Adding new mathematical methods to mathy

[davud2635]

Hi Justin, I'am a bit confused about which file/files I have to modify, in order to add new methods like Differentiation, integration etc. Can you tell me which folder or file, I have to modify ?

[justindujardin]

Hey Davud,

If you want to add differentiation to the expression trees, you'll need to modify the expressions.py file in the mathy_core repository.

You can find the relevant files here: https://github.com/mathy/mathy_core/blob/master/mathy_core/expressions.py

The older version of mathy_core had differentiation built-in to the expressions, so here's an example of what it might look like for the MultiplyExpression:

class MultiplyExpression(BinaryExpression):
    """Multiply one and two"""

    def operate(self, one, two):
        return one * two

    #      f(x) = g(x)*h(x)
    #     f'(x) = g(x)*h'(x) + g'(x)*h(x)
    def differentiate(self, by_variable):
        return AddExpression(
            MultiplyExpression(self.left, self.right.differentiate(by_variable)),
            MultiplyExpression(self.left.differentiate(by_variable), self.right),
        )