689 lines
30 KiB
Fortran
689 lines
30 KiB
Fortran
SUBROUTINE ZGEDMDQ( JOBS, JOBZ, JOBR, JOBQ, JOBT, JOBF, &
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WHTSVD, M, N, F, LDF, X, LDX, Y, &
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LDY, NRNK, TOL, K, EIGS, &
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Z, LDZ, RES, B, LDB, V, LDV, &
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S, LDS, ZWORK, LZWORK, WORK, LWORK, &
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IWORK, LIWORK, INFO )
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! March 2023
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!.....
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USE iso_fortran_env
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IMPLICIT NONE
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INTEGER, PARAMETER :: WP = real64
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!.....
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! Scalar arguments
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CHARACTER, INTENT(IN) :: JOBS, JOBZ, JOBR, JOBQ, &
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JOBT, JOBF
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INTEGER, INTENT(IN) :: WHTSVD, M, N, LDF, LDX, &
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LDY, NRNK, LDZ, LDB, LDV, &
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LDS, LZWORK, LWORK, LIWORK
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INTEGER, INTENT(OUT) :: INFO, K
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REAL(KIND=WP), INTENT(IN) :: TOL
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! Array arguments
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COMPLEX(KIND=WP), INTENT(INOUT) :: F(LDF,*)
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COMPLEX(KIND=WP), INTENT(OUT) :: X(LDX,*), Y(LDY,*), &
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Z(LDZ,*), B(LDB,*), &
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V(LDV,*), S(LDS,*)
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COMPLEX(KIND=WP), INTENT(OUT) :: EIGS(*)
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COMPLEX(KIND=WP), INTENT(OUT) :: ZWORK(*)
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REAL(KIND=WP), INTENT(OUT) :: RES(*)
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REAL(KIND=WP), INTENT(OUT) :: WORK(*)
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INTEGER, INTENT(OUT) :: IWORK(*)
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!.....
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! Purpose
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! =======
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! ZGEDMDQ computes the Dynamic Mode Decomposition (DMD) for
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! a pair of data snapshot matrices, using a QR factorization
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! based compression of the data. For the input matrices
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! X and Y such that Y = A*X with an unaccessible matrix
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! A, ZGEDMDQ computes a certain number of Ritz pairs of A using
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! the standard Rayleigh-Ritz extraction from a subspace of
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! range(X) that is determined using the leading left singular
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! vectors of X. Optionally, ZGEDMDQ returns the residuals
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! of the computed Ritz pairs, the information needed for
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! a refinement of the Ritz vectors, or the eigenvectors of
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! the Exact DMD.
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! For further details see the references listed
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! below. For more details of the implementation see [3].
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!
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! References
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! ==========
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! [1] P. Schmid: Dynamic mode decomposition of numerical
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! and experimental data,
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! Journal of Fluid Mechanics 656, 5-28, 2010.
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! [2] Z. Drmac, I. Mezic, R. Mohr: Data driven modal
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! decompositions: analysis and enhancements,
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! SIAM J. on Sci. Comp. 40 (4), A2253-A2285, 2018.
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! [3] Z. Drmac: A LAPACK implementation of the Dynamic
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! Mode Decomposition I. Technical report. AIMDyn Inc.
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! and LAPACK Working Note 298.
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! [4] J. Tu, C. W. Rowley, D. M. Luchtenburg, S. L.
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! Brunton, N. Kutz: On Dynamic Mode Decomposition:
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! Theory and Applications, Journal of Computational
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! Dynamics 1(2), 391 -421, 2014.
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!
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! Developed and supported by:
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! ===========================
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! Developed and coded by Zlatko Drmac, Faculty of Science,
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! University of Zagreb; drmac@math.hr
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! In cooperation with
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! AIMdyn Inc., Santa Barbara, CA.
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! and supported by
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! - DARPA SBIR project "Koopman Operator-Based Forecasting
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! for Nonstationary Processes from Near-Term, Limited
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! Observational Data" Contract No: W31P4Q-21-C-0007
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! - DARPA PAI project "Physics-Informed Machine Learning
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! Methodologies" Contract No: HR0011-18-9-0033
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! - DARPA MoDyL project "A Data-Driven, Operator-Theoretic
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! Framework for Space-Time Analysis of Process Dynamics"
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! Contract No: HR0011-16-C-0116
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! Any opinions, findings and conclusions or recommendations
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! expressed in this material are those of the author and
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! do not necessarily reflect the views of the DARPA SBIR
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! Program Office.
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!============================================================
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! Distribution Statement A:
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! Approved for Public Release, Distribution Unlimited.
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! Cleared by DARPA on September 29, 2022
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!============================================================
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!......................................................................
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! Arguments
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! =========
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! JOBS (input) CHARACTER*1
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! Determines whether the initial data snapshots are scaled
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! by a diagonal matrix. The data snapshots are the columns
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! of F. The leading N-1 columns of F are denoted X and the
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! trailing N-1 columns are denoted Y.
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! 'S' :: The data snapshots matrices X and Y are multiplied
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! with a diagonal matrix D so that X*D has unit
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! nonzero columns (in the Euclidean 2-norm)
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! 'C' :: The snapshots are scaled as with the 'S' option.
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! If it is found that an i-th column of X is zero
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! vector and the corresponding i-th column of Y is
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! non-zero, then the i-th column of Y is set to
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! zero and a warning flag is raised.
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! 'Y' :: The data snapshots matrices X and Y are multiplied
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! by a diagonal matrix D so that Y*D has unit
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! nonzero columns (in the Euclidean 2-norm)
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! 'N' :: No data scaling.
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!.....
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! JOBZ (input) CHARACTER*1
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! Determines whether the eigenvectors (Koopman modes) will
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! be computed.
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! 'V' :: The eigenvectors (Koopman modes) will be computed
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! and returned in the matrix Z.
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! See the description of Z.
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! 'F' :: The eigenvectors (Koopman modes) will be returned
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! in factored form as the product Z*V, where Z
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! is orthonormal and V contains the eigenvectors
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! of the corresponding Rayleigh quotient.
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! See the descriptions of F, V, Z.
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! 'Q' :: The eigenvectors (Koopman modes) will be returned
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! in factored form as the product Q*Z, where Z
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! contains the eigenvectors of the compression of the
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! underlying discretized operator onto the span of
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! the data snapshots. See the descriptions of F, V, Z.
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! Q is from the initial QR factorization.
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! 'N' :: The eigenvectors are not computed.
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!.....
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! JOBR (input) CHARACTER*1
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! Determines whether to compute the residuals.
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! 'R' :: The residuals for the computed eigenpairs will
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! be computed and stored in the array RES.
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! See the description of RES.
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! For this option to be legal, JOBZ must be 'V'.
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! 'N' :: The residuals are not computed.
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!.....
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! JOBQ (input) CHARACTER*1
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! Specifies whether to explicitly compute and return the
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! unitary matrix from the QR factorization.
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! 'Q' :: The matrix Q of the QR factorization of the data
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! snapshot matrix is computed and stored in the
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! array F. See the description of F.
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! 'N' :: The matrix Q is not explicitly computed.
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!.....
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! JOBT (input) CHARACTER*1
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! Specifies whether to return the upper triangular factor
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! from the QR factorization.
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! 'R' :: The matrix R of the QR factorization of the data
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! snapshot matrix F is returned in the array Y.
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! See the description of Y and Further details.
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! 'N' :: The matrix R is not returned.
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!.....
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! JOBF (input) CHARACTER*1
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! Specifies whether to store information needed for post-
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! processing (e.g. computing refined Ritz vectors)
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! 'R' :: The matrix needed for the refinement of the Ritz
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! vectors is computed and stored in the array B.
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! See the description of B.
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! 'E' :: The unscaled eigenvectors of the Exact DMD are
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! computed and returned in the array B. See the
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! description of B.
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! 'N' :: No eigenvector refinement data is computed.
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! To be useful on exit, this option needs JOBQ='Q'.
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!.....
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! WHTSVD (input) INTEGER, WHSTVD in { 1, 2, 3, 4 }
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! Allows for a selection of the SVD algorithm from the
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! LAPACK library.
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! 1 :: ZGESVD (the QR SVD algorithm)
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! 2 :: ZGESDD (the Divide and Conquer algorithm; if enough
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! workspace available, this is the fastest option)
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! 3 :: ZGESVDQ (the preconditioned QR SVD ; this and 4
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! are the most accurate options)
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! 4 :: ZGEJSV (the preconditioned Jacobi SVD; this and 3
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! are the most accurate options)
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! For the four methods above, a significant difference in
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! the accuracy of small singular values is possible if
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! the snapshots vary in norm so that X is severely
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! ill-conditioned. If small (smaller than EPS*||X||)
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! singular values are of interest and JOBS=='N', then
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! the options (3, 4) give the most accurate results, where
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! the option 4 is slightly better and with stronger
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! theoretical background.
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! If JOBS=='S', i.e. the columns of X will be normalized,
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! then all methods give nearly equally accurate results.
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!.....
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! M (input) INTEGER, M >= 0
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! The state space dimension (the number of rows of F).
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!.....
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! N (input) INTEGER, 0 <= N <= M
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! The number of data snapshots from a single trajectory,
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! taken at equidistant discrete times. This is the
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! number of columns of F.
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!.....
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! F (input/output) COMPLEX(KIND=WP) M-by-N array
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! > On entry,
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! the columns of F are the sequence of data snapshots
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! from a single trajectory, taken at equidistant discrete
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! times. It is assumed that the column norms of F are
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! in the range of the normalized floating point numbers.
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! < On exit,
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! If JOBQ == 'Q', the array F contains the orthogonal
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! matrix/factor of the QR factorization of the initial
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! data snapshots matrix F. See the description of JOBQ.
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! If JOBQ == 'N', the entries in F strictly below the main
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! diagonal contain, column-wise, the information on the
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! Householder vectors, as returned by ZGEQRF. The
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! remaining information to restore the orthogonal matrix
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! of the initial QR factorization is stored in ZWORK(1:MIN(M,N)).
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! See the description of ZWORK.
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!.....
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! LDF (input) INTEGER, LDF >= M
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! The leading dimension of the array F.
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!.....
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! X (workspace/output) COMPLEX(KIND=WP) MIN(M,N)-by-(N-1) array
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! X is used as workspace to hold representations of the
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! leading N-1 snapshots in the orthonormal basis computed
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! in the QR factorization of F.
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! On exit, the leading K columns of X contain the leading
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! K left singular vectors of the above described content
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! of X. To lift them to the space of the left singular
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! vectors U(:,1:K) of the input data, pre-multiply with the
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! Q factor from the initial QR factorization.
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! See the descriptions of F, K, V and Z.
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!.....
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! LDX (input) INTEGER, LDX >= N
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! The leading dimension of the array X.
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!.....
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! Y (workspace/output) COMPLEX(KIND=WP) MIN(M,N)-by-(N) array
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! Y is used as workspace to hold representations of the
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! trailing N-1 snapshots in the orthonormal basis computed
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! in the QR factorization of F.
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! On exit,
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! If JOBT == 'R', Y contains the MIN(M,N)-by-N upper
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! triangular factor from the QR factorization of the data
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! snapshot matrix F.
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!.....
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! LDY (input) INTEGER , LDY >= N
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! The leading dimension of the array Y.
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!.....
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! NRNK (input) INTEGER
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! Determines the mode how to compute the numerical rank,
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! i.e. how to truncate small singular values of the input
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! matrix X. On input, if
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! NRNK = -1 :: i-th singular value sigma(i) is truncated
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! if sigma(i) <= TOL*sigma(1)
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! This option is recommended.
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! NRNK = -2 :: i-th singular value sigma(i) is truncated
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! if sigma(i) <= TOL*sigma(i-1)
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! This option is included for R&D purposes.
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! It requires highly accurate SVD, which
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! may not be feasible.
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! The numerical rank can be enforced by using positive
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! value of NRNK as follows:
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! 0 < NRNK <= N-1 :: at most NRNK largest singular values
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! will be used. If the number of the computed nonzero
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! singular values is less than NRNK, then only those
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! nonzero values will be used and the actually used
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! dimension is less than NRNK. The actual number of
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! the nonzero singular values is returned in the variable
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! K. See the description of K.
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!.....
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! TOL (input) REAL(KIND=WP), 0 <= TOL < 1
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! The tolerance for truncating small singular values.
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! See the description of NRNK.
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!.....
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! K (output) INTEGER, 0 <= K <= N
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! The dimension of the SVD/POD basis for the leading N-1
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! data snapshots (columns of F) and the number of the
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! computed Ritz pairs. The value of K is determined
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! according to the rule set by the parameters NRNK and
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! TOL. See the descriptions of NRNK and TOL.
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!.....
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! EIGS (output) COMPLEX(KIND=WP) (N-1)-by-1 array
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! The leading K (K<=N-1) entries of EIGS contain
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! the computed eigenvalues (Ritz values).
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! See the descriptions of K, and Z.
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!.....
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! Z (workspace/output) COMPLEX(KIND=WP) M-by-(N-1) array
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! If JOBZ =='V' then Z contains the Ritz vectors. Z(:,i)
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! is an eigenvector of the i-th Ritz value; ||Z(:,i)||_2=1.
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! If JOBZ == 'F', then the Z(:,i)'s are given implicitly as
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! Z*V, where Z contains orthonormal matrix (the product of
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! Q from the initial QR factorization and the SVD/POD_basis
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! returned by ZGEDMD in X) and the second factor (the
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! eigenvectors of the Rayleigh quotient) is in the array V,
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! as returned by ZGEDMD. That is, X(:,1:K)*V(:,i)
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! is an eigenvector corresponding to EIGS(i). The columns
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! of V(1:K,1:K) are the computed eigenvectors of the
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! K-by-K Rayleigh quotient.
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! See the descriptions of EIGS, X and V.
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!.....
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! LDZ (input) INTEGER , LDZ >= M
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! The leading dimension of the array Z.
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!.....
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! RES (output) REAL(KIND=WP) (N-1)-by-1 array
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! RES(1:K) contains the residuals for the K computed
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! Ritz pairs,
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! RES(i) = || A * Z(:,i) - EIGS(i)*Z(:,i))||_2.
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! See the description of EIGS and Z.
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!.....
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! B (output) COMPLEX(KIND=WP) MIN(M,N)-by-(N-1) array.
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! IF JOBF =='R', B(1:N,1:K) contains A*U(:,1:K), and can
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! be used for computing the refined vectors; see further
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! details in the provided references.
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! If JOBF == 'E', B(1:N,1;K) contains
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! A*U(:,1:K)*W(1:K,1:K), which are the vectors from the
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! Exact DMD, up to scaling by the inverse eigenvalues.
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! In both cases, the content of B can be lifted to the
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! original dimension of the input data by pre-multiplying
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! with the Q factor from the initial QR factorization.
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! Here A denotes a compression of the underlying operator.
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! See the descriptions of F and X.
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! If JOBF =='N', then B is not referenced.
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!.....
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! LDB (input) INTEGER, LDB >= MIN(M,N)
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! The leading dimension of the array B.
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!.....
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! V (workspace/output) COMPLEX(KIND=WP) (N-1)-by-(N-1) array
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! On exit, V(1:K,1:K) V contains the K eigenvectors of
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! the Rayleigh quotient. The Ritz vectors
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! (returned in Z) are the product of Q from the initial QR
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! factorization (see the description of F) X (see the
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! description of X) and V.
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!.....
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! LDV (input) INTEGER, LDV >= N-1
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! The leading dimension of the array V.
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!.....
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! S (output) COMPLEX(KIND=WP) (N-1)-by-(N-1) array
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! The array S(1:K,1:K) is used for the matrix Rayleigh
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! quotient. This content is overwritten during
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! the eigenvalue decomposition by ZGEEV.
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! See the description of K.
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!.....
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! LDS (input) INTEGER, LDS >= N-1
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! The leading dimension of the array S.
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!.....
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! ZWORK (workspace/output) COMPLEX(KIND=WP) LWORK-by-1 array
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! On exit,
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! ZWORK(1:MIN(M,N)) contains the scalar factors of the
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! elementary reflectors as returned by ZGEQRF of the
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! M-by-N input matrix F.
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! If the call to ZGEDMDQ is only workspace query, then
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! ZWORK(1) contains the minimal complex workspace length and
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! ZWORK(2) is the optimal complex workspace length.
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! Hence, the length of work is at least 2.
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! See the description of LZWORK.
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!.....
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! LZWORK (input) INTEGER
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! The minimal length of the workspace vector ZWORK.
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! LZWORK is calculated as follows:
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! Let MLWQR = N (minimal workspace for ZGEQRF[M,N])
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! MLWDMD = minimal workspace for ZGEDMD (see the
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! description of LWORK in ZGEDMD)
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! MLWMQR = N (minimal workspace for
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! ZUNMQR['L','N',M,N,N])
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! MLWGQR = N (minimal workspace for ZUNGQR[M,N,N])
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! MINMN = MIN(M,N)
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! Then
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! LZWORK = MAX(2, MIN(M,N)+MLWQR, MINMN+MLWDMD)
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! is further updated as follows:
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! if JOBZ == 'V' or JOBZ == 'F' THEN
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! LZWORK = MAX(LZWORK, MINMN+MLWMQR)
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! if JOBQ == 'Q' THEN
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! LZWORK = MAX(ZLWORK, MINMN+MLWGQR)
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!
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!.....
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! WORK (workspace/output) REAL(KIND=WP) LWORK-by-1 array
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! On exit,
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! WORK(1:N-1) contains the singular values of
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! the input submatrix F(1:M,1:N-1).
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! If the call to ZGEDMDQ is only workspace query, then
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! WORK(1) contains the minimal workspace length and
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! WORK(2) is the optimal workspace length. hence, the
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! length of work is at least 2.
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! See the description of LWORK.
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!.....
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! LWORK (input) INTEGER
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! The minimal length of the workspace vector WORK.
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! LWORK is the same as in ZGEDMD, because in ZGEDMDQ
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! only ZGEDMD requires real workspace for snapshots
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! of dimensions MIN(M,N)-by-(N-1).
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! If on entry LWORK = -1, then a workspace query is
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! assumed and the procedure only computes the minimal
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! and the optimal workspace length for WORK.
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!.....
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! IWORK (workspace/output) INTEGER LIWORK-by-1 array
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! Workspace that is required only if WHTSVD equals
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! 2 , 3 or 4. (See the description of WHTSVD).
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! If on entry LWORK =-1 or LIWORK=-1, then the
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! minimal length of IWORK is computed and returned in
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! IWORK(1). See the description of LIWORK.
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!.....
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! LIWORK (input) INTEGER
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! The minimal length of the workspace vector IWORK.
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! If WHTSVD == 1, then only IWORK(1) is used; LIWORK >=1
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! Let M1=MIN(M,N), N1=N-1. Then
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! If WHTSVD == 2, then LIWORK >= MAX(1,8*MIN(M1,N1))
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! If WHTSVD == 3, then LIWORK >= MAX(1,M1+N1-1)
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! If WHTSVD == 4, then LIWORK >= MAX(3,M1+3*N1)
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! If on entry LIWORK = -1, then a workspace query is
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! assumed and the procedure only computes the minimal
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! and the optimal workspace lengths for both WORK and
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! IWORK. See the descriptions of WORK and IWORK.
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!.....
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! INFO (output) INTEGER
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! -i < 0 :: On entry, the i-th argument had an
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! illegal value
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! = 0 :: Successful return.
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! = 1 :: Void input. Quick exit (M=0 or N=0).
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! = 2 :: The SVD computation of X did not converge.
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! Suggestion: Check the input data and/or
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|
! repeat with different WHTSVD.
|
|
! = 3 :: The computation of the eigenvalues did not
|
|
! converge.
|
|
! = 4 :: If data scaling was requested on input and
|
|
! the procedure found inconsistency in the data
|
|
! such that for some column index i,
|
|
! X(:,i) = 0 but Y(:,i) /= 0, then Y(:,i) is set
|
|
! to zero if JOBS=='C'. The computation proceeds
|
|
! with original or modified data and warning
|
|
! flag is set with INFO=4.
|
|
!.............................................................
|
|
!.............................................................
|
|
! Parameters
|
|
! ~~~~~~~~~~
|
|
REAL(KIND=WP), PARAMETER :: ONE = 1.0_WP
|
|
REAL(KIND=WP), PARAMETER :: ZERO = 0.0_WP
|
|
! COMPLEX(KIND=WP), PARAMETER :: ZONE = ( 1.0_WP, 0.0_WP )
|
|
COMPLEX(KIND=WP), PARAMETER :: ZZERO = ( 0.0_WP, 0.0_WP )
|
|
!
|
|
! Local scalars
|
|
! ~~~~~~~~~~~~~
|
|
INTEGER :: IMINWR, INFO1, MINMN, MLRWRK, &
|
|
MLWDMD, MLWGQR, MLWMQR, MLWORK, &
|
|
MLWQR, OLWDMD, OLWGQR, OLWMQR, &
|
|
OLWORK, OLWQR
|
|
LOGICAL :: LQUERY, SCCOLX, SCCOLY, WANTQ, &
|
|
WNTTRF, WNTRES, WNTVEC, WNTVCF, &
|
|
WNTVCQ, WNTREF, WNTEX
|
|
CHARACTER(LEN=1) :: JOBVL
|
|
!
|
|
! External functions (BLAS and LAPACK)
|
|
! ~~~~~~~~~~~~~~~~~
|
|
LOGICAL LSAME
|
|
EXTERNAL LSAME
|
|
!
|
|
! External subroutines (BLAS and LAPACK)
|
|
! ~~~~~~~~~~~~~~~~~~~~
|
|
EXTERNAL ZGEQRF, ZLACPY, ZLASET, ZUNGQR, &
|
|
ZUNMQR, XERBLA
|
|
|
|
! External subroutines
|
|
! ~~~~~~~~~~~~~~~~~~~~
|
|
EXTERNAL ZGEDMD
|
|
|
|
! Intrinsic functions
|
|
! ~~~~~~~~~~~~~~~~~~~
|
|
INTRINSIC MAX, MIN, INT
|
|
!..........................................................
|
|
!
|
|
! Test the input arguments
|
|
WNTRES = LSAME(JOBR,'R')
|
|
SCCOLX = LSAME(JOBS,'S') .OR. LSAME( JOBS, 'C' )
|
|
SCCOLY = LSAME(JOBS,'Y')
|
|
WNTVEC = LSAME(JOBZ,'V')
|
|
WNTVCF = LSAME(JOBZ,'F')
|
|
WNTVCQ = LSAME(JOBZ,'Q')
|
|
WNTREF = LSAME(JOBF,'R')
|
|
WNTEX = LSAME(JOBF,'E')
|
|
WANTQ = LSAME(JOBQ,'Q')
|
|
WNTTRF = LSAME(JOBT,'R')
|
|
MINMN = MIN(M,N)
|
|
INFO = 0
|
|
LQUERY = ( (LZWORK == -1) .OR. (LWORK == -1) .OR. (LIWORK == -1) )
|
|
!
|
|
IF ( .NOT. (SCCOLX .OR. SCCOLY .OR. &
|
|
LSAME(JOBS,'N')) ) THEN
|
|
INFO = -1
|
|
ELSE IF ( .NOT. (WNTVEC .OR. WNTVCF .OR. WNTVCQ &
|
|
.OR. LSAME(JOBZ,'N')) ) THEN
|
|
INFO = -2
|
|
ELSE IF ( .NOT. (WNTRES .OR. LSAME(JOBR,'N')) .OR. &
|
|
( WNTRES .AND. LSAME(JOBZ,'N') ) ) THEN
|
|
INFO = -3
|
|
ELSE IF ( .NOT. (WANTQ .OR. LSAME(JOBQ,'N')) ) THEN
|
|
INFO = -4
|
|
ELSE IF ( .NOT. ( WNTTRF .OR. LSAME(JOBT,'N') ) ) THEN
|
|
INFO = -5
|
|
ELSE IF ( .NOT. (WNTREF .OR. WNTEX .OR. &
|
|
LSAME(JOBF,'N') ) ) THEN
|
|
INFO = -6
|
|
ELSE IF ( .NOT. ((WHTSVD == 1).OR.(WHTSVD == 2).OR. &
|
|
(WHTSVD == 3).OR.(WHTSVD == 4)) ) THEN
|
|
INFO = -7
|
|
ELSE IF ( M < 0 ) THEN
|
|
INFO = -8
|
|
ELSE IF ( ( N < 0 ) .OR. ( N > M+1 ) ) THEN
|
|
INFO = -9
|
|
ELSE IF ( LDF < M ) THEN
|
|
INFO = -11
|
|
ELSE IF ( LDX < MINMN ) THEN
|
|
INFO = -13
|
|
ELSE IF ( LDY < MINMN ) THEN
|
|
INFO = -15
|
|
ELSE IF ( .NOT. (( NRNK == -2).OR.(NRNK == -1).OR. &
|
|
((NRNK >= 1).AND.(NRNK <=N ))) ) THEN
|
|
INFO = -16
|
|
ELSE IF ( ( TOL < ZERO ) .OR. ( TOL >= ONE ) ) THEN
|
|
INFO = -17
|
|
ELSE IF ( LDZ < M ) THEN
|
|
INFO = -21
|
|
ELSE IF ( (WNTREF.OR.WNTEX ).AND.( LDB < MINMN ) ) THEN
|
|
INFO = -24
|
|
ELSE IF ( LDV < N-1 ) THEN
|
|
INFO = -26
|
|
ELSE IF ( LDS < N-1 ) THEN
|
|
INFO = -28
|
|
END IF
|
|
!
|
|
IF ( WNTVEC .OR. WNTVCF .OR. WNTVCQ ) THEN
|
|
JOBVL = 'V'
|
|
ELSE
|
|
JOBVL = 'N'
|
|
END IF
|
|
IF ( INFO == 0 ) THEN
|
|
! Compute the minimal and the optimal workspace
|
|
! requirements. Simulate running the code and
|
|
! determine minimal and optimal sizes of the
|
|
! workspace at any moment of the run.
|
|
IF ( ( N == 0 ) .OR. ( N == 1 ) ) THEN
|
|
! All output except K is void. INFO=1 signals
|
|
! the void input. In case of a workspace query,
|
|
! the minimal workspace lengths are returned.
|
|
IF ( LQUERY ) THEN
|
|
IWORK(1) = 1
|
|
ZWORK(1) = 2
|
|
ZWORK(2) = 2
|
|
WORK(1) = 2
|
|
WORK(2) = 2
|
|
ELSE
|
|
K = 0
|
|
END IF
|
|
INFO = 1
|
|
RETURN
|
|
END IF
|
|
|
|
MLRWRK = 2
|
|
MLWORK = 2
|
|
OLWORK = 2
|
|
IMINWR = 1
|
|
MLWQR = MAX(1,N) ! Minimal workspace length for ZGEQRF.
|
|
MLWORK = MAX(MLWORK,MINMN + MLWQR)
|
|
|
|
IF ( LQUERY ) THEN
|
|
CALL ZGEQRF( M, N, F, LDF, ZWORK, ZWORK, -1, &
|
|
INFO1 )
|
|
OLWQR = INT(ZWORK(1))
|
|
OLWORK = MAX(OLWORK,MINMN + OLWQR)
|
|
END IF
|
|
CALL ZGEDMD( JOBS, JOBVL, JOBR, JOBF, WHTSVD, MINMN,&
|
|
N-1, X, LDX, Y, LDY, NRNK, TOL, K, &
|
|
EIGS, Z, LDZ, RES, B, LDB, V, LDV, &
|
|
S, LDS, ZWORK, -1, WORK, -1, IWORK,&
|
|
-1, INFO1 )
|
|
MLWDMD = INT(ZWORK(1))
|
|
MLWORK = MAX(MLWORK, MINMN + MLWDMD)
|
|
MLRWRK = MAX(MLRWRK, INT(WORK(1)))
|
|
IMINWR = MAX(IMINWR, IWORK(1))
|
|
IF ( LQUERY ) THEN
|
|
OLWDMD = INT(ZWORK(2))
|
|
OLWORK = MAX(OLWORK, MINMN+OLWDMD)
|
|
END IF
|
|
IF ( WNTVEC .OR. WNTVCF ) THEN
|
|
MLWMQR = MAX(1,N)
|
|
MLWORK = MAX(MLWORK,MINMN+MLWMQR)
|
|
IF ( LQUERY ) THEN
|
|
CALL ZUNMQR( 'L','N', M, N, MINMN, F, LDF, &
|
|
ZWORK, Z, LDZ, ZWORK, -1, INFO1 )
|
|
OLWMQR = INT(ZWORK(1))
|
|
OLWORK = MAX(OLWORK,MINMN+OLWMQR)
|
|
END IF
|
|
END IF
|
|
IF ( WANTQ ) THEN
|
|
MLWGQR = MAX(1,N)
|
|
MLWORK = MAX(MLWORK,MINMN+MLWGQR)
|
|
IF ( LQUERY ) THEN
|
|
CALL ZUNGQR( M, MINMN, MINMN, F, LDF, ZWORK, &
|
|
ZWORK, -1, INFO1 )
|
|
OLWGQR = INT(ZWORK(1))
|
|
OLWORK = MAX(OLWORK,MINMN+OLWGQR)
|
|
END IF
|
|
END IF
|
|
IF ( LIWORK < IMINWR .AND. (.NOT.LQUERY) ) INFO = -34
|
|
IF ( LWORK < MLRWRK .AND. (.NOT.LQUERY) ) INFO = -32
|
|
IF ( LZWORK < MLWORK .AND. (.NOT.LQUERY) ) INFO = -30
|
|
END IF
|
|
IF( INFO /= 0 ) THEN
|
|
CALL XERBLA( 'ZGEDMDQ', -INFO )
|
|
RETURN
|
|
ELSE IF ( LQUERY ) THEN
|
|
! Return minimal and optimal workspace sizes
|
|
IWORK(1) = IMINWR
|
|
ZWORK(1) = MLWORK
|
|
ZWORK(2) = OLWORK
|
|
WORK(1) = MLRWRK
|
|
WORK(2) = MLRWRK
|
|
RETURN
|
|
END IF
|
|
!.....
|
|
! Initial QR factorization that is used to represent the
|
|
! snapshots as elements of lower dimensional subspace.
|
|
! For large scale computation with M >> N, at this place
|
|
! one can use an out of core QRF.
|
|
!
|
|
CALL ZGEQRF( M, N, F, LDF, ZWORK, &
|
|
ZWORK(MINMN+1), LZWORK-MINMN, INFO1 )
|
|
!
|
|
! Define X and Y as the snapshots representations in the
|
|
! orthogonal basis computed in the QR factorization.
|
|
! X corresponds to the leading N-1 and Y to the trailing
|
|
! N-1 snapshots.
|
|
CALL ZLASET( 'L', MINMN, N-1, ZZERO, ZZERO, X, LDX )
|
|
CALL ZLACPY( 'U', MINMN, N-1, F, LDF, X, LDX )
|
|
CALL ZLACPY( 'A', MINMN, N-1, F(1,2), LDF, Y, LDY )
|
|
IF ( M >= 3 ) THEN
|
|
CALL ZLASET( 'L', MINMN-2, N-2, ZZERO, ZZERO, &
|
|
Y(3,1), LDY )
|
|
END IF
|
|
!
|
|
! Compute the DMD of the projected snapshot pairs (X,Y)
|
|
CALL ZGEDMD( JOBS, JOBVL, JOBR, JOBF, WHTSVD, MINMN, &
|
|
N-1, X, LDX, Y, LDY, NRNK, TOL, K, &
|
|
EIGS, Z, LDZ, RES, B, LDB, V, LDV, &
|
|
S, LDS, ZWORK(MINMN+1), LZWORK-MINMN, &
|
|
WORK, LWORK, IWORK, LIWORK, INFO1 )
|
|
IF ( INFO1 == 2 .OR. INFO1 == 3 ) THEN
|
|
! Return with error code. See ZGEDMD for details.
|
|
INFO = INFO1
|
|
RETURN
|
|
ELSE
|
|
INFO = INFO1
|
|
END IF
|
|
!
|
|
! The Ritz vectors (Koopman modes) can be explicitly
|
|
! formed or returned in factored form.
|
|
IF ( WNTVEC ) THEN
|
|
! Compute the eigenvectors explicitly.
|
|
IF ( M > MINMN ) CALL ZLASET( 'A', M-MINMN, K, ZZERO, &
|
|
ZZERO, Z(MINMN+1,1), LDZ )
|
|
CALL ZUNMQR( 'L','N', M, K, MINMN, F, LDF, ZWORK, Z, &
|
|
LDZ, ZWORK(MINMN+1), LZWORK-MINMN, INFO1 )
|
|
ELSE IF ( WNTVCF ) THEN
|
|
! Return the Ritz vectors (eigenvectors) in factored
|
|
! form Z*V, where Z contains orthonormal matrix (the
|
|
! product of Q from the initial QR factorization and
|
|
! the SVD/POD_basis returned by ZGEDMD in X) and the
|
|
! second factor (the eigenvectors of the Rayleigh
|
|
! quotient) is in the array V, as returned by ZGEDMD.
|
|
CALL ZLACPY( 'A', N, K, X, LDX, Z, LDZ )
|
|
IF ( M > N ) CALL ZLASET( 'A', M-N, K, ZZERO, ZZERO, &
|
|
Z(N+1,1), LDZ )
|
|
CALL ZUNMQR( 'L','N', M, K, MINMN, F, LDF, ZWORK, Z, &
|
|
LDZ, ZWORK(MINMN+1), LZWORK-MINMN, INFO1 )
|
|
END IF
|
|
!
|
|
! Some optional output variables:
|
|
!
|
|
! The upper triangular factor R in the initial QR
|
|
! factorization is optionally returned in the array Y.
|
|
! This is useful if this call to ZGEDMDQ is to be
|
|
! followed by a streaming DMD that is implemented in a
|
|
! QR compressed form.
|
|
IF ( WNTTRF ) THEN ! Return the upper triangular R in Y
|
|
CALL ZLASET( 'A', MINMN, N, ZZERO, ZZERO, Y, LDY )
|
|
CALL ZLACPY( 'U', MINMN, N, F, LDF, Y, LDY )
|
|
END IF
|
|
!
|
|
! The orthonormal/unitary factor Q in the initial QR
|
|
! factorization is optionally returned in the array F.
|
|
! Same as with the triangular factor above, this is
|
|
! useful in a streaming DMD.
|
|
IF ( WANTQ ) THEN ! Q overwrites F
|
|
CALL ZUNGQR( M, MINMN, MINMN, F, LDF, ZWORK, &
|
|
ZWORK(MINMN+1), LZWORK-MINMN, INFO1 )
|
|
END IF
|
|
!
|
|
RETURN
|
|
!
|
|
END SUBROUTINE ZGEDMDQ
|
|
|