Module:Rational: Difference between revisions
All the special cases in as_ket make no sense |
Document this mess, starting with the first function |
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local p = {} | local p = {} | ||
-- | -- enter a numerator n and denominator m | ||
-- returns a table of prime factors | |||
-- similar to a monzo, but the indices are prime numbers. | |||
function p.new(n, m) | function p.new(n, m) | ||
m = m or 1 | m = m or 1 | ||
| Line 14: | Line 16: | ||
end | end | ||
local sign = utils.signum(n) * utils.signum(m) | local sign = utils.signum(n) * utils.signum(m) | ||
-- ensure n and m are positive | |||
n = n * utils.signum(n) | n = n * utils.signum(n) | ||
m = m * utils.signum(m) | m = m * utils.signum(m) | ||
-- factorize n and m separately | |||
local n_factors = utils.prime_factorization_raw(n) | local n_factors = utils.prime_factorization_raw(n) | ||
local m_factors = utils.prime_factorization_raw(m) | local m_factors = utils.prime_factorization_raw(m) | ||
local factors = n_factors | local factors = n_factors | ||
factors.sign = sign | factors.sign = sign | ||
-- subtract the factors of m from the factors of n | |||
for factor, power in pairs(m_factors) do | for factor, power in pairs(m_factors) do | ||
factors[factor] = factors[factor] or 0 | factors[factor] = factors[factor] or 0 | ||
factors[factor] = factors[factor] - power | factors[factor] = factors[factor] - power | ||
if factors[factor] == 0 then | if factors[factor] == 0 then | ||
factors[factor] = nil | factors[factor] = nil -- clear the zeros | ||
end | end | ||
end | end | ||