scale/offset clarified

To: netcdf-hdf@xxxxxxxxxxxxxxxx
Subject: scale/offset clarified
From: John Caron <caron@xxxxxxxxxxxxxxxx>
Date: Tue, 20 Jul 2004 09:30:36 -0600

try that last part again:

To compute the scale and offset:

   add_offset = dataMin
   scale_factor = (2^nbits - 2) / (dataMax - dataMin)

The precision of the data will be 1.0 / scale_factor.

To move between packed and unpacked values:

unpacked = (packed == 2^nbits-1) ? missing value : packed *scale_factor + add_offset

Follow-Ups:
- Re: scale/offset clarified
  - From: Robert E. McGrath