Why do I get the error "Too many input arguments"

my_recorder = audiorecorder;
recordblocking(my_recorder,2)
x= getaudiodata(my_recorder);
LPF0=LPF;
x0=filter(LPF0,Num_LPF,1,x);

Code written above is my matlab code.

But when I activated this, "Too many input arguments" message is shown on the command window.

How can I solve this problem?

function Hd = LPF

% MATLAB Code
% Generated by MATLAB(R) 9.2 and the Signal Processing Toolbox 7.4.
% Generated on: 08-Dec-2017 11:47:53

% Equiripple Lowpass filter designed using the FIRPM function.

% All frequency values are in Hz.
Fs = 48000;  % Sampling Frequency

Fpass = 200;             % Passband Frequency
Fstop = 300;             % Stopband Frequency
Dpass = 0.057501127785;  % Passband Ripple
Dstop = 0.0001;          % Stopband Attenuation
dens  = 20;              % Density Factor

% Calculate the order from the parameters using FIRPMORD.
[N, Fo, Ao, W] = firpmord([Fpass, Fstop]/(Fs/2), [1 0], [Dpass, Dstop]);

% Calculate the coefficients using the FIRPM function.
b  = firpm(N, Fo, Ao, W, {dens});
Hd = dfilt.dffir(b);

% [EOF]

and this is my LPF.

[KSSV]

Which line shows the error? How did you run the code? It doesn't show any error in my pc.

[minsoo kim]

error occurs at x0=filter(LPF0,Num_LPF,1,x);

And I entered "crtl+enter"

Answer 1

[Honglei Chen]

It should just be

x0=filter(LPF0,x);

the coefficients is already in LPF0.

HTH

[Abhinaba Dey]

Error using filter2 Too many input arguments.

Error in find_sift (line 48) I_X = filter2(G_X, I, 'same'); % vertical edges

I get the same error. How can I solve it??