What's the difference between sage class ZZ (rings/integer_ring.pyx) and Integer (rings/integer.pyx)?
Is one preferred over the other in some cases? Do they provide different functionality?
Maybe instances of Integer are elements of ZZ?!
a = ZZ(10)
b = Integer(3)
c = a + b
print a, b, c
print "Type of elements:", type(a), "vs", type(b), "vs", type(c)
print "Type of classes: ", ZZ, "vs", Integer
Sage uses the parent/element pattern for most mathematical objects, see the documentation on coercion for details. For integers the parent is IntegerRing (with ZZ as shortcut) and the element are Integer.
sage: i = 1
sage: type(i)
sage.rings.integer.Integer
sage: type(i.parent())
sage.rings.integer_ring.IntegerRing_class
sage: ZZ is IntegerRing() is i.parent()
True
Yes, Integer is the type of elements in ZZ. ZZ refers to the ring of integers, whereas Integer refers to the type of an element of the ring ZZ. When you execute, say ZZ(int(10)), int(10) is coerced to an Integer. In your example above you can verify this.
sage: print "Type of elements:", type(a), "vs", type(b), "vs", type(c)
Type of elements: <type 'sage.rings.integer.Integer'> vs <type 'sage.rings.integer.Integer'> vs <type 'sage.rings.integer.Integer'>
The elements a, b, and c are of the same type.
Asked: 2013-04-02 10:46:47 +0200
Seen: 2,101 times
Last updated: Apr 03 '13
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