Thanks Matthew
Armel
----- Original Message -----
From: Matthew Pocock <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, December 04, 1999 5:08 PM
Subject: Re: [JAVA3D] Tuple classe???
> In mathematics and set theory, a tuple is an ordered set of items where
the type
> of the item in a particular place is fixed. For example, you could have a
tuple
> of numbers, in which case it would be a vector. You could have a tuple of
(name,
> age, phonenumber), in which case it looks like a struct in C. The
locations of
> the items in the tuple can be represented by integers (1 to length, or 0
to
> length-1, depending on how you like to count). Since this defines a map
from the
> set {1..length} to the corresponding values, you can define an identity
> relationship between the set {1..length} and another equaly sized set of
names,
> or keys. This has the knock-on effecth that you can retrieve values by
name,
> making a tuple look very much like a hash table. This is how Perl models
> objects, or JavaBeans model properties (with the indexes being replaced
with
> unique property names).
>
> In programming, tuples are normaly represented as lists or arrays. When
the type
> of each element can be different, then structs or simple objects are used.
> Sparse tuples (where most values are empty or zero) can efficiently be
> represented by a hash table or map. In a database, each table defines a
type of
> tuple, and the SQL join operations boil down to cross and dot products of
these
> tuples.
>
> Hope that helps.
>
> Matthew
>
> armel wrote:
>
> > Hello,
> > Tuple, what does it mean exactly, I understand it used to represent
tuples
> > by the javax.vecmath package.
> > But wich is the origin of this word in programmation ? Perhaps it help
me to
> > understand.
> >
> > Thanks
> > Armel
> > ---
> > '' � cette heure, des enfants naissent en Bretagne.
> > Seront-ils bretons ? Nul ne le sait.
> > � chacun, l'�ge venu, la d�couverte ou l'ignorance.'' Lebesque Morvan
> >
> >
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>
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>
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