tools.py 文件源码

def calculateDeltas(data, n = 10):
  """create the distnances travelled since the last n time steps"""

  dx = np.diff(data[:,0]);
  dy = np.diff(data[:,1]);

  dx0 = dx.copy();
  dy0 = dy.copy();

  delta = np.zeros((dx.shape[0], n));
  for i in range(n):
    delta[:,i] = np.sqrt(dx * dx + dy * dy);
    if i < n-1:
      dx0 = np.concatenate([[np.NaN], dx0[:-1]]);
      dy0 = np.concatenate([[np.NaN], dy0[:-1]]);
      dx += dx0;
      dy += dy0;

  return delta;