%s=importdata('disp_data.dat'); %save the contents in displacement_data.dat as s
clear all;close all;clc
load disp_data

time=trace_x(1,:)'; %first column in data is saved as time
d_data=trace_y(2,:)';%second column in data is saved as experimental displacements
%maxval=max(d_data');
%  vval = max(d_data)
%  index=find(d_data==vval)
%  time=time(index:end,1)-time(index,1); %first column in data is saved as time
%  d_data=d_data(index:end);
vel=diff(d_data)./diff(time(1:2));
accel=diff(diff(d_data))./diff(time(1:2)).^2;
X=[vel(2:end) accel];
subplot(3,1,1)
plot(d_data(3:100));
subplot(3,1,2)
plot(vel(2:99));
subplot(3,1,3);
plot(accel(1:98));