There is no documented 'omitnan' argument for rms in current Matlab versions, see: https://www.mathworks.com/help/signal/ref/rms.html (link). I get:
A=repmat([NaN 1 2 3],3,1
rms(A, 'omitnan')
>> [NaN, 1, 2, 3]
But I observe this:
rms(A')
[NaN, 1, 2, 3]
rms(A', 'omitnan')
[2.1602, 2.1602, 2.1602]
This happens, because the dim argument is forwarded to mean without a check inside rms.m:
y = sqrt(mean(x .* x), dim);
If you want the 'omitnan' and the specified dimension, simply use an expanded rms version:
function y = rms2(x, varargin)
if isreal(x)
y = sqrt(mean(x .* x, varargin{:}));
else
absx = abs(x);
y = sqrt(mean(absx .* absx, varargin{:}));
end
end
Add documentation, tests of inputs and number of inputs in addition, as well as the more efficient method to get the absolute value for imaginary input.
If you want to, send an enhancement request to MathWorks, to catch the 'omitnan' flag explicitly.
