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20000505: packing- scale_factor and add_offset

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  • Subject: 20000505: packing- scale_factor and add_offset
  • Date: Fri, 05 May 2000 09:32:58 -0600
Takaya,

> To: address@hidden
> From: "takaya namba" <address@hidden>
> Subject: scale_factor and add_offset
> Organization: waumail.com
> Keywords: 200005050755.e457tJG28481

In the above message, you wrote:

> When scale_factor and add_offsets are defined in the netcdf file,
> is it possible to unpack the variable without the formular in fortran?
> 
> x=(x_packed-1)*scale_factor + add_offset.
> 
> Which mean whether we can obtain x value automatically without the above 
> calculation or not?  
> 
> For example,if the factor.cdf define the scale_factor and add_offset inside,
> ncdump factor.cdf >factor
> ncgen -f factor >factor.f
> 
> only this process bring the unpacked value or now?

The netCDF library returns packed values.  The software that uses the
netCDF library must perform the unpacking computation in order to obtain
the actual values -- the netCDF library does not do this automatically.

Regards,
Steve Emmerson   <http://www.unidata.ucar.edu>