[Phys-L] math symbols and other fancy symbols in email etc.

[John Denker <jsd@av8n.com>]

On 10/20/2015 07:56 AM, Donald G Polvani asked:

> >      A  :=  [ϕ/c, Ax, Ay, Az]
> ...
> > 	F  =  dA
> >  	   =  ∇∧A
>
> How did you get the Greek symbol (phi) and the math symbol (nabla or del) to print in this response?


It's as easy as π.

Seriously, the short answer is:
  *) front end:  cut-and-paste
  *) back end:   unicode

---------

In more detail:

1) Front-end operational issues:

1a) Usually the easiest way to put fancy characters into email is to 
cut-and-paste from a web page or other document that already has what 
you want.

I use the following web page to collect things that I use frequently:
   https://www.av8n.com/jsd/play.html

Examples include:
  Жуковский == Zhukovsky
  Ἀρχιμήδης == Archimedes
  杨辉三角 == Yang Hui triangle
  𝄞 == g clef

1b) As for the equations quoted above, I cut-and-pasted them from
   https://www.av8n.com/physics/lienard-wiechert.htm

1c) If there is some character that you would like, you can search for
 it by name and then cut-and-paste:
  https://www.google.com/search?q=unicode+letter+eth

1d) There are keyboard shortcuts for entering certain characters, 
 without cutting-and-pasting.  Alas, this doesn't cover all characters.
 YMMV, but I find the shortcuts to be not worth remembering.  For me,
 the cut-and-paste technique is easier.

---------

2) Back-end issues:

This requires support across numerous layers of software.  However, the
required features are very widely available, and have been for years.
Hint:  There is a large market for computers in Asia, and they pretty
much insist on good unicode support.

Specific suggestion:  Make sure your mailer is configured to use
"utf-8" as the default character encoding for outgoing mail.

Note that when replying to an email, your mailer "probably" uses
the same encoding as the original.  However, nowadays most folks
are using utf-8, so this usually isn't a problem.
Similarly, when creating web pages, make sure your tools are configured
to use utf-8 as the page's character encoding.

Note that the phys-l distribution system and archives are perfectly 
happy with utf-8.

Emacs is smart about utf8.  It lets you cut-and-paste.  It also will
let you enter unicode via the numerical value (^X8<enter>) and 
conversely will tell you the value of an existing char (^X=).

Also note that as of version 3, python is perfectly happy with
unicode.  For example, chr(0x2207) should give you the ∇ character.
Conversely ord('≡') should give you 8801 (decimal).

  Similar features are available under version 2.7, but the
  syntax differs slightly.

You can get similar results in perl, but you have to beseech it as follows:
  use utf8;
  binmode STDOUT, ":utf8";
  print ord('≡');