EngineParameters (DETROID 1.0.1 API)

Object
- EngineParameters

```
public abstract class EngineParameters
extends Object
```
An abstract base class for engine parameter definitions that influence the performance of the chess engine and thus should be highly optimized. It provides methods for the retrieval of the values of the fields of its sub classes which are utilized in the methods provided for writing the contents of an instance to a file or reading, parsing, and setting the fields of an instance based on such a file. It is possible to retrieve the values as an array of doubles or as a binary string that represents the genotype of the instance with each field's value gray coded and concatenated into a binary string. An array or string like that can be then used to set the values of the fields of instances with the same procedure reversed. Only those fields of the subclasses are handled by the class that are annotated with the Parameter annotation. The annotation also has an optional attribute binaryLengthLimit which marks the number of bits to consider when tuning the parameter. When applied to floating point values, its effects are less intuitive as instead of ignoring bits of the number's binary representation, it just sets a maximum for the values it can take on which will be equal to what this maximum would be for integer numbers (2^[limit] - 1). WARNING: No negative values are supported, thus the most significant bit of each signed primitive (all except boolean and char) field will be ignored when generating the binary string or setting the values of the fields based on a binary string and negative values will default to 0 when setting the fields based on a double array.

Author:

Viktor

Constructor Summary

Constructors
Modifier Constructor and Description

protected EngineParameters()
Constructs an instance and scans the fields of the (extending) class for ones annotated as Parameter.

Constructors
Modifier	Constructor and Description
`protected`	`EngineParameters()` Constructs an instance and scans the fields of the (extending) class for ones annotated as `Parameter`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`loadFrom(String filePath)` Reads the parameter values from an XML file and sets the instance's fields accordingly.
`double[]`	`maxValues()` Returns an array of doubles holding the maximum allowed values for all the fields declared as parameters by the `Parameter` annotation.
`double[]`	`maxValues(Set<ParameterType> types)` Returns an array of doubles holding the maximum allowed values for all the fields declared as parameters of the specified type by the `Parameter` annotation.
`boolean`	`set(double[] values)` Sets the values of the parameter fields of the instance.
`boolean`	`set(double[] values, Set<ParameterType> types)` Sets the values of the parameter fields of the specified type.
`boolean`	`set(String binaryString)` Sets the values of the parameter fields based on the binaryString in which each character represents a bit in the string of the individual gray code strings of the values of the parameter fields of the specified type in the order of declaration.
`boolean`	`set(String binaryString, Set<ParameterType> types)` Sets the values of the parameter fields of the specified type based on the binaryString in which each character represents a bit in the string of the individual gray code strings of the values of the parameter fields of the specified type in the order of declaration.
`String`	`toGrayCodeString()` Returns a binary string of all the bits of all the fields annotated as a `Parameter` concatenated field by field.
`String`	`toGrayCodeString(Set<ParameterType> types)` Returns a binary string of all the bits of the fields annotated as a `Parameter` of the specified type concatenated field by field.
`String`	`toString()`
`double[]`	`values()` Returns an array of doubles holding the values of all the fields declared as parameters by the `Parameter` annotation.
`double[]`	`values(Set<ParameterType> types)` Returns an array of doubles holding the values of all the fields declared as parameters of the specified type by the `Parameter` annotation.
`double[]`	`valuesFromMap(Map<String,Double> paramValues, Set<ParameterType> types)` Builds an array of values based on the entries of the provided map.
`boolean`	`writeToFile(String filePath)` Writes the parameters to the specified file.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - EngineParameters
```
protected EngineParameters()
                    throws ParameterException
```
    Constructs an instance and scans the fields of the (extending) class for ones annotated as Parameter.
    
    Throws:
    
    ParameterException - If a static or non-primitive field is annotated as Parameter.
- Method Detail
  - loadFrom
```
public final void loadFrom(String filePath)
                    throws Exception
```
    Reads the parameter values from an XML file and sets the instance's fields accordingly.
    
    Parameters:
    
    filePath - The path to the file.
    
    Throws:
    
    Exception - If an error occurs from which it is not possible to recover.
  - writeToFile
```
public final boolean writeToFile(String filePath)
```
    Writes the parameters to the specified file. If it does not exist, this method will attempt to create it. The method returns whether writing to the file was successful.
    
    Parameters:
    
    filePath - The path to the file.
    
    Returns:
    
    Whether the parameters could be successfully written to the file.
  - set
```
public final boolean set(double[] values)
```
    Sets the values of the parameter fields of the instance. If a value in the array is negative, it will be taken for 0; if a value is greater than what the respective field's type or the bit limit specified by the Parameter annotation's attribute would allow for, the field will be set to its maximum allowed value. If the array is longer than the number of parameter fields, the extra elements will be ignored; if it is shorter, the fields indexed higher than the length of the array will not be set. For boolean fields, a value greater than or equal to 1 will default to true, everything else will default to false.
    
    Parameters:
    
    values - An array of values for the parameter fields of the instance in the order of declaration.
    
    Returns:
    
    Whether the fields could be successfully set.
  - set
```
public final boolean set(double[] values,
                         Set<ParameterType> types)
```
    Sets the values of the parameter fields of the specified type. If a value in the array is negative, it will be taken for 0; if a value is greater than what the respective field's type or the bit limit specified by the Parameter annotation's attribute would allow for, the field will be set to its maximum allowed value. If the array is longer than the number of parameter fields of the specified type, the extra elements will be ignored; if it is shorter, the fields indexed higher than the length of the array will not be set. For boolean fields, a value greater than or equal to 1 will default to true, everything else will default to false.
    
    Parameters:
    
    values - An array of values for the parameter fields of the specified type in the order of declaration.
    
    types - A set of the types of parameter fields whose values should be set based on the input array. If it is null, the values will be applied to the set of all parameter fields.
    
    Returns:
    
    Whether the fields could be successfully set.
  - set
```
public final boolean set(String binaryString)
```
    Sets the values of the parameter fields based on the binaryString in which each character represents a bit in the string of the individual gray code strings of the values of the parameter fields of the specified type in the order of declaration.
    
    Parameters:
    
    binaryString - A binary string of gray code such as the output of toGrayCodeString.
    
    Returns:
    
    Whether the binary string could be successfully applied to the fields.
  - set
```
public final boolean set(String binaryString,
                         Set<ParameterType> types)
```
    Sets the values of the parameter fields of the specified type based on the binaryString in which each character represents a bit in the string of the individual gray code strings of the values of the parameter fields of the specified type in the order of declaration.
    
    Parameters:
    
    binaryString - A binary string of gray code such as the output of toGrayCodeString.
    
    types - A set of the types of parameter fields whose values should be derived from the binary string and set. If it is null, the values derived will be applied to all parameter fields.
    
    Returns:
    
    Whether the binary string could be successfully applied to the fields.
  - valuesFromMap
```
public final double[] valuesFromMap(Map<String,Double> paramValues,
                                    Set<ParameterType> types)
```
    Builds an array of values based on the entries of the provided map. All parameters not present in the map will have a default value of 0.
    
    Parameters:
    
    paramValues - A map of parameter names and their corresponding values.
    
    types - The types of parameters to include.
    
    Returns:
    
    The values array.
  - values
```
public final double[] values()
```
    Returns an array of doubles holding the values of all the fields declared as parameters by the Parameter annotation. Boolean values will be converted to either 1 or 0 depending on whether they are true or false.
    
    Returns:
    
    An array of doubles holding the values of all the parameter fields.
  - values
```
public final double[] values(Set<ParameterType> types)
```
    Returns an array of doubles holding the values of all the fields declared as parameters of the specified type by the Parameter annotation. Boolean values will be converted to either 1 or 0 depending on whether they are true or false.
    
    Parameters:
    
    types - A set of the types of parameter fields whose max values are to be returned. If it is null the max values for all parameter fields will be returned.
    
    Returns:
    
    An array of doubles holding the values of all the parameter fields of the specified type.
  - maxValues
```
public final double[] maxValues()
```
    Returns an array of doubles holding the maximum allowed values for all the fields declared as parameters by the Parameter annotation. The values are determined by the field type and the binaryLengthLimit attribute of the annotation.
    
    Returns:
    
    An array of doubles holding the maximum allowed values for all parameters.
  - maxValues
```
public final double[] maxValues(Set<ParameterType> types)
```
    Returns an array of doubles holding the maximum allowed values for all the fields declared as parameters of the specified type by the Parameter annotation. The values are determined by the field type and the binaryLengthLimit attribute of the annotation.
    
    Parameters:
    
    types - A set of the types of parameter fields whose max values are to be returned. If it is null the max values for all parameter fields will be returned.
    
    Returns:
    
    An array of doubles holding the maximum allowed values for the parameters of the specified type.
  - toGrayCodeString
```
public final String toGrayCodeString()
```
    Returns a binary string of all the bits of all the fields annotated as a Parameter concatenated field by field. Floating point values will be cast to integer values (float to int, double to long) for their binary representation which may result in information loss.
    
    Returns:
    
    A binary string of all the bits of all parameter fields concatenated field by field.
  - toGrayCodeString
```
public final String toGrayCodeString(Set<ParameterType> types)
```
    Returns a binary string of all the bits of the fields annotated as a Parameter of the specified type concatenated field by field. Floating point values will be cast to integer values (float to int, double to long) for their binary representation which may result in information loss.
    
    Parameters:
    
    types - A set of the types of parameters whose values are to be included in the string. If it is null, all parameters' values will be included.
    
    Returns:
    
    A binary string of all the bits of the parameter fields of the specified type concatenated field by field.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class EngineParameters

Constructor Summary

Method Summary

Methods inherited from class Object

Constructor Detail

EngineParameters

Method Detail

loadFrom

writeToFile

set

set

set

set

valuesFromMap

values

values

maxValues

maxValues

toGrayCodeString

toGrayCodeString

toString