How to differentiate distance in relation to time?

Hello,

I am new to matllab, i want to differentiate distance (vector L ) in relation to time (vector t) to get the velocity. Then differentiate velocity in relation to time and get acceleration. And then plot acceleration over time. I know, that the values are way to small and there is a problem somewhere.

How can i tell MATLAB to differentiate in relation to time vector?

L=linspace(0,0.007,720); %distance (m)
t=linspace(0,0.0185,720); %time (s)

v=gradient(L); %velocity (m/s)
a=gradient(v); %acceleration (m/s^2)

plot(t,a); %plot acceleration over time

Answer 1

[Jan]

Your observation "the values are way to small" is the right way to find the problem. Find out the factor by which the result is too small. You find a relation between this value and the differences between the elements of t, e.g. t(2)-t(1).

L = linspace(0,0.007,720); %distance (m)
t = linspace(0,0.0185,720); %time (s)
v = gradient(L, t); %velocity (m/s)
%               ^
a = gradient(v, t); %acceleration (m/s^2)
%               ^

If you do not specify the time in gradient it is assume to have a stepsize of 1.

[Matas Mendelis]

Thank you!!! As always with MATLAB, it is simple when you know what and how to type in :D