Numbers

    Abstract supertype for all number types.

    Core.Real — Type.

    1. Real <: Number

    Abstract supertype for all real numbers.

    Core.AbstractFloat — Type.

    1. AbstractFloat <: Real

    Abstract supertype for all floating point numbers.

    Core.Integer — Type.

    1. Integer <: Real

    Abstract supertype for all integers.

    Core.Signed — Type.

    1. Signed <: Integer

    Abstract supertype for all signed integers.

    Core.Unsigned — Type.

    1. Unsigned <: Integer

    Abstract supertype for all unsigned integers.

    Base.AbstractIrrational — Type.

    1. AbstractIrrational <: Real

    Number type representing an exact irrational value.

    Core.Float16 — Type.

    1. Float16 <: AbstractFloat

    16-bit floating point number type.

    Core.Float32 — Type.

    1. Float32 <: AbstractFloat

    32-bit floating point number type.

    Core.Float64 — Type.

    1. Float64 <: AbstractFloat

    64-bit floating point number type.

    Base.MPFR.BigFloat — Type.

    1. BigFloat <: AbstractFloat

    Arbitrary precision floating point number type.

    Core.Bool — Type.

    1. Bool <: Integer

    Boolean type, containing the values true and false.

    Core.Int8 — Type.

    1. Int8 <: Signed

    8-bit signed integer type.

    Core.UInt8 — Type.

    1. UInt8 <: Unsigned

    8-bit unsigned integer type.

    Core.Int16 — Type.

    1. Int16 <: Signed

    16-bit signed integer type.

    Core.UInt16 — Type.

    1. UInt16 <: Unsigned

    16-bit unsigned integer type.

    Core.Int32 — Type.

    1. Int32 <: Signed

    32-bit signed integer type.

    Core.UInt32 — Type.

    1. UInt32 <: Unsigned

    32-bit unsigned integer type.

    Core.Int64 — Type.

    1. Int64 <: Signed

    64-bit signed integer type.

    Core.UInt64 — Type.

    1. UInt64 <: Unsigned

    64-bit unsigned integer type.

    Core.Int128 — Type.

    1. Int128 <: Signed

    128-bit signed integer type.

    Core.UInt128 — Type.

    1. UInt128 <: Unsigned

    128-bit unsigned integer type.

    Base.GMP.BigInt — Type.

    1. BigInt <: Signed

    Arbitrary precision integer type.

    Base.Complex — Type.

    1. Complex{T<:Real} <: Number

    Complex number type with real and imaginary part of type T.

    ComplexF16, ComplexF32 and ComplexF64 are aliases for Complex{Float16}, Complex{Float32} and Complex{Float64} respectively.

    Base.Rational — Type.

    1. Rational{T<:Integer} <: Real

    Rational number type, with numerator and denominator of type T. Rationals are checked for overflow.

    Base.Irrational — Type.

    1. Irrational{sym} <: AbstractIrrational

    Number type representing an exact irrational value denoted by the symbol sym.

    Base.digits — Function.

    1. digits([T<:Integer], n::Integer; base::T = 10, pad::Integer = 1)

    Return an array with element type T (default Int) of the digits of n in the given base, optionally padded with zeros to a specified size. More significant digits are at higher indices, such that n == sum([digits[k]*base^(k-1) for k=1:length(digits)]).

    Examples

    1. julia> digits(10, base = 10)
    2. 2-element Array{Int64,1}:
    3.  0
    4.  1
    6. julia> digits(10, base = 2)
    7. 4-element Array{Int64,1}:
    8.  0
    9.  1
    10.  0
    11.  1
    13. julia> digits(10, base = 2, pad = 6)
    14. 6-element Array{Int64,1}:
    15.  0
    16.  1
    17.  0
    18.  1
    19.  0
    20.  0

    Base.digits! — Function.

    1. digits!(array, n::Integer; base::Integer = 10)

    Fills an array of the digits of n in the given base. More significant digits are at higher indices. If the array length is insufficient, the least significant digits are filled up to the array length. If the array length is excessive, the excess portion is filled with zeros.

    Examples

    1. julia> digits!([2,2,2,2], 10, base = 2)
    2. 4-element Array{Int64,1}:
    3.  0
    4.  1
    5.  0
    6.  1
    8. julia> digits!([2,2,2,2,2,2], 10, base = 2)
    9. 6-element Array{Int64,1}:
    10.  0
    11.  1
    12.  0
    13.  1
    14.  0
    15.  0

    Base.bitstring — Function.

    1. bitstring(n)

    A string giving the literal bit representation of a number.

    Examples

    1. julia> bitstring(4)
    2. "0000000000000000000000000000000000000000000000000000000000000100"
    4. julia> bitstring(2.2)
    5. "0100000000000001100110011001100110011001100110011001100110011010"

    Base.parse — Function.

    1. parse(type, str; base)

    Parse a string as a number. For Integer types, a base can be specified (the default is 10). For floating-point types, the string is parsed as a decimal floating-point number. Complex types are parsed from decimal strings of the form "R±Iim" as a Complex(R,I) of the requested type; "i" or "j" can also be used instead of "im", and "R" or "Iim" are also permitted. If the string does not contain a valid number, an error is raised.

    Julia 1.1

    parse(Bool, str) requires at least Julia 1.1.

    Examples

    1. julia> parse(Int, "1234")
    2. 1234
    4. julia> parse(Int, "1234", base = 5)
    5. 194
    7. julia> parse(Int, "afc", base = 16)
    8. 2812
    10. julia> parse(Float64, "1.2e-3")
    11. 0.0012
    13. julia> parse(Complex{Float64}, "3.2e-1 + 4.5im")
    14. 0.32 + 4.5im

    Base.tryparse — Function.

    1. tryparse(type, str; base)

    Like , but returns either a value of the requested type, or nothing if the string does not contain a valid number.

    Base.big — Function.

    1. big(x)

    Convert a number to a maximum precision representation (typically or BigFloat). See BigFloat for information about some pitfalls with floating-point numbers.

    Base.signed — Function.

    1. signed(x)

    Convert a number to a signed integer. If the argument is unsigned, it is reinterpreted as signed without checking for overflow.

    Base.unsigned — Function.

    1. unsigned(x) -> Unsigned

    Convert a number to an unsigned integer. If the argument is signed, it is reinterpreted as unsigned without checking for negative values.

    Examples

    1. julia> unsigned(-2)
    2. 0xfffffffffffffffe
    4. julia> unsigned(2)
    5. 0x0000000000000002
    7. julia> signed(unsigned(-2))
    8. -2

    Base.float — Method.

    1. float(x)

    Convert a number or array to a floating point data type.

    Base.Math.significand — Function.

    1. significand(x)

    Examples

    1. julia> significand(15.2)/15.2
    2. 0.125
    4. julia> significand(15.2)*8
    5. 15.2

    Base.Math.exponent — Function.

    1. exponent(x) -> Int

    Get the exponent of a normalized floating-point number.

    Base.complex — Method.

    1. complex(r, [i])

    Convert real numbers or arrays to complex. i defaults to zero.

    Examples

    Base.bswap — Function.

    1. bswap(n)

    Reverse the byte order of n.

    Examples

    1. julia> a = bswap(0x10203040)
    2. 0x40302010
    4. 0x10203040
    6. julia> string(1, base = 2)
    7. "1"
    9. julia> string(bswap(1), base = 2)
    10. "100000000000000000000000000000000000000000000000000000000"

    Base.hex2bytes — Function.

    1. hex2bytes(s::Union{AbstractString,AbstractVector{UInt8}})

    Given a string or array s of ASCII codes for a sequence of hexadecimal digits, returns a Vector{UInt8} of bytes corresponding to the binary representation: each successive pair of hexadecimal digits in s gives the value of one byte in the return vector.

    The length of s must be even, and the returned array has half of the length of s. See also for an in-place version, and bytes2hex for the inverse.

    Examples

    1. julia> s = string(12345, base = 16)
    2. "3039"
    4. julia> hex2bytes(s)
    5. 2-element Array{UInt8,1}:
    6.  0x30
    7.  0x39
    9. julia> a = b"01abEF"
    10. 6-element Base.CodeUnits{UInt8,String}:
    11.  0x30
    12.  0x31
    13.  0x61
    14.  0x62
    15.  0x45
    16.  0x46
    19. 3-element Array{UInt8,1}:
    20.  0x01
    21.  0xab
    22.  0xef

    Base.hex2bytes! — Function.

    1. hex2bytes!(d::AbstractVector{UInt8}, s::Union{String,AbstractVector{UInt8}})

    Convert an array s of bytes representing a hexadecimal string to its binary representation, similar to except that the output is written in-place in d. The length of s must be exactly twice the length of d.

    source

    — Function.

    1. bytes2hex(a::AbstractArray{UInt8}) -> String
    2. bytes2hex(io::IO, a::AbstractArray{UInt8})

    Convert an array a of bytes to its hexadecimal string representation, either returning a String via bytes2hex(a) or writing the string to an io stream via bytes2hex(io, a). The hexadecimal characters are all lowercase.

    Examples

    1. julia> a = string(12345, base = 16)
    2. "3039"
    4. julia> b = hex2bytes(a)
    5. 2-element Array{UInt8,1}:
    6.  0x30
    7.  0x39
    9. julia> bytes2hex(b)
    10. "3039"

    source

    — Function.

    1. one(x)
    2. one(T::type)

    Return a multiplicative identity for x: a value such that one(x)*x == x*one(x) == x. Alternatively one(T) can take a type T, in which case one returns a multiplicative identity for any x of type T.

    If possible, one(x) returns a value of the same type as x, and one(T) returns a value of type T. However, this may not be the case for types representing dimensionful quantities (e.g. time in days), since the multiplicative identity must be dimensionless. In that case, one(x) should return an identity value of the same precision (and shape, for matrices) as x.

    If you want a quantity that is of the same type as x, or of type T, even if x is dimensionful, use oneunit instead.

    Examples

    1. julia> one(3.7)
    2. 1.0
    4. julia> one(Int)
    5. 1
    7. julia> import Dates; one(Dates.Day(1))
    8. 1

    Base.oneunit — Function.

    1. oneunit(x::T)
    2. oneunit(T::Type)

    Returns T(one(x)), where T is either the type of the argument or (if a type is passed) the argument. This differs from for dimensionful quantities: one is dimensionless (a multiplicative identity) while oneunit is dimensionful (of the same type as x, or of type T).

    Examples

    1. julia> oneunit(3.7)
    2. 1.0
    4. julia> import Dates; oneunit(Dates.Day)
    5. 1 day

    source

    — Function.

    1. zero(x)

    Get the additive identity element for the type of x (x can also specify the type itself).

    Examples

    1. julia> zero(1)
    2. 0
    4. julia> zero(big"2.0")
    5. 0.0
    7. julia> zero(rand(2,2))
    8. 2×2 Array{Float64,2}:
    9.  0.0  0.0
    10.  0.0  0.0

    source

    — Constant.

    1. im

    The imaginary unit.

    Examples

    1. julia> im * im
    2. -1 + 0im

    source

    — Constant.

    1. π
    2. pi

    The constant pi.

    Examples

    1. julia> pi
    2. π = 3.1415926535897...

    source

    — Constant.

    1. ℯ
    2. e

    The constant ℯ.

    Examples

    1. julia> ℯ
    2. ℯ = 2.7182818284590...

    source

    — Constant.

    1. catalan

    Catalan’s constant.

    Examples

    1. julia> Base.MathConstants.catalan
    2. catalan = 0.9159655941772...

    source

    — Constant.

    1. γ
    2. eulergamma

    Euler’s constant.

    Examples

    1. julia> Base.MathConstants.eulergamma
    2. γ = 0.5772156649015...

    source

    — Constant.

    1. φ
    2. golden

    The golden ratio.

    Examples

    1. julia> Base.MathConstants.golden
    2. φ = 1.6180339887498...

    source

    — Constant.

    1. Inf, Inf64

    Positive infinity of type Float64.

    Base.Inf32 — Constant.

    1. Inf32

    Positive infinity of type .

    source

    — Constant.

    1. Inf16

    Positive infinity of type Float16.

    Base.NaN — Constant.

    1. NaN, NaN64

    A not-a-number value of type .

    source

    — Constant.

    1. NaN32

    A not-a-number value of type Float32.

    Base.NaN16 — Constant.

    1. NaN16

    A not-a-number value of type .

    source

    — Function.

    1. issubnormal(f) -> Bool

    Test whether a floating point number is subnormal.

    source

    — Function.

    1. isfinite(f) -> Bool

    Test whether a number is finite.

    Examples

    1. julia> isfinite(5)
    2. true
    4. julia> isfinite(NaN32)
    5. false

    source

    — Function.

    1. isinf(f) -> Bool

    Test whether a number is infinite.

    source

    — Function.

    1. isnan(f) -> Bool

    Test whether a floating point number is not a number (NaN).

    source

    — Function.

    1. iszero(x)

    Return true if x == zero(x); if x is an array, this checks whether all of the elements of x are zero.

    Examples

    1. julia> iszero(0.0)
    2. true
    4. julia> iszero([1, 9, 0])
    5. false
    7. true

    source

    — Function.

    1. isone(x)

    Return true if x == one(x); if x is an array, this checks whether x is an identity matrix.

    Examples

    1. julia> isone(1.0)
    2. true
    4. julia> isone([1 0; 0 2])
    5. false
    7. julia> isone([1 0; 0 true])
    8. true

    source

    — Function.

    1. nextfloat(x::AbstractFloat, n::Integer)

    The result of n iterative applications of nextfloat to x if n >= 0, or -n applications of prevfloat if n < 0.

    source

    1. nextfloat(x::AbstractFloat)

    Return the smallest floating point number y of the same type as x such x < y. If no such y exists (e.g. if x is Inf or NaN), then return x.

    Base.prevfloat — Function.

    1. prevfloat(x::AbstractFloat, n::Integer)

    The result of n iterative applications of prevfloat to x if n >= 0, or -n applications of nextfloat if n < 0.

    Return the largest floating point number y of the same type as x such y < x. If no such y exists (e.g. if x is -Inf or NaN), then return x.

    source

    — Function.

    1. isinteger(x) -> Bool

    Examples

    1. julia> isinteger(4.0)
    2. true

    source

    — Function.

    1. isreal(x) -> Bool

    Test whether x or all its elements are numerically equal to some real number including infinities and NaNs. is true if isequal(x, real(x)) is true.

    Examples

    1. julia> isreal(5.)
    2. true
    4. julia> isreal(Inf + 0im)
    5. true
    7. julia> isreal([4.; complex(0,1)])
    8. false

    source

    — Method.

    1. Float32(x [, mode::RoundingMode])

    Create a Float32 from x. If x is not exactly representable then mode determines how x is rounded.

    Examples

    1. julia> Float32(1/3, RoundDown)
    2. 0.3333333f0
    4. julia> Float32(1/3, RoundUp)
    5. 0.33333334f0

    See RoundingMode for available rounding modes.

    Core.Float64 — Method.

    1. Float64(x [, mode::RoundingMode])

    Create a Float64 from x. If x is not exactly representable then mode determines how x is rounded.

    Examples

    1. julia> Float64(pi, RoundDown)
    2. 3.141592653589793
    4. julia> Float64(pi, RoundUp)
    5. 3.1415926535897936

    See for available rounding modes.

    source

    — Function.

    1. rounding(T)

    Get the current floating point rounding mode for type T, controlling the rounding of basic arithmetic functions (+, , *, and sqrt) and type conversion.

    See for available modes.

    source

    — Method.

    1. setrounding(T, mode)

    Set the rounding mode of floating point type T, controlling the rounding of basic arithmetic functions (+, , *, and sqrt) and type conversion. Other numerical functions may give incorrect or invalid values when using rounding modes other than the default .

    Note that this is currently only supported for T == BigFloat.

    Warning

    This function is not thread-safe. It will affect code running on all threads, but its behavior is undefined if called concurrently with computations that use the setting.

    source

    — Method.

    1. setrounding(f::Function, T, mode)

    Change the rounding mode of floating point type T for the duration of f. It is logically equivalent to:

    1. old = rounding(T)
    2. setrounding(T, mode)
    3. f()
    4. setrounding(T, old)

    See RoundingMode for available rounding modes.

    Base.Rounding.get_zero_subnormals — Function.

    1. get_zero_subnormals() -> Bool

    Return false if operations on subnormal floating-point values (“denormals”) obey rules for IEEE arithmetic, and true if they might be converted to zeros.

    Warning

    This function only affects the current thread.

    Base.Rounding.set_zero_subnormals — Function.

    1. set_zero_subnormals(yes::Bool) -> Bool

    If yes is false, subsequent floating-point operations follow rules for IEEE arithmetic on subnormal values (“denormals”). Otherwise, floating-point operations are permitted (but not required) to convert subnormal inputs or outputs to zero. Returns true unless yes==true but the hardware does not support zeroing of subnormal numbers.

    set_zero_subnormals(true) can speed up some computations on some hardware. However, it can break identities such as (x-y==0) == (x==y).

    Warning

    This function only affects the current thread.

    Base.count_ones — Function.

    1. count_ones(x::Integer) -> Integer

    Number of ones in the binary representation of x.

    Examples

    1. julia> count_ones(7)
    2. 3

    Base.count_zeros — Function.

    1. count_zeros(x::Integer) -> Integer

    Number of zeros in the binary representation of x.

    Examples

    1. julia> count_zeros(Int32(2 ^ 16 - 1))
    2. 16

    Base.leading_zeros — Function.

    1. leading_zeros(x::Integer) -> Integer

    Number of zeros leading the binary representation of x.

    Examples

    1. julia> leading_zeros(Int32(1))
    2. 31

    Base.leading_ones — Function.

    1. leading_ones(x::Integer) -> Integer

    Number of ones leading the binary representation of x.

    Examples

    1. julia> leading_ones(UInt32(2 ^ 32 - 2))
    2. 31

    Base.trailing_zeros — Function.

    1. trailing_zeros(x::Integer) -> Integer

    Number of zeros trailing the binary representation of x.

    Examples

    1. julia> trailing_zeros(2)
    2. 1

    Base.trailing_ones — Function.

    1. trailing_ones(x::Integer) -> Integer

    Number of ones trailing the binary representation of x.

    Examples

    1. julia> trailing_ones(3)
    2. 2

    Base.isodd — Function.

    1. isodd(x::Integer) -> Bool

    Return true if x is odd (that is, not divisible by 2), and false otherwise.

    Examples

    1. julia> isodd(9)
    2. true
    4. julia> isodd(10)
    5. false

    Base.iseven — Function.

    1. iseven(x::Integer) -> Bool

    Return true is x is even (that is, divisible by 2), and false otherwise.

    Examples

    1. julia> iseven(9)
    2. false
    4. julia> iseven(10)
    5. true

    Core.@int128_str — Macro.

    1. @int128_str str
    2. @int128_str(str)

    @int128_str parses a string into a Int128 Throws an ArgumentError if the string is not a valid integer

    Core.@uint128_str — Macro.

    1. @uint128_str str
    2. @uint128_str(str)

    @uint128_str parses a string into a UInt128 Throws an ArgumentError if the string is not a valid integer

    The BigFloat and types implements arbitrary-precision floating point and integer arithmetic, respectively. For BigFloat the is used, and for BigInt the is used.

    Base.MPFR.BigFloat — Method.

    1. BigFloat(x::Union{Real, AbstractString} [, rounding::RoundingMode=rounding(BigFloat)]; [precision::Integer=precision(BigFloat)])

    Create an arbitrary precision floating point number from x, with precision precision. The rounding argument specifies the direction in which the result should be rounded if the conversion cannot be done exactly. If not provided, these are set by the current global values.

    BigFloat(x::Real) is the same as convert(BigFloat,x), except if x itself is already BigFloat, in which case it will return a value with the precision set to the current global precision; convert will always return x.

    BigFloat(x::AbstractString) is identical to . This is provided for convenience since decimal literals are converted to Float64 when parsed, so BigFloat(2.1) may not yield what you expect.

    Julia 1.1

    precision as a keyword argument requires at least Julia 1.1. In Julia 1.0 precision is the second positional argument (BigFloat(x, precision)).

    Examples

    1. julia> BigFloat(2.1) # 2.1 here is a Float64
    2. 2.100000000000000088817841970012523233890533447265625
    4. julia> BigFloat("2.1") # the closest BigFloat to 2.1
    5. 2.099999999999999999999999999999999999999999999999999999999999999999999999999986
    7. julia> BigFloat("2.1", RoundUp)
    8. 2.100000000000000000000000000000000000000000000000000000000000000000000000000021
    10. julia> BigFloat("2.1", RoundUp, precision=128)
    11. 2.100000000000000000000000000000000000007

    See also

    Base.precision — Function.

    1. precision(num::AbstractFloat)

    Get the precision of a floating point number, as defined by the effective number of bits in the mantissa.

    Base.precision — Method.

    1. precision(BigFloat)

    Get the precision (in bits) currently used for arithmetic.

    source

    — Function.

    1. setprecision([T=BigFloat,] precision::Int)

    Set the precision (in bits) to be used for T arithmetic.

    Warning

    This function is not thread-safe. It will affect code running on all threads, but its behavior is undefined if called concurrently with computations that use the setting.

    source

    1. setprecision(f::Function, [T=BigFloat,] precision::Integer)

    Change the T arithmetic precision (in bits) for the duration of f. It is logically equivalent to:

    1. old = precision(BigFloat)
    2. setprecision(BigFloat, precision)
    3. f()
    4. setprecision(BigFloat, old)

    Often used as setprecision(T, precision) do ... end

    Note: nextfloat(), prevfloat() do not use the precision mentioned by setprecision

    Base.GMP.BigInt — Method.

    1. BigInt(x)

    Create an arbitrary precision integer. x may be an Int (or anything that can be converted to an Int). The usual mathematical operators are defined for this type, and results are promoted to a .

    Instances can be constructed from strings via parse, or using the big string literal.

    Examples

    1. julia> parse(BigInt, "42")
    2. 42
    4. julia> big"313"
    5. 313

    Core.@big_str — Macro.

    1. @big_str str
    2. @big_str(str)

    Parse a string into a or BigFloat, and throw an ArgumentError if the string is not a valid number. For integers _ is allowed in the string as a separator.

    Examples

    1. julia> big"123_456"
    2. 123456
    4. julia> big"7891.5"