DifferentiableMultivariateRealFunction (Commons Math 2.2 API)

All Superinterfaces:

MultivariateRealFunction
```
public interface DifferentiableMultivariateRealFunction
extends MultivariateRealFunction
```
Extension of MultivariateRealFunction representing a differentiable multivariate real function.

Since:

2.0

Version:

$Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`MultivariateVectorialFunction`	`gradient()`	Returns the gradient function.
`MultivariateRealFunction`	`partialDerivative(int k)`	Returns the partial derivative of the function with respect to a point coordinate.

Methods inherited from interface org.apache.commons.math.analysis.MultivariateRealFunction
value

- Method Detail
  - partialDerivative
```
MultivariateRealFunction partialDerivative(int k)
```
    Returns the partial derivative of the function with respect to a point coordinate.
    The partial derivative is defined with respect to point coordinate x_k. If the partial derivatives with respect to all coordinates are needed, it may be more efficient to use the gradient() method which will compute them all at once.
    
    Parameters:
    
    k - index of the coordinate with respect to which the partial derivative is computed
    
    Returns:
    
    the partial derivative function with respect to k^th point coordinate
  - gradient
```
MultivariateVectorialFunction gradient()
```
    Returns the gradient function.
    If only one partial derivative with respect to a specific coordinate is needed, it may be more efficient to use the partialDerivative(int) method which will compute only the specified component.
    
    Returns:
    
    the gradient function