Changes in version 11.7:

1. Skipped bootstrap calibration if there are only B and no S variables.

2. Skipped bootstrap calibration for constant models.

3. Corrected a bug introduced in 11.6.

4. Reverted back to default choice of "1" for "r" variables.

5. Updated lapack and lapack95 libraries to 3.4.1 and 3.0, resp.

Changes in version 11.6:

1. Corrected several bugs that affected Poisson and proportional hazards models.

2. Corrected bug that left out bootstrap calibration.

3. Changed the maximum length of character data entries to 50.

4. Added several traps for floating over and underflows.

Changes in version 11.5:

1. Fixed a bug about file name of predicted probabilities for kernel classification.

2. Fixed a bug in batch file creation for longitudinal data.

Changes in version 11.4:

1. Made non-exhaustive search the default.

2. Corrected some inconsistencies with regard to R variables.

3. Changed the license to BSD.

Changes in version 11.3:

1. Corrected a bug that affected missing D values in multiresponse data.

2. Changed LaTeX output to indicate where missing values go.

3. Changed LaTeX output for multiresponse and longitudinal data.

4. Added more options for treatment (R) variables.

Changes in version 11.2:

1. Corrected a bug involving names of variables that are too long in
   output for polynomial models.

Changes in version 11.1:

1. Re-introduced choice of mean or median based CV pruning.

2. Added ability to deal with unbalanced observation times in longitudinal models.

3. Corrected some bugs in proportional hazards models when there are
   cases with censored survival times less than smallest uncensored
   survival time. 

4. Made median (instead of mean) CV estimate the default for pruning
   for proportional hazards models.

5. Numerous cosmetic changes.

Changes in version 10.6:

1. Corrected a bug that mixed itpos with izpos in proportional hazards models.

2. Required data for fitting proportional hazards models to have some
   censored and some uncensored data.

3. Automatically discounted cases with censored survival times less
   than smallest uncensored time.

Changes in version 10.5:

1. Stopped R variables from being used to split the nodes.

2. Made a node terminal during LDA splits if the LDA routine returns an error.

Changes in version 10.4:

1. Changed the default grouping for multiple dependent variables to be
   ungrouped; up to 20 groups are allowed.

2. Corrected a mistake in the LaTeX figure caption.

3. Added two-sided p-values beside t-statistics in output.

Changes in version 10.3:

1. Allowed use of N variables in importance score option.

Changes in version 10.2:

1. Changed the output of importance scores.

2. Corrected a consistency problem in importance scores for quantile regression.

3. Added printing of D variable name(s) in output file.

Changes in version 10.1:

1. Corrected a bug in computation of linear discriminant splits.

Changes in version 10.0:

1. Corrected a bug in computation of chi-squared test statistic.

2. Corrected a bug in computation of linear splits.

3. Added "R" variable type to indicate treatment variables.

4. Added option for multi-response and longitudinal data.

5. Added option to draw LaTeX trees sidways.

Changes in version 9.4:

1. Corrected another bug concerning splits on missing predictor values.

Changes in version 9.3:

1. Corrected a bug concerning splits on missing predictor values.

2. Allowed importance scoring for piecewise-linear regression models.

Changes in version 9.2:

1. Corrected a bug that occurs with missing values in the D variable for classification.

Changes in version 9.1:

1. Corrected a bug that occurs with missing values in the D variable for regression.

Changes in version 9.0:

1. Changed the way missing values for ordered variables are
handled. Now if there are missing values in a split variable, a split
on missingness is one of the splits considered. If a split is on a
non-missing value, observations with missing values are channeled
through the split by replacing them with the mean of the non-missing
values in the split variable.

2. Added an option for multi-response dependent variables.

3. Increased maximum length of character strings to 80.

Changes in version 8.4:

1. Corrected a bug (introduced in ver.8.2) in calculation of
chi-square probabilities. The Wilson-Hilferty approximation is used
for very small p-values.

2. Fixed a bug in interaction splits on one categorical and one ordered variable.

Changes in version 8.3:

1. Fixed some bugs with batch file creation and execution.

Changes in version 8.2:

1. Corrected a bug that affected batch operation for importance scoring.

2. Changed to direct chi-square conversion instead of Wilson-Hilferty
approximation if df < 10.

3. Corrected bug in printing of importance scores.

Changes in version 8.1:

1. Corrected a bug triggered by missing values in the dependent variable.

Changes in version 8.0:

1. Added option for bagging and random forest ensembles.

2. Changed method of dealing with missing values. Missing values in
   ordered variables used for splitting are treated as negative
   infinity and observations are predicted with node sample mean if
   there are missing values in regressors.

3. Added an option to obtain importance scores in two applications of GUIDE.

4. Added linear splits for classification trees.

5. Better control of interaction and linear split searches.

6. Improved split point and value set selection in interaction splits.

7. Fixed many small bugs.

Changes in version 7.9:

1. Added kernel and nearest-neighbor models for classification trees

Changes in version 7.8:

1. Corrected more bugs in polynomial regression option

Changes in version 7.7:

1. Corrected a bug in polynomial regression option

Changes in version 7.6:

1. Added the option to output a separate file containing scaled
   importance scores and variable names.

2. Implemented an improved variable split selection method for data
   with missing values.

Changes in version 7.5:

1. Corrected a bug in option #3 when there is no D variable in description file

2. Corrected a bug that affects formatting of ARFF data (option 3).

Changes in version 7.4:

1. Corrected a bug in linear splits when some observations have
   missing values in the dependent variable

2. Added the option to draw LaTeX classification trees without node colors

Changes in version 7.3:

1. Require at least one B variable for stepwise simple ANCOVA

Changes in version 7.2:

1. Added checks to prevent over-writing of files

2. Changed default SE-rule to 0 for proportional hazards models

3. Fixed a (cosmetic) bug in the output of split values for
   categorical variables with many values

4. Changed node information in LaTeX figures for classification trees

5. Eliminated printout of variable roles in importance ranking output

6. Increased the number of colored leaf nodes to 18 for classification
   tree LateX diagrams

Changes in version 7.1:

1. Fixed a bug introduced in 7.0 that affected stepwise and polynomial models

2. Fixed a bug involving importance score cut-off

Changes in version 7.0:

1. Added kernel and nearest-neigbor models for classification trees

2. Added splits on linear combinations of two variables for classification

3. Improved the way variables are selected for splits and the way
   split points are selected

4. Added coloring and other cosmetic features to LaTeX output

5. Improved the importance ranking method

Changes in version 6.2:

1. Changed algorithm for splits on categorical variables in classification

2. Added new data formats: C4.5 and ARFF

Changes in version 6.1:

1. Fixed a bug that wrote messages to fort file during batch file creation

2. Fixed a bug in calculation of estimated class priors when there is
   a weight variable

Changes in version 6.0.1:

1. Fixed a bug that miscalculated test sample misclassification cost
   when some classes are absent in the test sample

Changes in version 6.0:

1. Added classification tree capability

2. Added random forest capability

3. Made some changes to split selection algorithms

Changes in version 5.3:

1. Corrected a bug that affected latex files when there are no
   categorical variables

Changes in version 5.2:

1. Changed variable selection for interaction tests to use two-levels
   of splits

2. Reverted to true stepwise and ancova fitting for split selection
   for these options

Changes in version 5.1:

1. Fixed a bug caused by missing values while reading data

Changes in version 5.0:

1. Improved approach to interaction tests to account for their number

2. Changed default SE for constant fit to 0

3. Added option for variable importance scores and for identification
   of unimportant variables

Changes in version 4.4:

1. Fixed a bug in split variable selection routine that affected "s"
   variables

Changes in version 4.3:

1. Made the program output progress after each CV iteration.

2. Extended the length of variable names from 8 to 10 for data
   conversion to SAS.

3. Added code for PROC GLM and PROC REG if SAS output is selected.

4. Added a suggestion to use white or yellow colors if leaf node
   numbers are selected.

5. Allow execution to continue if an excluded variable contains values
   longer than 20 characters.

6. Allow option 3 (data conversion) to proceed if there are data
   values longer than 20 characters, with a warning that they are
   truncated.

Changes in version 4.2:

1. Corrected a bug that affects relative risk regression when some D
   or T variables have missing values.

2. Added an option for weighted or unweighted error estimation when a
   weight variable exists. The default is unweighted.

3. Changed from zero-truncated normal to 1-df chi-square statistic for
   split variable selection.

Changes in version 4.1:

1. Corrected a bug in output for truncation type 2.

2. Reverted default value of mindat to 0 for stepwise option.

Changes in version 4.0:

1. Added an option for least median of squares (robust) regression for
   multiple and best simple linear fitting.

2. Increased amount of information output to (optional) file containing
   names and regression coefficients in leaf nodes.

3. Changed absolute z to truncated z for variable selection and
   bootstrap bias correction.

4. Added an option to save multiple regression coefs in a separate file.

5. Added an option to fit piecewise least-squares multiple linear
   regression without intercept terms.

6. Added an option to not truncate, truncate fitted values, or
   truncate x-values before prediction.

7. Added option to drop insignificant leading powers in polynomial models.

8. Added option for stepwise simple linear ANCOVA.

9. Allowed stepwise linear option to use "c" or "b" categorical variables.

10. Fixed a bug that affected datasets with missing values but without
    weight variables.

11. Fixed a bug in split point selection to use total mean deviance
    instead of total deviance.

12. Added option for all subsets regression.

13. Improved search over split points for non-exhaustive search.

14. Changed option for non-exhaustive search from fraction to number.

Changes in version 3.1:

1. For stepwise and polynomial regression, added option to write the
   leaf node number and the selected regressors into a separate file.

2. Added option for colored leaf nodes and improved font sizes in
   LaTeX tree diagrams.

3. Added optional file of node IDs and fitted values of a column to
   indicate training observation.

4. Added R-squared value for tree model (least-squares fit only).

5. Fixed bug in interaction test. Now preference for "c" variable is
   given on to multiple linear regression.

6. Increased number of trees in pruning sequence.