ZLAQR4 - ZLAQR4 compute the eigenvalues of a Hessenberg matrix H and, optionally, the matrices T and Z from the Schur decomposition H = Z T Z**H, where T is an upper triangular matrix (the Schur form), and Z is the unitary matrix of Schur vectors ...
Several strategies for pivot selection in Givens reduction to upper triangular form and for row ordering within major steps of the reduction are compared o... IS Duff - 《Computing》 被引量: 95发表: 1974年 A parallel algorithm for the reduction of a nonsymmetric matrix to block upper-Hessenber...
A preliminary unitary similarity transformation to H... R Vandebril - 《Siam Journal on Matrix Analysis & Applications》 被引量: 34发表: 2011年 A Generalization of the Multishift QR Algorithm . . } , then H = V ∗ AV is a block upper triangular matrix containing Hessenberg blocks and ...
cgehrd reduces a complex general matrix A to upper Hessenberg form H by a unitary similarity transformation: Q' * A * Q = H .ARGUMENTSN (input) The order of the matrix A. N > = 0. ILO (input) It is assumed that A is already upper triangular in rows and columns 1:ILO-1 and...