changelog

krigging model for interpolating data

 c :  comment
 * :  bug fixed
 + :  new feature/function
 x :  changed functionality

--------------------------------------------------------------------
Version 2.5, September 4, 2002

 *  REGPOLY2  did not work properly for dimension greater than 2
    Bug fixed.

--------------------------------------------------------------------
Version 2.4, September 3, 2002

 x  DACEFIT  gives an error return in case of a rank deficient matrix F.  
    May arise with a poor combination of choice of regression model 
    and distribution of design sites.

--------------------------------------------------------------------
Version 2.3, August 30, 2002

 x  DACEFIT  gives an error return in case of zero columns in matrix F.  
    May arise with a poor combination of choice of regression model 
    and distribution of design sites.

--------------------------------------------------------------------
Version 2.2, August 27, 2002

 x  DACEFIT  allows design data with standard deviation zero 
    in one or more directions.

--------------------------------------------------------------------
Version 2.1, August 26, 2002

 *  PREDICTOR  returned erroneous mse-values in case of single 
    response, multiple entry.  This bug is fixed.

--------------------------------------------------------------------
Version 2.0, August 5, 2002

 x  The element  dmodel.regress  is renamed to  dmodel.regr
    in  DACEFIT, lines 19, 106
    in  PREDICTOR, lines 58, 90, 107
    
 c  Documentation is adapted to the new version. A separate report
    documenting the algorithm and other special parts of the toolbox
    is available.

--------------------------------------------------------------------
Version 1.3, July 3, 2002

 *  A developer debug statement in PREDICTOR line 52:

      save NX x

    is removed.

 +  DSMERGE is a new function for merging data sets with multiple
    design sites (i.e., sites sampled more than one time).
    See 'help dsmerge' for more information.

 +  PREDICTOR now return Jacobian matrices for model and mean
    squared error also for cases with multiple response functions.

 c  We would like to acknowledge the comments and suggestions from
    Thierry Dalon, from Siemens VDO Automotive AG, which is a great
    help in improving this software.

--------------------------------------------------------------------
Version 1.2, June 25, 2002

 +  DACEFIT now has a second output parameter

        [dmodel, perf] = dacefit(S, Y, regr, corr, theta0)

    or        

        [dmodel, perf] = dacefit(S, Y, regr, corr, theta0, lob, upb)
        
    The second output parameter gives the convergence history of the
    optimization - see 'help dacefit' for more information.

 +  DACEFIT now allows the second input argument to be an m*q matrix,
    i.e., allows q response functions to be modelled, the elements of
    dmodel: beta, gamma, sigma2, Ysc are changed accordingly.
    
 c  The optimization method in DACEFIT is changed. A separate report
    documenting the algorithm and other special parts of the toolbox
    will be available in August 2002.
    
 +  PREDICTOR is adapted to the changes in DACEFIT, though in case
    of multiple response functions it does not yet return the
    Jacobian matrices for the predicted models and their respective
    mean squared errors.
    
 +  CORRCUBIC is the new name of the function named CORRSPLINE
    in version 1.1. See 'help corrcubic' for more information.
    
 x  CORRSPLINE gives a correlation function based on a cubic
    spline. See 'help corrspline' for more information.
    The above mentioned report will also discuss this new 
    correlation model.
    
 x  The  parameter vector q in GRIDSAMP is changed so that now it 
    is the number of equidistant points in each coordinate direction.
    This is in accordance with the similar parameter in LHSAMP
    and LINSPACE.

--------------------------------------------------------------------
Version 1.1, June 7, 2002
	
 *  A sign error in the gradient calculation in CORRGAUSS is
    corrected: line 33 in the file is changed from
   
      dr = repmat(-2*theta(:).',m,1) .* d .* repmat(r,1,n);

    to

      dr = -2*repmat(-theta(:).',m,1) .* d .* repmat(r,1,n);

--------------------------------------------------------------------
Version 1.0, April 16, 2002

 c  First version released