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Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

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<strong>Sage</strong> <strong>Reference</strong> <strong>Manual</strong>: <strong>Matrices</strong> <strong>and</strong> <strong>Spaces</strong> <strong>of</strong> <strong>Matrices</strong>, Release 6.1.1<br />

sage: t.column_module()<br />

Vector space <strong>of</strong> degree 3 <strong>and</strong> dimension 2 over Rational Field<br />

Basis matrix:<br />

[ 1 0 -1]<br />

[ 0 1 2]<br />

column_space()<br />

Return the vector space over the base ring spanned by the columns <strong>of</strong> this matrix.<br />

EXAMPLES:<br />

sage: M = MatrixSpace(QQ,3,3)<br />

sage: A = M([1,9,-7,4/5,4,3,6,4,3])<br />

sage: A.column_space()<br />

Vector space <strong>of</strong> degree 3 <strong>and</strong> dimension 3 over Rational Field<br />

Basis matrix:<br />

[1 0 0]<br />

[0 1 0]<br />

[0 0 1]<br />

sage: W = MatrixSpace(CC,2,2)<br />

sage: B = W([1, 2+3*I,4+5*I,9]); B<br />

[ 1.00000000000000 2.00000000000000 + 3.00000000000000*I]<br />

[4.00000000000000 + 5.00000000000000*I 9.00000000000000]<br />

sage: B.column_space()<br />

Vector space <strong>of</strong> degree 2 <strong>and</strong> dimension 2 over Complex Field with 53 bits <strong>of</strong> precision<br />

Basis matrix:<br />

[ 1.00000000000000 0.000000000000000]<br />

[0.000000000000000 1.00000000000000]<br />

conjugate()<br />

Return the conjugate <strong>of</strong> self, i.e. the matrix whose entries are the conjugates <strong>of</strong> the entries <strong>of</strong> self.<br />

EXAMPLES:<br />

sage: A = matrix(CDF, [[1+I,1],[0,2*I]])<br />

sage: A.conjugate()<br />

[1.0 - 1.0*I 1.0]<br />

[ 0.0 -2.0*I]<br />

A matrix over a not-totally-real number field:<br />

sage: K. = NumberField(x^2+5)<br />

sage: M = matrix(K, [[1+j,1], [0,2*j]])<br />

sage: M.conjugate()<br />

[-j + 1 1]<br />

[ 0 -2*j]<br />

There is a shortcut for the conjugate:<br />

sage: M.C<br />

[-j + 1 1]<br />

[ 0 -2*j]<br />

There is also a shortcut for the conjugate transpose, or “Hermitian transpose”:<br />

sage: M.H<br />

[-j + 1 0]<br />

[ 1 -2*j]<br />

Conjugates work (trivially) for matrices over rings that embed canonically into the real numbers:<br />

142 Chapter 7. Base class for matrices, part 2

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