one way:
sage: symbolic_expression(list(zero_vector(k)))
# k, dim. of vector, k is some fixed integer, e.g. k = 10,
# many thanks to @tmonteil but it is too long!!
You can make your expression shorter by typing:
sage: w = zero_vector(SR, 10) ; w
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)You can check that it is the same object:
sage: v = symbolic_expression(list(zero_vector(10)))
sage: v
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
sage: v == w
TrueThanks! Yes, that is what I want! SR = Symbolic Ring, super.
Can we create a list whose entries are all 1, using a similar method?
For the follow-up question posted as a comment to @tmonteil's answer:
vector(SR, [1]*10)is worth mentioning as well. Here, [1]*10 is just the Python way of
constructing a list with 10 repeats of 1.
A version with 14 characters
sage: (SR^10).zero()
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)that could even be shorten to 9
sage: (SR^10)()
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)This is an answer to the follow-up question posted as a comment to @tmonteil's answer.
There is no function ones_vector but we can define
a vector of ones as the first row of a matrix of ones:
sage: v = matrix.ones(SR, 1, 10)[0]
sage: v
(1, 1, 1, 1, 1, 1, 1, 1, 1, 1)
sage: v.parent()
Vector space of dimension 10 over Symbolic RingIt lives in the same space as the zero vector:
sage: u = zero_vector(SR, 10)
sage: u
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
sage: u.parent()
Vector space of dimension 10 over Symbolic RingAsked: 11 years ago
Seen: 5,055 times
Last updated: Apr 20 '19
Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
Can you make your wish more explicit ? Is k a fixed number ? Wich order of magnitude ?
Sorry, it is some fixed integer, e.g. k = 10
what do you mean by "it is too long" ?
the length of the string "symbolic_expression(list(zero_vector(k)))", can we use some command like "zero_list(k)"?