Im trying to plot the dynamic brownian motion variance for my movement dataset using:

plot(Timestamp(var), getMotionVariance(var), type='s')

I received this error:

error in evaluating the argument 'x' in selecting a method for function 'plot'

This error wasn't cropping up before but now it is. 

I have attached the file below. 

Also, I want to plot the variance against time. How may I do so?

My timestamp is in the format: 4/17/2015 12:00