Path: steve
Newsgroups: rec.juggling
Distribution: local
Followup-To: 
From: steve@geosys.co.uk (Steve Hawtin)
Reply-To: steve@geosys.co.uk
Organization: Oilfield Systems Ltd.
Subject: Another notation
Keywords: notation juggle



I have read of a number of "languages" for describing juggling
patterns, as yet I have not found one that "feels right",
however I thought I might have a go at creating such a language. 
Now while I am only an ameteur juggler I am a professional
programmer so over a weekend I put together a program that takes
pattern descriptions in an "English like" language, and displays
them on a computer screen.

I have sent the program off to 

    piggy.cogsci.indiana.edu

and I understand that it is available via ftp or ftpmail.

The program is called "jug" you will require a 'C' compiler on
your system to compile the source code once it has been compiled
you can start it with a command such as

    jug five.jug

the second parameter is the file describing the juggle you want
it to perform for you.  The basic output relies on just having
an ASCII terminal, so it should be possible to use the program
on any machine with a compiler.  There are some problems with
porting to some systems, if you find any fixes for your system
please mail them to me and I will put them in the standard
version. 


Of course the main element of interest is the description of
juggles to perform, so here is some idea of how the language
works. 


When I do a pattern it can be split into three steps,

    1.  Pick up the balls, clubs, rings or cats.  
    2.  Throw some of them into the air
    3.  Now that everything is moving start the pattern

With this in mind a pattern description should contain a
description of these three steps. 

The first step just tells me what to pick up in which hand, and
possibly where my hands should be, for example if I have a red
ball, a green club and a blue cat

    right red green
    left blue

but what about where my hand should be? It seems logical to me
that my right hand is at 0 when throwing in the cascade, with
positive positions going towards my left hand, and the same in
reverse for my left hand, so say postion 3 on my right hand is
the same as position 0 on my left hand

    # right   -2  -1   0   1   2   3   4   5
    # left     5   4   3   2   1   0  -1  -2

of course we have more than one dimension, otherwise juggling
would be slightly harder than it currently is, so we could
specify the position as

    right red green at -1,1,1

where the second component, height, is positive upwards, and the
third component is positive away from you. 

Now that we know where to start from the second step is to
describe what to throw up to get the pattern started, when we
have instructions there are a number of things that must be
specified.  First we have the time at which to do the action, we
can do this by having a "time label" such as "89:" for time 89. 
Next we need to know what to do, so if at time 0 we want to do a
throw we could say

    0: throw green right from -1,2

with a throw we must also specify how far across to throw the
ball and how high to throw it.  One way to do this is to say
where the ball should be when it falls back to the level it
started from, and how many moves later this should be, so if we
say

    0: throw green right from 0,0 towards 3,4

then at time 4 the green ball will be at 3,0 on its way to the
floor.  So we could add

    4: catch left green at 0

since 3,0 for the right hand is the same as 0,0 for the left. 
Of course we could also have moved the hand at time 3 and caught
the ball at time 4 by saying

    3: move left 0,0
    4: catch left

Now we have a number of objects travelling arround under the
influence of gravity, we need to specify a pattern of actions to
stop them hitting the floor.  Using the same instructions that
were used for the second stage a simple cascade could be

    3: throw left towards 4,4 	# No need to specify ball, only one there
    4: catch left		# Just catch the nearest at -1,0
    6: swap hand		# Using the other hand
       loop time 3		# Go back to label 3 and do again

Of course the '#' character introduces a comment that lasts until the 
end of the line.

So we can now have a complete description of a shower, it could be

    # Right hand shower

    # First where the balls are to start with
    right red green	
    left blue

    # Next how to get into the pattern
    0: throw right green towards 3,6 from 0

    # Finally the pattern itself
    3: throw right towards 3,6
       throw left towards 3,2
    5: catch right
    6: catch left
       loop 3

Unfortunately this language still does not feel right, it seems
to be too complicated and requires too many explicit numbers in
the commands.  However it does allow the description of more
complex patterns than site swaping and the interpreter makes the
job of creating new juggles easier. 

If anyone has any ideas for improvements, please get in touch.

Steve Hawtin			EMAIL    : steve@geosys.co.uk
Oilfield Systems Ltd.,		BANGNET  : ...!uunet!mcsun!uknet!geosys!steve
Worthy Park House,		PHONE    : +44 962 882448
Abbots Worthy, Winchester,	FAX      : +44 962 885085
Hants. SSO21 1AN, ENGLAND.