[NBThelp] Help with DFA using NBT

[David Fernandez-F. <dfe...@me...>]

Hello:

My name is David Fernandez-Fidalgo and I am a researcher at the National Intrepid Center of Excellence (NICoE) at Walter Reed Naval Hospital in Bethesda, MD. I have been trying to teach myself how to use NBT to perform DFA on MEG data and calculate the DFA exponent for various datasets. I have been using the information and examples on the wiki page (https://www.nbtwiki.net/doku.php?id=tutorial:detrended_fluctuation_analysis_dfa#computing_dfa_using_nbt) to learn how to remove artifacts from the signal and perform DFA. I keep running into an error every time I try to use the "nbt_filter_fir" function to filter a matrix of random numbers "Fs = 300; Signal = randn(20*60*Fs,1);" from the example provided in the wiki. The error I keep observing is:

"??? Error using ==> mtimes
Inner matrix dimensions must agree.

Error in ==> firls at 80
cos_ints = [omega; sin((1:N)' * omega)];

Error in ==> fir1 at 98
hh = firls(L-1,ff,aa);

Error in ==> nbt_filter_fir at 108
b = fir1(floor(fir_order*fs),[hp lp]/(fs/2));

Error in ==> test at 14
[Data_filtered] = nbt_filter_fir(Signal, highpass, lowpass, Fs, 2/8);"

Do you have any suggestions for how I can resolve this error and filter the dataset?

Thank You,
David FF