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add schur decomposition wrappers #88
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@@ -70,6 +70,361 @@ def mc01td(dico,dp,p): | |
| return out[:-2] | ||
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| def mb03vd(n, ilo, ihi, A): | ||
| """ HQ, Tau = mb03vd(n, ilo, ihi, A) | ||
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| To reduce a product of p real general matrices A = A_1*A_2*...*A_p | ||
| to upper Hessenberg form, H = H_1*H_2*...*H_p, where H_1 is | ||
| upper Hessenberg, and H_2, ..., H_p are upper triangular, by using | ||
| orthogonal similarity transformations on A, | ||
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| Q_1' * A_1 * Q_2 = H_1, | ||
| Q_2' * A_2 * Q_3 = H_2, | ||
| ... | ||
| Q_p' * A_p * Q_1 = H_p. | ||
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| Parameters | ||
| ---------- | ||
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| n : int | ||
| The order of the square matrices A_1, A_2, ..., A_p. | ||
| n >= 0. | ||
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| ilo, ihi : int | ||
| It is assumed that all matrices A_j, j = 2, ..., p, are | ||
| already upper triangular in rows and columns [:ilo-1] and | ||
| [ihi:n], and A_1 is upper Hessenberg in rows and columns | ||
| [:ilo-1] and [ihi:n], with A_1[ilo-1,ilo-2] = 0 (unless | ||
| ilo = 1), and A_1[ihi,ihi-1] = 0 (unless ihi = n). | ||
| If this is not the case, ilo and ihi should be set to 1 | ||
| and n, respectively. | ||
| 1 <= ilo <= max(1,n); min(ilo,n) <= ihi <= n. | ||
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| A : ndarray | ||
| A[:n,:n,:p] must contain the matrices of factors to be reduced; | ||
| specifically, A[:,:,j-1] must contain A_j, j = 1, ..., p. | ||
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| Returns | ||
| ------- | ||
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| HQ : ndarray | ||
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Collaborator
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. I think specifying the exact size of Similarly, could you say what the size of
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There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more.
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There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Isn't it worth adding this to the docstring? If
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There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Yes that's the way many of the SLICOT routines do it. Adding this to the docstring and rebasing once more. We have a bunch of different docstring styles for the various functions. Opening another issue for that.
Collaborator
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Thank you. Do you agree with this, from #88 (comment):
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There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Agree. General rule is:
Or put differently:
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There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Fix committed |
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| 3D array with same shape as A. The upper triangle and the first | ||
| subdiagonal of HQ[:n,:n,0] contain the upper Hessenberg | ||
| matrix H_1, and the elements below the first subdiagonal, | ||
| with the first column of the array Tau represent the | ||
| orthogonal matrix Q_1 as a product of elementary | ||
| reflectors. See FURTHER COMMENTS. | ||
| For j > 1, the upper triangle of HQ[:n,:n,j-1] | ||
| contains the upper triangular matrix H_j, and the elements | ||
| below the diagonal, with the j-th column of the array TAU | ||
| represent the orthogonal matrix Q_j as a product of | ||
| elementary reflectors. See FURTHER COMMENTS. | ||
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| Tau : ndarray | ||
| 2D array with shape (max(1, n-1), p). | ||
| The leading n-1 elements in the j-th column contain the | ||
| scalar factors of the elementary reflectors used to form | ||
| the matrix Q_j, j = 1, ..., p. See FURTHER COMMENTS. | ||
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| Raises | ||
| ------ | ||
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| ValueError : e | ||
| e.info contains information about the exact type of exception | ||
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| Further Comments | ||
| ---------------- | ||
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| Each matrix Q_j is represented as a product of (ihi-ilo) | ||
| elementary reflectors, | ||
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| Q_j = H_j(ilo) H_j(ilo+1) . . . H_j(ihi-1). | ||
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| Each H_j(i), i = ilo, ..., ihi-1, has the form | ||
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| H_j(i) = I - tau_j * v_j * v_j', | ||
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| where tau_j is a real scalar, and v_j is a real vector with | ||
| v_j(1:i) = 0, v_j(i+1) = 1 and v_j(ihi+1:n) = 0; v_j(i+2:ihi) | ||
| is stored on exit in A_j(i+2:ihi,i), and tau_j in TAU(i,j). | ||
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| The contents of A_1 are illustrated by the following example | ||
| for n = 7, ilo = 2, and ihi = 6: | ||
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| on entry on exit | ||
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| ( a a a a a a a ) ( a h h h h h a ) | ||
| ( 0 a a a a a a ) ( 0 h h h h h a ) | ||
| ( 0 a a a a a a ) ( 0 h h h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 h h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 v3 h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 v3 v4 h h h ) | ||
| ( 0 0 0 0 0 0 a ) ( 0 0 0 0 0 0 a ) | ||
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| where a denotes an element of the original matrix A_1, h denotes | ||
| a modified element of the upper Hessenberg matrix H_1, and vi | ||
| denotes an element of the vector defining H_1(i). | ||
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| The contents of A_j, j > 1, are illustrated by the following | ||
| example for n = 7, ilo = 2, and ihi = 6: | ||
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| on entry on exit | ||
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| ( a a a a a a a ) ( a h h h h h a ) | ||
| ( 0 a a a a a a ) ( 0 h h h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 h h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 v3 h h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 v3 v4 h h h ) | ||
| ( 0 a a a a a a ) ( 0 v2 v3 v4 v5 h h ) | ||
| ( 0 0 0 0 0 0 a ) ( 0 0 0 0 0 0 a ) | ||
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| where a denotes an element of the original matrix A_j, h denotes | ||
| a modified element of the upper triangular matrix H_j, and vi | ||
| denotes an element of the vector defining H_j(i). (The element | ||
| (1,2) in A_p is also unchanged for this example.) | ||
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| """ | ||
| hidden = ' (hidden by the wrapper)' | ||
| arg_list = ['n', 'p' + hidden, | ||
| 'ilo', 'ihi', 'a', | ||
| 'lda1' + hidden, 'lda2' + hidden, 'tau', | ||
| 'ldtau' + hidden, 'dwork' + hidden, 'info'] | ||
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| HQ, Tau, info = _wrapper.mb03vd(n, ilo, ihi, A) | ||
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| if info != 0: | ||
| e = ValueError( | ||
| "Argument '{}' had an illegal value".format(arg_list[-info-1])) | ||
| e.info = info | ||
| raise e | ||
| return (HQ, Tau) | ||
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| def mb03vy(n, ilo, ihi, A, Tau, ldwork=None): | ||
| """ Q = mb03vy(n, ilo, ihi, A, Tau, [ldwork]) | ||
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| To generate the real orthogonal matrices Q_1, Q_2, ..., Q_p, | ||
| which are defined as the product of ihi-ilo elementary reflectors | ||
| of order n, as returned by SLICOT Library routine MB03VD: | ||
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| Q_j = H_j(ilo) H_j(ilo+1) . . . H_j(ihi-1). | ||
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| Parameters | ||
| ---------- | ||
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| n : int | ||
| The order of the matrices Q_1, Q_2, ..., Q_p. N >= 0. | ||
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| ilo, ihi : int | ||
| The values of the indices ilo and ihi, respectively, used | ||
| in the previous call of the SLICOT Library routine MB03VD. | ||
| 1 <= ilo <= max(1,n); min(ilo,n) <= ihi <= n. | ||
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| A : ndarray | ||
| A[:n,:n,j-1] must contain the vectors which define the | ||
| elementary reflectors used for reducing A_j, as returned | ||
| by SLICOT Library routine MB03VD, j = 1, ..., p. | ||
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| Tau : ndarray | ||
| The leading N-1 elements in the j-th column must contain | ||
| the scalar factors of the elementary reflectors used to | ||
| form the matrix Q_j, as returned by SLICOT Library routine | ||
| MB03VD. | ||
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| ldwork : int, optional | ||
| The length of the internal array DWORK. ldwork >= max(1, n). | ||
| For optimum performance ldwork should be larger. | ||
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| Returns | ||
| ------- | ||
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| Q : ndarray | ||
| 3D array with same shape as A. Q[:n,:n,j-1] contains the | ||
| N-by-N orthogonal matrix Q_j, j = 1, ..., p. | ||
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| Raises | ||
| ------ | ||
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| ValueError : | ||
| e.info contains the number of the argument that was invalid | ||
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| """ | ||
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| hidden = ' (hidden by the wrapper)' | ||
| arg_list = ['n', 'p' + hidden, | ||
| 'ilo', 'ihi', 'a', | ||
| 'lda1' + hidden, 'lda2' + hidden, 'tau', | ||
| 'ldtau' + hidden, 'dwork' + hidden, 'ldwork', 'info' + hidden] | ||
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| if not ldwork: | ||
| ldwork = max(1, 2 * n) | ||
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| Q, info = _wrapper.mb03vy(n, ilo, ihi, A, Tau, ldwork) | ||
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| if info != 0: | ||
| e = ValueError( | ||
| "Argument '{}' had an illegal value".format(arg_list[-info-1])) | ||
| e.info = info | ||
| raise e | ||
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| return Q | ||
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| def mb03wd(job, compz, n, ilo, ihi, iloz, ihiz, H, Q, ldwork=None): | ||
| """ T, Z, Wr = mb03wd(job, compz, n, ilo, ihi, iloz, ihiz, H, Q, [ldwork]) | ||
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| To compute the Schur decomposition and the eigenvalues of a | ||
| product of matrices, H = H_1*H_2*...*H_p, with H_1 an upper | ||
| Hessenberg matrix and H_2, ..., H_p upper triangular matrices, | ||
| without evaluating the product. Specifically, the matrices Z_i | ||
| are computed, such that | ||
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| Z_1' * H_1 * Z_2 = T_1, | ||
| Z_2' * H_2 * Z_3 = T_2, | ||
| ... | ||
| Z_p' * H_p * Z_1 = T_p, | ||
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| where T_1 is in real Schur form, and T_2, ..., T_p are upper | ||
| triangular. | ||
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| The routine works primarily with the Hessenberg and triangular | ||
| submatrices in rows and columns ilo to ihi, but optionally applies | ||
| the transformations to all the rows and columns of the matrices | ||
| H_i, i = 1,...,p. The transformations can be optionally | ||
| accumulated. | ||
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| Parameters | ||
| ---------- | ||
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| job : {'E', 'S'} | ||
| Indicates whether the user wishes to compute the full | ||
| Schur form or the eigenvalues only, as follows: | ||
| = 'E': Compute the eigenvalues only; | ||
| = 'S': Compute the factors T_1, ..., T_p of the full | ||
| Schur form, T = T_1*T_2*...*T_p. | ||
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| compz : {'N', 'I', 'V'} | ||
| Indicates whether or not the user wishes to accumulate | ||
| the matrices Z_1, ..., Z_p, as follows: | ||
| = 'N': The matrices Z_1, ..., Z_p are not required; | ||
| = 'I': Z_i is initialized to the unit matrix and the | ||
| orthogonal transformation matrix Z_i is returned, | ||
| i = 1, ..., p; | ||
| = 'V': Z_i must contain an orthogonal matrix Q_i on | ||
| entry, and the product Q_i*Z_i is returned, | ||
| i = 1, ..., p. | ||
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| n : int | ||
| The order of the matrix H. n >= 0 | ||
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| ilo, ihi : int | ||
| It is assumed that all matrices H_j, j = 2, ..., p, are | ||
| already upper triangular in rows and columns [:ilo-1] and | ||
| [ihi:n], and H_1 is upper quasi-triangular in rows and | ||
| columns [:ilo-1] and [ihi:n], with H_1[ilo-1,ilo-2] = 0 | ||
| (unless ilo = 1), and H_1[ihi,ihi-1] = 0 (unless ihi = n). | ||
| The routine works primarily with the Hessenberg submatrix | ||
| in rows and columns ilo to ihi, but applies the | ||
| transformations to all the rows and columns of the | ||
| matrices H_i, i = 1,...,p, if JOB = 'S'. | ||
| 1 <= ilo <= max(1,n); min(ilo,n) <= ihi <= n. | ||
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| iloz, ihiz : int | ||
| Specify the rows of Z to which the transformations must be | ||
| applied if compz = 'I' or compz = 'V'. | ||
| 1 <= iloz <= ilo; ihi <= ihiz <= n. | ||
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| H : ndarray | ||
| H[:n,:n,0] must contain the upper Hessenberg matrix H_1 and | ||
| H[:n,:n,j-1] for j > 1 must contain the upper triangular matrix | ||
| H_j, j = 2, ..., p. | ||
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| Q : ndarray | ||
| If compz = 'V', Q[:n,:n,:p] must contain the current matrix Q of | ||
| transformations accumulated by SLICOT Library routine | ||
| MB03VY. | ||
| If compz = 'I', Q is ignored | ||
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| ldwork : int, optinal | ||
| The length of the cache array. The default value is | ||
| ihi-ilo+p-1 | ||
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| Returns | ||
| ------- | ||
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| T : ndarray | ||
| 3D array with the same shape as H. | ||
| If JOB = 'S', T[:n,:n,0] is upper quasi-triangular in rows | ||
| and columns [ilo-1:ihi], with any 2-by-2 diagonal blocks | ||
| corresponding to a pair of complex conjugated eigenvalues, and | ||
| T[:n,:n,j-1] for j > 1 contains the resulting upper | ||
| triangular matrix T_j. | ||
| If job = 'E', T is None | ||
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| Z : ndarray | ||
| 3D array with the same shape as Q. | ||
| If compz = 'V', or compz = 'I', the leading | ||
| N-by-N-by-P part of this array contains the transformation | ||
| matrices which produced the Schur form; the | ||
| transformations are applied only to the submatrices | ||
| Z[iloz-1:ihiz,ilo-1:ihi,j-1], j = 1, ..., p. | ||
| If compz = 'N', Z is None | ||
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| W : ndarray (dtype=complex) | ||
| 1D array with shape (n). | ||
| The computed eigenvalues ilo to ihi. If two eigenvalues | ||
| are computed as a complex conjugate pair, they are stored | ||
| in consecutive elements of W say the i-th and | ||
| (i+1)th, with imag(W][i]) > 0 and imag(W[i+1]) < 0. | ||
| If JOB = 'S', the eigenvalues are stored in the same order | ||
| as on the diagonal of the Schur form returned in H. | ||
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| Raises | ||
| ------ | ||
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| ValueError : e | ||
| e.info contains information about the exact type of exception | ||
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| """ | ||
| hidden = ' (hidden by the wrapper)' | ||
| arg_list = ['job', 'compz', 'n', 'p' + hidden, | ||
| 'ilo', 'ihi', 'iloz', 'ihiz', | ||
| 'h', 'ldh1' + hidden, 'ldh2' + hidden, | ||
| 'z', 'ldz1' + hidden, 'ldz2' + hidden, | ||
| 'wr', 'wi', | ||
| 'dwork' + hidden, 'ldwork', 'info' + hidden] | ||
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| if not ldwork: | ||
| p = H.shape[2] | ||
| ldwork = max(1, ihi - ilo + p - 1) | ||
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| T, Z, Wr, Wi, info = _wrapper.mb03wd( | ||
| job, compz, n, ilo, ihi, iloz, ihiz, H, Q, ldwork) | ||
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| if info < 0: | ||
| e = ValueError( | ||
| "Argument '{}' had an illegal value".format(arg_list[-info-1])) | ||
| e.info = info | ||
| raise e | ||
| elif info > 0: | ||
| warnings.warn(("failed to compute all the eigenvalues {ilo} to {ihi} " | ||
| "in a total of 30*({ihi}-{ilo}+1) iterations " | ||
| "the elements {i}:{ihi} of Wr contain those " | ||
| "eigenvalues which have been successfully computed." | ||
| ).format(i=info, ilo=ilo, ihi=ihi)) | ||
| if job == 'E': | ||
| T = None | ||
| if compz == 'N': | ||
| Z = None | ||
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| W = Wr + Wi*1J | ||
| return (T, Z, W) | ||
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| def mb05md(a, delta, balanc='N'): | ||
| """Ar, Vr, Yr, VAL = mb05md(a, delta, balanc='N') | ||
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@@ -166,7 +521,7 @@ def mb05md(a, delta, balanc='N'): | |
| from slycot import mb05nd | ||
| import numpy as np | ||
| a = np.mat('[-2. 0; 0.1 -3.]') | ||
| mb05nd(a.shape[0], a, 0.1) | ||
| mb05nd(a.shape[0], a, 0.1) | ||
| """ | ||
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| def mb05nd(a, delta, tol=1e-7): | ||
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