polynomialmani.pl/README.md

# POLYnomial MANI.PuLation

A symbolic polynomial calculator in Prolog

## How to run

In a terminal, run

    $ swipl

Inside the REPl, load the file
   
    ?- ["polymani.pl"].

> Note: Don't forget the dot at the end of the line.

The user available funtions are:
  1) poly2list/2
  2) simpoly_list/2
  3) simpoly/2
  4) scalepoly/3
  5) addpoly/3

`poly2list/2` - transforms a list representing a polynomial (second argument) 
into a polynomial represented as an expression (first argument) 
and vice-versa.

`simpolylist/2` - simplifies a polynomial represented as a list into
another polynomial as a list.

`simpoly/2` - simplifies a polynomial represented as an expression
as another polynomial as an expression.

`scalepoly/3` - multiplies a polynomial represented as an expression by a scalar
resulting in a second polynomial. The two first arguments are assumed to
be ground. The polynomial resulting from the sum is in simplified form.

`addpoly/3` - adds two polynomials as expressions resulting in a
third one. The two first arguments are assumed to be ground.
The polynomial resulting from the sum is in simplified form.

> Note: `foo/N` means the funciton `foo` has `N` parameters.
  These names are the ones requested in the assignment.

## Tests

```
:- ["polymani.pl"].
%@ true.

?- poly2list(2*x^2+3*x+5*x^17-7*x^21+3*x^3+25*x^5-4.3, S).
%@ S = [-4.3, 25*x^5, 3*x^3, -7*x^21, 5*x^17, 3*x, 2*x^2].

?- simpoly_list([x*x*x, x^3, 5*x^3, 4.2*z, 2, 42.6, 42*y, 5*z, z^7, z*y^1337, 0], L).
%@ L = [44.6, 7*x^3, 9.2*z, 42*y, y^1337*z, z^7].

?- simpoly(1+x+1+x+1+x+1+x^3+5*x^3+42*x^1337+0, S).
%@ S = 42*x^1337+6*x^3+3*x+4.

?- scalepoly(2*x^2+3*x+5*x^17-7*x^21+3*x^3-23*x^4+25*x^5-4.3, 42, S).
%@ S = 1050*x^5+210*x^17+126*x^3+126*x+84*x^2-294*x^21-966*x^4-180.6.

?- addpoly(2*x^2+3*x+5*x^17-x^4+25*x^5-4.3, 42*x^1337+0-5, S).
%@ S = 42*x^1337+25*x^5+5*x^17+3*x+2*x^2-1*x^4-9.3.
```

## License