# -*- coding: utf-8 -*- # # Copyright (C) 2010-2016 GEM Foundation # # The SacLib is free software: you can redistribute # it and/or modify it under the terms of the GNU Affero General Public # License as published by the Free Software Foundation, either version # 3 of the License, or (at your option) any later version. # # SacLib is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Affero General Public License for more details. # # You should have received a copy of the GNU Affero General Public License # with this download. If not, see # # Author: Poggi Valerio """ An simple Python library for SAC file I/O """ from struct import pack, unpack from copy import deepcopy from os.path import isfile #----------------------------------------------------------------------------------------- class Sac(): def __init__(self, File=[], ByteOrder=[]): """ Main class ----------------------- Usage: S = SacLib.Sac S = SacLib.Sac('MyFile.sac') Optional parameters: ByteOrder - 'le' (Little Endian, default) - 'be' (Big Endian) Attributes: S.Head - SAC header information S.Data[0] - SAC trace S.Data[1] - SAC trace (optional block) S.Byte - Byte-Order Methods: S.Read - Read SAC file from disk S.Write - Write SAC file to disk S.Copy - Create copy of SAC object S.Print - Print header information """ # Variable initialisation self.Head = {} self.Data = [[],[]] self.Byte = 'le' if ByteOrder: # Set byte order self.Byte = ByteOrder if File: # Import SAC file self.Read(File) else: # Set header defaults for H in _HdrStruc: self.Head[H[0]] = H[3] #--------------------------------------------------------------------------------------- def Read(self, FileName, ByteOrder=[]): """ Read SAC file from disk ----------------------- Usage: S.Read('MyFile.sac') S.Read('MyFile.sac',ByteOrder='be') """ if ByteOrder: # Set byte order self.Byte = ByteOrder # Open input SAC file with open(FileName, 'rb') as fid: # Import header for H in _HdrStruc: self.Head[H[0]] = _fread(fid, H[1], H[2], self.Byte) # Import first block of data for N in range(0,self.Head['NPTS']): self.Data[0].append(_fread(fid, 4, 'f', self.Byte)); # Import second block of data if self.Head['LEVEN'] != 1 or self.Head['IFTYPE'] in (2, 3): for N in range(0,self.Head['NPTS']): self.Data[1].append(_fread(fid, 4, 'f', self.Byte)); fid.close() return # Warn user if model file does not exist print 'Error: File not found' #--------------------------------------------------------------------------------------- def Write(self, FileName, ByteOrder='le', OverWrite=False): """ Write SAC file to disk ----------------------- Usage: S.Write('MyFile.sac') S.Write('MyFile.sac',ByteOrder='be') S.Write('MyFile.sac',OverWrite=True) """ if isfile(FileName) and not OverWrite: print 'Error: Not overwriting file' return if ByteOrder: # Set byte order (le/be) self.Byte = ByteOrder # Open output SAC file with open(FileName, 'wb') as fid: # Export header for H in _HdrStruc: _fwrite(fid, self.Head[H[0]], H[1], H[2], self.Byte) # Export first block of data for D in self.Data[0]: _fwrite(fid, D, 4, 'f', self.Byte) # Export second block of data if self.Data[1]: for D in self.Data[1]: _fwrite(fid, D, 4, 'f', self.Byte) fid.close() return # Warn user if model file does not exist print 'Error: File not found' #--------------------------------------------------------------------------------------- def Copy(self): """ Create a hard-copy of an existing SAC object ----------------------- Usage: SacNew = Sac.Copy() """ SacNew = deepcopy(self) return SacNew #--------------------------------------------------------------------------------------- def Print(self): """ Print header details ----------------------- Usage: Sac.Print() """ print '------------' for H in _HdrStruc: Data = self.Head[H[0]] if Data != H[3]: print '{0:>12} = {1}'.format(H[0],Data) #----------------------------------------------------------------------------------------- # INTERNAL: bytewise read def _fread(fid, bnum, bkey, bord): hex = fid.read(bnum) if bkey == 's': bkey = str(bnum) + bkey if bord == 'be': bkey = '>' + bkey if bord == 'le': bkey = '<' + bkey data = unpack(bkey, hex)[0] return data #----------------------------------------------------------------------------------------- # INTERNAL: bytewise write def _fwrite(fid, data, bnum, bkey, bord): if bkey == 's': bkey = str(bnum) + bkey if bord == 'be': bkey = '>' + bkey if bord == 'le': bkey = '<' + bkey hex = pack(bkey, data) fid.write(hex) #----------------------------------------------------------------------------------------- # Header Structure (sorted): # [0] - Field Name # [1] - Length in Bytes # [2] - Variable Type # [3] - Default Vaule _HdrStruc = [('DELTA',4,'f',-12345), ('DEPMIN',4,'f',-12345), ('DEPMAX',4,'f',-12345), ('SCALE',4,'f',-12345), ('ODELTA',4,'f',-12345), ('B',4,'f',-12345), ('E',4,'f',-12345), ('O',4,'f',-12345), ('A',4,'f',-12345), ('INTERNAL1',4,'f',-12345), ('T0',4,'f',-12345), ('T1',4,'f',-12345), ('T2',4,'f',-12345), ('T3',4,'f',-12345), ('T4',4,'f',-12345), ('T5',4,'f',-12345), ('T6',4,'f',-12345), ('T7',4,'f',-12345), ('T8',4,'f',-12345), ('T9',4,'f',-12345), ('F',4,'f',-12345), ('RESP0',4,'f',-12345), ('RESP1',4,'f',-12345), ('RESP2',4,'f',-12345), ('RESP3',4,'f',-12345), ('RESP4',4,'f',-12345), ('RESP5',4,'f',-12345), ('RESP6',4,'f',-12345), ('RESP7',4,'f',-12345), ('RESP8',4,'f',-12345), ('RESP9',4,'f',-12345), ('STLA',4,'f',-12345), ('STLO',4,'f',-12345), ('STEL',4,'f',-12345), ('STDP',4,'f',-12345), ('EVLA',4,'f',-12345), ('EVLO',4,'f',-12345), ('EVEL',4,'f',-12345), ('EVDP',4,'f',-12345), ('MAG',4,'f',-12345), ('USER0',4,'f',-12345), ('USER1',4,'f',-12345), ('USER2',4,'f',-12345), ('USER3',4,'f',-12345), ('USER4',4,'f',-12345), ('USER5',4,'f',-12345), ('USER6',4,'f',-12345), ('USER7',4,'f',-12345), ('USER8',4,'f',-12345), ('USER9',4,'f',-12345), ('DIST',4,'f',-12345), ('AZ',4,'f',-12345), ('BAZ',4,'f',-12345), ('GCARC',4,'f',-12345), ('INTERNAL2',4,'f',-12345), ('INTERNAL3',4,'f',-12345), ('DEPMEN',4,'f',-12345), ('CMPAZ',4,'f',-12345), ('CMPINC',4,'f',-12345), ('XMINIMUM',4,'f',-12345), ('XMAXIMUM',4,'f',-12345), ('YMINIMUM',4,'f',-12345), ('YMAXIMUM',4,'f',-12345), ('UNUSED1',4,'f',-12345), ('UNUSED2',4,'f',-12345), ('UNUSED3',4,'f',-12345), ('UNUSED4',4,'f',-12345), ('UNUSED5',4,'f',-12345), ('UNUSED6',4,'f',-12345), ('UNUSED7',4,'f',-12345), ('NZYEAR',4,'i',-12345), ('NZJDAY',4,'i',-12345), ('NZHOUR',4,'i',-12345), ('NZMIN',4,'i',-12345), ('NZSEC',4,'i',-12345), ('NZMSEC',4,'i',-12345), ('NVHDR',4,'i',6), ('NORID',4,'i',-12345), ('NEVID',4,'i',-12345), ('NPTS',4,'i',-12345), ('INTERNAL4',4,'i',-12345), ('NWFID',4,'i',-12345), ('NXSIZE',4,'i',-12345), ('NYSIZE',4,'i',-12345), ('UNUSED8',4,'i',-12345), ('IFTYPE',4,'i',1), ('IDEP',4,'i',-12345), ('IZTYPE',4,'i',-12345), ('UNUSED9',4,'i',-12345), ('IINST',4,'i',-12345), ('ISTREG',4,'i',-12345), ('IEVREG',4,'i',-12345), ('IEVTYP',4,'i',-12345), ('IQUAL',4,'i',-12345), ('ISYNTH',4,'i',-12345), ('IMAGTYP',4,'i',-12345), ('IMAGSRC',4,'i',-12345), ('UNUSED10',4,'i',-12345), ('UNUSED11',4,'i',-12345), ('UNUSED12',4,'i',-12345), ('UNUSED13',4,'i',-12345), ('UNUSED14',4,'i',-12345), ('UNUSED15',4,'i',-12345), ('UNUSED16',4,'i',-12345), ('UNUSED17',4,'i',-12345), ('LEVEN',4,'i',1), ('LPSPOL',4,'i',0), ('LOVROK',4,'i',1), ('LCALDA',4,'i',1), ('UNUSED18',4,'i',0), ('KSTNM',8,'s','-12345 '), ('KEVNM',16,'s','-12345 -12345 '), ('KHOLE',8,'s','-12345 '), ('KO',8,'s','-12345 '), ('KA',8,'s','-12345 '), ('KT0',8,'s','-12345 '), ('KT1',8,'s','-12345 '), ('KT2',8,'s','-12345 '), ('KT3',8,'s','-12345 '), ('KT4',8,'s','-12345 '), ('KT5',8,'s','-12345 '), ('KT6',8,'s','-12345 '), ('KT7',8,'s','-12345 '), ('KT8',8,'s','-12345 '), ('KT9',8,'s','-12345 '), ('KF',8,'s','-12345 '), ('KUSER0',8,'s','-12345 '), ('KUSER1',8,'s','-12345 '), ('KUSER2',8,'s','-12345 '), ('KCMPNM',8,'s','-12345 '), ('KNETWK',8,'s','-12345 '), ('KDATRD',8,'s','-12345 '), ('KINST',8,'s','-12345 ')]