No BSD License  

Highlights from
Advanced Mathematics and Mechanics Applications Using MATLAB, 3rd Edition

image thumbnail

Advanced Mathematics and Mechanics Applications Using MATLAB, 3rd Edition

by

Howard Wilson

 

14 Oct 2002 (Updated )

Companion Software (amamhlib)

z=vibfun(x)
function z=vibfun(x)
%
% z=vibfun(x)
% ~~~~~~~~~~~
%
% This function evalautes the least square  
% error for a set of vibration data. The data
% vectors timdat and ydat are passed as global
% variables. The function to be fitted is:
%
%   y=a*exp(b*t)*cos(c*t+d)
%
% x - a vector defining a,b,c and d
%
% z - the square of the norm for the vector 
%     of error deviations between the data and 
%     results the equation gives for current 
%     parameter values
%
% User m functions called:  none
%----------------------------------------------

global timdat ydat
a=x(1); b=-abs(x(2)); c=abs(x(3)); d=x(4);
z=a*exp(b*timdat).*cos(c*timdat+d); 
z=norm(z-ydat)^2;

Contact us