simonbyrne

simonbyrne

const HI = prevfloat(log10(prevfloat(Inf)))

function test(n)
    xx = 0.0
    zz = 0.0
    for i = 1:n
        x = reinterpret(Float64, rand(reinterpret(UInt64, 1e-18):reinterpret(UInt64, HI)))
        if rand(Bool)
            x = -x
        end

simonbyrne

# sudo apt install llvm-3.9-dev libopenblas-dev libfftw3-dev libgmp3-dev libmpfr-dev libarpack2-dev libopenspecfun-dev libssh2-1-dev libcurl4-openssl-dev

USE_SYSTEM_LLVM:=1
LLVM_CONFIG:=llvm-config-3.9

USE_SYSTEM_BLAS:=1
LIBBLAS:=-lopenblas
LIBBLASNAME:=libopenblas
USE_SYSTEM_LAPACK:=1
USE_SYSTEM_LIBM:=1

simonbyrne

import Base: TwicePrecision, significand_bits, significand_mask, exponent_mask, exponent_bias

# Bits of 1/2π
#   1/2π == sum(x / 0x1p64^i for i,x = enumerate(INV2PI))
# Can be obtained by:
#
#    setprecision(BigFloat, 4096)
#    I = 0.5/big(pi)
#    for i = 1:19
#        I *= 0x1p64

simonbyrne

@eval macro $(Symbol("ccall"))(expr)
    expr.head == :(::) && expr.args[1].head == :call || error("Invalid use of @ccall")
    rettype = expr.args[2]
    fname = expr.args[1].args[1]
    cargs = expr.args[1].args[2:end]

    arglist = []
    typlist = []
    tupexpr = :(())
    ccexpr = :(ccall($(esc(fname)), $(esc(rettype)), $(esc(tupexpr))))

simonbyrne

# read from Raspbery Pi Sense HAT joystick

function _stick_input_dev()
    try
        for devname in readdir("/sys/class/input")
            sysfname = joinpath("/sys/class/input",devname,"device","name")
            if startswith(devname, "event") && isfile(sysfname)
                if startswith(readstring(sysfname),"Raspberry Pi Sense HAT Joystick")
                    return joinpath("/dev/input",devname)
                end

simonbyrne

using SenseHat
import SenseHat: RGB565

function spooky(decay, arriv, refresh)
    x = rand()
    while true
        x *= exp(-decay*refresh)
        if rand() < arriv*refresh
            x += (1-x)*rand()
        end

simonbyrne

function lerp0(j, d, a, b)
    linspace(a,b,d+1)[j+1]
end
function lerp1(j, d, a, b)
    s = (d-j)/d; t = j/d
    a*s + b*t
end
function lerp2(j, d, a, b)
    (a*(d-j) + b*j)/d
end

simonbyrne

using Unums

import Base: promote_rule

promote_rule{U<:Unums.Ubound}(::Type{U},::Type{Float64}) = U

# Constants
const solar_mass = 4 * pi * pi
const days_per_year = 365.24

simonbyrne

@inline function rotr(x,y)
    s = sizeof(x) << 3
    (x >> (y % s)) | (x << (-y % s))
end


function foo(state, n)   
    s = sizeof(state) << 3
    t = trailing_zeros(s)-1 # log2(s)-1
    p1 = (s>>1 + t)>>1