Given the row and column of a pixel in the output image, return the corresponding point on the complex plane. `bounds` is a pair giving the width and

Parse a pair of floating-point numbers separated by a comma as a complex number.

Parse the string `s` as a coordinate pair, like `"400x600"` or `"1.0,0.5"`. Specifically, `s` should have the form <left><sep><right>, where <sep> is

Try to determine if `c` is in the Mandelbrot set, using at most `limit` iterations to decide. If `c` is not a member, return `Some(i)`, where `i` is

Render a rectangle of the Mandelbrot set into a buffer of pixels. The `bounds` argument gives the width and height of the buffer `pixels`, which hold

Write the buffer `pixels`, whose dimensions are given by `bounds`, to the file named `filename`.