AddGravity.py

#! /usr/bin/env python

#Adds GravityBoundaryType to a hierarchy file
#Probably does subgrids properly, but need to double check.  

#Call from unix prompt:
# %> AddGravity.py <HierarchyName>
#
# Doesn't error check, so only run if you know gravity isn't on. (Or, write the error check)
# Saves the old hierarchy as hierarchyname.Old

# Parse of command line and call happens after definition primary (only) routine "ag"
#
# Flow:
# 1.) Open file, read all lines
# 2.) Declare empty Hierarchy
# 3.) Put each Old line in New Hierarchy.
# 4.) Flag if finished with the root grid (which always comes first.)
# 5.) Root Grids get GravityBoundaryType = 0, Subgrids get 2.  Insert the proper one after
#     the line NumberOfParticles.

def ag(filename="data0001.hierarchy"):

#   Open file and read lines, declare new (empty) hierarchy

    file = open(filename, "r")
    AllLines = file.readlines()
    NewLines = []
#   close file.  (duh.)        
    file.close()

#   Loop over lines.  For each one, query for "NumberOfParticles", because boundary type
#   needs to go after it.

#   The root grids all come first, so ThisIsASubGrid is 0 until NextGridTHisLevel = 0,
#   whence its chaged to 1.  True, there will be more than one NGTL = 0, but only
#   the first one is important for us.
    ThisIsASubGrid = 0

    for line in AllLines:

        NewLines.append(line)
#       Set Grid Number.  Not used right now, but may be necessary later.
        if line.find("Grid =") != -1:
            GridNumber = int( line[6:-1] )

#       If NextGridThisLevel == 0, then we're done with the root grid.  All others are
#       SubGrids, and should get the appropriate SubGrid flag.  (may still be buggy...)

        
        if line.find("NextGridThisLevel = 0") != -1:
            ThisIsASubGrid = 1

#       The GravityBoundaryType needs to go after NumberOfParticles.
        if line.find("NumberOfParticles") != -1:
            if ThisIsASubGrid == 0:        
                NewLines.append("GravityBoundaryType = 1\n")
            else:
                NewLines.append("GravityBoundaryType = 2\n")


#   Now that we're done with the parse, write the new hierarchy file.


    OldFileName = filename + ".OLD"
    NewFilename = filename

#   write new file
    file = open(NewFilename, "w")
    print(" ")
    print("writing ", NewFilename, ", saving the old as", OldFileName)
    print("Also: change MaximumGravityRefinementLevel to reflect the new change in gravity")
    print("      It should be at least the same as MaximumRefinementLevel")
    print("Also Also: turn on SelfGravity and set GravitationalConstant to something meaningful.")
    print(" ")
    for newline in NewLines:
        file.write(newline)    
    file.close()

#   write Old File
    file = open(OldFileName, "w")
    for newline in AllLines:
        file.write(newline)
    file.close()
#end

#
# Now the command line parse.
#

import sys


if len(sys.argv) == 1:
    print("Add's the Gravity Boundary to the Hierarchy File.")
    print("%> AddGravity <HierarchyName>")
    print("   Returns HierarchyName with the gravity added, saves the old one as HierarchyName.OLD")
else:
    for Filename in sys.argv[1:]:
        ag(Filename)