[Tugindia] Comparison of input methods

[Duvvuri Venu Gopal]

A comparison of input method used by different programmers to 
input Indian symbols using English keyboard.

Some time back I promised to do a comparative study of the various 
key strokes used by different programmes. This is the culimination 
of the study. I had studied three different packages - Devnag of 
Velthuis, Telugu TeX of Mukkavilli Lakshi and iLeap developed by 
C-DAC.

This study is necessitated because a Universal input method will 
make it easier to transliterate material from one Indian language 
to another. Particularly it is useful for the Sanskrit slokas, 
otherwise one has to type the same sloka for each language using 
different methods.

The Indian alphabet is derived from the Brahmi script and almost 
all the Indian languages have same vowels and consonents.

The first column denotes the vowel/consonent letter in Indian 
language (Sanskrit/Telugu), the second column shows the method 
adopted by Velthuis for his Devnag, the third column shows the 
method of Mukkavilli Lakshi and the last column of iLeap of 
C-DAC.

a	a		a	a
A	aa or A		A	A
i	i		i	i
I	ii or I		I	I
u	u		u	u
U	uu or U	U	U
ri	.r		rx	HRi
rI	.R		Rx	HRI
li	.l		lx	--
lI	.L		Lx	--
e	-		e	E
E	e		E	e
Ai	ai or E		y	AY
o	-		o	O
O	o		O	o
Au	au or O		ow	AW

Am	.m or M	M	M
Ah	.h or H		ah	:

k	k		k	k
kh	kh or K	kh	kh
g	g		g	g
gh	gh or G	gh	gh
ng	"n		NG	Ng

ch	c		c	ch
chh	ch or C		ch	chh
j	j		j	j
jh	jh or J		jh	jh
nj	~n		nx	Nj

T	.t		T	T
Th	.th or .T	Th	Th
D	.d		D	D
Dh	.dh or .D	Dh	Dh
na	.n		N	N

t	t		t	t
th	th or T		th	th
d	d		d	d
dh	dh or D	dh	dh
n	n		n	n

p	p		p	p
ph	ph or P		ph	pb
b	b		b	b
bh	bh or B	bh	bh
m	m		m	m

y	y		Y	y
r	r		r	r
rr	-		R	.r
l	l		l	l
L	L		L	L
v	v		v	v
sh	"s		S	sh
Sh	.s		Sh	Sh
s	s		s	s
h	h		h	h
ksh	-		Xh	kSh
gna	--		--	dny

Other characters
Punjabi R	R	-	R
Punjabi Dh	Rh	-	Rh
Urdu f		f	-	f
Urdu j		z	-	z
Urdu kh	.kh or.K -	K
Urdu g		.g	-	G
Urdu k		q	-	q
Marathi r	~r	-	.r

Chandrabindu	/	Mh	.M
avagraha	.a	\zzFF	.a
Om		O	-	OM

halant		&	x	X

 From the above it is evident that Mukkavilli Lakshmi and C-DAC 
followed a systematic pattern, except in a few instances where 
they differed. Whereas Devnag of Velthuis and the other two 
systems vary drastically in the T-varg. Velthuis also 
unnecessarily complicated by introducing two different types of 
inputs for the letters - A, I, U, ri, kh, gh, ch, jh, th, dh, th, 
dh, ph, bh. There is no mention about the characters ksha and  gna 
(as in Jnani) in Velthuis's Devnag.

It appears from the ITRANS 5.3 help pages this sort of 
standardization was already done by Avinash Chopde for ITRANS. The 
problem is I could install it properly and there is no help 
available.

Conclusion:

All the developers of Indic TeX may follow the system developed by 
either Mukkavilli Lakshmi or C-DAC, as the roman input is more 
readable than Velthuis's format. In that case it is necessary to 
change the Velthuis's Devnag preprocesser also for 
Sanskrit/Marathi/Hindi appropriately.