jdk.math.BigDecimal — clojure-interop/java.math 1.0.2

Immutable, arbitrary-precision signed decimal numbers. A BigDecimal consists of an arbitrary precision integer unscaled value and a 32-bit integer scale. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. The value of the number represented by the BigDecimal is therefore (unscaledValue × 10-scale).

The BigDecimal class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing, and format conversion. The toString() method provides a canonical representation of a BigDecimal.

The BigDecimal class gives its user complete control over rounding behavior. If no rounding mode is specified and the exact result cannot be represented, an exception is thrown; otherwise, calculations can be carried out to a chosen precision and rounding mode by supplying an appropriate MathContext object to the operation. In either case, eight rounding modes are provided for the control of rounding. Using the integer fields in this class (such as ROUND_HALF_UP) to represent rounding mode is largely obsolete; the enumeration values of the RoundingMode enum, (such as RoundingMode.HALF_UP) should be used instead.

When a MathContext object is supplied with a precision setting of 0 (for example, MathContext.UNLIMITED), arithmetic operations are exact, as are the arithmetic methods which take no MathContext object. (This is the only behavior that was supported in releases prior to 5.) As a corollary of computing the exact result, the rounding mode setting of a MathContext object with a precision setting of 0 is not used and thus irrelevant. In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a nonterminating decimal expansion and the operation is specified to return an exact result, an ArithmeticException is thrown. Otherwise, the exact result of the division is returned, as done for other operations.

When the precision setting is not 0, the rules of BigDecimal arithmetic are broadly compatible with selected modes of operation of the arithmetic defined in ANSI X3.274-1996 and ANSI X3.274-1996/AM 1-2000 (section 7.4). Unlike those standards, BigDecimal includes many rounding modes, which were mandatory for division in BigDecimal releases prior to 5. Any conflicts between these ANSI standards and the BigDecimal specification are resolved in favor of BigDecimal.

Since the same numerical value can have different representations (with different scales), the rules of arithmetic and rounding must specify both the numerical result and the scale used in the result's representation.

In general the rounding modes and precision setting determine how operations return results with a limited number of digits when the exact result has more digits (perhaps infinitely many in the case of division) than the number of digits returned.

First, the total number of digits to return is specified by the MathContext's precision setting; this determines the result's precision. The digit count starts from the leftmost nonzero digit of the exact result. The rounding mode determines how any discarded trailing digits affect the returned result.

For all arithmetic operators , the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading 9 digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×101. In such cases, the new 1 is the leading digit position of the returned result.

Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.

Preferred Scales for Results of Arithmetic Operations

OperationPreferred Scale of Result Addmax(addend.scale(), augend.scale()) Subtractmax(minuend.scale(), subtrahend.scale()) Multiplymultiplier.scale() multiplicand.scale() Dividedividend.scale() - divisor.scale()

These scales are the ones used by the methods which return exact arithmetic results; except that an exact divide may have to use a larger scale since the exact result may have more digits. For example, 1/32 is 0.03125.

Before rounding, the scale of the logical exact intermediate result is the preferred scale for that operation. If the exact numerical result cannot be represented in precision digits, rounding selects the set of digits to return and the scale of the result is reduced from the scale of the intermediate result to the least scale which can represent the precision digits actually returned. If the exact result can be represented with at most precision digits, the representation of the result with the scale closest to the preferred scale is returned. In particular, an exactly representable quotient may be represented in fewer than precision digits by removing trailing zeros and decreasing the scale. For example, rounding to three digits using the floor rounding mode,

19/100 = 0.19 // integer=19, scale=2

but

21/110 = 0.190 // integer=190, scale=3

Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new high-order digit position, an additional digit of the result is discarded than when no new digit position is created.

Other methods may have slightly different rounding semantics. For example, the result of the pow method using the specified algorithm can occasionally differ from the rounded mathematical result by more than one unit in the last place, one ulp.

Two types of operations are provided for manipulating the scale of a BigDecimal: scaling/rounding operations and decimal point motion operations. Scaling/rounding operations (setScale and round) return a BigDecimal whose value is approximately (or exactly) equal to that of the operand, but whose scale or precision is the specified value; that is, they increase or decrease the precision of the stored number with minimal effect on its value. Decimal point motion operations (movePointLeft and movePointRight) return a BigDecimal created from the operand by moving the decimal point a specified distance in the specified direction.

For the sake of brevity and clarity, pseudo-code is used throughout the descriptions of BigDecimal methods. The pseudo-code expression (i j) is shorthand for a BigDecimal whose value is that of the BigDecimal i added to that of the BigDecimal j. The pseudo-code expression (i == j) is shorthand for true if and only if the BigDecimal i represents the same value as the BigDecimal j. Other pseudo-code expressions are interpreted similarly. Square brackets are used to represent the particular BigInteger and scale pair defining a BigDecimal value; for example [19, 2] is the BigDecimal numerically equal to 0.19 having a scale of 2.

Note: care should be exercised if BigDecimal objects are used as keys in a SortedMap or elements in a SortedSet since BigDecimal's natural ordering is inconsistent with equals. See Comparable, SortedMap or SortedSet for more information.

All methods and constructors for this class throw NullPointerException when passed a null object reference for any input parameter.

*-one clj

Static Constant.

The value 1, with a scale of 0.

type: java.math.BigDecimal

*-round-ceiling clj

Static Constant.

Rounding mode to round towards positive infinity. If the BigDecimal is positive, behaves as for ROUND_UP; if negative, behaves as for ROUND_DOWN. Note that this rounding mode never decreases the calculated value.

type: int

*-round-down clj

Static Constant.

Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value.

type: int

*-round-floor clj

Static Constant.

Rounding mode to round towards negative infinity. If the BigDecimal is positive, behave as for ROUND_DOWN; if negative, behave as for ROUND_UP. Note that this rounding mode never increases the calculated value.

type: int

*-round-half-down clj

Static Constant.

Rounding mode to round towards nearest neighbor unless both neighbors are equidistant, in which case round down. Behaves as for ROUND_UP if the discarded fraction is > 0.5; otherwise, behaves as for ROUND_DOWN.

type: int

*-round-half-even clj

Static Constant.

Rounding mode to round towards the nearest neighbor unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as for ROUND_HALF_UP if the digit to the left of the discarded fraction is odd; behaves as for ROUND_HALF_DOWN if it's even. Note that this is the rounding mode that minimizes cumulative error when applied repeatedly over a sequence of calculations.

type: int

*-round-half-up clj

Static Constant.

Rounding mode to round towards nearest neighbor unless both neighbors are equidistant, in which case round up. Behaves as for ROUND_UP if the discarded fraction is ≥ 0.5; otherwise, behaves as for ROUND_DOWN. Note that this is the rounding mode that most of us were taught in grade school.

type: int

*-round-unnecessary clj

Static Constant.

Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an ArithmeticException is thrown.

type: int

*-round-up clj

Static Constant.

Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value.

type: int

*-ten clj

Static Constant.

The value 10, with a scale of 0.

type: java.math.BigDecimal

*-zero clj

Static Constant.

The value 0, with a scale of 0.

type: java.math.BigDecimal

*value-of clj

(*value-of val)

(*value-of unscaled-val scale)

Translates a long unscaled value and an int scale into a BigDecimal. This static factory method is provided in preference to a (long, int) constructor because it allows for reuse of frequently used BigDecimal values..

unscaled-val - unscaled value of the BigDecimal. - long scale - scale of the BigDecimal. - int

returns: a BigDecimal whose value is (unscaledVal × 10-scale). - java.math.BigDecimal

->big-decimal clj

(->big-decimal in)

(->big-decimal in mc)

(->big-decimal in offset len)

(->big-decimal in offset len mc)

Constructor.

Translates a character array representation of a BigDecimal into a BigDecimal, accepting the same sequence of characters as the BigDecimal(String) constructor, while allowing a sub-array to be specified and with rounding according to the context settings.

Note that if the sequence of characters is already available within a character array, using this constructor is faster than converting the char array to string and using the BigDecimal(String) constructor .

in - char array that is the source of characters. - char[] offset - first character in the array to inspect. - int len - number of characters to consider.. - int mc - the context to use. - java.math.MathContext

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

abs clj

(abs this)

(abs this mc)

Returns a BigDecimal whose value is the absolute value of this BigDecimal, with rounding according to the context settings.

mc - the context to use. - java.math.MathContext

returns: abs(this), rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

add clj

(add this augend)

(add this augend mc)

Returns a BigDecimal whose value is (this augend), with rounding according to the context settings.

If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is used as the result.

augend - value to be added to this BigDecimal. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: this augend, rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

byte-value-exact clj

(byte-value-exact this)

Converts this BigDecimal to a byte, checking for lost information. If this BigDecimal has a nonzero fractional part or is out of the possible range for a byte result then an ArithmeticException is thrown.

returns: this BigDecimal converted to a byte. - byte

throws: java.lang.ArithmeticException - if this has a nonzero fractional part, or will not fit in a byte.

compare-to clj

(compare-to this val)

Compares this BigDecimal with the specified BigDecimal. Two BigDecimal objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. This method is provided in preference to individual methods for each of the six boolean comparison operators (<, ==,

, >=, !=, <=). The suggested idiom for performing these comparisons is: (x.compareTo(y) <op> 0), where <op> is one of the six comparison operators.

val - BigDecimal to which this BigDecimal is to be compared. - java.math.BigDecimal

returns: -1, 0, or 1 as this BigDecimal is numerically less than, equal to, or greater than val. - int

divide clj

(divide this divisor)

(divide this divisor rounding-mode)

(divide this divisor scale rounding-mode)

Returns a BigDecimal whose value is (this / divisor), and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.

The new divide(BigDecimal, int, RoundingMode) method should be used in preference to this legacy method.

divisor - value by which this BigDecimal is to be divided. - java.math.BigDecimal scale - scale of the BigDecimal quotient to be returned. - int rounding-mode - rounding mode to apply. - int

returns: this / divisor - java.math.BigDecimal

throws: java.lang.ArithmeticException - if divisor is zero, roundingMode==ROUND_UNNECESSARY and the specified scale is insufficient to represent the result of the division exactly.

divide-and-remainder clj

(divide-and-remainder this divisor)

(divide-and-remainder this divisor mc)

Returns a two-element BigDecimal array containing the result of divideToIntegralValue followed by the result of remainder on the two operands calculated with rounding according to the context settings.

Note that if both the integer quotient and remainder are needed, this method is faster than using the divideToIntegralValue and remainder methods separately because the division need only be carried out once.

divisor - value by which this BigDecimal is to be divided, and the remainder computed. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: a two element BigDecimal array: the quotient (the result of divideToIntegralValue) is the initial element and the remainder is the final element. - java.math.BigDecimal[]

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY, or mc.precision > 0 and the result of this.divideToIntgralValue(divisor) would require a precision of more than mc.precision digits.

divide-to-integral-value clj

(divide-to-integral-value this divisor)

(divide-to-integral-value this divisor mc)

Returns a BigDecimal whose value is the integer part of (this / divisor). Since the integer part of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned by this method. The preferred scale of the result is (this.scale() - divisor.scale()). An ArithmeticException is thrown if the integer part of the exact quotient needs more than mc.precision digits.

divisor - value by which this BigDecimal is to be divided. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: The integer part of this / divisor. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if mc.precision > 0 and the result requires a precision of more than mc.precision digits.

double-value clj

(double-value this)

Converts this BigDecimal to a double. This conversion is similar to the narrowing primitive conversion from double to float as defined in section 5.1.3 of The Java™ Language Specification: if this BigDecimal has too great a magnitude represent as a double, it will be converted to Double.NEGATIVE_INFINITY or Double.POSITIVE_INFINITY as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the BigDecimal value.

returns: this BigDecimal converted to a double. - double

equals clj

(equals this x)

Compares this BigDecimal with the specified Object for equality. Unlike compareTo, this method considers two BigDecimal objects equal only if they are equal in value and scale (thus 2.0 is not equal to 2.00 when compared by this method).

x - Object to which this BigDecimal is to be compared. - java.lang.Object

returns: true if and only if the specified Object is a BigDecimal whose value and scale are equal to this BigDecimal's. - boolean

float-value clj

(float-value this)

Converts this BigDecimal to a float. This conversion is similar to the narrowing primitive conversion from double to float as defined in section 5.1.3 of The Java™ Language Specification: if this BigDecimal has too great a magnitude to represent as a float, it will be converted to Float.NEGATIVE_INFINITY or Float.POSITIVE_INFINITY as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the BigDecimal value.

returns: this BigDecimal converted to a float. - float

hash-code clj

(hash-code this)

Returns the hash code for this BigDecimal. Note that two BigDecimal objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.

returns: hash code for this BigDecimal. - int

int-value clj

(int-value this)

Converts this BigDecimal to an int. This conversion is analogous to the narrowing primitive conversion from double to short as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this BigDecimal will be discarded, and if the resulting BigInteger is too big to fit in an int, only the low-order 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this BigDecimal value as well as return a result with the opposite sign.

returns: this BigDecimal converted to an int. - int

int-value-exact clj

(int-value-exact this)

Converts this BigDecimal to an int, checking for lost information. If this BigDecimal has a nonzero fractional part or is out of the possible range for an int result then an ArithmeticException is thrown.

returns: this BigDecimal converted to an int. - int

throws: java.lang.ArithmeticException - if this has a nonzero fractional part, or will not fit in an int.

long-value clj

(long-value this)

Converts this BigDecimal to a long. This conversion is analogous to the narrowing primitive conversion from double to short as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this BigDecimal will be discarded, and if the resulting BigInteger is too big to fit in a long, only the low-order 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this BigDecimal value as well as return a result with the opposite sign.

returns: this BigDecimal converted to a long. - long

long-value-exact clj

(long-value-exact this)

Converts this BigDecimal to a long, checking for lost information. If this BigDecimal has a nonzero fractional part or is out of the possible range for a long result then an ArithmeticException is thrown.

returns: this BigDecimal converted to a long. - long

throws: java.lang.ArithmeticException - if this has a nonzero fractional part, or will not fit in a long.

max clj

(max this val)

Returns the maximum of this BigDecimal and val.

val - value with which the maximum is to be computed. - java.math.BigDecimal

returns: the BigDecimal whose value is the greater of this BigDecimal and val. If they are equal, as defined by the compareTo method, this is returned. - java.math.BigDecimal

min clj

(min this val)

Returns the minimum of this BigDecimal and val.

val - value with which the minimum is to be computed. - java.math.BigDecimal

returns: the BigDecimal whose value is the lesser of this BigDecimal and val. If they are equal, as defined by the compareTo method, this is returned. - java.math.BigDecimal

move-point-left clj

(move-point-left this n)

Returns a BigDecimal which is equivalent to this one with the decimal point moved n places to the left. If n is non-negative, the call merely adds n to the scale. If n is negative, the call is equivalent to movePointRight(-n). The BigDecimal returned by this call has value (this × 10-n) and scale max(this.scale()+n, 0).

n - number of places to move the decimal point to the left. - int

returns: a BigDecimal which is equivalent to this one with the decimal point moved n places to the left. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if scale overflows.

move-point-right clj

(move-point-right this n)

Returns a BigDecimal which is equivalent to this one with the decimal point moved n places to the right. If n is non-negative, the call merely subtracts n from the scale. If n is negative, the call is equivalent to movePointLeft(-n). The BigDecimal returned by this call has value (this × 10n) and scale max(this.scale()-n, 0).

n - number of places to move the decimal point to the right. - int

returns: a BigDecimal which is equivalent to this one with the decimal point moved n places to the right. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if scale overflows.

multiply clj

(multiply this multiplicand)

(multiply this multiplicand mc)

Returns a BigDecimal whose value is (this × multiplicand), with rounding according to the context settings.

multiplicand - value to be multiplied by this BigDecimal. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: this * multiplicand, rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

negate clj

(negate this)

(negate this mc)

Returns a BigDecimal whose value is (-this), with rounding according to the context settings.

mc - the context to use. - java.math.MathContext

returns: -this, rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

plus clj

(plus this)

(plus this mc)

Returns a BigDecimal whose value is (+this), with rounding according to the context settings.

The effect of this method is identical to that of the round(MathContext) method.

mc - the context to use. - java.math.MathContext

returns: this, rounded as necessary. A zero result will have a scale of 0. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

pow clj

(pow this n)

(pow this n mc)

Returns a BigDecimal whose value is (thisn). The current implementation uses the core algorithm defined in ANSI standard X3.274-1996 with rounding according to the context settings. In general, the returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that future releases may use a different algorithm with a decreased allowable error bound and increased allowable exponent range.

The X3.274-1996 algorithm is:

An ArithmeticException exception is thrown if

abs(n) > 999999999
mc.precision == 0 and n < 0
mc.precision > 0 and n has more than
mc.precision decimal digits

if n is zero, ONE is returned even if this is zero, otherwise

if n is positive, the result is calculated via

the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as in mc except for a precision increased to mc.precision elength 1 where elength is the number of decimal digits in n.

if n is negative, the result is calculated as if

n were positive; this value is then divided into one using the working precision specified above.

The final value from either the positive or negative case

is then rounded to the destination precision.

n - power to raise this BigDecimal to. - int mc - the context to use. - java.math.MathContext

returns: thisn using the ANSI standard X3.274-1996 algorithm - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY, or n is out of range.

precision clj

(precision this)

Returns the precision of this BigDecimal. (The precision is the number of digits in the unscaled value.)

The precision of a zero value is 1.

returns: the precision of this BigDecimal. - int

remainder clj

(remainder this divisor)

(remainder this divisor mc)

Returns a BigDecimal whose value is (this % divisor), with rounding according to the context settings. The MathContext settings affect the implicit divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the remainder may contain more than mc.getPrecision() digits.

The remainder is given by this.subtract(this.divideToIntegralValue(divisor, mc).multiply(divisor)). Note that this is not the modulo operation (the result can be negative).

divisor - value by which this BigDecimal is to be divided. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: this % divisor, rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY, or mc.precision > 0 and the result of this.divideToIntgralValue(divisor) would require a precision of more than mc.precision digits.

round clj

(round this mc)

Returns a BigDecimal rounded according to the MathContext settings. If the precision setting is 0 then no rounding takes place.

The effect of this method is identical to that of the plus(MathContext) method.

mc - the context to use. - java.math.MathContext

returns: a BigDecimal rounded according to the MathContext settings. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the rounding mode is UNNECESSARY and the BigDecimal operation would require rounding.

scale clj

(scale this)

Returns the scale of this BigDecimal. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. For example, a scale of -3 means the unscaled value is multiplied by 1000.

returns: the scale of this BigDecimal. - int

scale-by-power-of-ten clj

(scale-by-power-of-ten this n)

Returns a BigDecimal whose numerical value is equal to (this * 10n). The scale of the result is (this.scale() - n).

n - the exponent power of ten to scale by - int

returns: a BigDecimal whose numerical value is equal to (this * 10n) - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the scale would be outside the range of a 32-bit integer.

set-scale clj

(set-scale this new-scale)

(set-scale this new-scale rounding-mode)

Returns a BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.

Note that since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated.

new-scale - scale of the BigDecimal value to be returned. - int rounding-mode - The rounding mode to apply. - java.math.RoundingMode

returns: a BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if roundingMode==UNNECESSARY and the specified scaling operation would require rounding.

short-value-exact clj

(short-value-exact this)

Converts this BigDecimal to a short, checking for lost information. If this BigDecimal has a nonzero fractional part or is out of the possible range for a short result then an ArithmeticException is thrown.

returns: this BigDecimal converted to a short. - short

throws: java.lang.ArithmeticException - if this has a nonzero fractional part, or will not fit in a short.

signum clj

(signum this)

Returns the signum function of this BigDecimal.

returns: -1, 0, or 1 as the value of this BigDecimal is negative, zero, or positive. - int

strip-trailing-zeros clj

(strip-trailing-zeros this)

Returns a BigDecimal which is numerically equal to this one but with any trailing zeros removed from the representation. For example, stripping the trailing zeros from the BigDecimal value 600.0, which has [BigInteger, scale] components equals to [6000, 1], yields 6E2 with [BigInteger, scale] components equals to [6, -2]. If this BigDecimal is numerically equal to zero, then BigDecimal.ZERO is returned.

returns: a numerically equal BigDecimal with any trailing zeros removed. - java.math.BigDecimal

subtract clj

(subtract this subtrahend)

(subtract this subtrahend mc)

Returns a BigDecimal whose value is (this - subtrahend), with rounding according to the context settings.

If subtrahend is zero then this, rounded if necessary, is used as the result. If this is zero then the result is subtrahend.negate(mc).

subtrahend - value to be subtracted from this BigDecimal. - java.math.BigDecimal mc - the context to use. - java.math.MathContext

returns: this - subtrahend, rounded as necessary. - java.math.BigDecimal

throws: java.lang.ArithmeticException - if the result is inexact but the rounding mode is UNNECESSARY.

to-big-integer clj

(to-big-integer this)

Converts this BigDecimal to a BigInteger. This conversion is analogous to the narrowing primitive conversion from double to long as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this BigDecimal will be discarded. Note that this conversion can lose information about the precision of the BigDecimal value.

To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is discarded), use the toBigIntegerExact() method.

returns: this BigDecimal converted to a BigInteger. - java.math.BigInteger

to-big-integer-exact clj

(to-big-integer-exact this)

Converts this BigDecimal to a BigInteger, checking for lost information. An exception is thrown if this BigDecimal has a nonzero fractional part.

returns: this BigDecimal converted to a BigInteger. - java.math.BigInteger

throws: java.lang.ArithmeticException - if this has a nonzero fractional part.

to-engineering-string clj

(to-engineering-string this)

Returns a string representation of this BigDecimal, using engineering notation if an exponent is needed.

Returns a string that represents the BigDecimal as described in the toString() method, except that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the scale of the zero value is preserved. Note that unlike the output of toString(), the output of this method is not guaranteed to recover the same [integer, scale] pair of this BigDecimal if the output string is converting back to a BigDecimal using the string constructor. The result of this method meets the weaker constraint of always producing a numerically equal result from applying the string constructor to the method's output.

returns: string representation of this BigDecimal, using engineering notation if an exponent is needed. - java.lang.String

to-plain-string clj

(to-plain-string this)

Returns a string representation of this BigDecimal without an exponent field. For values with a positive scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero or negative scale, the resulting string is generated as if the value were converted to a numerically equal value with zero scale and as if all the trailing zeros of the zero scale value were present in the result.

The entire string is prefixed by a minus sign character '-' ('-') if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.

Note that if the result of this method is passed to the string constructor, only the numerical value of this BigDecimal will necessarily be recovered; the representation of the new BigDecimal may have a different scale. In particular, if this BigDecimal has a negative scale, the string resulting from this method will have a scale of zero when processed by the string constructor.

(This method behaves analogously to the toString method in 1.4 and earlier releases.)

returns: a string representation of this BigDecimal without an exponent field. - java.lang.String

to-string clj

(to-string this)

Returns the string representation of this BigDecimal, using scientific notation if an exponent is needed.

A standard canonical string form of the BigDecimal is created as though by the following steps: first, the absolute value of the unscaled value of the BigDecimal is converted to a string in base ten using the characters '0' through '9' with no leading zeros (except if its value is zero, in which case a single '0' character is used).

Next, an adjusted exponent is calculated; this is the negated scale, plus the number of characters in the converted unscaled value, less one. That is, -scale+(ulength-1), where ulength is the length of the absolute value of the unscaled value in decimal digits (its precision).

If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to -6, the number will be converted to a character form without using exponential notation. In this case, if the scale is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the scale specifying the number of characters to the right of the decimal point. '0' characters are added to the left of the converted unscaled value as necessary. If no character precedes the decimal point after this insertion then a conventional '0' character is prefixed.

Otherwise (that is, if the scale is negative, or the adjusted exponent is less than -6), the number will be converted to a character form using exponential notation. In this case, if the converted BigInteger has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter 'E' followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters '0' through '9' with no leading zeros, and is always prefixed by a sign character '-' ('-') if the adjusted exponent is negative, '+' ('+') otherwise).

Finally, the entire string is prefixed by a minus sign character '-' ('-') if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.

Examples: For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.

[123,0] 123 [-123,0] -123 [123,-1] 1.23E+3 [123,-3] 1.23E+5 [123,1] 12.3 [123,5] 0.00123 [123,10] 1.23E-8 [-123,12] -1.23E-10

Notes:

There is a one-to-one mapping between the distinguishable BigDecimal values and the result of this conversion. That is, every distinguishable BigDecimal value (unscaled value and scale) has a unique string representation as a result of using toString. If that string representation is converted back to a BigDecimal using the BigDecimal(String) constructor, then the original value will be recovered.

The string produced for a given number is always the same; it is not affected by locale. This means that it can be used as a canonical string representation for exchanging decimal data, or as a key for a Hashtable, etc. Locale-sensitive number formatting and parsing is handled by the NumberFormat class and its subclasses.

The toEngineeringString() method may be used for presenting numbers with exponents in engineering notation, and the setScale method may be used for rounding a BigDecimal so it has a known number of digits after the decimal point.

The digit-to-character mapping provided by Character.forDigit is used.

returns: string representation of this BigDecimal. - java.lang.String

ulp clj

(ulp this)

Returns the size of an ulp, a unit in the last place, of this BigDecimal. An ulp of a nonzero BigDecimal value is the positive distance between this value and the BigDecimal value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale of this. The result is stored with the same scale as this so the result for zero and nonzero values is equal to [1, this.scale()].

returns: the size of an ulp of this - java.math.BigDecimal

unscaled-value clj

(unscaled-value this)

Returns a BigInteger whose value is the unscaled value of this BigDecimal. (Computes (this * 10this.scale()).)

returns: the unscaled value of this BigDecimal. - java.math.BigInteger