NeuralUtils (Stanford CoreNLP API)

java.lang.Object
- edu.stanford.nlp.neural.NeuralUtils

```
public class NeuralUtils
extends Object
```
Includes a bunch of utility methods usable by projects which use RNN, such as the parser and sentiment models. Some methods convert iterators of SimpleMatrix objects to and from a vector. Others are general utility methods on SimpleMatrix objects.

Author:

John Bauer, Richard Socher, Thang Luong

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static org.ejml.simple.SimpleMatrix`	`concatenate(org.ejml.simple.SimpleMatrix... vectors)` Concatenates several column vectors into one large column vector
`static org.ejml.simple.SimpleMatrix`	`concatenateWithBias(org.ejml.simple.SimpleMatrix... vectors)` Concatenates several column vectors into one large column vector, adds a 1.0 at the end as a bias term
`static org.ejml.simple.SimpleMatrix`	`convertTextMatrix(String text)`
`static double`	`cosine(org.ejml.simple.SimpleMatrix vector1, org.ejml.simple.SimpleMatrix vector2)` Compute cosine distance between two column vectors.
`static double`	`dot(org.ejml.simple.SimpleMatrix vector1, org.ejml.simple.SimpleMatrix vector2)` Compute dot product between two vectors.
`static org.ejml.simple.SimpleMatrix`	`elementwiseApplyLog(org.ejml.simple.SimpleMatrix input)` Applies log to each of the entries in the matrix.
`static org.ejml.simple.SimpleMatrix`	`elementwiseApplyTanh(org.ejml.simple.SimpleMatrix input)` Applies tanh to each of the entries in the matrix.
`static org.ejml.simple.SimpleMatrix`	`elementwiseApplyTanhDerivative(org.ejml.simple.SimpleMatrix input)` Applies the derivative of tanh to each of the elements in the vector.
`static boolean`	`isZero(org.ejml.simple.SimpleMatrix matrix)` Returns true iff every element of matrix is 0
`static org.ejml.simple.SimpleMatrix`	`loadTextMatrix(File file)` Convert a file into a text matrix.
`static org.ejml.simple.SimpleMatrix`	`loadTextMatrix(String path)` Convert a file into a text matrix.
`static double[]`	`paramsToVector(double scale, int totalSize, Iterator<org.ejml.simple.SimpleMatrix>... matrices)` Given a sequence of iterators over the matrices, builds a vector out of those matrices in the order given.
`static double[]`	`paramsToVector(int totalSize, Iterator<org.ejml.simple.SimpleMatrix>... matrices)` Given a sequence of iterators over the matrices, builds a vector out of those matrices in the order given.
`static org.ejml.simple.SimpleMatrix`	`randomGaussian(int numRows, int numCols, Random rand)` Returns a vector with random Gaussian values, mean 0, std 1
`static double`	`sigmoid(double x)` Returns a sigmoid applied to the input `x`.
`static org.ejml.simple.SimpleMatrix`	`softmax(org.ejml.simple.SimpleMatrix input)` Applies softmax to all of the elements of the matrix.
`static String`	`toString(org.ejml.simple.SimpleMatrix matrix, String format)`
`static void`	`vectorToParams(double[] theta, Iterator<org.ejml.simple.SimpleMatrix>... matrices)` Given a sequence of Iterators over SimpleMatrix, fill in all of the matrices with the entries in the theta vector.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - loadTextMatrix
```
public static org.ejml.simple.SimpleMatrix loadTextMatrix(String path)
```
    Convert a file into a text matrix. The expected format one row per line, one entry per column. Not too efficient for large matrices, but you shouldn't store large matrices in text files anyway. This specific format is not supported by ejml, which expects the number of rows and columns in its text matrices.
  - loadTextMatrix
```
public static org.ejml.simple.SimpleMatrix loadTextMatrix(File file)
```
    Convert a file into a text matrix. The expected format one row per line, one entry per column. Not too efficient for large matrices, but you shouldn't store large matrices in text files anyway. This specific format is not supported by ejml, which expects the number of rows and columns in its text matrices.
  - convertTextMatrix
```
public static org.ejml.simple.SimpleMatrix convertTextMatrix(String text)
```
  - toString
```
public static String toString(org.ejml.simple.SimpleMatrix matrix,
                              String format)
```
    Parameters:
    
    matrix - The matrix to return as a String
    
    format - The format to use for each value in the matrix, eg "%f"
  - cosine
```
public static double cosine(org.ejml.simple.SimpleMatrix vector1,
                            org.ejml.simple.SimpleMatrix vector2)
```
    Compute cosine distance between two column vectors.
  - dot
```
public static double dot(org.ejml.simple.SimpleMatrix vector1,
                         org.ejml.simple.SimpleMatrix vector2)
```
    Compute dot product between two vectors.
  - vectorToParams
```
@SafeVarargs
public static void vectorToParams(double[] theta,
                                               Iterator<org.ejml.simple.SimpleMatrix>... matrices)
```
    Given a sequence of Iterators over SimpleMatrix, fill in all of the matrices with the entries in the theta vector. Errors are thrown if the theta vector does not exactly fill the matrices.
  - paramsToVector
```
@SafeVarargs
public static double[] paramsToVector(int totalSize,
                                                   Iterator<org.ejml.simple.SimpleMatrix>... matrices)
```
    Given a sequence of iterators over the matrices, builds a vector out of those matrices in the order given. Asks for an expected total size as a time savings. AssertionError thrown if the vector sizes do not exactly match.
  - paramsToVector
```
@SafeVarargs
public static double[] paramsToVector(double scale,
                                                   int totalSize,
                                                   Iterator<org.ejml.simple.SimpleMatrix>... matrices)
```
    Given a sequence of iterators over the matrices, builds a vector out of those matrices in the order given. The vector is scaled according to the scale parameter. Asks for an expected total size as a time savings. AssertionError thrown if the vector sizes do not exactly match.
  - sigmoid
```
public static double sigmoid(double x)
```
    Returns a sigmoid applied to the input x.
  - softmax
```
public static org.ejml.simple.SimpleMatrix softmax(org.ejml.simple.SimpleMatrix input)
```
    Applies softmax to all of the elements of the matrix. The return matrix will have all of its elements sum to 1. If your matrix is not already a vector, be sure this is what you actually want.
  - elementwiseApplyLog
```
public static org.ejml.simple.SimpleMatrix elementwiseApplyLog(org.ejml.simple.SimpleMatrix input)
```
    Applies log to each of the entries in the matrix. Returns a new matrix.
  - elementwiseApplyTanh
```
public static org.ejml.simple.SimpleMatrix elementwiseApplyTanh(org.ejml.simple.SimpleMatrix input)
```
    Applies tanh to each of the entries in the matrix. Returns a new matrix.
  - elementwiseApplyTanhDerivative
```
public static org.ejml.simple.SimpleMatrix elementwiseApplyTanhDerivative(org.ejml.simple.SimpleMatrix input)
```
    Applies the derivative of tanh to each of the elements in the vector. Returns a new matrix.
  - concatenateWithBias
```
public static org.ejml.simple.SimpleMatrix concatenateWithBias(org.ejml.simple.SimpleMatrix... vectors)
```
    Concatenates several column vectors into one large column vector, adds a 1.0 at the end as a bias term
  - concatenate
```
public static org.ejml.simple.SimpleMatrix concatenate(org.ejml.simple.SimpleMatrix... vectors)
```
    Concatenates several column vectors into one large column vector
  - randomGaussian
```
public static org.ejml.simple.SimpleMatrix randomGaussian(int numRows,
                                                          int numCols,
                                                          Random rand)
```
    Returns a vector with random Gaussian values, mean 0, std 1
  - isZero
```
public static boolean isZero(org.ejml.simple.SimpleMatrix matrix)
```
    Returns true iff every element of matrix is 0

Class NeuralUtils

Method Summary

Methods inherited from class java.lang.Object

Method Detail

loadTextMatrix

loadTextMatrix

convertTextMatrix

toString

cosine

dot

vectorToParams

paramsToVector

paramsToVector

sigmoid

softmax

elementwiseApplyLog

elementwiseApplyTanh

elementwiseApplyTanhDerivative

concatenateWithBias

concatenate

randomGaussian

isZero