langt(3) Library Functions Manual langt(3) NAME langt - langt: general matrix, tridiagonal SYNOPSIS Functions real function clangt (norm, n, dl, d, du) CLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. 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. real function slangt (norm, n, dl, d, du) SLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. double precision function zlangt (norm, n, dl, d, du) ZLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. Detailed Description Function Documentation real function clangt (character norm, integer n, complex, dimension( * ) dl, complex, dimension( * ) d, complex, dimension( * ) du) CLANGT 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: CLANGT returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex tridiagonal matrix A. Returns CLANGT CLANGT = ( 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 CLANGT as described above. N N is INTEGER The order of the matrix A. N >= 0. When N = 0, CLANGT is set to zero. DL DL is COMPLEX array, dimension (N-1) The (n-1) sub-diagonal elements of A. D D is COMPLEX array, dimension (N) The diagonal elements of A. DU DU is COMPLEX 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. Definition at line 105 of file clangt.f. double precision function dlangt (character norm, integer n, 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. Definition at line 105 of file dlangt.f. real function slangt (character norm, integer n, real, dimension( * ) dl, real, dimension( * ) d, real, dimension( * ) du) SLANGT 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: SLANGT 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 SLANGT SLANGT = ( 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 SLANGT as described above. N N is INTEGER The order of the matrix A. N >= 0. When N = 0, SLANGT is set to zero. DL DL is REAL array, dimension (N-1) The (n-1) sub-diagonal elements of A. D D is REAL array, dimension (N) The diagonal elements of A. DU DU is REAL 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. Definition at line 105 of file slangt.f. double precision function zlangt (character norm, integer n, complex*16, dimension( * ) dl, complex*16, dimension( * ) d, complex*16, dimension( * ) du) ZLANGT 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: ZLANGT returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex tridiagonal matrix A. Returns ZLANGT ZLANGT = ( 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 ZLANGT as described above. N N is INTEGER The order of the matrix A. N >= 0. When N = 0, ZLANGT is set to zero. DL DL is COMPLEX*16 array, dimension (N-1) The (n-1) sub-diagonal elements of A. D D is COMPLEX*16 array, dimension (N) The diagonal elements of A. DU DU is COMPLEX*16 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. Definition at line 105 of file zlangt.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 langt(3)