The Communications of the TEX Users Group Volume 29 ... - TUG

Stanislav Jan ˇ Sarman
use the traditional Bézier spline circle segment approximation
for the segments 1–7 (see the 7 th segment
on the left) z( 1/2) = 1, so that δ0 = δ1 =
4/3 tan(θ/4) and κi = −(1 − sin 4 (θ/4)). Using this
value as left point curvature of the 8 th segment (see
on the right) and demanding κ1 = 0, the Hermite
interpolation with the equations (1)–(2) for the unknowns
δ0 und δ1 can be solved for segments with
θ < 60 ◦ .
z + 0
z − 1
z0
κ0 ≈ −1
κ1 ≈ −1
z1
a
z0
κ0 ≈ −1
θ
z + 0 z − 1
a
κ1 = 0
Figure 3: 7 th and 8 th segment (θ = 45 ◦ ) of our unit
right circle spline approximation
For CV C joinings 7×7 cases are possible in
all —many of them can be transformed by reflection
and rotation into one another. All these joinings can
be made G (2) continuous. It must be decided before
writing a right consonant, whether the loop is to be
written as a left or as a right loop, compare:
team (t)+[i](m) � vs. � (m)-[i](t) meet
CV C � �� �� �� �� �� �� ��
�
� �
�
�
�
�
�
�
� �
�
�
�
�
�
�
� �
�
�
� �
�
�
�
�
�
��
� � � � � � �
� �
� �� � � � � �
�
Technically speaking the shorthand glyphs are
realized as
• an array of G (0) –G (2) continuous METAFONTpaths
and
• an array of discontinous marker paths.
Slanting (default 22.5 ◦ ) and tilting 3 of characters
is done at the time of their shipping.
3 G (2) continuity is invariant under affine transformations.
θ
z1
2 Phonetic writing
Gregg shorthand uses its own orthography, which
must be acquired by the shorthand learner and in
a system such as ours, the pronunciation of a word
has to be known. We use the Unisyn multi-accent
lexicon 4 with about 118,000 entries[4] comprising
British and American spelling variants. The fields
of lexicon entries are: spelling, optional identifier,
part-of-speech, pronunciation, enriched orthography,
and frequency. Examples are:
owed;;VBD/VBN; { * ouw }> d >;{owe}>ed>;2588
live;1;VB/VBP; { l * i v } ;{live};72417
live;2;JJ; { l * ae v } ;{live};72417}
Homonyma cases such as “live” above, in which
the pronunciation helps to identify word meaning
are much more rarer than the cases in which the
use of pronunciation yields homophones resulting in
shorthand homographs. Consider the very frequent
right, rite, wright, write: { r * ai t } with short-
hand glyph (r)+[ai](t)� or the heterophones
read;1;VB/NN/NNP/VBP; { r * ii d };{read};94567
read;2;VBN/VBD; { r * e d };{read};94567
both written as � (r)+[e|i](d). Thus phonetic
writing may speed up the shorthand recording, but
the newly-created homographs complicate the deciphering
of written notes.
The pronunciation of a word has to be transformed
to the above defined metaform, e.g.:
needed: { n * ii d }.> I7 d >⇒ (n)-[i](dd)
needing: { n * ii d }.> i ng >⇒ (n)-[i](,d,ing)
This major task consists of a number of transformations
done in this order:
• Elimination of minor (redundant) vowels such
as the schwa @r in
fewer: { f y * iu }> @r r >.
There is a general problem with the schwas (@).
Which are to be ruled out and which of them are
to be backtransformed 5 to the spelling equivalent?
Consider
data: { d * ee . t == @ } ⇒ (d)-[a](t]-[a]
upon: { @ . p * o n } ⇒ (u)(p)(n)
Both @ are backtransformed, but stressed o is
cancelled.
• Finding of prefixes (un-, re-, . ..), suffixes (-ing,
-ly, . ..), handling of semiconsonants h, w.
• Creation of ligatures such as dd, parenthesizing
consonants and bracketing circular vowels.
• Finding the proper orientation of loops.
These tranformations are done through a series of
cascaded context dependent rewrite rules, realized
4 which itself is a part of a text-to-speech system
5 by a lex program
460 TUGboat, Volume 29 (2008), No. 3 — Proceedings of the 2008 Annual Meeting