Skip to content

Latest commit

 

History

History
299 lines (203 loc) · 8.27 KB

NEWS.md

File metadata and controls

299 lines (203 loc) · 8.27 KB
Raw

News

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

The format is based on Keep a Changelog.

Unreleased

Added

  • New dataframe::front() public member function which allows simple access to the first element of a dataframe.

  • dataframe::read_csv now supports a header row. Also the output column can be specified (before it always was the first column):

    dataframe d;

dataframe::params p;
p.has_header = true;
p.output_index = 2;

d.read_csv("filename.csv", p);

Changed

  • BREAKING CHANGE. Sources require a C++17 compatible compiler.

  • BREAKING CHANGE. The interpreter class performs calculation using std::variant insted of std::any.

    This gives a performance improvements without important limitations of use cases.

  • BREAKING CHANGE. dataframe::get_column and dataframe::columns have been removed / merged. The dataframe::columns public data member contains information about all the columns of the dataframe.

    So:

    1. d.columns.size() replaces d.columns()
    2. d.columns[3].name replaces d.get_column(3).name
    3. d.columns[3].category_id replaces d.get_column(3).category_id

1.1.0 - 2019-12-11

This is the last C++14 compatible version. Next versions of the framework will assume a C++17 compiler.

Changed

  • BREAKING CHANGE. Fluent interface for the search / src_search / ga_search classes.

    Insted of:

    search<...> engine(...);
engine.set_training_evaluator<...>(...);
engine.set_validation_evaluator<...>(...);
engine.set_validator<...>(...);

    you should write:

    search<...> engine(...)
            .training_evaluator<...>(...)
  		  .validation_evaluator<...>(...)
  		  .validation_strategy<...>(...);

    This benefits the class user by reducing the amount he has to type and makes the interface more natural.

  • BREAKING CHANGE. Removed read_csv(filename) / read_xrff(filename) from the interface of the dataframe class.

    Both the member functions can be replaced with the already existing dataframe::read(filename) which uses the filename extension to identify the data format.

  • Clearer format when exporting individuals.

    Part of the redundant parentheses has been removed.

    So, instead of ((sin(X1)) + (ln(((X1)+(X2))) you get (sin(X1) + ln(X1+X2))

1.0.0 - 2019-03-22

Added

  • Simpler way to setup Genetic Algorithm / Differential Evolution tasks. We now have the ga_problem and de_problem facades. Their constructors cover the standard situation of a sequence of uniform parameters (possibly in distinct numeric intervals).

    Examples are been rewritten to take advantage of the new classes.

Removed

  • problem::chromosome help function. It was a bit of a stretch, now instead of:

    class ad_hoc_integer_like_class { /* ... */ };

vita::problem prob;
prob.chromosome<ad_hoc_integer_like_class>(nr_of_parameters);

    you should write:

    vita::ga_problem prob(nr_of_parameters, {min, max});

  • standalone Makefile-based build system. Now the only supported build system is CMake. This greatly simplify multi-platform testing and documentation.

Changed

  • BREAKING CHANGE. GA-individuals match integer vectors. This allow a faster management, a simpler access to the genome and simpler code.

    Where we wrote:

    genome[i].as<int>()

    we now have:

    genome[i]

  • BREAKING CHANGE. Completely revised validation strategies. The search class now allows specifying two evaluation (a.k.a fitness) functions via the set_training_evaluator and set_validation_evaluator methods.

    This:

    • gives users the option to adopt distinct training / validation strategies;
    • allows a simpler implementation.

    More details are contained in the the validation.md wiki page.

  • BREAKING CHANGE. Removed switch to default initialize an environment object.

    So, instead of:

    environment e(initialization::standard);

    you should write:

    environment e;
e.init();  // initialization

    Usually the initialization is only needed in debug code. The common approach is:

    • left parameters in the environment struct unitialized (auto-tune);
    • leave to the search::run() function the task of identifying the "best" values.

  • BREAKING CHANGE. dataframe::load... renamed to dataframe::read... for uniformity with Pands' dataframe.

  • BREAKING CHANGE. example::tag method has been renamed to label; example::cast_output has been renamed to label_as. Both are now free functions.

    The new naming improves consistency and adopts standard terminology.

  • BREAKING CHANGE. Simpler method to specify GAs parameters.

    Instead of:

    for (unsigned i(0); i < n_jobs; ++i)
  prob.sset.insert(ga::parameter(i, {-0.5, 23.5}));

    use:

    // problem prob;
for (unsigned i(0); i < n_jobs; ++i)
  prob.sset.insert<ga::real>( range(-0.5, 23.5) );

    or equivalently:

    // de_problem prob;
for (unsigned i(0); i < n_jobs; ++i)
  prob.insert( range(-0.5, 23.5) );

    or, even better:

    de_problem prob(n_jobs, {-0.5, 23.5});

    Note that:

    • the parameter index doesn't appear anymore;
    • the range is clearly stated.

    The same approach applies to GAs.

    The ga::parameter help function has been removed.

0.9.14 - 2017-12-11

Added

  • Code of conduct for contributors.
  • Complete control of the generational-gap between subset-selection (DSS algorithm).
  • Simpler setup for GA problems.

Changed

  • symbol_set::roulette() function has the same probability of extracting a terminal / a function regardeless of the specific symbols' weights.

    If all symbols have the same probability to appear into a chromosome, there could be some problems. For instance, if our problem has many variables (let's say 100) and the function set has only 4 symbols we cannot get too complex trees because the functions have a reduced chance to appear in the chromosome (e.g. it happens in the Forex example).

  • BREAKING CHANGE. Enable/disable logging of specific information is a bit simpler.

    Instead of

    env.dynamic = true;
env_dyn_name = "dynamic.txt";

    this is enough:

    env.dynamic_file = "dynamic.txt"

  • BREAKING CHANGE. i_mep::compress function renamed to i_mep::cse (Common Subexpression Elimination).

  • BREAKING CHANGE. Serialization file format for cache and fitness has changed.

    The new format produces files up to 20% smaller omitting:

    1. the seal value which is assumed equal to the cache::seal value
    2. the fitness vector size (and assuming that all the components of the vector are on the same line)

  • BREAKING CHANGE. Instead of:

    symbol_set sset;
environment e(&sset, initialization::standard);

evolution<i_mep, std_es> evo(env, *eva);

    you should write:

    problem p(initialization::standard);

evolution<i_mep, std_es> evo(p, *eva);

    The problem object aggregates an environment and a symbol_set (which are almost always used together).

    This also permits to remove the pointer from the environment to the symbol_set.

  • BREAKING CHANGE. Replaced the search::set_evaluator method: Instead of:

    std::unique_ptr<E> eva(f);
std::search engine(prob);
engine.set_evaluator(std::move(eva));

    you can write:

    std::search engine(prob);
engine.set_evaluator<E>(f);

  • Uniform output results for make / cmake build systems.

0.9.13 - 2017-09-15

Added

  • New printing system for i_mep individuals. You can now export C / C++ / Python / MQL code.
  • Self-adaptive crossover operator.
  • Forex example.

Changed

  • More robust implementation for real functions.
  • New uniform crossover implementation.
  • ALPS can remove multiple identical layers.

Fixed

  • Various compilation warning with recent version of gcc (7.x).