diff options
Diffstat (limited to 'SRC/cposvxx.f')
| -rw-r--r-- | SRC/cposvxx.f | 60 |
1 files changed, 20 insertions, 40 deletions
diff --git a/SRC/cposvxx.f b/SRC/cposvxx.f index 7550ea5f..fb1c6df8 100644 --- a/SRC/cposvxx.f +++ b/SRC/cposvxx.f @@ -167,8 +167,7 @@ *> the strictly upper triangular part of A is not referenced. A is *> not modified if FACT = 'F' or 'N', or if FACT = 'E' and EQUED = *> 'N' on exit. -*> \endverbatim -*> \verbatim +*> *> On exit, if FACT = 'E' and EQUED = 'Y', A is overwritten by *> diag(S)*A*diag(S). *> \endverbatim @@ -187,14 +186,12 @@ *> factorization A = U**T*U or A = L*L**T, in the same storage *> format as A. If EQUED .ne. 'N', then AF is the factored *> form of the equilibrated matrix diag(S)*A*diag(S). -*> \endverbatim -*> \verbatim +*> *> If FACT = 'N', then AF is an output argument and on exit *> returns the triangular factor U or L from the Cholesky *> factorization A = U**T*U or A = L*L**T of the original *> matrix A. -*> \endverbatim -*> \verbatim +*> *> If FACT = 'E', then AF is an output argument and on exit *> returns the triangular factor U or L from the Cholesky *> factorization A = U**T*U or A = L*L**T of the equilibrated @@ -313,37 +310,31 @@ *> 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 @@ -352,8 +343,7 @@ *> 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 @@ -364,14 +354,12 @@ *> 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 @@ -379,26 +367,22 @@ *> 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 @@ -409,8 +393,7 @@ *> 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 @@ -429,8 +412,7 @@ *> 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 @@ -441,8 +423,7 @@ *> 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 @@ -452,8 +433,7 @@ *> 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 |