Subject: TSCAL and TZEROn with P datatypes

From: pence at tetra.gsfc.nasa.gov (William Pence)
Date: Wed, 16 Mar 94 16:30:40 EST

Barry Schlesinger wrote:

>> table.  The heap facility that is proposed for binary tables serves our
>> needs well but again with one exception - unsigned types are not supported in
>> heap storage (one cannot even apply TSCAL and TZERO to heap data)....
>
>Not being able to scale heap values is a problem and probably an 
>oversight.  One possible proposal would be to change the rule to allow 
>the use of TSCALn and TZEROn in fields with P data types, with the 
>understanding that the scaling is to be applied to the heap data.

I also think this was just an oversight.  The main text of the binary
table proposal is correct in stating that the use of the TSCALn keyword
is not defined for the P format fields, because the use of the P format
is also not defined in the main text.  The use of TSCALn and TZEROn to
refer to the heap data in P type fields probably should have been
discussed in appendix A, however, where the 'variable length array'
facility is described in detail.  Since the convention described in
Appendix A is "still undergoing trials" and has not been offically
voted on, there should be little problem in correcting this oversight.

-Bill Pence