SEECBC/FrontEnd/components/playground/gradient-descent/functions.ts

export interface SingleVarFunction {
  f: (x: number) => number
  df: (x: number) => number
  domain: [number, number]
  range: [number, number]
}

const function1: SingleVarFunction = {
  f: (x: number) => x * x,
  df: (x: number) => 2 * x,
  domain: [-3, 3],
  range: [0, 9]
}

const function2: SingleVarFunction = {
  f: (x: number) => x ** 3,
  df: (x: number) => 3 * x * x,
  domain: [-3, 3],
  range: [-27, 27]
}

const function3: SingleVarFunction = {
  domain: [-4.0, 4.0],
  range: [-50.0, 150.0],
  f: (x: number) => (x ** 2 - x * 4 + 4) * (x ** 2 + x * 4 + 2),
  df: (x: number) => 4 * (x - 2) * (x + 1 + Math.sqrt(2)) * (x + 1 - Math.sqrt(2))
}

export const singleVarfunctions = {
  'y = x^2': function1,
  'y = x^3': function2,
  'y = (x^2 - 4x + 4)(x^2 + 4x + 2)': function3
} as { [name: string]: SingleVarFunction }