diff options
author | julie <julielangou@users.noreply.github.com> | 2011-11-01 22:02:31 +0000 |
---|---|---|
committer | julie <julielangou@users.noreply.github.com> | 2011-11-01 22:02:31 +0000 |
commit | d5c30c90bdecf38da1064e2ed52583634573e741 (patch) | |
tree | 480fc5ff31ee14b83116b6428aad79ea6e89362d /SRC/dporfsx.f | |
parent | 04670a68760fa27333f8bcef8172f71adc6880ef (diff) | |
download | lapack-d5c30c90bdecf38da1064e2ed52583634573e741.tar.gz lapack-d5c30c90bdecf38da1064e2ed52583634573e741.tar.bz2 lapack-d5c30c90bdecf38da1064e2ed52583634573e741.zip |
Never say never...
Diffstat (limited to 'SRC/dporfsx.f')
-rw-r--r-- | SRC/dporfsx.f | 51 |
1 files changed, 17 insertions, 34 deletions
diff --git a/SRC/dporfsx.f b/SRC/dporfsx.f index 941cc747..3772991e 100644 --- a/SRC/dporfsx.f +++ b/SRC/dporfsx.f @@ -211,37 +211,31 @@ *> 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) * dlamch('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) * dlamch('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) * dlamch('Epsilon') to determine if the error @@ -250,8 +244,7 @@ *> 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 @@ -262,14 +255,12 @@ *> 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 @@ -277,26 +268,22 @@ *> 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) * dlamch('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) * dlamch('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) * dlamch('Epsilon') to determine if the error @@ -307,8 +294,7 @@ *> 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 @@ -327,8 +313,7 @@ *> 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: 1.0D+0 @@ -339,8 +324,7 @@ *> 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 @@ -350,8 +334,7 @@ *> 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 |