Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

Sage Reference Manual: Matrices and Spaces of Matrices, Release 6.1.1
[2 1]
[5 4]
[0 7]
matrix_from_rows(rows)
Return the matrix constructed from self using rows with indices in the rows list.
EXAMPLES:
sage: M = MatrixSpace(Integers(8),3,3)
sage: A = M(range(9)); A
[0 1 2]
[3 4 5]
[6 7 0]
sage: A.matrix_from_rows([2,1])
[6 7 0]
[3 4 5]
matrix_from_rows_and_columns(rows, columns)
Return the matrix constructed from self from the given rows and columns.
EXAMPLES:
sage: M = MatrixSpace(Integers(8),3,3)
sage: A = M(range(9)); A
[0 1 2]
[3 4 5]
[6 7 0]
sage: A.matrix_from_rows_and_columns([1], [0,2])
[3 5]
sage: A.matrix_from_rows_and_columns([1,2], [1,2])
[4 5]
[7 0]
Note that row and column indices can be reordered or repeated:
sage: A.matrix_from_rows_and_columns([2,1], [2,1])
[0 7]
[5 4]
For example here we take from row 1 columns 2 then 0 twice, and do this 3 times.
sage: A.matrix_from_rows_and_columns([1,1,1],[2,0,0])
[5 3 3]
[5 3 3]
[5 3 3]
AUTHORS:
•Jaap Spies (2006-02-18)
•Didier Deshommes: some Pyrex speedups implemented
matrix_over_field()
Return copy of this matrix, but with entries viewed as elements of the fraction field of the base ring
(assuming it is defined).
EXAMPLES:
sage: A = MatrixSpace(IntegerRing(),2)([1,2,3,4])
sage: B = A.matrix_over_field()
sage: B
106 Chapter 6. Base class for matrices, part 1