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Interpreting formulas with ΣΣ (two sigma) in Python


Consider the function f(x,y) that equals two sigma (ΣΣ) where i ranges from 1 to 10 and (first sigma) and j ranges from 1 to 10 (second sigma) of the quantity {ix^2 + jy^3)

I believe the first sigma would be an inner loop and the second sigma an outer loop, but I am having trouble rewriting this into Python.

How can I convert this into Python?

Please click to see the mathematical expression. I cannot embed


Solution

  • I'm no mathematician, but as far as I could tell, that would translate to

    def f(x, y):
        return sum(
            sum(
                i * x ** 2 + j * y ** 3
                for j in range(1, 11)
            )
            for i in range(1, 11)
        )
    

    or written out as for loops,

    def f(x, y):
        value = 0
        for i in range(1, 11):
            for j in range(1, 11):
                value += i * x ** 2 + j * y ** 3
        return value