take the derivative of a function in swift

main.swift
import org.apache.commons.math3.analysis.differentiation.DerivativeStructure

// Define your function, e.g. f(x, y) = x^2 + 2y
func f(x: Double, y: Double) -> Double {
    return x*x + 2*y
}

// Define the order of the derivative you want to find, and the number of variables in your function
let order = 1 // first derivative
let numVars = 2 // x and y

// Create a DerivativeStructure object with the same values for x and y as your function
let ds = DerivativeStructure(numVars, order, 0, f(1, 2))

// Find the partial derivative of f with respect to x
let df_dx = ds.getPartialDerivative(1) // should be 2x = 2

// Find the partial derivative of f with respect to y
let df_dy = ds.getPartialDerivative(2) // should be 2

// Note that you can also create arrays of DerivativeStructure objects to find higher-order derivatives or multiple partial derivatives at once
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