duffing oscillator

Hello, i have quite an intense maths project i would like a quote for please. in the swift playground only (no ios app or any sort of visual output) i need a duffing oscillator created with accurate Lagrangian and eulers method to simulate the motion. I need no run time errors and for everything to compile. It should take 7ish hours. I would also need comments on the code so its easy to follow for myself. I'd be excited to discuss options. I would need it complete within 6-7 days thankyou. Read Less