Package opennlp.tools.ml.maxent.quasinewton

## Class NegLogLikelihood

- java.lang.Object
- - opennlp.tools.ml.maxent.quasinewton.NegLogLikelihood

- All Implemented Interfaces:
    `Function`
  Direct Known Subclasses:
    `ParallelNegLogLikelihood`

      public class NegLogLikelihood
      extends Object
      implements Function

  Evaluate negative log-likelihood and its gradient from DataIndexer.

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `NegLogLikelihood​(DataIndexer indexer)` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `int` | `getDimension()` |
    `double[]` | `getInitialPoint()` |
    `double[]` | `gradientAt​(double[] x)` | Compute gradient
    `double` | `valueAt​(double[] x)` | Negative log-likelihood

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### NegLogLikelihood

          public NegLogLikelihood​(DataIndexer indexer)

  - ### Method Detail

    - #### getDimension

          public int getDimension()

      Specified by:
        `getDimension` in interface `Function`

    - #### getInitialPoint

          public double[] getInitialPoint()

    - #### valueAt

          public double valueAt​(double[] x)

      Negative log-likelihood
      Specified by:
        `valueAt` in interface `Function`

    - #### gradientAt

          public double[] gradientAt​(double[] x)

      Compute gradient
      Specified by:
        `gradientAt` in interface `Function`