newton.m is a function that can be used in the following ways

newton(f, df, x0, tol)

f - a function defined by the user df - the derivative of the function f x0 - the starting point for the root finding method tol - the tolerance (difference between consecutive terms)

cfnewt.m is a function that can be used in the following way

cfnewt(a, b, c, d, x1, y1, x2, y2, n)

a, b, c, d - coefficients of polynomial ax^3 + bx^2 + cx + d x1, y1 - bottom left coordinate on plot x2, y2 - top right coordinate on plot n - number of columns of pixels (total number of pixels is n^2

>> cfnewt(1, 0, 0, 1, -5, -5, 5, 5, 500)

Starting rendering process... Working on pixel column 100 out of 500 Working on pixel column 200 out of 500 Working on pixel column 300 out of 500 Working on pixel column 400 out of 500 Working on pixel column 500 out of 500

Plotting...

Roots

Red: -1.000000+0.000000i

Green: 0.500000+0.866025i

Blue: 0.500000-0.866025i

The number of uncolored pixels is 0

Elapsed time is 14.815667 seconds.