Hi, I've got a column vector and I need to transpose it. But when i do:
v=v.column() it says column() takes at least 1 positional argument (0 given)
I've also tried doing v=Matrix([[1, 0, 0],[0, 1, 0], [0, 0, 1],])*v.column() which worked before but still doesn't work.
What is the problem here?
Thank you
Note that you are trying to multiply a matrix by a list. Instead of using a list you should use another matrix. Here's a way you can do it:
m = Matrix([[1, 0, 0],[0, 1, 0], [0, 0, 1]])
v = Matrix(3,1,[1,2,3])
m * v
Note several things
m = Matrix.identity(3)Sage is written in the Python language. Python is an object-oriented programming language. You can think of an object as a way to store some data together with functions which operate on it an modify it. Everything in Python is an object; numbers are objects, lists are objects, etc. List is a very basic object which does not support many operations; you can index a list, you can join two lists, and you can do a few other things. Matrix is an object which supports many more operations. For example, you can compute the Jordan form of a matrix, you can multiply two matrices of appropriate sizes, etc. So a object of type Matrix corresponds better to the abstract mathematical notion of matrix than does an object of type list.
Maybe you don't need to transpose your column vector. If A is a matrix and v is a vector, then A * v will use v as a column vector, and v * A will use v as a row vector.
If you want to make v a row vector, you can do v.row().
the column method is for extracting a column of a matrix. You need to specify the index of the column (from 0 to nrows - 1).
Illustration:
sage: m = Matrix([[1, 1, 0],[0, 2, 0], [0, 0, 3],])
sage: v = m.column(1)
sage: v
(1, 2, 0)
sage: m * v
(3, 4, 0)
sage: v * m
(1, 5, 0)
sage: u = v.row()
sage: u
[1 2 0]
sage: w = u.transpose()
sage: w
[1]
[2]
[0]
sage: u * w
[5]
sage: w * u
[1 2 0]
[2 4 0]
[0 0 0]
I need to transpose the vector because when i use it in a sum it says unsupported operand parent(s) for '+': 'Full MatrixSpace of 3 by 1 dense matrices over Symbolic Ring' and 'Vector space of dimension 3 over Symbolic Ring' , so i thought maybe it was because it had to be a row vector.
v.row() it still says row() takes at least 1 positional argument (0 given) ?Asked: 2015-01-12 19:04:10 +0100
Seen: 14,179 times
Last updated: Jan 12 '15
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