Not enough input arguments - something simple i'm sure

I'm getting the above error when trying to execute this code,

close all
clear all
m = 0.05;   %mass of cone and coil together (Kg)
k = 1000;   %stiffness (N/m)
R = 1;      %damping (Ns/m
F = 1;      %Force amplitude (N)
t = 0.01;   %Time of the snapshot
f = linspace(0,99,10000); %frequency (Hz)
Zm = abs(R + 1i.*(m*2*pi.*f-k./(2*pi.*f))); %mechanical impedance
Xm = m*2*pi.*f - k./2*pi.*f;    %mechanical reactance
th = atan*(Xm/R);   %phase angle
us = F.*cos(2*pi*f*t-th);   %velocity response

What are arguments anyway? (apart from the obvious)

[Matt Fig]

I'm getting the above error when trying to execute this code,

close all clear all m = 0.05; %mass of cone and coil together (Kg) k = 1000; %stiffness (N/m) R = 1; %damping (Ns/m F = 1; %Force amplitude (N) t = 0.01; %Time of the snapshot f = linspace(0,99,10000); %frequency (Hz) Zm = abs(R + 1i.*(m*2*pi.*f-k./(2*pi.*f))); %mechanical impedance Xm = m*2*pi.*f - k./2*pi.*f; %mechanical reactance th = atan*(Xm/R); %phase angle us = F.*cos(2*pi*f*t-th); %velocity response

What are arguments anyway? (apart from the obvious)

Answer 1

[Walter Roberson]

atan*(Xm/R) should be atan(Xm/R)

The expression as written is the same as

atan() * (Xm/R)

which is calling atan with no arguments (parameters)

[Tom]

Brilliant thanks Walter

Tom