示例#1
0
def ball_move(inAtom,atomIndex):
  """takes an atom defined by atomIndex inside of inAtom
  and moves it somewhere within the core of the atom randomly.
  Atoms will almost always end up inside the sphere which
  contains 85% of the atoms, centered at the center of mass."""
  #  we're going to be changing the position of atomIndex inside inAtom
  #  we'll take atom of index atomIndex and throw it somewhere inside the core
  #  make sure that you remove any crazy outliers before you do this
  #  or else it'll just make a bunch more outliers, which is a poor idea
  try:
    #get all the distances from the center of mass
    inCOM = inAtom.get_center_of_mass()
    inDistances = distanceCenter(inAtom)
    #figure out the distance from the core to the 85th percentile
    #we'll consider "the core" to be the sphere which contains 85% of the atoms
    eightyFifthRadius = stats.scoreatpercentile(inDistances,85)
    #pick a new distance from center somewhere inside that 85th percentile limit
    randomNewRadius = random.normal(eightyFifthRadius/2, eightyFifthRadius/3 )
    xFromCenter = random.uniform(0,randomNewRadius)
    randomNewRadius = ((randomNewRadius**2) - (xFromCenter**2))**0.5
    yFromCenter = random.uniform(0,randomNewRadius)
    zFromCenter = ((randomNewRadius**2) - (yFromCenter**2))**0.5
    newXPosition = inCOM[0] + plusOrMinus()*xFromCenter
    newYPosition = inCOM[1] + plusOrMinus()*yFromCenter
    newZPosition = inCOM[2] + plusOrMinus()*zFromCenter
    positionArray = inAtom.get_positions()
    positionArray[atomIndex] = (newXPosition,newYPosition,newZPosition)
    inAtom.set_positions(positionArray)
    return inAtom
  except IndexError:
    print "The index of the atom you wanted to move is too high or too low."
    print "Please check your function call of ball_move(a,b)"
    print "-Jeff"
示例#2
0
def shell_move(inAtom,atomIndex):
  #  we're going to be changing the position of atomIndex inside inAtom
  #  make sure that you remove any crazy outliers before you do this
  #  or else it'll just make a bunch more outliers, which is a poor idea
  #  make sure atomIndex comes from range(len(inAtom.get_positions())) so we don't get out of bounds
  try:
    inCOM = inAtom.get_center_of_mass()
    inDistances = distanceCenter(inAtom)
    ninetyNinthRadius = stats.scoreatpercentile(inDistances,99)
    ninetyFifthRadius = stats.scoreatpercentile(inDistances,95)
    outerFourRadius = ninetyNinthRadius - ninetyFifthRadius

    randomNewRadius = random.normal( (ninetyNinthRadius+ninetyFifthRadius)/2 , (ninetyNinthRadius - ninetyFifthRadius)/2 )
    xFromCenter = random.uniform(0,randomNewRadius)
    randomNewRadius = ((randomNewRadius**2) - (xFromCenter**2))**0.5
    yFromCenter = random.uniform(0,randomNewRadius)
    zFromCenter = ((randomNewRadius**2) - (yFromCenter**2))**0.5

    newXPosition = inCOM[0] + plusOrMinus()*xFromCenter
    newYPosition = inCOM[1] + plusOrMinus()*yFromCenter
    newZPosition = inCOM[2] + plusOrMinus()*zFromCenter

    positionArray = inAtom.get_positions()
    positionArray[atomIndex] = (newXPosition,newYPosition,newZPosition)
    inAtom.set_positions(positionArray)

    return inAtom

  except IndexError:
    print "The index of the atom you wanted to move is too high or too low."
    print "Please check your function call of shell_move(a,b)"
    print "-Jeff"