message: updated nelder mead example
diff: @@ -7,11 +7,10 @@ use argmin::testfunctions::{rosenbrock, rosenbrock_derivative, sphere, sphere_de
  fn run() -> Result<(), Box<std::error::Error>> {
  // Define cost function
  let cost = |x: &Vec<f64>| -> f64 { rosenbrock(x, 1_f64, 100_f64).unwrap() };
  - // let gradient = |x: &Vec<f64>| -> Vec<f64> { rosenbrock_derivative(x, 1_f64, 100_f64).unwrap() };
  // let cost = |x: &Vec<f64>| -> f64 { sphere(x).unwrap() };
  - // let gradient = |x: &Vec<f64>| -> Vec<f64> { sphere_derivative(x).unwrap() };
  // Define bounds
  + // Bounds are not satisfied yet.
  let lower_bound: Vec<f64> = vec![-1.5, -0.5];
  let upper_bound: Vec<f64> = vec![2.0, 3.0];
  @@ -20,9 +19,10 @@ fn run() -> Result<(), Box<std::error::Error>> {
  // Set up GradientDecent solver
  let mut solver = NelderMead::new();
  - // solver.max_iters(50);
  solver.max_iters(100);
  + // Choose the starting points.
  + // Randomly chosen starting points may make Nelder Mead converge very slowly.
  // let init_params = vec![
  // prob.random_param()?,
  // prob.random_param()?,
  @@ -30,7 +30,6 @@ fn run() -> Result<(), Box<std::error::Error>> {
  // ];
  let init_params = vec![vec![0.0, 0.1], vec![2.0, 1.5], vec![2.0, -1.0]];
  - // solver.init(&prob)?;
  let result = solver.run(&prob, &init_params)?;
  // print result
  