Math extension of Cactoos library
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README.md

EO principles respected here DevOps By Rultor.com

Build Status License

Cactoos-Math is math extension of Cactoos (my blog post about this).

Motivation:

  • Math classes is overkill for Cactoos, but it can be useful and interesting.
  • It is generally accepted that FP, rather than OOP, is more suitable for math.
  • Practice in OOP.

Principles. These are the design principles behind Cactoos.

Java version required: 1.8+.

Funcs

Please use a Func<X, Func<Y, Z>> instead of BiFunc<X, Y, Z> (a little bit about that).

BiFunc<Integer, Long, Number> bifunc = (fst, snd) -> fst + snd;
Func<Integer, Func<Long, Number>> funcfunc = new BiFuncFunc<>(bifunc);

Partial application:

Func<Long, Long> func = new PartApply<>(bifunc, 2);

This is equivalent to:

Func<Long, Long> func = new BiFuncFunc<>(bifunc).apply(2)

Seq

Natural Number:

new Seq(0, a -> a + 1)

Stream of random double greater than or equal to 6 and less than 16:

new Seq(new Random(6, 16), a -> new Random(6, 16))

BiSeq

Fibonacci number:

new BiSeq<>(0, 1, (fst, snd) -> fst + snd)

Lucas number:

new BiSeq<>(2, 1, fst -> snd -> snd + fst)

Matrix

Identity matrix 6x6:

new MatrixOf<>(
    row -> col -> row.equals(col) ? 1 : 0,
    6, 6
)

The product of two matrices:

new MatrixProd<>(
    new MatrixOf<>(
        new Integer[][]{
            {1, 2},
            {3, 4},
        }
    ),
    new MatrixOf<>(
        new Long[][]{
            {9L, 8L},
            {7L, 6L},
        }
    ),
    a -> b -> a * b,
    a -> b -> a + b,
    0L
)

Determinant:

new IntDet<>(
    new MatrixOf<>(
        new Integer[][]{
            {1, 2},
            {3, 4},
        }
    )
)

Graphs

Remove node:

new RemoveNode<>(
    new GraphOf<>(
        new ListOf<>(1, 2, 3),
        node -> new ListOf<>(1, 2, 3)
    ),
    2
)

Scalars

Random number in [2; 4]:

new Random(() -> 2, () -> 4);

Factorial of 5:

new ReduceLeft<>(
    new Limited<>(
        5,
        new Seq<>(1, a -> a + 1)
    ),
    fst -> snd -> fst * snd
);

Other scalars: Abs, Cbrt, Constant, Cos, Exp, FoldLeft, FoldRight, ReduceLeft, ReduceRight, Round, Sin, Sqrt, Tan.

How to contribute?

Just fork the repo and send us a pull request.

Make sure your branch builds without any warnings/issues:

mvn clean install -Pqulice

Contributors

MIT License

Copyright (c) 2017-2018 Vseslav Sekorin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.