History.txt

=== 1.4.0 / 2014-10-11
  * Replaced README.txt for README.md
  * Replace File.exists? for File.exist?
  + New Dataset.join to join two dataset based on some fields
  * Deleted MLE based regression (Probit and logistic). Now all GML methods are on statsample-glm
  
=== 1.3.1 / 2014-06-26

  * Example referred to a SimpleRegression class which doesn't exist. Updated to working example.
  * Merge pull request #15 from Blahah/patch-1
  * Updated Gemfile
  * Updated README.txt for v1.3.0
  * Updated to ruby 2.1.0

=== 1.3.0 / 2013-09-19

  * Merge remote-tracking branch 'vpereira/master' into vpereira
  * New Wilcoxon Signed Rank test
  * Remove TimeSeries class. Now is available on gem "bio-statsample-timeseries" [GSOC 2013 project :) ]
  * Update shoulda support
  * added Bundle depds
  * improved the csv read method (requires tests)
  * open svg on mac osx

=== 1.2.0 / 2011-12-15
  
  * Added support for time series (TimeSeries object): MA, EMA, MACD, acf, lag and delta. [Rob Britton]
  * Changed summary attribute to properly display 'b' value for simple linear regression [hstove]
  * Merge pull request #6 from hstove/patch-1Changed summary attribute to properly display 'b' value for simple linear regression [Claudio Bustos]
  * fix example code for CovariateMatrix [James Kebinger]

=== 1.1.0 / 2011-06-02

* New Statsample::Anova::Contrast
* Jacknife and bootstrap for Vector. Thanks to John Firebaugh for the idea
* Improved Statsample::Analysis API
* Updated CSV.read. Third argument is a Hash with options to CSV class  
* Added restriction on Statsample::Excel.read
* Updated spanish po 
* Better summary for Vector
* Improving summary of t related test (confidence interval and estimate output)
* Replaced c for vector on Statsample::Analysis examples
* Added Vector#median_absolute_deviation
* First implementation of Kolmogorov Smirnov test. Returns correct D value, but without Kolmogorov distribution isn't very useful.

=== 1.0.1 / 2011-01-28

* Updated spanish po.
* Update distribution gem dependence. On Ruby 1.8.7, distribution 0.2.0 raises an error.

=== 1.0.0 / 2011-01-27

* Added Statsample::Analysis, a beautiful DSL to perform fast statistical analysis using statsample. See directory /examples
* Created benchmarks directory 
* Removed Distribution module from statsample and moved to a gem. Changes on code to reflect new API
* Optimized simple regression.  Better library detection
* New 'should_with_gsl' to test methods with gsl. Refactored Factor::MAP
* Almost complete GSL cleanup on Vector
* Updated some doc on Vector
* Used GSL::Matrix on Factor classes when available
* SkillScaleAnalysis doesn't crash with one or more vectors with 0 variance
* Modified examples using Statsample::Analysis
* Simplified eigen calculations
* Updated some examples. Added correlation matrix speed suite
* Correlation matrix optimized. Better specs 
* Optimized correlation matrix. Use gsl matrix algebra or pairwise correlations depending on empiric calculated equations. See benchmarks/correlation_matrix.rb to see implementation of calculation 
* Moved tests fixtures from data to test/fixtures
* Fixed some errors on tests
* Bug fix: constant_se on binomial regression have an error 
* All test should work on ruby 1.9.3 
* New Vector.[] and Vector.new_scale
* Detect linearly dependent predictors on OLS. 

=== 0.18.0 / 2011-01-07
* New Statsample.load_excel 
* New Statsample.load_csv
* Statsample::Dataset#[] accepts an array of fields and uses clone
* New Dataset#correlation_matrix  and Statsample::Dataset#covariance_matrix
* Statsample::Dataset.filter add labels to vectors
* Principal Components generation complete on PCA (covariance matrix prefered)
* Added note on Statsample::Factor::PCA about erratic signs on eigenvalues,
* Statsample::Factor::PCA.component_matrix calculated different for covariance matrix
* Improved summary for PCA using covariance matrix
* New attribute :label_angle for Statsample::Graph::Boxplot
* Fixed Scatterplots scaling problems
* New attributes for Scatterplots: groups, minimum_x, minimum_y, maximum_x, 
* New Statsample::Multiset#union allows to create a new dataset based on a m
* New Statsample::Multiset#each to traverse through datasets
* Bug fix: Vector#standarized and Vector#percentile crash on nil data
* Bug fix: Vector#mean and Vector#sd crash on data without valid values
* Modified methods names on Statsample::Factor::PCA : feature_vector to feature_matrix, data_transformation to principal_components
* Added Statsample::Vector.vector_centered
* Factor::MAP.with_dataset() implemented 
* Bug fix: Factor::MAP with correlation matrix with non-real eigenvalues crashes * Added documentation for Graph::Histogram 
* Added MPA to Reliability::MultiScaleAnalysis
* Added custom names for returned vectors and datasets 
* Updated spanish traslation 
* Graph::Histogram updated. Custom x and y max and min, optional normal distribution drawing 
* Updated Histogram class, with several new methods compatibles with GSL::Histogram

=== 0.17.0 / 2010-12-09
* Added Statsample::Graph::Histogram and Statsample::Graph::Boxplot
* Added Statsample::Reliability::SkillScaleAnalysis for analysis of skill based scales.
* Delete combination and permutation clases. Backport for ruby 1.8.7 widely available
* Deleted unused variables (thanks, ruby-head)

=== 0.16.0 / 2010-11-13
* Works on ruby 1.9.2 and HEAD. Updated Rakefile and manifest
* Removed all graph based on Svg::Graph. 
* First operative version of Graph with Rubyvis
* Corrected bug on Distribution::Normal.cdf. 
* Added reference on references.txt
* Ruby-based random gaussian distribution generator when gsl not available
* Added population average deviation [Al Chou]

=== 0.15.1 / 2010-10-20
* Statsample::Excel and Statsample::PlainText add name to vectors equal to field name 
* Statsample::Dataset.delete_vector accept multiple fields.
* Statsample::Dataset.dup_only_valid allows duplication of specific fields 
* ScaleAnalysis doesn't crash on one-item scales 
* Updated references

=== 0.15.0 / 2010-09-07
* Added class Statsample::Reliability::ICC for calculation of Intra-class correlation (Shrout & Fleiss, 1979; McGraw & Wong, 1996). Tested with SPSS and R values.
* References: Updated and standarized references on many classes. Added grab_references.rb script, to create a list of references for library
* Added Spearman-Brown prophecy on Reliability module
* Distribution::F uses Gsl when available
* Added mean r.p.b. and item sd on Scale Analysis
* Corrected bug on Vector.ary_method and example of Anova Two Way using vector.  


=== 0.14.1 / 2010-08-18

* Added extra information on $DEBUG=true. 
* Changed ParallelAnalysis: with_random_data parameters, bootstrap_method options are data and random, resolve bug related to number of factors to preserve, resolved bug related to original eigenvalues, can support failed bootstrap of data for Tetrachoric  correlation. 
* Optimized eigenpairs on Matrix when GSL is available. 
* Added test for parallel analysis using data bootstraping
* Updated .pot and Manifest.txt
* Added test for kmo(global and univariate), bartlett and anti-image. Kmo and Bartlett have test based on Dziuban and Shirkey with correct results
* Complete set of test to test if a correlation matrix is appropriate for factor analysis: test of sphericity, KMO and anti-image (see Dziuban and Shirkey, 1974)
* Updated Parallel Analysis to work on Principal Axis Analysis based on O'Connors formulae
* Added reference for Statsample::Factor::MAP

=== 0.14.0 / 2010-08-16
* Added Statsample::Factor::MAP, to execute Velicer's (1976) MAP to determine the number of factors to retain on EFA 
* Bug fix on test suite on Ruby 1.8.7
* Horn's Parallel Analysis operational and tested for pure random data
* Fixed bug on Excel writer on Ruby1.9 (frozen string on header raises an error). 
* Extra information on Factorial Analysis on summaries
* Fixed bug on Factor::Rotation when used ::Matrix without field method. 
* Added Vector#vector_percentil method
* Summaries for PCA, Rotation, MultiScale and ScaleAnalysis created or improved. 
* Factor::PCA could have rotation and parallel analysis on summary.
* Cronbach's alpha from covariance matrix raise an error on size<2 
* MultiScaleAnalysis could have Parallel Analysis on summary.
* Added Chi Square test
* Added new information on README.txt

=== 0.13.1 / 2010-07-03

* Rserve extensions for dataset and vector operational
* On x86_64, variance from gsl is not exactly equal to sum of variance-covariance on Statsample::Reliability::Scale, but in delta 1e-10
* Updated README.txt
* Reliability::ScaleAnalysis uses covariance matrix for 'if deleted' calculations to optimize memory and speed. Test for 'if deleted' statistics
* More string translated. Added dependency on tetrachoric on parallel analysis

=== 0.13.0 / 2010-06-13

* Polychoric and Tetrachoric moved to gem statsample-bivariate-extension
* All classes left with summary method include Summarizable now. Every method which return localizable string is now parsed with _()
* Correct implementation of Reliability::MultiScaleAnalysis. 
* Spanish translation for Mann-Whitney's U
* Added example for Mann-Whitney's U test
* Better summary for Mann-Whitney's U Test
* Added Statsample::Bivariate::Pearson class to retrieve complete analysis for r correlations
* Bug fix on DominanceAnalysis::Bootstrap

=== 0.12.0 / 2010-06-09

* Modified Rakefile to remove dependencies based on C extensions. These are moved to statsample-optimization
* T test with unequal variance fixed on i686
* API Change: Renamed Reliability::ItemAnalysis and moved to independent file 
* New Reliability::MultiScaleAnalysis for easy analysis of scales on a same survey, includind reliability, correlation matrix and Factor Analysis
* Updated README to reflect changes on Reliability module
* SvgGraph works with reportbuilder. 
* Added methods on Polychoric based on Olsson(1979): the idea is estimate using second derivatives.
* Distribution test changed (reduced precision on 32 bits system

=== 0.11.2 / 2010-05-05
* Updated dependency for 'extendedmatrix' to 0.2 (Matrix#build method)

=== 0.11.1 / 2010-05-04
* Removed Matrix almost all Matrix extensions and replaced by dependency on 'extendmatrix' gem
* Added dependency to gsl >=1.12.109. Polychoric with joint method fails without this explicit dependency
=== 0.11.0 / 2010-04-16
<b>New features:</b>
* Added Statsample::Anova::TwoWay and Statsample::Anova::TwoWayWithVectors
* Added Statsample.clone_only valid and Statsample::Dataset.clone_only_valid, for cheap copy on already clean vectors
<b>Optimizations and bug fix</b> 
* Removed library statistics2 from package. Used gem statistics2 instead, because have a extension version
* Added example for Reliability class
* Bug fix on Statsample::DominanceAnalysis

=== 0.10.0 / 2010-04-13

<b>API modifications</b>
* Refactoring of Statsample::Anova module. 
  * Statsample::Anova::OneWay :implementation of generic ANOVA One-Way, used by Multiple Regression, for example.
  * Statsample::Anova::OneWayWithVectors: implementation of ANOVA One-Way to test differences of means.

<b>New features</b>
* New Statsample::Factor::Parallel Analysis, to performs Horn's 'parallel analysis' to a PCA, to adjust for sample bias on retention of components.
* New Statsample.only_valid_clone and Statsample::Dataset.clone, which allows to create shallow copys of valid vector and datasets. Used by correlation matrix methods to optimize calculations
* New module Statsample::Summarizable, which add GetText and ReportBuilder support to classes. Better summaries for Vector, Dataset, Crosstab, PrincipalAxis, PCA and Regression::Multiple classes

<b>Optimizations and bug fix</b>

* Refactoring of Statsample::Regression::Multiple classes. Still needs works
* Bug fix on Statsample::Factor::PCA and Statsample::Factor::PrincipalAxis
* Bug fix on Statsample::Bivariate::Polychoric.new_with_vectors. Should be defined class method, no instance method.
* Optimized correlation and covariance matrix. Only calculates the half of matrix and the other half is returned from cache
* More tests coverage. RCOV Total: 82.51% , Code: 77.83%

=== 0.9.0 / 2010-04-04
* New Statsample::Test::F. Anova::OneWay subclasses it and Regression classes uses it.
=== 0.8.2 / 2010-04-01
* Statsample::PromiseAfter replaced by external package DirtyMemoize [http://rubygems.org/gems/dirty-memoize]
=== 0.8.1 / 2010-03-29
* Fixed Regression summaries
=== 0.8.0 / 2010-03-29
* New Statsample::Test::T module, with classes and methods to do Student's t tests for one and two samples. 
* Statsample::PromiseAfter module to set a number of variables without explicitly call the compute or iterate method
* All tests ported to MiniUnit
* Directory 'demo' renamed to 'examples'
* Bug fix on report_building on Statsample::Regression::Multiple classes

=== 0.7.0 / 2010-03-25
* Ported to ReportBuilder 1.x series
* Implementation of ruby based covariance and correlation changed to a clearer code
* Statsample::Vector#svggraph_frequencies accepts IO
* Some test ported to Miniunit
* CSV on Ruby1.8 uses FasterCSV

=== 0.6.7 / 2010-03-23
* Bug fix: dependency on ReportBuilder should be set to "~>0.2.0", not "0.2"
=== 0.6.6 / 2010-03-22
* Set ReportBuilder dependency to '0.2.~' version, because future API break
* Removed Alglib dependency
* Factor::PrincipalAxis and Factor::PCA reworked
* Standarization of documentation on almost every file
* New Statsample::Test::Levene, to test equality of variances
* Constant HAS_GSL replaced by Statsample.has_gsl?
* PCA and Principal Axis test based on R and SPSS results
* Bug fix on test_dataset.rb / test_saveload
* Added Rakefile
* Demos for levene, Principal Axis

=== 0.6.5 / 2010-02-24

* Bug fix on test: Use tempfile instead of tempdir
* Multiple Regression: Calculation of constant standard error , using covariance matrix.
* Calculation of R^2_yx and P^2_yx for Regresion on Multiple Dependents variables
* Dominance Analysis could use Correlation or Covariance Matrix as input.
* Dominance Analysis extension to multiple dependent variables (Azen & Budescu, 2006)
* Two-step estimate of Polychoric correlation uses minimization gem, so could be executed without rb-gsl


=== 0.6.4 / 2010-02-19
* Dominance Analysis and Dominance Analysis Bootstrap allows multivariate dependent analysis. 
* Test suite for Dominance Analysis, using Azen and Budescu papers as references
* X^2 for polychoric correlation

=== 0.6.3 / 2010-02-15
* Statsample::Bivariate::Polychoric have joint estimation.
* Some extra documentation and bug fixs

=== 0.6.2 / 2010-02-11
* New Statsample::Bivariate::Polychoric. For implement: X2 and G2
* New matrix.rb, for faster development of Contingence Tables and Correlation Matrix

=== 0.6.1 / 2010-02-08
* Bug fix on DominanceAnalysis summary for Ruby1.9
* Some extra documentation
=== 0.6.0 / 2010-02-05
* New Statsample::Factor module. Include classes for extracting factors (Statsample::Factor::PCA and  Statsample::Factor::PrincipalAxis) and rotate component matrix  ( Statsample::Factor::Rotation subclasses). For now, only orthogonal rotations
* New Statsample::Dataset.crosstab_with_asignation, Statsample::Dataset.one_to_many
* New class Statsample::Permutation to produce permutations of a given array
* New class Statsample::Histogram, with same interface as GSL one 
* New class Statsample::Test::UMannWhitney, to perform Mann-Whitney's U test. Gives z based and exact calculation of probability
* Improved support for ReportBuilder
* Statsample::Codification module reworked
* Fixed bugs on Dominance Analysis classes
* Fixed bugs on Statsample::Vector.kurtosis and Statsample::Vector.skew 

=== 0.5.1 / 2009-10-06

* New class Statsample::Bivariate::Tetrachoric, for calculation of tetrachoric correlations. See http://www.john-uebersax.com/stat/tetra.htm for information.
* New Statsample::Dataset.merge
* New Statsample::Vector.dichotomize
* New ItemReliability.item_difficulty_analysis
* New module Statsample::SPSS, to export information to SPSS. For now, only tetrachoric correlation matrix are provided
* All SpreadSheet based importers now accept repeated variable names and renames they on the fly
* MultipleRegression::BaseEngine moved to new file
* Bug fix for MultipleRegression::GslEngine checks for Alglib, not GSL

=== 0.5.0 / 2009-09-26
* Vector now uses a Hash as a third argument
* Tested on Ruby 1.8.6, 1.8.7 and 1.9.1 with multiruby

=== 0.4.1 / 2009-09-12
* More methods and usage documentation
* Logit tests
* Bug fix: rescue for requires doesn't specify LoadError
* Binomial::BaseEngine new methods: coeffs_se, coeffs, constant and constant_se

=== 0.4.0 / 2009-09-10
* New Distribution module, based on statistics2.rb by Shin-ichiro HARA. Replaces all instances of GSL distributions pdf and cdf calculations for native calculation.
* New Maximum Likehood Estimation for Logit, Probit and Normal Distribution using Von Tessin(2005) algorithm. See MLE class and subclasses for more information.
* New Binomial regression subclasses (Logit and Probit), usign MLE class
* Added tests for gsl, Distribution, MLE and Logit
* Bug fix on svggraph.rb. Added check_type for scale graphics
* Bug fix on gdchart. Replaced old Nominal, Ordinal and Scale for Vector

=== 0.3.4 / 2009-08-21
* Works with statsample-optimization 2.0.0
* Vector doesn't uses delegation. All methods are part of Vector
* Added Combination. Generates all combination of n elements taken r at a time
* Bivariate#prop_pearson now can uses as a second parameter :both, :left, :right, :positive or :negative
* Added LICENSE.txt

=== 0.3.3 / 2009-08-11
* Added i18n support. For now, only spanish translation available
* Bug fix: Test now load libraries on ../lib path
* Excel and CSV importers automatically modify type of vector to Scale when all data are numbers or nils values

=== 0.3.2 / 2009-08-04

* Added Regression::Multiple::GslEngine
* Added setup.rb
* Crosstab#row_label and #column_name
* DominanceAnalysis and DominanceAnalysisBootstrap uses Dataset#labels for Vector names.

=== 0.3.1 / 2009-08-03

* Name and logic of Regression classes changed. Now, you have Regression::Simple class and Regression::Multiple module with two engines: RubyEngine and AlglibEngne
* New Crosstab#summary

=== 0.3.0 / 2009-08-02

* Statsample renamed to Statsample
* Optimization extension goes to another gem: ruby-statsample-optimization

=== 0.2.0 / 2009-08-01

* One Way Anova on Statsample::Anova::OneWay
* Dominance Analysis!!!! The one and only reason to develop a Multiple Regression on pure ruby.
* Multiple Regression on Multiple Regression module. Pairwise (pure ruby) or MultipleRegressionPairwise and Listwise (optimized) on MultipleRegressionAlglib and 
* New Dataset#to_gsl_matrix, #from_to,#[..],#bootstrap,#vector_missing_values, #vector_count_characters, #each_with_index, #collect_with_index
* New Vector#box_cox_transformation
* Module Correlation renamed to Bivariate
* Some fancy methods and classes to create Summaries
* Some documentation about Algorithm used on doc_latex
* Deleted 'distributions' extension. Ruby/GSL has all the pdf and cdf you ever need.
* Tests work without any dependency. Only nags about missing deps. 
* Test for MultipleRegression, Anova, Excel, Bivariate.correlation_matrix and many others 

=== 0.1.9 / 2009-05-22

* Class Vector: new method vector_standarized_pop, []=, min,max
* Class Dataset: global variable $RUBY_SS_ROW stores the row number on each() and related methods. dup() with argument returns a copy of the dataset only for given fields. New methods: standarize, vector_mean, collect, verify,collect_matrix
* Module Correlation: new methods covariance, t_pearson, t_r, prop_pearson, covariance_matrix, correlation_matrix, correlation_probability_matrix
* Module SRS: New methods estimation_n0 and estimation_n
* Module Reliability: new ItemCharacteristicCurve class
* New HtmlReport class
* New experimental SPSS Class. 
* Converters: Module CSV with new options. Added write() method for GGobi module 
* New Mx exporter (http://www.vcu.edu/mx/)
* Class SimpleRegression: new methods standard error

* Added tests for regression and reliability, Vector#vector_mean, Dataset#dup (partial)  and Dataset#verify


=== 0.1.8 / 2008-12-10
* Added Regression and Reliability modules
* Class Vector: added methods vector_standarized, recode, inspect, ranked
* Class Dataset: added methods vector_by_calculation, vector_sum, filter_field
* Module Correlation: added methods like spearman, point biserial and tau-b
* Added tests for Vector#ranked, Vector#vector_standarized,  Vector#sum_of_squared_deviation, Dataset#vector_by_calculation, Dataset#vector_sum, Dataset#filter_field and various test for Correlation module
* Added demos: item_analysis and sample_test

=== 0.1.7 / 2008-10-1
* New module for codification
* ...
=== 0.1.6 / 2008-09-26
* New modules for SRS and stratified sampling
* Statsample::Database for read and write onto databases.
  You could use Database and CSV on-tandem for mass-editing and reimport
  of databases

=== 0.1.5 / 2008-08-29
* New extension statsampleopt for optimizing some functions on Statsample submodules
* New submodules Correlation and Test

=== 0.1.4 / 2008-08-27

* New extension, with cdf functions for
  chi-square, t, gamma and normal distributions. 
  Based on dcdflib (http://www.netlib.org/random/)
  Also, has a function to calculate the tail for a noncentral T distribution

=== 0.1.3 / 2008-08-22

* Operational versions of Vector, Dataset, Crosstab and Resample
* Read and write CSV files
* Calculate chi-square for 2 matrixes

=== 0.1.1 - 0.1.2 / 2008-08-18

* Included several methods on Ruby::Type classes
* Organized dirs with sow


=== 0.1.0 / 2008-08-12

* First version.