Module:Harmonics in edo

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Used in Template:Odd harmonics in edo.

---

local p = {}

local function edoprox(edo, odds, title, prec)
  local f = 1/edo
  local todd = {'! | Odd harmonic '}
  local tapprox = {'! | Approximation '}
  local tabs = {'! | Error ([[cent|¢]]) '}
  local tdeg = {'! | Steps'}
  local fmt_approx = string.format(' %%.%df', prec)
  local fmt_abs = string.format(' %%+.%df', prec)
  local fmt_rel = ' %+.0f'
  for _, p in pairs(odds) do
    s = math.log(p) / math.log(2)
    v = s*edo
    ev = math.floor(v + .5)
    table.insert(todd, ' ' .. p .. '/' .. 2^math.floor(s) )
    table.insert(tapprox, string.format(fmt_approx, 1200*(ev % edo)/edo) )
    table.insert(tabs, string.format(fmt_abs, 1200 * (ev - v ) / edo))
    table.insert(tdeg, ' ' .. ev % edo .. ' ')
  end
  local titleMarkup = ''
  if title then
	titleMarkup = '|-\n|+ ' .. title .. '\n'

  end
  return '{| class="wikitable center-all"\n' ..
	titleMarkup ..
	'|-\n' ..
	table.concat(todd, '\n!') .. '\n' ..
    '|-\n' ..
    table.concat(tapprox, '\n|') .. '\n' ..
    '|-\n' ..
    table.concat(tabs, '\n|') .. '\n' ..
    '|-\n' ..
  table.concat(tdeg, '\n|') .. '\n' ..
    '|}'
end

local odds = { 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43 }

function p.harmonics_in_edo (frame)
  local edo = frame.args[1] or frame.args['edo'] or 12 -- edo (default=12)
  local columns = frame.args['columns'] or 8 -- number of columns
  local start = frame.args['start'] or 1 -- start column, default: start with harmonic 3
  local title = frame.args['title'] or 'Approximation of odd harmonics in ' .. edo .. ' EDO'
  local prec = frame.args['prec'] or 1 -- for now only variable precision for abs error
  return edoprox( edo, {unpack(odds, start, start+columns-1)}, title, prec)
end

return p;