#!/usr/bin/ruby

# Create displaced POSCAR files for phonon calculation.
# Require "DISP" and "SPOSCAR" files.
#
# First written by k-fleak
#   Time-stamp: <05/10/03>
#
# Usage: makePhonPOSCAR.rb [OPTION]
#
# OPTION (int or float (default=1.0))
# : Normalize factor for displacement of "DISP" file.

require "./parseDISP.rb"
require "./parsePoscar.rb"

class PositionInfo
  def initialize
    poscar = ParsePoscar.new("SPOSCAR")
    @initPos = poscar.getPosition
    
    dataDISP = ParseDISP.new("DISP")
    @disp = dataDISP.getDispPos
    @atomIndex = dataDISP.getAtomIndex
    
  end
  
  def getFinalPosition(dispNum, fact=1.0)
    @finalPos = moveAtoms(dispNum, fact)
  end
  
  def getMoveAtomIndex
    @atomIndex
  end
  
  def getNumDisp
    @atomIndex.size
  end
  
  def writePosition(dispNum)
    header = File.open("SPOSCAR")
    file = File.new( "POSCAR-disp#{dispNum}", "w")
    header.each_with_index do |lines, i|
      printf(file, "#{lines}")
      break if i >= 6
    end
    @finalPos.each do |f|
      printf(file, "%12.8f %12.8f %12.8f\n", f[0], f[1], f[2])
    end
    header.close
    file.close
  end
  
  private
  
  def moveAtoms(dispNum,fact)
    tmpPos = Marshal.load(Marshal.dump(@initPos))
    3.times do |j|
      tmpPos[@atomIndex[dispNum]-1][j] += @disp[dispNum][j]*fact
    end
    tmpPos
  end

end 

if ARGV[0] =~ /^\d+|^\f+/ then
  afactor = ARGV[0].to_f
else
  afactor = 1.0
end

position = PositionInfo.new()
position.getNumDisp.times do |i|
  position.getFinalPosition(i, afactor)
  position.writePosition(i)
end