## [04c1e0]: inst / lombnormcoeff.m  Maximize  Restore  History

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 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46``` ```## Copyright (c) 2012 Benjamin Lewis ## ## This program is free software; you can redistribute it and/or modify it under ## the terms of the GNU General Public License as published by the Free Software ## Foundation; either version 2 of the License, or (at your option) any later ## version. ## ## This program is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more ## details. ## ## You should have received a copy of the GNU General Public License along with ## this program; if not, see . ## -*- texinfo -*- ## @deftypefn {Function File} {c =} lombnormcoeff (time, mag, freq) ## ## Return the coefficient of the Lomb Normalised Periodogram at the ## specified @var{frequency} of the periodogram applied to the ## (@var{time}, @var{mag}) series. ## ## @end deftypefn function coeff = lombnormcoeff (T, X, omega) tau = atan2 (sum (sin (2 .* omega .*T)), sum (cos (2 .* omega .* T))) / 2; coeff = ((sum (X .* cos (omega .* T - tau)) .^ 2 / sum (cos (omega .* T - tau) .^ 2) + sum (X .* sin (omega .* T - tau)) .^ 2 / sum (sin (omega .* T - tau) .^ 2 )) / (2 * var(X))); endfunction %!shared t, x, o, maxfreq %! maxfreq = 4 / (2 * pi); %! t = linspace (0, 8); %! x = (2 .* sin (maxfreq .* t) + %! 3 .* sin ((3/4) * maxfreq .* t) - %! 0.5 .* sin((1/4) * maxfreq .* t) - %! 0.2 .* cos (maxfreq .* t) + %! cos ((1/4) * maxfreq .*t)); %! o = [maxfreq , (3/4 * maxfreq) , (1/4 * maxfreq)]; %!assert (lombnormcoeff (t,x,o(1)), 63.3294946603949, 5e-10); %!assert (lombnormcoeff (t,x,o(2)), 73.2601360674868, 5e-10); %!assert (lombnormcoeff (t,x,o(3)), 53.0799752083903, 5e-10); ```