langt - langt: general matrix, tridiagonal

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Thu Aug 7 2025 17:26:25 langt(3)

realfunctionclangt(characternorm,integern,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. ParametersNORM 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. doubleprecisionfunctiondlangt(characternorm,integern,doubleprecision,dimension(*)dl,doubleprecision,dimension(*)d,doubleprecision,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. ParametersNORM 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. realfunctionslangt(characternorm,integern,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. ParametersNORM 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. doubleprecisionfunctionzlangt(characternorm,integern,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. ParametersNORM 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.

langt - langt: general matrix, tridiagonal

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.