DIPY create_qtable function

Hi everyone,

I am new to processing diffusion data and I am trying to create a qtable from the b-table used in our DSI data to visualize the points in q-space we are sampling from. I have done so using the create_qtable function in dipy, but I don’t fully understand the process of the function. See below for the last three lines:

bv = np.sqrt(bv / bmin)
qtable = np.vstack((bv, bv, bv)).T * gtab.bvecs
return np.floor(qtable + .5)

  1. Why take the square root of bv/bmin?
  2. Why do we return the floor value?

Thank you,