topic Re: ascii problems: pyramids, to raster etc... in Data Management Questions

ascii problems: pyramids, to raster etc...

LornaMurison — Wed, 26 Jan 2011 18:30:39 GMT

Hi everyone,
I have several ascii files representing climate data. I would like to use them to calculate zonal statistics and cell statistics. Here are some of the issues I have been having:

1. If I try to add one of the ascii files to ArcMap and build pyramids it takes about 3 seconds to get to 51% then just stops without giving any error messages. The same happens if I try to build pyramids from ArcCatalog. Same thing happens with all the files, always stops at 51%.
2. I tried calculating cell statistics on two files and it took over an hour without finishing (it covers all of US and Canada, so it may have worked if I'd just left it though...)
3. Trying to convert ascii to raster fails with error 010067.
4. Trying to run extract by mask (so I am not using all of US and Canada) also fails with error 010092: invalid output extent. The output extent is set to intersection of inputs.

If anyone has suggestions regarding any of the above problems it would be greatly appreciated.

only ascii integer grids will work

LornaMurison — Thu, 27 Jan 2011 13:29:53 GMT

Here is an update.
Some of my ascii grids appear to be working. The working ones are in integer format, and the non-working ones have decimals.
All of the integer grids work perfectly. Cell statistics completes in a few seconds, pyramids work, and they can be converted to esri GRID.
The float grids have all the problems listed in my first post. Anyone know why this is happening?

Thanks

Re: ascii problems: pyramids, to raster etc...

NiklasNorrthon — Thu, 27 Jan 2011 19:17:38 GMT

Could it be a decimal point / decimal comma issue? Wouldn't be the first time in ArcGIS.

Re: ascii problems: pyramids, to raster etc...

LornaMurison — Fri, 28 Jan 2011 12:13:21 GMT

What do you mean by decimal point/comma issue? My grids don't contain any commas.
Here is what mine looks like:

NCOLS 2784
NROWS 1440
XLLCORNER -168.00000000000
YLLCORNER 25.000000000000
CELLSIZE 0.41666668839753E-01
NODATA_VALUE -9999.000
-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00
-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00-9999.00

Do you see any problems with it?
I tried changing Cellsize to 0.04166... with no E but that didn't help.

Thank you,

Re: ascii problems: pyramids, to raster etc...

LornaMurison — Fri, 28 Jan 2011 12:56:16 GMT

There were no spaces in between all the no data values!
I opened the grid in MS word and replaced all "-9999.00" with " -9999.00". Now it works. Luckily the actual values have correct spacing, it was only the NoData values that were causing problems.