Typing Greek letters (Shallow Thoughts)

Akkana's Musings on Open Source Computing and Technology, Science, and Nature.

Tue, 25 Apr 2017

Typing Greek letters

I'm taking a MOOC that includes equations involving Greek letters like epsilon. I'm taking notes online, in Emacs, using the iimage mode tricks for taking MOOC class notes in emacs that I worked out a few years back.

Iimage mode works fine for taking screenshots of the blackboard in the videos, but sometimes I'd prefer to just put the equations inline in my file. At first I was typing out things like E = epsilon * sigma * T^4 but that's silly, and of course the professor isn't spelling out the Greek letters like that when he writes the equations on the blackboard. There's got to be a way to type Greek letters on this US keyboard.

I know how to type things like accented characters using the "Multi key" or "Compose key". In /etc/default/keyboard I have XKBOPTIONS="ctrl:nocaps,compose:menu,terminate:ctrl_alt_bksp" which, among other things, sets the compose key to be my "Menu" key, which I never used otherwise. And there's a file, /usr/share/X11/locale/en_US.UTF-8/Compose, that includes all the built-in compose key sequences. I have a shell function in my .zshrc,

composekey() {
  grep -i $1 /usr/share/X11/locale/en_US.UTF-8/Compose
}
so I can type something like composekey epsilon and find out how to type specific codes. But that didn't work so well for Greek letters. It turns out this is how you type them:
<dead_greek> <A>            : "Α"   U0391    # GREEK CAPITAL LETTER ALPHA
<dead_greek> <a>            : "α"   U03B1    # GREEK SMALL LETTER ALPHA
<dead_greek> <B>            : "Β"   U0392    # GREEK CAPITAL LETTER BETA
<dead_greek> <b>            : "β"   U03B2    # GREEK SMALL LETTER BETA
<dead_greek> <D>            : "Δ"   U0394    # GREEK CAPITAL LETTER DELTA
<dead_greek> <d>            : "δ"   U03B4    # GREEK SMALL LETTER DELTA
<dead_greek> <E>            : "Ε"   U0395    # GREEK CAPITAL LETTER EPSILON
<dead_greek> <e>            : "ε"   U03B5    # GREEK SMALL LETTER EPSILON
... and so forth. And this <dead_greek> key isn't actually defined in most US/English keyboard layouts: you can check whether it's defined for you with: xmodmap -pke | grep dead_greek

Of course you can use xmodmap to define a key to be <dead_greek>. I stared at my keyboard for a bit, and decided that, considering how seldom I actually need to type Greek characters, I didn't see the point of losing a key for that purpose (though if you want to, here's a thread on how to map <dead_greek> with xmodmap).

I decided it would make much more sense to map it to the compose key with a prefix, like 'g', that I don't need otherwise. I can do that in ~/.XCompose like this:

<Multi_key> <g> <A>            : "Α"   U0391    # GREEK CAPITAL LETTER ALPHA
<Multi_key> <g> <a>            : "α"   U03B1    # GREEK SMALL LETTER ALPHA
<Multi_key> <g> <B>            : "Β"   U0392    # GREEK CAPITAL LETTER BETA
<Multi_key> <g> <b>            : "β"   U03B2    # GREEK SMALL LETTER BETA
<Multi_key> <g> <D>            : "Δ"   U0394    # GREEK CAPITAL LETTER DELTA
<Multi_key> <g> <d>            : "δ"   U03B4    # GREEK SMALL LETTER DELTA
<Multi_key> <g> <E>            : "Ε"   U0395    # GREEK CAPITAL LETTER EPSILON
<Multi_key> <g> <e>            : "ε"   U03B5    # GREEK SMALL LETTER EPSILON
... and so forth.

And now I can type [MENU] g e and a lovely ε appears, at least in any app that supports Greek fonts, which is most of them nowadays.

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[ 12:57 Apr 25, 2017    More linux | permalink to this entry | comments ]
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