ReadRecord.py

import os

def ReadRecord(inFilename, outFilename):
    # search inFilename. If its filename extension is .at2, call ReadRecord_PEER.
    # If it's .txt (1st data col is time, 2nd col is accel), call ReadRecord_TXT.
    # 
    # Arguments:
    #   inFilename: no filename extension
    #   outFilename: '.dat' filename extension
    if os.path.exists(inFilename + '.at2'):
        dt, npts = ReadRecord_PEER (inFilename + '.at2', outFilename)
    elif os.path.exists(inFilename + '.txt'):
        dt, npts = ReadRecord_TXT (inFilename + '.txt', outFilename)
    else:
        print('ERROR: Cant find record file!')
        dt = None
        npts = None
    return dt, npts

def ReadRecord_TXT (inFilename, outFilename):
    
    inFileID = open(inFilename, 'r')
    outFileID = open(outFilename, 'w')

    time_1 = 0.0
    time_2 = 0.0
    npts=0
    for line in inFileID:
        if line == '\n':
            continue
        else:
            words = str.replace(line,',',' ').split()
            lengthLine = len(words)
            if lengthLine == 2:
                npts+=1
                if npts==1:
                    time_1=float(words[0])
                elif npts==2:
                    time_2=float(words[0])
                outFileID.write(words[1])
                outFileID.write('\n')
    dt = time_2 - time_1
    
    inFileID.close()
    outFileID.close()

    return dt, npts

def ReadRecord_PEER (inFilename, outFilename):
    # ReadRecord.py
    # ------------------------------------------------------------------------------------------------------------
    #
    # Written: minjie
    # Date: May 2016

    # A procedure which parses a ground motion record from the PEER
    # strong motion database by finding dt in the record header, then
    # echoing data values to the output file.
    #
    # Formal arguments
    #	inFilename -- file which contains PEER strong motion record
    #	outFilename -- file to be written in format G3 can read
    # Return values
    #	dt -- time step determined from file header
    #	nPts -- number of data points from file header
    #
    # Assumptions
    #	The header in the PEER record is, e.g., formatted as 1 of following:
    #  1) new PGA database
    #	 PACIFIC ENGINEERING AND ANALYSIS STRONG-MOTION DATA
    #	  IMPERIAL VALLEY 10/15/79 2319, EL CENTRO ARRAY 6, 230                           
    #	  ACCELERATION TIME HISTORY IN UNITS OF G                                         
    #	  3930 0.00500 NPTS, DT

    #   2) old SMD database
    #	 PACIFIC ENGINEERING AND ANALYSIS STRONG-MOTION DATA
    #	  IMPERIAL VALLEY 10/15/79 2319, EL CENTRO ARRAY 6, 230                           
    #	  ACCELERATION TIME HISTORY IN UNITS OF G                                         
    #	  NPTS=  3930, DT= .00500 SEC

    dt = 0.0
    npts = 0
    
    # Open the input file and catch the error if it can't be read
    inFileID = open(inFilename, 'r')
    
    # Open output file for writing
    outFileID = open(outFilename, 'w')
	
    # Flag indicating dt is found and that ground motion
    # values should be read -- ASSUMES dt is on last line
    # of header!!!
    flag = 0
	
    # Look at each line in the file
    for line in inFileID:
        if line == '\n':
            # Blank line --> do nothing
            continue
        elif flag == 1:
            # Echo ground motion values to output file
            outFileID.write(line)
        else:
            # Search header lines for dt
            words = line.split()
            lengthLine = len(words)

            if lengthLine >= 4:

                if words[0] == 'NPTS=':
                    # old SMD format
                    for word in words:
                        if word != '':
                            # Read in the time step
                            if flag == 1:
                                dt = float(word)
                                break

                            if flag == 2:
                                npts = int(word.strip(','))
                                flag = 0

                            # Find the desired token and set the flag
                            if word == 'DT=' or word == 'dt':
                                flag = 1

                            if word == 'NPTS=':
                                flag = 2
                        
                    
                elif words[-1] == 'DT':
                    # new NGA format
                    count = 0
                    for word in words:
                        if word != '':
                            if count == 0:
                                npts = int(word)
                            elif count == 1:
                                dt = float(word)
                            elif word == 'DT':
                                flag = 1
                                break

                            count += 1

                        

    inFileID.close()
    outFileID.close()

    return dt, npts