Revision Revision Revision ODRPACK c

Found at: ftp.icm.edu.pl:70/packages/netlib/odrpack/changes

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\chapter*{Revision History}
\addcontentsline{toc}{chapter}{Revision History}
\lhead{Revision History}

\settowidth{\lblwdth}{1.88 (88-88-88)}


\item[2.01 (06-19-92)]  ODRPACK 2.01 corrects two minor errors.  The
                        first affected the derivative checking procedure, and
                        the second affected the values specified by {\tt
                        NDIGIT}.  The solutions found by ODRPACK 2.00 were not
                        affected in any way by the first of these errors, and
                        were not seriously affected by the second.

                        Version 2.01 also encorporates several other minor
                        modifications that further improve the code.  The most
                        significant of these modifications changes how the
                        scale values are used within the solution procedure.
                        This change should increase the robustness of the
                        procedure for poorly scaled problems, and will result
                        in slightly different computed results for all
                        problems.  Another of these changes is to the report
                        generated by the derivative checking procedure.  This
                        report now includes the user supplied derivative value,
                        as well as the relative difference between the user
                        supplied value and the finite difference value it was
                        checked against.  This should help users assess the
                        validity of the checking procedure results.

                        The ``ODRPACK 2.01 User's Reference Guide'' is
                        essentially the same as the version 2.00 Guide (NISTIR
                        89-4103, Revised).  The major differences are that
                        \item the minimum length of array {\tt WORK} has been 
                              increased by $(p+m)q$ locations, and
                        \item the sample programs and output shown in
                              Chapter~2, and the discussion of the derivative
                              checking results in Chapter~5 have been modified
                              to reflect the above mentioned changes.

\item[2.00 (03-04-92)]  ODRPACK 2.00 adds several new features to those
                        available in version 1.8 and earlier versions.
                          \item With version 2.00, ODRPACK can now easily
                                accommodate complex and other types of
                                multiresponse data, i.e., data where each
                                observation is multidimensional.
                          \item It can handle implicit as well as explicit
                          \item The weighting scheme has been enhanced to allow
                                for instances when the components of a
                                multidimensional observation are correlated.
                          \item A facility for computing central finite
                                difference derivatives has been added.
                          \item The amount of work space required for the
                                computations has been reduced for most
                        {\em Because of these new features, the argument lists
                        for the ODRPACK 2.00 user callable subroutines,
                        including the user supplied subroutine {\tt FCN} that now
                        comprises the functionality of subroutines {\tt FUN} and
                        {\tt JAC}, are not the same as for earlier versions.}  The
                        interpretations of some arguments have changed, and new
                        arguments have been added.  In addition, the arguments
                        have been reordered, with arguments having similar
                        purpose now grouped together.  Those who have been
                        using an earlier release of ODRPACK should be
                        especially careful to examine the new calling
                        sequences, and the definitions for subroutine arguments
                        {\tt FCN}, {\tt JOB}, {\tt WE} and {\tt WD}.

\item[1.80 (12-18-90)]  ODRPACK 1.80, a test release with only limited
                        distribution, differs from prior releases in several
                          \item The number of function evaluations required to
                                find the solution has been reduced, and the
                                ``restart'' facility has been modified to
                                better accommodate cases where the user
                                supplied subroutines {\tt FUN} and/or {\tt JAC} are
                                very time consuming.
                          \item The printed reports have been redesigned to
                                identify parameters that induce rank
                                deficiency, and to include a 95\% confidence
                                interval for the estimated parameters.
                          \item Several enhancements have been added to the
                                covariance matrix computations, including the
                                option of constructing the covariance matrix
                                without incurring any additional derivative
                          \item The finite difference approximation to the
                                Jacobian matrix has been improved.

\item[1.71 (07-27-89)]  ODRPACK 1.71 corrects an error in the code that
                        performs the computation of finite difference
                        derivatives with respect to the errors $\Delta$ when
                        $m\ge2$ and the default value of {\tt IFIXX} is invoked.
                        (The default value of {\tt IFIXX} is invoked when {\tt
                        IFIXX(1,1)} is set to a negative value or when ODRPACK
                        routines {\tt DODR} or {\tt SODR} are called.)  This error
                        could result in incorrect ``fixing'' of the explanatory
                        variables, which would affect the final solution.  Such
                        ``fixing'' could be detected by observing the presence
                        of estimated values for $\Delta$ that are identically
                        zero.  The error could go undetected by the user,
                        however, if the values of $\Delta$ were not examined
                        after the fit.