Math Module

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--MATH FUNCTIONS--
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function math.root(a,b)
    return math.pow(a,(1/b))
end
function math.logx(a,b)
    return math.log10(a)/math.log10(b)
end
function math.digits(a,b)
    b = b or 10
    return math.floor(math.logx(a,b))
end
function math.summation(a,b)
    if a == 1 then return b*(b+1)/2 end
    local r = 0
    for i = a, b do
        r = r+i
    end
    return r
end
function math.factorial(x)
    if x == 1 or x == 0 then return 1 end
    local r = 1
    for i=2, x do
        r = r * i
    end
    return r
end
function math.powerset(s,n)
    n = n or 1
    if n>#s then
        return {{}}
    end
    local r = math.powerset(s,n+1)
    for i=1,#r do
        r[#r+1] = {s[n], table.unpack(r[i])}
    end
    return r
end

function math.normalizerad(r)
    if r>math.pi then
        r = -math.pi+r%math.pi
    elseif r<-math.pi then
        r = math.pi-(math.pi-r%math.pi)
    end
    return r
end