[Cfp-interest 2741] Re: Definition of the 'carg' function

[Damian McGuckin]

I have structured the text as if it were to go into CD2 style spreadsheet.

Comments please?

Clause/Subclause:
-----------------
     7.3.9.1

Paragraph/Figure/Table
----------------------
     2,3,Index

Type of Comment
---------------
     ed

Comment:
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     The term used in the description, 'phase angle' disagrees with that in the
     definitions used in the Digital Library of Mathematical Functions (DLMF)
     from the (US) National Institute of Standards and Technology (NIST). As the
     above mentioned NIST reference attests, the concept in brackets should more
     correctly be called just 'phase', where said phase is an angle. This concurs
     with numerous openly available university-level course notes on the topic.

     Also, C23 currently says that this function computes the argument and notes
     that phase is an alternative name, NIST does the reverse. This avoids the
     confusion possible when using the term 'argument'. It is proposed that C23
     follows what NIST does. NIST's DLMF, the successor to Abramowitz & Stegun's
     Handbook of Mathematical Functions, seems to have worldwide acceptance.

     The original text excluding the cross reference in the Index is:

     Description
2   The carg functions compute the argument (also called phase angle) of
     z, with a branch cut along the negative real axis.

     Returns
3   The carg functions return the value of the argument in the interval
     [-pi, +pi]

Proposed Change
---------------

2   The carg functions compute the phase (also called argument) of z, an
     angle expressed in radians, with a branch cut along the negative real
     axis.

3   The carg functions return the value of the phase in the interval
     [-pi,+pi]

and in the INDEX

     For the currently used term 'phase angle', there should be
     parentheses put around the word angle as in

         phase (angle), of a complex number, 195

     For the currently used term 'argument, complex', it should
     more succinctly be written as

         argument, of a complex number, 195

     Note - Reformatting may change 195, the page number of 7.3.9.1