Mousetrap: velocity and bimodality
I have two questions, both of which are inspired by Freeman (2014) "Abrupt category shifts during real-time person perception": https://pdfs.semanticscholar.org/4116/e3240369ac70da21253f29e9b0f735636407.pdf
One, is it possible to produce velocity plots like the one shown in B and D below from Freeman (2014):
Given that the Y-axis is x-coordinate velocity, I'm interpreting this as meaning that the positive and negative values of velocity indicate velocity in the left or right direction. This looks like an extremely useful way to plot data. Is this possible in the mousetrap R package?
Two, the paper uses maximum deviation to help identify abrupt changes in trajectory. Specifically, he states that "trajectories exceeding an MD threshold of 0.9 were marked as reversals." Although it's never explicitly stated, I'm assuming this refers to the standardized z-scored values of MD which I can produce using the mt_standardize function in R. Does this assumption sound correct?
Thank you to anyone that can provide assistance.