# Changelog
All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [0.9.0] - Unreleased
### Added
- [Preprocessing] Implement LabelEncoder
- [Preprocessing] Implement ColumnFilter
- [Preprocessing] Implement LambdaTransformer
- [Preprocessing] Implement NumberConverter
- [Preprocessing] Implement OneHotEncoder
- [Workflow] Implement FeatureUnion
- [Metric] Add Regression metrics: meanSquaredError, meanSquaredLogarithmicError, meanAbsoluteError, medianAbsoluteError, r2Score, maxError
- [Regression] Implement DecisionTreeRegressor 

## [0.8.0] - 2019-03-20
### Added
- [Tokenization] Added NGramTokenizer (#350)
- editorconfig file (#355)
### Fixed
- [Dataset] FilesDataset read samples without additional array (#363)
- [Tokenization] fixed error with numeric token values (#363)
### Changed
- [Math] improved performance with pow and sqrt replacement (#350) 
- [Math] reduce duplicated code in distance metrics (#348)
- update phpunit to 7.5.1 (#335)
- code style fixes (#334)

## [0.7.0] - 2018-11-07
### Added
- [Clustering] added KMeans associative clustering (#262)
- [Dataset] added removeColumns function to ArrayDataset (#249)
- [Dataset] added a SvmDataset class for SVM-Light (or LibSVM) format files (#237)
- [Dataset] added Mnist Dataset for MNIST file format (#326)
- [Internal] Add performance test for LeastSquares (#263)

### Changed
- [Internal] implement Keep a Changelog format
- [Classification] changed the default kernel type in SVC to Kernel::RBF (#267)
- [Optimizer] removed $initialTheta property and renamed setInitialTheta method to setTheta (#252)
- [Imputer] Throw exception when trying to transform without train data (#314)
- [Math] Micro optimization for matrix multiplication (#255)
- [Internal] Throw proper exception (#259, #251)
- [MLPClassifier] return labels in output (#315)
- [Internal] Update phpstan to 0.10.5 (#320)

### Fixed
- [SVM] ensure DataTransformer::testSet samples array is not empty (#204)
- [Optimizer] optimizer initial theta randomization (#239) 
- [Internal] travis build on osx (#281)
- [SVM] SVM locale (non-locale aware) (#288)
- [Internal] typo, tests, code styles and documentation fixes (#265, #261, #254, #253, #251, #250, #248, #245, #243, #317, #328)
- [Classification] Check if feature exist when predict target in NaiveBayes (#327)

## [0.6.2] - 2018-02-22
### Fixed
- Fix Apriori array keys (#238)

## [0.6.1] - 2018-02-18
### Fixed
- Fix KMeans and EigenvalueDecomposition (#235)

## [0.6.0] - 2018-02-16
- feature [FeatureSelection] implement SelectKBest with scoring functions (#232)
- feature [FeatureSelection] implement VarianceThreshold - simple baseline approach to feature selection.  (#228)
- feature [Classification] support probability estimation in SVC (#218)
- feature [NeuralNetwork] configure an Activation Function per hidden layer (#208)
- feature [NeuralNetwork] Ability to update learningRate in MLP (#160)
- feature [Metric] Choose averaging method in classification report (#205)
- enhancement Add phpstan strict rules (#233)
- enhancement Flatten directory structure (#220)
- enhancement Update phpunit/phpunit (#219)
- enhancement Cache dependencies installed with composer on Travis (#215)
- enhancement Add support for coveralls.io (#153)
- enhancement Add phpstan and easy coding standards (#156, #168)
- enhancement Throw exception when libsvm command fails to run (#200, #202)
- enhancement Normalize composer.json and sort packages (#214, #210)
- enhancement Rewrite DBSCAN (#185)
- fix phpunit include tests path (#230)
- fix support of a rule in Apriori (#229)
- fix apriori generates an empty array as a part of the frequent item sets (#224)
- fix backpropagation random error (#157)
- fix logistic regression implementation (#169)
- fix activation functions support (#163)
- fix string representation of integer labels issue in NaiveBayes (#206)
- fix the implementation of conjugate gradient method (#184)
- typo, tests and documentation fixes (#234, #221, #181, #183, #155, #159, #165, #187, #154, #191, #203, #209, #213, #212, #211)

## [0.5.0] - 2017-11-14
- general [php] Upgrade to PHP 7.1 (#150)
- general [coding standard] fix imports order and drop unused docs typehints
- feature [NeuralNetwork] Add PReLU activation function (#128)
- feature [NeuralNetwork] Add ThresholdedReLU activation function (#129)
- feature [Dataset] Support CSV with long lines (#119)
- feature [NeuralNetwork] Neural networks partial training and persistency (#91)
- feature Add french stopwords (#92)
- feature New methods: setBinPath, setVarPath in SupportVectorMachine (#73)
- feature Linear Discrimant Analysis (LDA) (#82)
- feature Linear algebra operations, Dimensionality reduction and some other minor changes (#81)
- feature Partial training base (#78)
- feature Add delimiter option for CsvDataset (#66)
- feature LogisticRegression classifier & Optimization methods (#63)
- feature Additional training for SVR (#59)
- optimization Comparison - replace eval (#130)
- optimization Use C-style casts (#124)
- optimization Speed up DataTransformer (#122)
- bug DBSCAN fix for associative keys and array_merge performance optimization (#139)
- bug Ensure user-provided SupportVectorMachine paths are valid (#126)
- bug [DecisionTree] Fix string cast #120 (#121)
- bug fix invalid typehint for subs method (#110)
- bug Fix samples transformation in Pipeline training (#94)
- bug Fix division by 0 error during normalization (#83)
- bug Fix wrong docs references (#79)

## [0.4.0] - 2017-02-23
- feature [Classification] - Ensemble Classifiers : Bagging and RandomForest by Mustafa Karabulut
- feature [Classification] - RandomForest::getFeatureImportances() method by Mustafa Karabulut
- feature [Classification] - Linear classifiers: Perceptron, Adaline, DecisionStump by Mustafa Karabulut
- feature [Classification] - AdaBoost algorithm by Mustafa Karabulut
- bug [Math] - Check if matrix is singular doing inverse by Povilas Susinskas
- optimization - Euclidean optimization by Mustafa Karabulut

## [0.3.0] - 2017-02-04
- feature [Persistency] - ModelManager - save and restore trained models by David Monllaó
- feature [Classification] - DecisionTree implementation by Mustafa Karabulut
- feature [Clustering] - Fuzzy C Means implementation by Mustafa Karabulut
- other small fixes and code styles refactors

## [0.2.1] - 2016-11-20
- feature [Association] - Apriori algorithm implementation
- bug [Metric] - division by zero

## [0.2.0] - 2016-08-14
- feature [NeuralNetwork] - MultilayerPerceptron and Backpropagation training

## [0.1.2] - 2016-07-24
- feature [Dataset] - FilesDataset - load dataset from files (folder names as targets)
- feature [Metric] - ClassificationReport - report about trained classifier
- bug [Feature Extraction] - fix problem with token count vectorizer array order
- tests [General] - add more tests for specific conditions

## [0.1.1] - 2016-07-12
- feature [Cross Validation] Stratified Random Split - equal distribution for targets in split
- feature [General] Documentation - add missing pages (Pipeline, ConfusionMatrix and TfIdfTransformer) and fix links

## [0.1.0] - 2016-07-08
- first develop release
- base tools for Machine Learning: Algorithms, Cross Validation, Preprocessing, Feature Extraction
- bug [General] #7 - PHP-ML doesn't work on Mac