.
SECTION 1b (of 4): Determining Offmap Flow.
SECTION 2: A* Search.
SECTION 3a: Accumulating Surface Flow with MFD.
SECTION 3b: Adjusting drainage directions.
SECTION 4: Closing Maps.
(Thu Jan 07 11:38:49 2016) Command finished (4 sec)
r.univar -e map=accum_wg64bit@watershedtest
total null and non-null cells: 2025000
total null cells: 0
Of the non-null cells:
----------------------
n: 2025000
minimum: -638533
maximum: 330838
range: 969371
mean: -262.231
mean of absolute values: 685.177
standard deviation: 13021.3
variance: 1.69554e+008
variation coefficient: -4965.58 %
sum: -531016814.625176
1st quartile: 2.03496
median (even number of cells): 4.11548
3rd quartile: 9.49
90th percentile: 34.8313
(Thu Jan 07 11:39:36 2016) Command finished (6 sec)
}}}
{{{
r.mapcalc expression=difftestepsilon = if( abs(
accum_wg32bit@watershedtest - accum_wg64bit@watershedtest ) <= 1.0e-15 ,
1 ,100 )
}}}
{{{
r.univar -e map=difftestepsilon@watershedtest
total null and non-null cells: 2025000
total null cells: 0
Of the non-null cells:
----------------------
n: 2025000
minimum: 1
maximum: 100
range: 99
mean: 32.5001
mean of absolute values: 32.5001
standard deviation: 46.1113
variance: 2126.25
variation coefficient: 141.881 %
sum: 65812680
1st quartile: 1
median (even number of cells): 1
3rd quartile: 100
90th percentile: 100
}}}
[1] https://lists.osgeo.org/pipermail/grass-dev/2016-January/078282.html
--
Ticket URL: <https://trac.osgeo.org/grass/ticket/2854>
GRASS GIS <https://grass.osgeo.org>