I am using GRASS GIS 7.2 on a Windows 10 system with 32Gb ram. OSGEO4W 
distribution (with msys)

The region is lat/lon (-180 to 180, 90 to -90) and the resolution NS is 00:15 
and EW is 00:15

I am trying to export a raster into a grid (array) that I can use in Excel but 
am getting unusable output ... Here's what I do:

I create a text file in Excel with the data (University of Delaware - Global 
Monthly Mean Temperatures, 2014, using April) and add the header rows:

ncols 720
nrows 360
xllcorner -180
yllcorner -90
cellsize .50
nodata_value -99999
each cell has some value in it, if it isn't "-99999" then it is a floating 
point number (signed, 2 decimal places)

I save it as a space-sparated text file with a .asc extension

I import the raster using r.in.arc (r.in.arc input=AirTemp_Test2.asc 
output=AirTemp_Test2 type=FCELL --overwrite) which imports fine.

My region is set as described above and now I want to resample on the fly and 
export an ASCII grid I can use in Excel so I want new each row of data to have 
1440 columns (since the new resolution is 2x the original)

I have tried r.out.ascii (r.out.ascii -h -m input=AirTemp_Test2 
output=D:\air_temp_2014\Test2.txt precision=2 width=1440 --overwrite) but the 
problem I have is that it is floating point values and for some reason all of 
the data exported into the ASCII grid is in scientific notation with no 
separation between the values. In order to get an even 1440 x 720 ASCII grid, I 
need to check the "Write MODFLOW (USGS) ASCII array" box in the GUI and set the 
number of significant digits to 2 (otherwise you just get integers) and the 
wrapping number to 1440 ... this works fine for integers but defaults to the 
scientific notation for floating point which since there are no value 
separators, can't be worked with (integers are separated by a space). Two 
things: can we turn off scientific notation?, and add a separator for floating 
point values ... (please)

If I do not check the MODFLOW box, the grid output has the appropriate number 
of rows (720) but many of them have their data truncated. Every row should have 
1440 values.

I have tried r.out.arc (r.out.arc input=AirTemp_Test2 output=AirTest2 dp=2 
--overwrite) as well and while it generates the grid with space-separated 
values, they also seem to be truncated ... the truncation is not consistent 
either...

Am I doing something really wrong here ???

Thanks :)


Chris Bartolomei P.E.
bartolomei.ch...@ensco.com

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