Greetings all,
I am trying to run r.watershed on a county-wide LIDAR data layer. However, r.watershed returned a segment_format error during Section 1 of the analysis. Here is the error output:
SECTION 1 beginning: Initiating Variables. 5 sections total.
segment_format(fd,1,-1831011296,1,25,20): illegal value(s)
seg_open(): illegal configuration parameter(s)
Also, for reference, here is the information for the elevation input map being used:
Type of Map: raster Number of Categories: 255 | Data Type: FCELL | Rows: 44000 | Columns: 55999 | Total Cells: -1831011296 | Projection: State Plane | N: 589970.67755842 S: 479971.19725012 Res: 2.49998819 | E: 2226464.7485208 W: 2086468.7440966 Res: 2.49997329 | Range of data: min = 764.770020 max = 1324.199951 |
| Data Description: | generated by r.patch
The raster layer consists of about 530 separate grids that were patched together in stages using r.patch. The resolution of the layer is 2.50 feet.
I am not able to determine what would have caused the error. Are there too many rows/columns, or is the negative value for the "Total Cells" causing a problem? Perhaps I used the wrong approach in patching the individual grids together?
If any additional information is needed, let me know, and I will do my best to provide it. Many thanks for any and all assistance.
~Wes
Wes,
IMHO your problem indicates that you are exceeding the 32bit
limits for file size (I may be wrong but Total Cells: -1831011296
may indicate that).
GRASS >= 6.0 includes experimental support for reading and writing large files
(> 2GB) if it is possible in your operating system. If you compile with
configure [...] --enable-largefile
you should be able to have raster maps which are larger than 2GB.
Note that the support currently only applies to the core raster I/O code.
Individual programs may or may not work with large files - please report.
Markus
On Jan 29, 2008 2:26 PM, Wes Kent <wkent@medinaco.org> wrote:
Greetings all,
I am trying to run r.watershed on a county-wide LIDAR data layer.
However, r.watershed returned a segment_format error during Section 1 of
the analysis. Here is the error output:
SECTION 1 beginning: Initiating Variables. 5 sections total.
segment_format(fd,1,-1831011296,1,25,20): illegal value(s)
seg_open(): illegal configuration parameter(s)
Also, for reference, here is the information for the elevation input map
being used:
Type of Map: raster Number of Categories: 255
| Data Type:
FCELL
| Rows:
44000
| Columns:
55999
| Total Cells:
-1831011296
| Projection: State
Plane
| N: 589970.67755842 S: 479971.19725012 Res:
2.49998819
| E: 2226464.7485208 W: 2086468.7440966 Res:
2.49997329
| Range of data: min = 764.770020 max =
1324.199951
|
| Data
Description:
| generated by r.patch
The raster layer consists of about 530 separate grids that were patched
together in stages using r.patch. The resolution of the layer is 2.50 feet.
I am not able to determine what would have caused the error. Are there
too many rows/columns, or is the negative value for the "Total Cells"
causing a problem? Perhaps I used the wrong approach in patching the
individual grids together?
If any additional information is needed, let me know, and I will do my
best to provide it. Many thanks for any and all assistance.
~Wes