org.cytoscape.equations
Class FunctionUtil

java.lang.Object
  org.cytoscape.equations.FunctionUtil

public final class FunctionUtil
extends Object

A collection of static methods that may be useful for the implementation of built-in functions.

Cytoscape Backwards Compatibility (Static Class): This class is static and therefore can't be extended by users. This means that we may add methods for minor version updates. Methods will only be removed for major version updates.

Method Summary

static void	addScalarArgumentTypes(List<Class> argTypes) Adds the scalar types that equations use internally to the argument, i.e.
static double	calcSampleVariance(double[] x) Calculates the sample variance of some numbers.
static boolean	getArgAsBoolean(Object arg) Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "boolean".
static double	getArgAsDouble(Object arg) Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "double".
static long	getArgAsLong(Object arg) Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "long".
static String	getArgAsString(Object arg) Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "String".
static boolean[]	getBooleans(Object[] args) Attempts to convert all arguments, including Lists to a uniform array of booleans.
static double[]	getDoubles(Object[] args) Attempts to convert all arguments, including Lists to a uniform array of doubles.
static long[]	getLongs(Object[] args) Attempts to convert all arguments, including Lists to a uniform array of longs.
static String	getOrdinal(int i) Converts an integer to an ordinal string.
static String[]	getStrings(Object[] args) Converts all arguments, including Lists to a uniform array of strings.
static boolean	isScalarArgType(Class type) Tests whether the argument is one of the scalar types used by equations.
static boolean	isTypeOfList(Class listClassCandidate) Tests whether the argument is some kind of List.
static double[]	listToArray(List<Double> a) Converts a List to a regular double[]
static double	numericallySafeSum(double[] a) Carefully adds the numbers in "a" minimising loss of precision.
static Object	translateObjectType(Object input) Tries to map "input" to one of Double, Long, Boolean or String.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getArgAsDouble

public static double getArgAsDouble(Object arg)
                             throws IllegalArgumentException

Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "double".

Parameters:

arg - the object instance that will be converted to a double, if possible

Returns:

the converted argument as a "double"

Throws:

IllegalArgumentException - if the argument cannot be converted to a "double"

getArgAsString

public static String getArgAsString(Object arg)
                             throws IllegalArgumentException

Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "String".

Parameters:

arg - the object instance that will be converted to a String

Returns:

the converted argument as a "double"

Throws:

IllegalArgumentException - if the argument cannot be converted to a "double"

getArgAsLong

public static long getArgAsLong(Object arg)
                         throws IllegalArgumentException

Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "long".

Parameters:

arg - the object instance that will be converted to a long, if possible

Returns:

the converted argument as a "long"

Throws:

IllegalArgumentException - if the argument cannot be converted to a "long"

getArgAsBoolean

public static boolean getArgAsBoolean(Object arg)
                               throws IllegalArgumentException

Assumes that "arg" is a "String", "Boolean", "Long" or a "Double and converts it to "boolean".

Parameters:

arg - the object instance that will be converted to a boolean, if possible

Returns:

the converted argument as a "boolean"

Throws:

IllegalArgumentException - if the argument cannot be converted to a "boolean"

numericallySafeSum

public static double numericallySafeSum(double[] a)

Carefully adds the numbers in "a" minimising loss of precision.

Parameters:

a - the numbers that will be summed up

Returns:

the sum of the elements of "a"

getOrdinal

public static String getOrdinal(int i)

Converts an integer to an ordinal string.

Parameters:

i - the integer that will be converted

Returns:

the String representation of the ith ordinal

calcSampleVariance

public static double calcSampleVariance(double[] x)

Calculates the sample variance of some numbers.

Parameters:

x - the numbers whose sample variance will be calculated

Returns:

the sample variance of the numbers in x[]

listToArray

public static double[] listToArray(List<Double> a)

Converts a List to a regular double[]

Parameters:

a - the list that will be converted

Returns:

the converted array

isScalarArgType

public static boolean isScalarArgType(Class type)

Tests whether the argument is one of the scalar types used by equations.

Parameters:

type - the type that will be tested

Returns:

true, if type is Double.class, Long.class, String.class or Boolean.class, else false

isTypeOfList

public static boolean isTypeOfList(Class listClassCandidate)

Tests whether the argument is some kind of List.

Parameters:

listClassCandidate - the type that will be tested

Returns:

true if "listClassCandidate" is an implementer of interface List, else false

addScalarArgumentTypes

public static void addScalarArgumentTypes(List<Class> argTypes)

Adds the scalar types that equations use internally to the argument, i.e. adds Double.class, Long.class, String.class and Boolean.class to "argTypes".

Parameters:

argTypes - the list that will be augmented

getDoubles

public static double[] getDoubles(Object[] args)
                           throws FunctionError

Attempts to convert all arguments, including Lists to a uniform array of doubles.

Parameters:

args - the objects that will be converted to doubles, if possible

Returns:

the converted array

Throws:

FunctionError

IllegalArgumentException - if any scalar argument cannot be converted to a double or any list argument contains an element that cannot be converted to a number.

getLongs

public static long[] getLongs(Object[] args)
                       throws FunctionError

Attempts to convert all arguments, including Lists to a uniform array of longs.

Parameters:

args - the objects that will be converted to longs, if possible

Returns:

the converted array

Throws:

FunctionError

IllegalArgumentException - if any scalar argument cannot be converted to a long or any list argument contains an element that cannot be converted to a number.

getStrings

public static String[] getStrings(Object[] args)

Converts all arguments, including Lists to a uniform array of strings.

Parameters:

args - the objects that will be converted to Strings

Returns:

the converted array

getBooleans

public static boolean[] getBooleans(Object[] args)
                             throws FunctionError

Attempts to convert all arguments, including Lists to a uniform array of booleans.

Parameters:

args - the objects that will be converted to booleans, if possible

Returns:

the converted array

Throws:

FunctionError

IllegalArgumentException - if any scalar argument cannot be converted to a boolean or any list argument contains an element that cannot be converted to a number.

translateObjectType

public static Object translateObjectType(Object input)

Tries to map "input" to one of Double, Long, Boolean or String.

Parameters:

input - the object that will be mapped to one of the scalar types that are internally supported by equations

Returns:

null if the translation failed, the input object if no translation was necessary or a new object if a successful translation was possible