org.jboss.dna.common.math
Interface MathOperations<T>

Type Parameters:

T - the numeric class, usually a subclass of Number (although this is not required)

All Known Implementing Classes:

DoubleOperations, DurationOperations, FloatOperations, IntegerOperations, LongOperations, ShortOperations

public interface MathOperations<T>

The set of mathematic operations for a particular class of values. This is useful for generic classes that must work with one of the Number subclasses.

Method Summary

T	add(T value1, T value2) Add the two operands and return the sum.
BigDecimal	asBigDecimal(T value) Create a BigDecimal representation of the supplied value.
int	compare(T value1, T value2) Compare the two operands and return an integer that describes whether the first value is larger, smaller or the same as the second value.
T	create(double value) Convert the double representation into the natural object representation.
T	create(int value) Convert the integer representation into the natural object representation.
T	create(long value) Convert the long representation into the natural object representation.
T	createZeroValue() Create the object form of the "zero value".
double	divide(T value1, T value2) Divide the first operand by the second, and return the result.
double	doubleValue(T value) Convert the value to a double.
float	floatValue(T value) Convert the value to a float.
T	fromBigDecimal(BigDecimal value) Convert the BigDecimal representation into the natural object representation.
Comparator<T>	getComparator() Return a Comparator for this operand class.
int	getExponentInScientificNotation(T value) Get the exponent if the number were written in exponential form.
Class<T>	getOperandClass() Return the class that these operations operate upon.
T	increment(T value) Increment the supplied operand by 1.
int	intValue(T value) Convert the value to an integer.
T	keepSignificantFigures(T value, int numSigFigs)
long	longValue(T value) Convert the value to a long integer.
T	maximum(T value1, T value2) Compare the two operands and return the one that is larger.
T	minimum(T value1, T value2) Compare the two operands and return the one that is smaller.
T	multiply(T value1, T value2) Multiply the two operands and return the product.
T	negate(T value) Negate the supplied operand.
T	random(T minimum, T maximum, Random rng) Generate a random instance within the specified range.
T	roundDown(T value, int decimalShift) Round down the supplied value to the desired scale.
T	roundUp(T value, int decimalShift) Round up the supplied value to the desired scale.
short	shortValue(T value) Convert the value to a short.
double	sqrt(T value) Return the square root of the supplied operand.
T	subtract(T value1, T value2) Subtract the second operand from the first, and return the difference.

Method Detail

getOperandClass

Class<T> getOperandClass()

Return the class that these operations operate upon.

Returns:

the class

add

T add(T value1,
      T value2)

Add the two operands and return the sum. The zero value is used in place of any operand that is null.

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the sum of the two operands.

subtract

T subtract(T value1,
           T value2)

Subtract the second operand from the first, and return the difference. The zero value is used in place of any operand that is null.

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the difference between the two operands.

multiply

T multiply(T value1,
           T value2)

Multiply the two operands and return the product. The zero value is used in place of any operand that is null.

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the product of the two operands.

divide

double divide(T value1,
              T value2)

Divide the first operand by the second, and return the result. The zero value is used in place of any operand that is null.

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the result of the division

negate

T negate(T value)

Negate the supplied operand. The zero value is used in place of any operand that is null.

Parameters:

value - the value that is to be negated

Returns:

the result of the negation

increment

T increment(T value)

Increment the supplied operand by 1. (Note, the exact meaning of "1" is dependent upon the particular operand class. The zero value is used in place of any operand that is null.

Parameters:

value - the value that is to be incremented

Returns:

the incremented value

maximum

T maximum(T value1,
          T value2)

Compare the two operands and return the one that is larger. A null value is considered smaller than non-null values (including 0).

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the larger of the two operands

minimum

T minimum(T value1,
          T value2)

Compare the two operands and return the one that is smaller. A null value is considered larger than non-null values (including 0).

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

the smaller of the two operands

compare

int compare(T value1,
            T value2)

Compare the two operands and return an integer that describes whether the first value is larger, smaller or the same as the second value. The semantics are identical to those of Comparable. The zero value is used in place of any operand that is null.

Parameters:

value1 - the first operand

value2 - the second operand

Returns:

-1 if the first value is smaller than the second, 1 if the first value is larger than the second, or 0 if they are equal.

asBigDecimal

BigDecimal asBigDecimal(T value)

Create a BigDecimal representation of the supplied value.

Parameters:

value - the value that is to be converted to a BigDecimal

Returns:

the BigDecimal representation, or null if value is null

fromBigDecimal

T fromBigDecimal(BigDecimal value)

Convert the BigDecimal representation into the natural object representation. This may result in loss of some data (e.g., converting a decimal to an integer results in the loss of the fractional part of the number).

Parameters:

value - the BigDecimal value

Returns:

the natural representation, or null if value is null

doubleValue

double doubleValue(T value)

Convert the value to a double. This may result in a loss of information depending upon the operand class.

Parameters:

value - the value

Returns:

the representation as a double

floatValue

float floatValue(T value)

Convert the value to a float. This may result in a loss of information depending upon the operand class.

Parameters:

value - the value

Returns:

the representation as a float

intValue

int intValue(T value)

Convert the value to an integer. This may result in a loss of information depending upon the operand class.

Parameters:

value - the value

Returns:

the representation as an integer

shortValue

short shortValue(T value)

Convert the value to a short. This may result in a loss of information depending upon the operand class.

Parameters:

value - the value

Returns:

the representation as a short

longValue

long longValue(T value)

Convert the value to a long integer. This may result in a loss of information depending upon the operand class.

Parameters:

value - the value

Returns:

the representation as a long

createZeroValue

T createZeroValue()

Create the object form of the "zero value". This is often used to create an uninitialized object.

Returns:

the object that represents zero.

create

T create(int value)

Convert the integer representation into the natural object representation.

Parameters:

value - the integer value

Returns:

the object representation of the integer

create

T create(long value)

Convert the long representation into the natural object representation.

Parameters:

value - the long value

Returns:

the object representation of the long integer

create

T create(double value)

Convert the double representation into the natural object representation.

Parameters:

value - the double value

Returns:

the object representation of the floating point number

sqrt

double sqrt(T value)

Return the square root of the supplied operand.

Parameters:

value - the value whose root is to be found; may not be null or 0

Returns:

the square root of the value

getComparator

Comparator<T> getComparator()

Return a Comparator for this operand class. The implementation is free to return the same comparator instance from multiple invocations of this method.

Returns:

a comparator

getExponentInScientificNotation

int getExponentInScientificNotation(T value)

Get the exponent if the number were written in exponential form.

Parameters:

value - the value

Returns:

the scale

roundUp

T roundUp(T value,
          int decimalShift)

Round up the supplied value to the desired scale. This process works (conceptually) by shifting the decimal point of the value by decimalShift places, rounding, and then shifting the decimal point of the rounded value by -decimalShift

For example, consider the number 10.000354. This can be rounded to 10.0004 by calling this method and supplying the value and an "exponentToKeep" value of -4.

Parameters:

value - the value to be rounded

decimalShift - the number of places the decimal point should be shifted before rounding

Returns:

the rounded value

roundDown

T roundDown(T value,
            int decimalShift)

Round down the supplied value to the desired scale. This process works (conceptually) by shifting the decimal point of the value by decimalShift places, rounding, and then shifting the decimal point of the rounded value by -decimalShift

For example, consider the number 10.000354. This can be rounded to 10.0003 by calling this method and supplying the value and an "exponentToKeep" value of -4.

Parameters:

value - the value to be rounded

decimalShift - the number of places the decimal point should be shifted before rounding

Returns:

the rounded value

keepSignificantFigures

T keepSignificantFigures(T value,
                         int numSigFigs)

random

T random(T minimum,
         T maximum,
         Random rng)

Generate a random instance within the specified range.

Parameters:

minimum - the minimum value, or null if the zero-value should be used for the minimum

maximum - the maximum value, or null if the zero-value should be used for the maximum

rng - the random number generator to use

Returns:

an instance of the operand class placed within the desired range using a random distribution, or null if this class does not support generating random instances