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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: (~M * M).simplify_rational()<br />

[1 0 0]<br />

[0 1 0]<br />

[0 0 1]<br />

sage: matrix(SR, 1, 1, 1).inverse()<br />

[1]<br />

sage: matrix(SR, 0, 0).inverse()<br />

[]<br />

sage: matrix(SR, 3, 0).inverse()<br />

Traceback (most recent call last):<br />

...<br />

ArithmeticError: self must be a square matrix<br />

Transposition:<br />

sage: m = matrix(SR, 2, [sqrt(2), -1, pi, e^2])<br />

sage: m.transpose()<br />

[sqrt(2) pi]<br />

[ -1 e^2]<br />

.T is a convenient shortcut for the transpose:<br />

sage: m.T<br />

[sqrt(2) pi]<br />

[ -1 e^2]<br />

Test pickling:<br />

sage: m = matrix(SR, 2, [sqrt(2), 3, pi, e]); m<br />

[sqrt(2) 3]<br />

[ pi e]<br />

sage: TestSuite(m).run()<br />

Comparison:<br />

sage: m = matrix(SR, 2, [sqrt(2), 3, pi, e])<br />

sage: cmp(m,m)<br />

0<br />

sage: cmp(m,3) != 0<br />

True<br />

sage: m = matrix(SR,2,[1..4]); n = m^2<br />

sage: (exp(m+n) - exp(m)*exp(n)).simplify_rational() == 0<br />

True<br />

# indirect test<br />

Determinant:<br />

sage: M = matrix(SR, 2, 2, [x,2,3,4])<br />

sage: M.determinant()<br />

4*x - 6<br />

sage: M = matrix(SR, 3,3,range(9))<br />

sage: M.det()<br />

0<br />

sage: t = var(’t’)<br />

sage: M = matrix(SR, 2, 2, [cos(t), sin(t), -sin(t), cos(t)])<br />

sage: M.det()<br />

cos(t)^2 + sin(t)^2<br />

Permanents:<br />

304 Chapter 16. Symbolic matrices

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