Package dev.nm.analysis.differentiation.univariate

Class Dfdx

java.lang.Object
dev.nm.analysis.function.rn2r1.AbstractRealScalarFunction
dev.nm.analysis.function.rn2r1.univariate.AbstractUnivariateRealFunction
dev.nm.analysis.differentiation.univariate.Dfdx
All Implemented Interfaces:
Function<Vector,Double>, RealScalarFunction, UnivariateRealFunction
public class Dfdx extends AbstractUnivariateRealFunction
The first derivative is a measure of how a function changes as its input changes. In other words, a derivative is how much a quantity changes if the input changes (by a very small amount). The derivative of a function at a particular point is the best linear approximation of the function at that point. For a univariate real function, the derivative at a point is the slope of the tangent line to the function at that point.

This implementation is a simple wrapper class around the built-in derivative functions, e.g., DBeta, DErf, and the numerical derivative computation classes, e.g., FiniteDifference and Ridders.

See Also:

  • Constructor Details

    • Dfdx

      public Dfdx(UnivariateRealFunction f, Dfdx.Method method)
      Construct the first order derivative function of a univariate function f.
      Parameters:
      f - a univariate function
      method - the numerical method to use, c.f., Dfdx.Method

    • Dfdx

      public Dfdx(UnivariateRealFunction f)
      Construct, using the central finite difference, the first order derivative function of a univariate function f.
      Parameters:
      f - a univariate function

  • Method Details

    • evaluate

      public double evaluate(double x)
      Description copied from interface: UnivariateRealFunction
      Evaluate y = f(x).
      Parameters:
      x - x
      Returns:
      f(x)