[accel, vel, disp]=fnewmark(accel, dt, beta, gamma);

% --------------------------------------------------------------
%  Written by: WaiChing Sun [[e-mail]]
%     Purpose: generate the displacement history
%       Input: time and acceleration history as arrays 
%      Output: displacement and velocity as arrays 
% Last Update: 9/14/2006
%---------------------------------------------------------------

 function [accel, vel, disp]=fnewmark(accel, dt, beta, gamma);

dim = size(accel);
vel = zeros(dim);
disp = zeros(dim);

for i=1:1:(dim(1)-1)
    disp(i+1,1)= disp(i,1)+dt*vel(i,1)+0.5*(dt^2)*...
              ((1-2*beta)*accel(i,1)+2*beta*accel(i+1,1));
    vel(i+1,1) = vel(i,1)+ dt*((1-gamma)*accel(i,1)+gamma*accel(i+1,1));
end

save history.mat disp vel disp