Hello Jonny,
You don't mention which version of netCDF/netCDF utilities you are using, but
assuming they are a modern version then you should be fine. Both ncgen and
ncdump are capable of using exponential format for representing extreme
floating-point numbers. Consider the following cdl file:
netcdf fp_test {
dimensions:
latitude = 2 ;
variables:
float latitude(latitude) ;
data:
latitude = 2.5e-20, 0.00000000000000000000123456 ;
}
If I generate a netCDF file using `ncgen -b fp_test.cdl`, and then inspect the
contents with `ncdump fp_test.nc`, I see the following:
netcdf fp_test {
dimensions:
latitude = 3 ;
variables:
float latitude(latitude) ;
data:
latitude = 2.5e-20, 1.23456e-21 ;
}
I hope this helps; have a great day, let me know if any issues arise!
-Ward
> Hi.
>
> I use a software package called IGOR Pro, which has no native netCDF
> support. So I'm writing some tools to load/create netCDF files this
> thanks to the netCDF library's and ncgen/ncdump. This generally works
> well, but I've been thinking about trying to conserve data integrity as
> much as possible during conversion to netCDF.
>
> What I don't get a feel for is how ncgen deals with float and double
> data types. I can output number in decimal format with the correct
> number of sig figs, but if we consider the value 1.23456e-20, you need
> over 20 sig figs to represent that in decimal format in the CDL file
> (0.0000000000000000000123456). Does ncgen deal with this? Can it use
> exponential format with the "correct" number of significant figures?
>
> Thanks
>
> Jonny
>
> --
>
> =======================================================
> Dr Jonathan Crosier
> NCAS Weather Scientist
> School of Earth, Atmospheric & Environmental Sciences
> The University of Manchester
> Simon Building, Oxford Road
> Manchester
> M13 9PL
>
> tel: +44 161 306 8398
> fax: +44 161 306 3951
>
>
Ticket Details
===================
Ticket ID: LHC-295018
Department: Support netCDF
Priority: Normal
Status: Closed
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