title: Finding 3d distances using an inbuilt function in python
body: <p>I have 6 lists storing x,y,z coordinates of two sets of positions (3 lists each). I want to calculate the distance between each point in both sets. I have written my own distance function but it is slow. One of my lists has about 1 million entries.
  I have tried cdist, but it produces a distance matrix and I do not understand what it means. Is there another inbuilt function that can do this?</p>