# dlangt(3) [centos man page]

dlangt.f(3) LAPACK dlangt.f(3)NAME

dlangt.f-SYNOPSIS

Functions/Subroutines DOUBLE PRECISION function dlangt (NORM, N, DL, D, DU) DLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix.Function/Subroutine Documentation DOUBLE PRECISION function dlangt (characterNORM, integerN, double precision, dimension( * )DL, double precision, dimension( * )D, double precision, dimension( * )DU) DLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. Purpose: DLANGT returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real tridiagonal matrix A. Returns: DLANGT DLANGT = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' or 'e' where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. Parameters: NORM NORM is CHARACTER*1 Specifies the value to be returned in DLANGT as described above. N N is INTEGER The order of the matrix A. N >= 0. When N = 0, DLANGT is set to zero. DL DL is DOUBLE PRECISION array, dimension (N-1) The (n-1) sub-diagonal elements of A. D D is DOUBLE PRECISION array, dimension (N) The diagonal elements of A. DU DU is DOUBLE PRECISION array, dimension (N-1) The (n-1) super-diagonal elements of A. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 107 of file dlangt.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 dlangt.f(3)

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dlanst.f(3) LAPACK dlanst.f(3)NAME

dlanst.f-SYNOPSIS

Functions/Subroutines DOUBLE PRECISION function dlanst (NORM, N, D, E) DLANST returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric tridiagonal matrix.Function/Subroutine Documentation DOUBLE PRECISION function dlanst (characterNORM, integerN, double precision, dimension( * )D, double precision, dimension( * )E) DLANST returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric tridiagonal matrix. Purpose: DLANST returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric tridiagonal matrix A. Returns: DLANST DLANST = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' or 'e' where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. Parameters: NORM NORM is CHARACTER*1 Specifies the value to be returned in DLANST as described above. N N is INTEGER The order of the matrix A. N >= 0. When N = 0, DLANST is set to zero. D D is DOUBLE PRECISION array, dimension (N) The diagonal elements of A. E E is DOUBLE PRECISION array, dimension (N-1) The (n-1) sub-diagonal or super-diagonal elements of A. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 101 of file dlanst.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 dlanst.f(3)