| 16807 | } /* dlanst_ */ |
| 16808 | |
| 16809 | doublereal dlansy_(char *norm, char *uplo, integer *n, doublereal *a, integer |
| 16810 | *lda, doublereal *work) |
| 16811 | { |
| 16812 | /* System generated locals */ |
| 16813 | integer a_dim1, a_offset, i__1, i__2; |
| 16814 | doublereal ret_val, d__1, d__2, d__3; |
| 16815 | |
| 16816 | /* Local variables */ |
| 16817 | static integer i__, j; |
| 16818 | static doublereal sum, absa, scale; |
| 16819 | extern logical lsame_(char *, char *); |
| 16820 | static doublereal value; |
| 16821 | extern /* Subroutine */ int dlassq_(integer *, doublereal *, integer *, |
| 16822 | doublereal *, doublereal *); |
| 16823 | |
| 16824 | |
| 16825 | /* |
| 16826 | -- LAPACK auxiliary routine (version 3.2) -- |
| 16827 | -- LAPACK is a software package provided by Univ. of Tennessee, -- |
| 16828 | -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
| 16829 | November 2006 |
| 16830 | |
| 16831 | |
| 16832 | Purpose |
| 16833 | ======= |
| 16834 | |
| 16835 | DLANSY returns the value of the one norm, or the Frobenius norm, or |
| 16836 | the infinity norm, or the element of largest absolute value of a |
| 16837 | real symmetric matrix A. |
| 16838 | |
| 16839 | Description |
| 16840 | =========== |
| 16841 | |
| 16842 | DLANSY returns the value |
| 16843 | |
| 16844 | DLANSY = ( max(abs(A(i,j))), NORM = 'M' or 'm' |
| 16845 | ( |
| 16846 | ( norm1(A), NORM = '1', 'O' or 'o' |
| 16847 | ( |
| 16848 | ( normI(A), NORM = 'I' or 'i' |
| 16849 | ( |
| 16850 | ( normF(A), NORM = 'F', 'f', 'E' or 'e' |
| 16851 | |
| 16852 | where norm1 denotes the one norm of a matrix (maximum column sum), |
| 16853 | normI denotes the infinity norm of a matrix (maximum row sum) and |
| 16854 | normF denotes the Frobenius norm of a matrix (square root of sum of |
| 16855 | squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. |
| 16856 | |
| 16857 | Arguments |
| 16858 | ========= |
| 16859 | |
| 16860 | NORM (input) CHARACTER*1 |
| 16861 | Specifies the value to be returned in DLANSY as described |
| 16862 | above. |
| 16863 | |
| 16864 | UPLO (input) CHARACTER*1 |
| 16865 | Specifies whether the upper or lower triangular part of the |
| 16866 | symmetric matrix A is to be referenced. |