Derivative of a Function Plot

[mohamedibr752]

Hi,

I am a beginner in LabView and I am having some trouble to plot the derivative of a function on XY Graph.

The problem is that the last point shoot down very much and I don't know how the derivative function work. Can anyone help ?

Thanks in advance

[johnsold]

The definition of the derivative given in the detailed help defines y[i] = (x[i+1] - x[i-1])/(2 * dt).  When i = N-1 (last element), what is the value of x[i+1]?  That data point does not exist, so the default value will be used.

If you want the ends of the plots to be meaningful, you need to use the Initial Condition and Final Condition inputs.  Read the Detailed Help for the Derivative VI for more information about how to use them.

Lynn

[mohamedibrahim752]

Thanks a lot John. Already solved the problem.