# scipy.sparse.linalg.ArpackError

exception scipy.sparse.linalg.ArpackError(info, infodict={'c': {- 9999: 'Could not build an Arnoldi factorization. IPARAM(5) returns the size of the current Arnoldi factorization. The user is advised to check that enough workspace and array storage has been allocated.', - 13: "NEV and WHICH = 'BE' are incompatible.", - 12: 'IPARAM(1) must be equal to 0 or 1.', - 11: "IPARAM(7) = 1 and BMAT = 'G' are incompatible.", - 10: 'IPARAM(7) must be 1,2,3.', - 9: 'Starting vector is zero.', - 8: 'Error return from LAPACK eigenvalue calculation;', - 7: 'Length of private work array WORKL is not sufficient.', - 6: "BMAT must be one of 'I' or 'G'.", - 5: " WHICH must be one of 'LM', 'SM', 'LR', 'SR', 'LI', 'SI'", - 4: 'The maximum number of Arnoldi update iterations allowed must be greater than zero.', - 3: 'NCV-NEV >= 2 and less than or equal to N.', - 2: 'NEV must be positive.', - 1: 'N must be positive.', 0: 'Normal exit.', 1: 'Maximum number of iterations taken. All possible eigenvalues of OP has been found. IPARAM(5) returns the number of wanted converged Ritz values.', 2: 'No longer an informational error. Deprecated starting with release 2 of ARPACK.', 3: 'No shifts could be applied during a cycle of the Implicitly restarted Arnoldi iteration. One possibility is to increase the size of NCV relative to NEV. '}, 'd': {- 9999: 'Could not build an Arnoldi factorization. IPARAM(5) returns the size of the current Arnoldi factorization. The user is advised to check that enough workspace and array storage has been allocated.', - 13: "NEV and WHICH = 'BE' are incompatible.", - 12: 'IPARAM(1) must be equal to 0 or 1.', - 11: "IPARAM(7) = 1 and BMAT = 'G' are incompatible.", - 10: 'IPARAM(7) must be 1,2,3,4.', - 9: 'Starting vector is zero.', - 8: 'Error return from LAPACK eigenvalue calculation;', - 7: 'Length of private work array WORKL is not sufficient.', - 6: "BMAT must be one of 'I' or 'G'.", - 5: " WHICH must be one of 'LM', 'SM', 'LR', 'SR', 'LI', 'SI'", - 4: 'The maximum number of Arnoldi update iterations allowed must be greater than zero.', - 3: 'NCV-NEV >= 2 and less than or equal to N.', - 2: 'NEV must be positive.', - 1: 'N must be positive.', 0: 'Normal exit.', 1: 'Maximum number of iterations taken. All possible eigenvalues of OP has been found. IPARAM(5) returns the number of wanted converged Ritz values.', 2: 'No longer an informational error. Deprecated starting with release 2 of ARPACK.', 3: 'No shifts could be applied during a cycle of the Implicitly restarted Arnoldi iteration. One possibility is to increase the size of NCV relative to NEV. '}, 's': {- 9999: 'Could not build an Arnoldi factorization. IPARAM(5) returns the size of the current Arnoldi factorization. The user is advised to check that enough workspace and array storage has been allocated.', - 13: "NEV and WHICH = 'BE' are incompatible.", - 12: 'IPARAM(1) must be equal to 0 or 1.', - 11: "IPARAM(7) = 1 and BMAT = 'G' are incompatible.", - 10: 'IPARAM(7) must be 1,2,3,4.', - 9: 'Starting vector is zero.', - 8: 'Error return from LAPACK eigenvalue calculation;', - 7: 'Length of private work array WORKL is not sufficient.', - 6: "BMAT must be one of 'I' or 'G'.", - 5: " WHICH must be one of 'LM', 'SM', 'LR', 'SR', 'LI', 'SI'", - 4: 'The maximum number of Arnoldi update iterations allowed must be greater than zero.', - 3: 'NCV-NEV >= 2 and less than or equal to N.', - 2: 'NEV must be positive.', - 1: 'N must be positive.', 0: 'Normal exit.', 1: 'Maximum number of iterations taken. All possible eigenvalues of OP has been found. IPARAM(5) returns the number of wanted converged Ritz values.', 2: 'No longer an informational error. Deprecated starting with release 2 of ARPACK.', 3: 'No shifts could be applied during a cycle of the Implicitly restarted Arnoldi iteration. One possibility is to increase the size of NCV relative to NEV. '}, 'z': {- 9999: 'Could not build an Arnoldi factorization. IPARAM(5) returns the size of the current Arnoldi factorization. The user is advised to check that enough workspace and array storage has been allocated.', - 13: "NEV and WHICH = 'BE' are incompatible.", - 12: 'IPARAM(1) must be equal to 0 or 1.', - 11: "IPARAM(7) = 1 and BMAT = 'G' are incompatible.", - 10: 'IPARAM(7) must be 1,2,3.', - 9: 'Starting vector is zero.', - 8: 'Error return from LAPACK eigenvalue calculation;', - 7: 'Length of private work array WORKL is not sufficient.', - 6: "BMAT must be one of 'I' or 'G'.", - 5: " WHICH must be one of 'LM', 'SM', 'LR', 'SR', 'LI', 'SI'", - 4: 'The maximum number of Arnoldi update iterations allowed must be greater than zero.', - 3: 'NCV-NEV >= 2 and less than or equal to N.', - 2: 'NEV must be positive.', - 1: 'N must be positive.', 0: 'Normal exit.', 1: 'Maximum number of iterations taken. All possible eigenvalues of OP has been found. IPARAM(5) returns the number of wanted converged Ritz values.', 2: 'No longer an informational error. Deprecated starting with release 2 of ARPACK.', 3: 'No shifts could be applied during a cycle of the Implicitly restarted Arnoldi iteration. One possibility is to increase the size of NCV relative to NEV. '}})

  ARPACK error

  with_traceback()

    Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

scipy.sparse.linalg.ArpackNoConvergence Compressed sparse graph routines (`scipy.sparse.csgraph`)