diff options
Diffstat (limited to 'SRC/chesvxx.f')
| -rw-r--r-- | SRC/chesvxx.f | 60 |
1 files changed, 20 insertions, 40 deletions
diff --git a/SRC/chesvxx.f b/SRC/chesvxx.f index bc134549..9c6ac832 100644 --- a/SRC/chesvxx.f +++ b/SRC/chesvxx.f @@ -166,8 +166,7 @@ *> N-by-N lower triangular part of A contains the lower *> triangular part of the matrix A, and the strictly upper *> triangular part of A is not referenced. -*> \endverbatim -*> \verbatim +*> *> On exit, if FACT = 'E' and EQUED = 'Y', A is overwritten by *> diag(S)*A*diag(S). *> \endverbatim @@ -185,8 +184,7 @@ *> contains the block diagonal matrix D and the multipliers *> used to obtain the factor U or L from the factorization A = *> U*D*U**T or A = L*D*L**T as computed by SSYTRF. -*> \endverbatim -*> \verbatim +*> *> If FACT = 'N', then AF is an output argument and on exit *> returns the block diagonal matrix D and the multipliers *> used to obtain the factor U or L from the factorization A = @@ -212,8 +210,7 @@ *> diagonal block. If UPLO = 'L' and IPIV(k) = IPIV(k+1) < 0, *> then rows and columns k+1 and -IPIV(k) were interchanged *> and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. -*> \endverbatim -*> \verbatim +*> *> If FACT = 'N', then IPIV is an output argument and on exit *> contains details of the interchanges and the block *> structure of D, as determined by CHETRF. @@ -324,37 +321,31 @@ *> For each right-hand side, this array contains information about *> various error bounds and condition numbers corresponding to the *> normwise relative error, which is defined as follows: -*> \endverbatim -*> \verbatim +*> *> Normwise relative error in the ith solution vector: *> max_j (abs(XTRUE(j,i) - X(j,i))) *> ------------------------------ *> max_j abs(X(j,i)) -*> \endverbatim -*> \verbatim +*> *> The array is indexed by the type of error information as described *> below. There currently are up to three pieces of information *> returned. -*> \endverbatim -*> \verbatim +*> *> The first index in ERR_BNDS_NORM(i,:) corresponds to the ith *> right-hand side. -*> \endverbatim -*> \verbatim +*> *> The second index in ERR_BNDS_NORM(:,err) contains the following *> three fields: *> err = 1 "Trust/don't trust" boolean. Trust the answer if the *> reciprocal condition number is less than the threshold *> sqrt(n) * slamch('Epsilon'). -*> \endverbatim -*> \verbatim +*> *> err = 2 "Guaranteed" error bound: The estimated forward error, *> almost certainly within a factor of 10 of the true error *> so long as the next entry is greater than the threshold *> sqrt(n) * slamch('Epsilon'). This error bound should only *> be trusted if the previous boolean is true. -*> \endverbatim -*> \verbatim +*> *> err = 3 Reciprocal condition number: Estimated normwise *> reciprocal condition number. Compared with the threshold *> sqrt(n) * slamch('Epsilon') to determine if the error @@ -363,8 +354,7 @@ *> appropriately scaled matrix Z. *> Let Z = S*A, where S scales each row by a power of the *> radix so all absolute row sums of Z are approximately 1. -*> \endverbatim -*> \verbatim +*> *> See Lapack Working Note 165 for further details and extra *> cautions. *> \endverbatim @@ -375,14 +365,12 @@ *> For each right-hand side, this array contains information about *> various error bounds and condition numbers corresponding to the *> componentwise relative error, which is defined as follows: -*> \endverbatim -*> \verbatim +*> *> Componentwise relative error in the ith solution vector: *> abs(XTRUE(j,i) - X(j,i)) *> max_j ---------------------- *> abs(X(j,i)) -*> \endverbatim -*> \verbatim +*> *> The array is indexed by the right-hand side i (on which the *> componentwise relative error depends), and the type of error *> information as described below. There currently are up to three @@ -390,26 +378,22 @@ *> componentwise accuracy is not requested (PARAMS(3) = 0.0), then *> ERR_BNDS_COMP is not accessed. If N_ERR_BNDS .LT. 3, then at most *> the first (:,N_ERR_BNDS) entries are returned. -*> \endverbatim -*> \verbatim +*> *> The first index in ERR_BNDS_COMP(i,:) corresponds to the ith *> right-hand side. -*> \endverbatim -*> \verbatim +*> *> The second index in ERR_BNDS_COMP(:,err) contains the following *> three fields: *> err = 1 "Trust/don't trust" boolean. Trust the answer if the *> reciprocal condition number is less than the threshold *> sqrt(n) * slamch('Epsilon'). -*> \endverbatim -*> \verbatim +*> *> err = 2 "Guaranteed" error bound: The estimated forward error, *> almost certainly within a factor of 10 of the true error *> so long as the next entry is greater than the threshold *> sqrt(n) * slamch('Epsilon'). This error bound should only *> be trusted if the previous boolean is true. -*> \endverbatim -*> \verbatim +*> *> err = 3 Reciprocal condition number: Estimated componentwise *> reciprocal condition number. Compared with the threshold *> sqrt(n) * slamch('Epsilon') to determine if the error @@ -420,8 +404,7 @@ *> current right-hand side and S scales each row of *> A*diag(x) by a power of the radix so all absolute row *> sums of Z are approximately 1. -*> \endverbatim -*> \verbatim +*> *> See Lapack Working Note 165 for further details and extra *> cautions. *> \endverbatim @@ -440,8 +423,7 @@ *> that entry will be filled with default value used for that *> parameter. Only positions up to NPARAMS are accessed; defaults *> are used for higher-numbered parameters. -*> \endverbatim -*> \verbatim +*> *> PARAMS(LA_LINRX_ITREF_I = 1) : Whether to perform iterative *> refinement or not. *> Default: 1.0 @@ -452,8 +434,7 @@ *> compilation environment does not support DOUBLE *> PRECISION. *> (other values are reserved for future use) -*> \endverbatim -*> \verbatim +*> *> PARAMS(LA_LINRX_ITHRESH_I = 2) : Maximum number of residual *> computations allowed for refinement. *> Default: 10 @@ -463,8 +444,7 @@ *> Gaussian elimination, the guarantees in *> err_bnds_norm and err_bnds_comp may no longer be *> trustworthy. -*> \endverbatim -*> \verbatim +*> *> PARAMS(LA_LINRX_CWISE_I = 3) : Flag determining if the code *> will attempt to find a solution with small componentwise *> relative error in the double-precision algorithm. Positive |