differentiateFunction function

double differentiateFunction(double x, Function f, { double dx = 0.00000001, })

Compute the numerical derivative of a function in a certain point

• x : point in the function to calculate the derivative
• f : function to derivate
• dx : optional, interval between the points of the derivative, need be very small numbers, default is 0.00000001

References

1. "Create A Derivative Calculator in Python". https://medium.com/@jamesetaylor/create-a-derivative-calculator-in-python-72ee7bc734a4. Retrieved 2019-08-01.
2. "Java 8 Derivative Approximation". https://gist.github.com/thekeenant/4bdab56307e5b8e909f308a037a668ce. Retrieved 2019-08-01.
3. "scipy.misc.derivative". https://docs.scipy.org/doc/scipy-0.15.1/reference/generated/scipy.misc.derivative.html. Retrieved 2019-08-01.

Examples

var f = (x) => x * x * x;

print(differentiateFunction(2, f));

/* output:
11.999999927070348
*/

Implementation

double differentiateFunction(double x, Function f, {double dx = 0.00000001}) {
  return (f(x + dx) - f(x)) / dx;
}