NAME

Math::AnyNum - Arbitrary size precision for integers, rationals, floating-points and complex numbers.

VERSION

Version 0.20

SYNOPSIS

Math::AnyNum provides a transparent and easy-to-use interface to Math::GMPz, Math::GMPq, Math::MPFR and Math::MPC.

use 5.014;
use Math::AnyNum qw(:overload factorial);

# Integers
say factorial(30);                            #=> 265252859812191058636308480000000

# Floating-point numbers
say sqrt(1 / factorial(100));                 #=> 1.0351378111756264713204945[...]e-79

# Rational numbers
my $x = 2/3;
say ($x * 3);                                 #=> 2
say (2 / $x);                                 #=> 3
say $x;                                       #=> 2/3

# Complex numbers
say 3 + 4*i;                                  #=> 3+4i
say sqrt(-4);                                 #=> 2i
say log(-1);                                  #=> 3.1415926535897932384626433832[...]i

DESCRIPTION

Math::AnyNum focuses primarily on providing a friendly interface and good performance. In most cases, it can be used as a drop-in replacement for the bignum and bigrat pragmas.

The philosophy of Math::AnyNum is that mathematics should just work, therefore the support for complex numbers is virtually transparent, without requiring any explicit conversions. All the conversions are done implicitly, using a fairly sophisticated promotion system, which tries really hard to do the right thing and as efficiently as possible.

Additionally, each Math::AnyNum object is immutable.

HOW IT WORKS

Internally, each Math::AnyNum object holds a reference to an object of type Math::GMPz, Math::GMPq, Math::MPFR or Math::MPC. Based on the internal types, it decides what functions to call on each operation and does automatic promotion whenever necessarily.

The promotion rules can be summarized as follows:

(Integer, Integer)   -> Integer  | Rational | Float   | Complex
(Integer, Rational)  -> Rational | Float    | Complex
(Integer, Float)     -> Float    | Complex
(Integer, Complex)   -> Complex

(Rational, Rational) -> Rational | Float    | Complex
(Rational, Float)    -> Float    | Complex
(Rational, Complex)  -> Complex

(Float, Float)       -> Float    | Complex
(Float, Complex)     -> Complex

(Complex, Complex)   -> Complex

For explicit conversions, Math::AnyNum provides the following functions:

int(x)          # converts x to an integer (NaN if not possible)
rat(x)          # converts x to a rational (NaN if not possible)
float(x)        # converts x to a real-float (NaN if not possible)
complex(x)      # converts x to a complex number (always possible)

IMPORT / EXPORT

The following functions are exportable:

:trig
    sin sinh asin asinh
    cos cosh acos acosh
    tan tanh atan atanh
    cot coth acot acoth
    sec sech asec asech
    csc csch acsc acsch
    atan2 rad2deg deg2rad

:special
    beta eta gamma lgamma lngamma digamma zeta
    Ai Ei Li Li2 LambertW BesselJ BesselY lgrt
    pow sqrt cbrt root exp exp2 exp10 ln log
    log2 log10 mod abs erf erfc sqr norm hypot
    agm bernreal harmreal polygonal_root
    polygonal_root2

:ntheory
    factorial dfactorial mfactorial primorial
    binomial lucas fibonacci bernfrac harmfrac
    lcm gcd valuation kronecker remdiv divmod
    iadd isub imul idiv imod ipow ipow2 ipow10
    iroot isqrt icbrt ilog ilog2 ilog10 invmod
    powmod isqrtrem irootrem is_power is_square
    is_prime is_coprime next_prime is_polygonal
    is_polygonal2 faulhaber_sum ipolygonal_root
    ipolygonal_root2 polygonal rising_factorial
    falling_factorial

:misc
    rand irand seed iseed floor ceil round sgn neg inv
    conj int rat float complex real imag reals digits
    numerator denominator nude popcount as_bin as_hex
    as_oct as_int as_dec as_frac is_pos is_neg is_int
    is_rat is_real is_imag is_complex is_inf is_ninf
    is_nan is_zero is_one is_mone is_even is_odd is_div
    rat_approx acmp

Each function can be exported individually, as:

use Math::AnyNum qw(zeta);

There is also the possibility of exporting an entire group of functions, as:

use Math::AnyNum qw(:trig);

Additionally, by specifying the :all keyword, will export all the exportable functions and all the constants.

use Math::AnyNum qw(:all);

The :overload keyword enables constant overloading, which makes each number a Math::AnyNum object and also exports the i, Inf and NaN constants:

use Math::AnyNum qw(:overload);
say 42;                                       #=> "42"   (as Int)
say 1/2;                                      #=> "1/2"  (as Rat)
say 0.5;                                      #=> "0.5"  (as Float)
say 3 + 4*i;                                  #=> "3+4i" (as Complex)

NOTE: :overload is lexical to the current scope only.

The syntax for disabling the :overload behavior in the current scope, is:

no Math::AnyNum;        # :overload will be disabled in the current scope

In addition to the exportable functions, Math::AnyNum also provides a list with useful mathematical constants that can be exported, such as:

i           # imaginary unit             sqrt(-1)
e           # e mathematical constant    2.718281828459...
pi          # PI constant                3.141592653589...
tau         # TAU constant               6.283185307179...
ln2         # natural logarithm of 2     0.693147180559...
phi         # golden ratio               1.618033988749...
euler       # Euler-Mascheroni constant  0.577215664901...
catalan     # Catalan constant           0.915965594177...
Inf         # positive Infinity
NaN         # Not-a-Number

The syntax for importing a constant, is:

use Math::AnyNum qw(pi);
say pi;                          # 3.141592653589...

Nothing is exported by default.

PRECISION

The default precision for floating-point numbers is 192 bits, which is equivalent with about 50 digits of precision in base 10.

The precision can be changed by modifying the $Math::AnyNum::PREC variable, such as:

local $Math::AnyNum::PREC = 1024;

or by specifying the precision at import (this sets the precision globally):

use Math::AnyNum PREC => 1024;

This precision is used internally whenever a Math::MPFR or a Math::MPC object is created.

For example, if we change the precision to 3 decimal digits (where 4 is the conversion factor), we get the following results:

local $Math::AnyNum::PREC = 3*4;
say sqrt(2);                                  #=> 1.41
say 98**7;                                    #=> 86812553324672
say 1 / 98**7                                 #=> 1/86812553324672

As shown above, integers and rational numbers do not obey this precision, because they can grow and shrink dynamically, without a specific limit.

Furthermore, a rational number never losses precision and accuracy in rational operations, therefore if we say:

my $x = 1/3;
say $x*3;                                     #=> 1
say 1/$x;                                     #=> 3
say 3/$x;                                     #=> 9

...the results are exact.

NOTATIONS

Methods that begin with an i followed by the actual name (e.g.: isqrt), do integer operations, by first truncating their arguments to integers, if necessary.

The returned types are noted as follows:

Any         # any type of number
Int         # an integer value
Rat         # a rational value
Float       # a floating-point value
Complex     # a complex value
NaN         # "Not-a-Number" value
Inf         # +/-Infinity
Bool        # a Boolean value (1 or 0)
Scalar      # a Perl scalar

When two or more types are separated with pipe characters (|), it means that the corresponding function can return any of the specified types.

INITIALIZATION / CONSTANTS

This section includes methods for creating new Math::AnyNum objects and some useful mathematical constants.

new

Math::AnyNum->new(n)                          #=> Any
Math::AnyNum->new(n, base)                    #=> Any

Returns a new AnyNum object with the value specified in the first argument, which can be a Perl numerical value, a string representing a number in a rational form, such as "1/2", a string holding a floating-point number, such as "0.5", a string holding an integer, such as "255" or a string holding a complex number, such as "3+4i".

my $z = Math::AnyNum->new('42');        # integer
my $r = Math::AnyNum->new('3/4');       # rational
my $f = Math::AnyNum->new('12.34');     # float
my $c = Math::AnyNum->new('3+4i');      # complex

The second argument specifies the base of the number, which can range from 2 to 36 inclusive and defaults to 10.

For setting an hexadecimal number, we can say:

my $n = Math::AnyNum->new("deadbeef", 16);

NOTE: no prefix, such as "0x" or "0b", is allowed as part of the number.

new_si

Math::AnyNum->new_si(n)                       #=> Int

Sets a signed native integer.

Example:

my $n = Math::AnyNum->new_si(-42);

new_ui

Math::AnyNum->new_ui(n)                       #=> Int

Sets an unsigned native integer.

Example:

my $n = Math::AnyNum->new_ui(42);

new_z

Math::AnyNum->new_z(str)                      #=> Int
Math::AnyNum->new_z(str, base)                #=> Int

Sets an arbitrary large integer from a given string. When no base is specified, it defaults to base 10.

Example:

my $n = Math::AnyNum->new_z("12345678910111213141516");
my $m = Math::AnyNum->new_z("fffffffffffffffffff", 16);

new_q

Math::AnyNum->new_q(frac)                     #=> Rat
Math::AnyNum->new_q(num, den)                 #=> Rat
Math::AnyNum->new_q(num, den, base)           #=> Rat

Sets an arbitrary large rational from a given string. When no base is specified, it defaults to base 10.

Example:

my $n = Math::AnyNum->new_q('12345/67890');
my $m = Math::AnyNum->new_q('12345', '67890');
my $o = Math::AnyNum->new_q('fffff', 'aaaaa', 16);

new_f

Math::AnyNum->new_f(str)                      #=> Float
Math::AnyNum->new_f(str, base)                #=> Float

Sets a floating-point real number from a given string. When no base is specified, it defaults to base 10.

Example:

my $n = Math::AnyNum->new_f('12.345');
my $m = Math::AnyNum->new_f('-1.2345e-12');
my $o = Math::AnyNum->new_f('ffffff', 16);

new_c

Math::AnyNum->new_c(real)                     #=> Complex
Math::AnyNum->new_c(real, imag)               #=> Complex
Math::AnyNum->new_c(real, imag, base)         #=> Complex

Sets a complex number from a given string. When no base is specified, it defaults to base 10.

Example:

my $n = Math::AnyNum->new_c('1.123');
my $m = Math::AnyNum->new_c('3', '4');
my $o = Math::AnyNum->new_c('f', 'a', 16);

nan

Math::AnyNum->nan                             #=> NaN

Returns an object holding the NaN value.

inf

Math::AnyNum->inf                             #=> Inf

Returns an object representing positive infinity.

ninf

Math::AnyNum->ninf                            #=> -Inf

Returns an object representing negative infinity.

one

Math::AnyNum->one                             #=> Int

Returns an object containing the value 1.

mone

Math::AnyNum->mone                            #=> Int

Returns an object containing the value -1.

zero

Math::AnyNum->zero                            #=> Int

Returns an object containing the value 0.

i

Math::AnyNum->i                               #=> Complex

Returns the imaginary unit, which is sqrt(-1).

e

Math::AnyNum->e                               #=> Float

Returns the e mathematical constant, which is 2.718....

pi

Math::AnyNum->pi                              #=> Float

Returns the number PI, which is 3.1415....

tau

Math::AnyNum->tau                             #=> Float

Returns the number TAU, which is 2*pi.

ln2

Math::AnyNum->ln2                             #=> Float

Returns the natural logarithm of 2.

phi

Math::AnyNum->phi                             #=> Float

Returns the value of the golden ratio, which is 1.61803....

euler

Math::AnyNum->euler                           #=> Float

Returns the Euler-Mascheroni constant, which is 0.57721....

catalan

Math::AnyNum->catalan                         #=> Float

Returns the Catalan constant, also known as Beta(2) or G, and starts as: 0.91596....

ARITHMETIC OPERATIONS

This section includes basic arithmetic operations.

add

x + y                                         #=> Any

Adds x and y and returns the result.

sub

x - y                                         #=> Any

Subtracts y from x and returns the result.

mul

x * y                                         #=> Any

Multiplies x by y and returns the result.

div

x / y                                         #=> Any

Divides x by y and returns the result.

mod

x % y                                         #=> Any
mod(x, y)                                     #=> Any

Remainder of x when is divided by y. Returns NaN when y is zero.

Implemented as:

x % y = x - y*floor(x/y)

conj

conj(x)                                       #=> Any

Complex conjugate of x. Return x when x is a real number.

Example:

conj("3+4i") = 3-4*i

inv

inv(x)                                        #=> Any

Multiplicative inverse of x. Equivalent with 1/x.

neg

neg(x)                                        #=> Any

Additive inverse of x. Equivalent with -x.

abs

abs(x)                                        #=> Any

Absolute value of x.

sqr

sqr(x)                                        #=> Any

Multiplies x with itself and returns the result. Equivalent with x*x.

norm

norm(x)                                       #=> Any

The square of the absolute value of x. Equivalent with abs(x)**2.

SPECIAL FUNCTIONS

This section includes the special functions.

sqrt

sqrt(x)                                       #=> Any

Square root of x. Returns a complex number when x is negative.

cbrt

cbrt(x)                                       #=> Any

Cube root of x. Returns a complex number when x is negative.

root

root(x, y)                                    #=> Any

The y root of x. Equivalent with x**(1/y).

polygonal_root

polygonal_root(n, k)                          #=> Any

Returns the k-gonal root of n. Also defined for complex numbers.

Example:

say polygonal_root($n, 3);      # triangular root
say polygonal_root($n, 5);      # pentagonal root

polygonal_root2

polygonal_root2(n, k)                         #=> Any

Returns the second k-gonal root of n. Also defined for complex numbers.

Example:

say polygonal_root2($n, 5);      # second pentagonal root

pow

x ** y                                        #=> Any
pow(x, y)                                     #=> Any

Raises x to power y and returns the result.

When x and y are both integers, it does integer exponentiation and returns the exact result.

When x is rational and y is an integer, it does rational exponentiation based on the identity: (a/b)**n = a**n / b**n, which also computes the exact result.

Otherwise, it does floating-point exponentiation, which is equivalent with exp(log(x) * y).

exp

exp(x)                                        #=> Any

Natural exponentiation of x (i.e.: e**x).

exp2

exp2(x)                                       #=> Any

Raises 2 to the power x. (i.e.: 2**x)

exp10

exp10(x)                                      #=> Any

Raises 10 to the power x. (i.e.: 10**x)

ln / log

ln(x)                                         #=> Any
log(x)                                        #=> Any
log(x, y)                                     #=> Any

Logarithm of x to base y (or base e when y is omitted).

NOTE: log(x, y) is equivalent with log(x) / log(y).

log2 / log10

log2(x)                                       #=> Any
log10(x)                                      #=> Any

Logarithm of x to base 2 and base 10, respectively.

lgrt

lgrt(x)                                       #=> Any

Logarithmic-root of x, which is the solution to a**a = x, where x is known. When the value of x is less than e**(-1/e), it returns a complex number. It also accepts a complex number as input.

Example:

lgrt(100)            # solves for x in `x**x = 100` and returns: `3.59728...`

LambertW

LambertW(x)                                   #=> Any

The Lambert-W function. When the value of x is less than -1/e, it returns a complex number. It also accepts a complex number as input.

Example:

exp(LambertW(log(100)))    # solves for x in `x**x = 100` and returns: `3.59728...`

bernfrac

bernfrac(n)                                   #=> Rat | NaN

Returns the nth-Bernoulli number B_n as an exact fraction, starting with bernfrac(0) = 1.

Algorithm due to Kevin J. McGown (December 8, 2005). Described in his paper: "Computing Bernoulli Numbers Quickly".

Returns NaN for negatives values of n.

bernreal

bernreal(n)                                   #=> Float | NaN

Returns the nth-Bernoulli number, as a floating-point approximation, with bernreal(0) = 1.

Returns NaN for negatives values of n.

harmfrac

harmfrac(n)                                   #=> Rat | NaN

Returns the nth-Harmonic number H_n. The harmonic numbers are the sum of reciprocals of the first n natural numbers: 1 + 1/2 + 1/3 + ... + 1/n.

For values greater than 7000, binary splitting (Fredrik Johansson's elegant formulation) is used.

harmreal

harmreal(n)                                   #=> Float | NaN

Returns the nth-Harmonic number, as a floating-point approximation, for any real value of n.

Returns NaN for negative integers.

Defined as:

harmreal(n) = digamma(n+1) + euler

where euler is the Euler-Mascheroni constant.

agm

agm(x, y)                                     #=> Any

Arithmetic-geometric mean of x and y. Also defined for complex numbers.

hypot

hypot(x, y)                                   #=> Any

The value of the hypotenuse for catheti x and y. Equivalent to sqrt(x**2 + y**2). Also defined for complex numbers.

gamma

gamma(x)                                      #=> Float | Inf | NaN

The Gamma function on x. Returns Inf when x is zero, and NaN when x is a negative integer.

lgamma

lgamma(x)                                     #=> Float | Inf | NaN

The logarithm of the absolute value of the Gamma function.

lngamma

lngamma(x)                                    #=> Float | Inf | NaN

The natural logarithm of the Gamma function on x.

digamma

digamma(x)                                    #=> Float | Inf | NaN

The Digamma function (sometimes called Psi). Returns NaN when x is negative, and -Inf when x is 0.

beta

beta(x, y)                                    #=> Float | Inf | NaN

The beta function (also called the Euler integral of the first kind).

Defined as:

beta(x, y) = gamma(x)*gamma(y) / gamma(x+y)

zeta

zeta(x)                                       #=> Float | Inf | NaN

The Riemann zeta function at x. Returns Inf when x is 1.

eta

eta(x)                                        #=> Float | Inf | NaN

The Dirichlet eta function at x.

Defined as:

eta(1) = ln(2)
eta(x) = (1 - 2**(1-x)) * zeta(x)

BesselJ

BesselJ(x, n)                                 #=> Float | NaN

The first order Bessel function, J_n(x), where n is a signed integer.

Example:

BesselJ(x, n)        # represents J_n(x)

BesselY

BesselY(x, n)                                 #=> Float | NaN

The second order Bessel function, Y_n(x), where n is a signed integer. Returns NaN for negative values of x.

Example:

BesselY(x, n)        # represents Y_n(x)

erf

erf(x)                                        #=> Float

The error function on x.

erfc

erfc(x)                                       #=> Float

Complementary error function on x.

Ai

Ai(x)                                         #=> Float

The Airy function on x.

Ei

Ei(x)                                         #=> Float | Inf | NaN

Exponential integral of x. Returns -Inf when x is zero, and NaN when x is negative.

Li

Li(x)                                         #=> Float | Inf | NaN

The logarithmic integral of x, defined as: Ei(ln(x)). Returns -Inf when x is 1, and NaN when x is less than or equal to 0.

Li2

Li2(x)                                        #=> Float

The dilogarithm function, defined as the integral of -log(1-t)/t from 0 to x.

TRIGONOMETRIC FUNCTIONS

sin / sinh / asin / asinh

sin(x)                                        #=> Any
sinh(x)                                       #=> Any
asin(x)                                       #=> Any
asinh(x)                                      #=> Any

Sine, hyperbolic sine, inverse sine and inverse hyperbolic sine.

cos / cosh / acos / acosh

cos(x)                                        #=> Any
cosh(x)                                       #=> Any
acos(x)                                       #=> Any
acosh(x)                                      #=> Any

Cosine, hyperbolic cosine, inverse cosine and inverse hyperbolic cosine.

tan / tanh / atan / atanh

tan(x)                                        #=> Any
tanh(x)                                       #=> Any
atan(x)                                       #=> Any
atanh(x)                                      #=> Any

Tangent, hyperbolic tangent, inverse tangent and inverse hyperbolic tangent.

cot / coth / acot / acoth

cot(x)                                        #=> Any
coth(x)                                       #=> Any
acot(x)                                       #=> Any
acoth(x)                                      #=> Any

Cotangent, hyperbolic cotangent, inverse cotangent and inverse hyperbolic cotangent.

sec / sech / asec / asech

sec(x)                                        #=> Any
sech(x)                                       #=> Any
asec(x)                                       #=> Any
asech(x)                                      #=> Any

Secant, hyperbolic secant, inverse secant and inverse hyperbolic secant.

csc / csch / acsc / acsch

csc(x)                                        #=> Any
csch(x)                                       #=> Any
acsc(x)                                       #=> Any
acsch(x)                                      #=> Any

Cosecant, hyperbolic cosecant, inverse cosecant and inverse hyperbolic cosecant.

atan2

atan2(x, y)                                   #=> Any

The arctangent of the quotient of its arguments (i.e.: atan(x/y)).

deg2rad

deg2rad(x)                                    #=> Any

Returns the value of x converted from degrees to radians.

Example:

deg2rad(180) = pi

rad2deg

rad2deg(x)                                    #=> Any

Returns the value of x converted from radians to degrees.

Example:

rad2deg(pi) = 180

INTEGER FUNCTIONS

All operations in this section are done with integers.

iadd / isub / imul / idiv / ipow

iadd(x, y)                                    #=> Int | NaN
isub(x, y)                                    #=> Int | NaN
imul(x, y)                                    #=> Int | NaN
idiv(x, y)                                    #=> Int | NaN
ipow(x, y)                                    #=> Int | NaN

Integer addition, subtraction, multiplication, division and exponentiation.

ipow2

ipow2(n)                                      #=> Int

Raises 2 to the power n, by first truncating n to an integer. Returns 0 when n is negative.

ipow10

ipow10(n)                                     #=> Int

Raises 10 to the power n, by first truncating n to an integer. Returns 0 when n is negative.

imod

imod(x, y)                                    #=> Int | NaN

The integer modulus operation. Returns NaN when y is zero.

divmod

divmod(x, y)                                  #=> (Int, Int) | (NaN, NaN)

Returns the quotient and the remainder from division of x by y, where both are integers. When y is zero, it returns two NaN values.

invmod

invmod(x, y)                                  #=> Int | NaN

Computes the inverse of x modulo y and returns the result. When no inverse exists, the NaN value is returned.

powmod

powmod(x, y, z)                               #=> Int | NaN

Computes (x ** y) % z, where all three values are integers.

Returns NaN when the third argument is 0, or when y is negative and gcd(x, z) != 1.

isqrt / icbrt

isqrt(n)                                      #=> Int | NaN
icbrt(n)                                      #=> Int | NaN

The integer square root of n and the integer cube root of n. Returns NaN when a real root does not exists.

isqrtrem

isqrtrem(n)                                   #=> (Int, Int) | (NaN, NaN)

The integer part of the square root of n and the remainder n - isqrt(n)**2, which will be zero when n is a perfect square.

iroot

iroot(n, m)                                   #=> Int | NaN

The integer m-th root of n. Returns NaN when a real does not exists.

irootrem

irootrem(n, m)                                #=> (Int, Int) | (NaN, NaN)

The integer part of the root of n and the remainder n - iroot(n,m)**m.

Returns (NaN,NaN) when a real root does not exists.

ilog

ilog(n)                                       #=> Int | NaN
ilog(n, m)                                    #=> Int | NaN

The integer part of the logarithm of n to base m or base e when m is not specified.

n must be greater than 0 and m must greater than 1. Returns NaN otherwise.

ilog2 / ilog10

ilog2(n)                                      #=> Int | NaN
ilog10(n)                                     #=> Int | NaN

The integer part of the logarithm of n to base 2 or base 10, respectively.

and / or / xor / not / lsft / rsft

x & y                                         #=> Int
x | y                                         #=> Int
x ^ y                                         #=> Int
~x                                            #=> Int
x << y                                        #=> Int
x >> y                                        #=> Int

The bitwise integer operations.

gcd

gcd(x, y)                                     #=> Int

The greatest common divisor of x and y.

lcm

lcm(x, y)                                     #=> Int

The least common multiple of x and y.

valuation

valuation(n, k)                               #=> Scalar

Returns the number of times n is divisible by k.

remdiv

remdiv(n, k)                                  #=> Int

Removes all occurrences of the divisor k from integer n.

In general, the following statement holds true:

remdiv(n, k) == n / k**(valuation(n, k))

kronecker

kronecker(n, m)                               #=> Scalar

Returns the Kronecker symbol (n|m), which is a generalization of the Jacobi symbol for all integers m.

faulhaber_sum

faulhaber_sum(n, k)                           #=> Int | NaN

Computes the sum 1**k + 2**k + 3**k +...+ n**k, using Faulhaber's formula.

k must be a non-negative integer. Returns NaN otherwise.

Example:

faulhaber_sum(5, 8) = 1**8 + 2**8 + 3**8 + 4**8 + 5**8

lucas

lucas(n)                                      #=> Int | NaN

The n-th Lucas number. Returns NaN when n is negative.

fibonacci

fibonacci(n)                                  #=> Int | NaN

The n-th Fibonacci number. Returns NaN when n is negative.

factorial

factorial(n)                                  #=> Int | NaN

Factorial of n (denoted as n!). Returns NaN when n is negative. (1*2*3*...*n)

dfactorial

dfactorial(n)                                 #=> Int | NaN

Double-factorial of n (denoted as n!!). Returns NaN when n is negative. (requires GMP>=5.1.0)

Example:

dfactorial(7)     # 1*3*5*7 = 105
dfactorial(8)     # 2*4*6*8 = 384

mfactorial

mfactorial(n, m)                              #=> Int | NaN

Generalized m-factorial of n. Returns NaN when n or m is negative. (requires GMP>=5.1.0)

rising_factorial

rising_factorial(n, k)                        #=> Int | Rat | NaN

Rising factorial, n * (n + 1) * ... * (n + k - 1), defined as:

binomial(n + k - 1, k) * k!

For negative values of k, rising factorial is defined as:

rising_factorial(n, -k) = 1/rising_factorial(n - k, k)

When the denominator is zero, NaN is returned.

falling_factorial

falling_factorial(n, k)                       #=> Int | Rat | NaN

Falling factorial, n * (n - 1) * ... * (n - k + 1), defined as:

binomial(n, k) * k!

For negative values of k, falling factorial is defined as:

falling_factorial(n, -k) = 1/falling_factorial(n + k, k)

When the denominator is zero, NaN is returned.

binomial

binomial(n, k)                                #=> Int

Calculates the binomial coefficient n over k, also called the "choose" function. The result is equivalent to:

( n )       n!
|   |  = -------
( k )    k!(n-k)!

primorial

primorial(n)                                  #=> Int

Returns the product of all the primes less than or equal to n. (requires GMP>=5.1.0)

next_prime

next_prime(n)                                 #=> Int

Returns the next prime after n.

is_prime

is_prime(n)                                   #=> Scalar
is_prime(n, r)                                #=> Scalar

Returns 2 if n is definitely prime, 1 if n is probably prime (without being certain), or 0 if n is definitely composite. This method does some trial divisions, then some Miller-Rabin probabilistic primality tests. It also accepts an optional argument for specifying the accuracy of the test. By default, it uses an accuracy value of 20.

Reasonable accuracy values are between 15 and 50.

See also:

is_coprime

is_coprime(n, k)                              #=> Bool

Returns a true value when n and k are relatively prime to each other. That is, when gcd(n, k) == 1.

is_power

is_power(n)
is_power(n, k)                                #=> Bool

Return a true value when n is a perfect power of a given integer k.

When n is not an integer, it always returns false. On the other hand, when k is not an integer, it will implicitly be truncated to an integer. If k is not positive after truncation, 0 is returned.

A true value is returned iff there exists some integer a satisfying the equation: a**k = n.

When k is not specified, it returns true if n can be expressed as a**b for some integers a and b, with b greater than 1.

Example:

is_power(100, 2)       # true: 100 is a square (10**2)
is_power(125, 3)       # true: 125 is a cube   ( 5**3)
is_power(279841)       # true: 279841 is 23**4

is_square

is_square(n)                                  #=> Bool

Returns a true value when n is a perfect square. When n is not an integer, a false value is returned.

polygonal

polygonal(n, k)                               #=> Int

Returns the nth k-gonal number. When n is negative, it returns the second k-gonal number.

Example:

say join(' ', map { polygonal( $_, 3) } 1..10);  # triangular numbers
say join(' ', map { polygonal( $_, 5) } 1..10);  # pentagonal numbers
say join(' ', map { polygonal(-$_, 5) } 1..10);  # second pentagonal numbers

ipolygonal_root

ipolygonal_root(n, k)                         #=> Int | NaN

Integer k-gonal root of n. Returns NaN when a real root does not exists.

Example:

say ipolygonal_root($n, 5);                  # integer pentagonal root
say ipolygonal_root(polygonal(10, 5), 5);    # prints: "10"

ipolygonal_root2

ipolygonal_root2(n, k)                        #=> Int | NaN

Second integer k-gonal root of n. Returns NaN when a real root does not exists.

Example:

say ipolygonal_root2($n, 5);                   # second integer pentagonal root
say ipolygonal_root2(polygonal(-10, 5), 5);    # prints: "-10"

is_polygonal

is_polygonal(n, k)                            #=> Bool

Returns a true value when n is a k-gonal number.

The values of n and k can be any arbitrary large integers.

Example:

say is_polygonal(145, 5);      #=> 1 ("145" is a pentagonal number)
say is_polygonal(155, 5);      #=> 0

is_polygonal2

is_polygonal2(n, k)                           #=> Bool

Returns a true value when n is a second k-gonal number.

The values of n and k can be any arbitrary large integers.

Example:

say is_polygonal2(145, 5);      #=> 0
say is_polygonal2(155, 5);      #=> 1 ("155" is a second-pentagonal number)

MISCELLANEOUS

This section includes various useful methods.

floor

floor(x)                                      #=> Any

Returns x if x is an integer, otherwise it rounds x towards -Infinity.

Example:

floor( 2.5) =  2
floor(-2.5) = -3

ceil

ceil(x)                                       #=> Any

Returns x if x is an integer, otherwise it rounds x towards +Infinity.

Example:

ceil( 2.5) =  3
ceil(-2.5) = -2

round

round(x)                                      #=> Any
round(x, p)                                   #=> Any

Rounds x to the nth place. A negative argument rounds that many digits after the decimal point, while a positive argument rounds that many digits before the decimal point.

Example:

round('1234.567')         = 1235
round('1234.567', 2)      = 1200
round('3.123+4.567i', -2) = 3.12+4.57*i

rand

rand(x)                                       #=> Float
rand(x, y)                                    #=> Float

Returns a pseudorandom floating-point value. When an additional argument is provided, it returns a number between x (inclusive) and y (exclusive). Otherwise, returns a number between 0 (inclusive) and x (exclusive).

The PRNG behind this function is called the "Mersenne Twister". Although it generates pseudorandom numbers of very good quality, it is NOT cryptographically secure!

Example:

rand(10)        # a random number in the interval [0, 10)
rand(10, 20)    # a random number in the interval [10, 20)

irand

irand(x)                                      #=> Int
irand(x, y)                                   #=> Int

Returns a pseudorandom integer. Unlike the rand() function, irand() is inclusive in both sides.

When an additional argument is provided, it returns an integer between x (inclusive) and y (inclusive), otherwise returns an integer between 0 (inclusive) and x (inclusive).

If x is greater that y, the returned result will be in the range [y, x].

The PRNG behind this function is called the "Mersenne Twister". Although it generates high-quality pseudorandom integers, it is NOT cryptographically secure!

Example:

irand(10)        # a random integer in the interval [0, 10]
irand(10, 20)    # a random integer in the interval [10, 20]

seed / iseed

seed(n)                                       #=> Int
iseed(n)                                      #=> Int

Reseeds the rand() and the irand() function, respectively, with the value of n, which can be any arbitrary large integer.

Returns back the integer part of n. If n cannot be truncated to an integer, the method dies with an appropriate error message.

sgn

sgn(x)                                        #=> Scalar | Complex

Returns -1 when x is negative, 1 when x is positive, and 0 when x is zero.

When x is a complex number, it computes the sign using the identity:

sgn(x) = x / abs(x)

length

$x->length                                    #=> Scalar

Returns the number of digits in the integer part of x. Returns -1 when x cannot be truncated to an integer.

For -1234.56, it returns 4.

inc

++$x                                          #=> Any
$x++                                          #=> Any

Returns x + 1.

dec

--$x                                          #=> Any
$x--                                          #=> Any

Return x - 1.

copy

$x->copy                                      #=> Any

Returns a deep-copy of the self-object.

popcount

popcount(n)                                   #=> Scalar

Returns the population count of the positive integer part of x, which is the number of 1 bits in its binary representation.

This value is also known as the Hamming weight.

* Introspection

is_int

is_int(x)                                     #=> Bool

Returns a true value when x is an integer.

is_rat

is_rat(x)                                     #=> Bool

Returns a true value when x is a rational number.

is_real

is_real(x)                                    #=> Bool

Returns a true value when x is a real number (i.e.: when the imaginary part is zero and it holds a real value in the real part).

Example:

is_real(complex('4'))           # true
is_real(complex('4i'))          # false (is imaginary)
is_real(complex('3+4i'))        # false (is complex)

is_imag

Returns a true value when x is an imaginary number (i.e.: when the real part is zero and it has a non-zero imaginary part).

Example:

is_imag(complex('4'))           # false (is real)
is_imag(complex('4i'))          # true
is_imag(complex('3+4i'))        # false (is complex)

is_complex

is_complex(x)                                 #=> Bool

Returns a true value when x is a complex number (i.e.: when the real part and the imaginary part are non-zero).

Example:

is_complex(complex('4'))        # false (is real)
is_complex(complex('4i'))       # false (is imaginary)
is_complex(complex('3+4i'))     # true

is_even

is_even(n)                                    #=> Bool

Returns a true value when n is a real integer divisible by 2.

is_odd

is_odd(n)                                     #=> Bool

Returns a true value when n is a real integer not divisible by 2.

is_div

is_div(x, y)                                  #=> Bool

Returns a true value when x is exactly divisible by y (i.e.: when the remainder x % y is zero).

This is a generalized version of the above two methods and it also works with complex numbers.

is_pos

is_pos(x)                                     #=> Bool

Returns a true value when x is positive.

is_neg

is_neg(x)                                     #=> Bool

Returns a true value when x is negative.

is_zero

is_zero(n)                                    #=> Bool

Returns a true value when n equals 0.

is_one

is_one(n)                                     #=> Bool

Returns a true value when n equals 1.

is_mone

is_mone(n)                                    #=> Bool

Returns a true value when n equals -1.

is_inf

is_inf(x)                                     #=> Bool

Returns a true value when x holds the positive Infinity special value.

is_ninf

is_ninf(x)                                    #=> Bool

Returns a true value when x holds the negative Infinity special value.

is_nan

is_nan(x)                                     #=> Bool

Returns a true value when x holds the Not-a-Number special value.

* Conversions

int

int(x)                                        #=> Int | NaN

Returns the integer part of x. Returns NaN when x cannot be truncated to an integer.

rat

rat(x)                                        #=> Rat | NaN
rat(str)                                      #=> Rat | NaN

Converts x to a rational number. Returns NaN when this conversion is not possible.

When the given argument is a decimal expansion string, it will be specially parsed as an exact fraction.

If x is a floating-point number, use rat_approx() instead.

Example:

rat('0.5')       = 1/2
rat('1234/5678') = 617/2839

rat_approx

rat_approx(n)                                 #=> Rat | NaN

Given a real number n, it returns a very good (sometimes exact) rational approximation to n, computed with continued fractions.

Example:

rat_approx(3.14)     = 22/7
rat_approx(zeta(-5)) = -1/252

Return NaN when n is not a real number.

float

float(x)                                      #=> Float | NaN
float(str)                                    #=> Float | NaN

Converts x to a floating-point real number.

Example:

float('3.14159') = 3.14159
float('777/222') = 3.5

complex

complex(x)                                    #=> Complex
complex(str)                                  #=> Complex

Converts x to a complex number.

Example:

complex("3+4i") = 3+4*i

stringify

"$x"                                          #=> Scalar

Returns a string representing the value of x, in base 10.

boolify

!!$x                                          #=> Bool

Returns a false value when the number is zero. True otherwise.

numify

$x->numify                                    #=> Scalar

Returns a Perl numerical scalar containing the value of x, truncated if necessary.

If x is an integer that fits inside a native signed or unsigned integer, the returned result will be exact, otherwise the result is returned as a double, with possible truncation.

If x is a complex number, only the real part is considered.

as_bin

as_bin(n)                                     #=> Scalar

Returns a string representing the integer part of n in binary (base 2).

Example:

as_bin(42) = "101010"

as_oct

as_oct(n)                                     #=> Scalar

Returns a string representing the integer part of n in octal (base 8).

Example:

as_oct(42) = "52"

as_hex

as_hex(n)                                     #=> Scalar

Returns a string representing the integer part of n in hexadecimal (base 16).

Example:

as_hex(42) = "2a"

as_int

as_int(n)                                     #=> Scalar
as_int(n, b)                                  #=> Scalar

Returns the integer part of n as a string, in a given base. When the base is omitted, it defaults to base 10.

Example:

as_int(255)     = "255"
as_int(255, 16) = "ff"

as_frac

as_frac(n)                                    #=> Scalar
as_frac(n, b)                                 #=> Scalar

Returns n as a fraction in a given base. When the base is omitted, it defaults to base 10.

Example:

as_frac(42)      = "42/1"
as_frac("1/2")   = "1/2"
as_frac(255, 16) = "ff/1"

as_dec

as_dec(n)                                     #=> Scalar
as_dec(n, digits)                             #=> Scalar

Returns n as a decimal expansion string, with an optional number of digits. When the second argument is undefined, it uses the default precision.

The value of n can also be a complex number.

Example:

as_dec(1/2)        = "0.5"
as_dec(sqrt(2), 3) = "1.41"

* Dissections

numerator

numerator(x)                                  #=> Int | NaN

Returns the numerator of x as a signed Math::AnyNum object. When x is not a rational number, it tries to convert it to a rational. Returns NaN when this conversion is not possible.

Example:

numerator("-42")  = -42
numerator("-3/4") = -3

denominator

denominator(x)                                #=> Int | NaN

Returns the denominator of x as an unsigned Math::AnyNum object. When x is not a rational number, it tries to convert it to a rational. Returns NaN when this conversion is not possible.

Example:

denominator("-42")  = 1
denominator("-3/4") = 4

nude

nude(x)                                       #=> (Int | NaN, Int | NaN)

Returns the numerator and the denominator of x.

Example:

nude("42")   = (42, 1)
nude("-3/4") = (-3, 4)

real

real(x)                                       #=> Any

Returns the real part of x.

Example:

real("42")   = 42
real("42i")  = 0
real("3-4i") = 3

imag

imag(x)                                       #=> Any

Returns the imaginary part of x, if any. Otherwise, returns zero.

Example:

imag("42")   =  0
imag("42i")  = 42
imag("3-4i") = -4

reals

reals(x)                                      #=> (Any, Any)

Return the real and the imaginary part of x as real numbers.

Example:

reals("42")   = (42, 0)
reals("42i")  = (0, 42)
reals("3-4i") = (3, -4)

digits

digits(n)                                     #=> (Scalar, Scalar, ...)
digits(n, b)                                  #=> (Scalar | Int, Scalar | Int, ...)

Returns a list with the digits of n in a given base. When no base is specified, it defaults to base 10.

Only the absolute integer part of n is considered.

The value of b must be greater than 1. Returns an empty list otherwise.

Example:

digits(12345)      = (5, 4, 3, 2, 1)
digits(12345, 100) = (45, 23, 1)

* Comparisons

eq

x == y                                        #=> Bool

Equality check: returns a true value when x and y are equal.

ne

x != y                                        #=> Bool

Inequality check: returns a true value when x and y are not equal.

gt

x > y                                         #=> Bool

Returns a true value when x is greater than y.

ge

x >= y                                        #=> Bool

Returns a true value when x is equal or greater than y.

lt

x < y                                         #=> Bool

Returns a true value when x is less than y.

le

x <= y                                        #=> Bool

Returns a true value when x is equal or less than y.

cmp

x <=> y                                       #=> Scalar

Compares x to y and returns a negative value when x is less than y, 0 when x and y are equal, and a positive value when x is greater than y.

Complex numbers are compared as:

(real(x) <=> real(y)) ||
(imag(x) <=> imag(y))

Comparing anything to NaN (including NaN itself), returns undef.

acmp

acmp(x, y)

Absolute comparison of x and y.

Defined as:

acmp(x, y) = abs(x) <=> abs(y)

PERFORMANCE

The performance varies greatly, but, in most cases, Math::AnyNum is between 2x up to 10x faster than Math::BigFloat with the GMP backend, and about 100x faster than Math::BigFloat without the GMP backend (to be modest).

Math::AnyNum is fast because of the following facts:

  • minimal overhead in object creations and conversions.

  • minimal Perl code is executed per operation.

  • the GMP, MPFR and MPC libraries are extremely efficient.

To achieve the best performance, try to:

  • use the i* functions/methods wherever applicable.

  • use floating-point numbers when accuracy is not important.

  • pass Perl integers as arguments to methods, if you can.

MOTIVATION

This module came into existence as a response to Dana Jacobsen's request for a transparent interface to Math::GMPz and Math::MPFR, which he talked about at the YAPC NA, in 2015.

See his great presentation at: https://www.youtube.com/watch?v=Dhl4_Chvm_g.

The main aim of this module is to provide a fast and correct alternative to Math::BigInt, Maht::BigFloat and Math::BigRat, as well as to bigint, bignum and bigrat pragmas.

The original project was called Math::BigNum, but because of some design flaws, it was very difficult to add support for complex numbers, therefore that project was abandoned and much of its code ended up in this module.

AUTHOR

Daniel Șuteu, <trizen@protonmail.com>

BUGS

Please report any bugs or feature requests to https://github.com/trizen/Math-AnyNum/issues. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Math::AnyNum

You can also look for information at:

SEE ALSO

  • Fast math libraries

    Math::GMP - High speed arbitrary size integer math.

    Math::GMPz - perl interface to the GMP library's integer (mpz) functions.

    Math::GMPq - perl interface to the GMP library's rational (mpq) functions.

    Math::MPFR - perl interface to the MPFR (floating point) library.

    Math::MPC - perl interface to the MPC (multi precision complex) library.

  • Portable math libraries

    Math::BigInt - Arbitrary size integer/float math package.

    Math::BigFloat - Arbitrary size floating point math package.

    Math::BigRat - Arbitrary big rational numbers.

  • Math utilities

    Math::Prime::Util - Utilities related to prime numbers, including fast sieves and factoring.

LICENSE AND COPYRIGHT

Copyright 2017-2018 Daniel Șuteu.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.