precision_diff.py

#!/usr/bin/env python

# $Id$

# script to find the difference between two Finesse .out files if they fall
# outside a given precision

# need the Numeric module so that can guarantee decent numerical precision
import math
from Numeric import *
import sys
import getopt  # argument parsing

def get_mantissa_data(fname):
    # read the string data in
    fp = open(fname, 'r')
    lines = fp.readlines()
    fp.close()

    # sometimes there is only a return character on a given line, if so,
    # remove it.
    line_index = 0
    for line in lines:
        if (line == "\n"):
            lines.pop(line_index)
        line_index += 1
        
    # find out the number of rows and columns
    num_rows = len(lines)
    if (num_rows == 0):
        raise ValueError, \
                "Zero rows returned when reading input file: %s" % fname
    
    num_cols = len(lines[0].split())
    if (num_cols == 0):
        raise ValueError, \
                "Zero columns returned when reading input file: %s" % fname
    
    # read in the data
    data = zeros( (num_rows, num_cols), typecode=Float)
    row_index = 0
    for line in lines:
        line_array = line.split()
        for col_index in range(num_cols):
            (mantissa, exponent) = math.frexp(float(line_array[col_index]))
            data[row_index][col_index] = mantissa
        row_index += 1

    return (data, num_rows, num_cols)

# print usage information
def usage():
    print """Usage:
    precision_diff.py [options]
    
    Finds the difference between two Finesse .out files

    options:
    [-h/--help]       Print usage information and exit
    [-r/--ref-file]   Reference file to compare to
    [-c/--check-file] The file to check against the reference
    """
# parse the input options
try:
    opts, args = getopt.getopt(sys.argv[1:], "hr:c:", 
	    ["help", "ref-file=", "check-file="])
except getopt.GetoptError:
    # print help information and exit:
    usage()
    sys.exit(2)

ref_fname = None
check_fname = None
for option, argument in opts:
    if option in ("-h", "--help"):
        usage()
        sys.exit()
    if option in ("-r", "--ref-file"):
        ref_fname = argument
    if option in ("-c", "--check-file"):
        check_fname = argument

# do some checking on the arguments
if (ref_fname is None):
    raise ValueError, "You need to enter a reference .out file name"

if (check_fname is None):
    raise ValueError, "You need to enter a .out file name to check"

(ref_data, ref_num_rows, ref_num_cols) = get_mantissa_data(ref_fname)
(check_data, check_num_rows, check_num_cols) = get_mantissa_data(check_fname)

# check the structure of both files
if (ref_num_rows != check_num_rows):
    raise ValueError, \
            "Reference and check files do not have the same number of rows!"

if (ref_num_cols != check_num_cols):
    raise ValueError, \
            "Reference and check files do not have the same number of columns!"

zero_data = zeros( (ref_num_rows, ref_num_cols), typecode=Float)
diff_data = abs(ref_data - check_data)

if ( diff_data != zero_data ):
    print "Reference file %s and check file %s differ" % \
            (ref_fname, check_fname)
    print "Maximum absolute difference = %g" % max(max(diff_data))
    diff_fname = check_fname + ".pdiff"
    print "Writing diff file: %s" % diff_fname
    fp_diff = open(diff_fname, "w")
    (num_rows, num_cols) = shape(diff_data)
    for row_index in range(num_rows):
        for col_index in range(num_cols-1):
            fp_diff.write(str(diff_data[row_index][col_index]))
            fp_diff.write(" ")
        fp_diff.write(str(diff_data[num_rows-1][num_cols-1]))
        fp_diff.write("\n")
    fp_diff.close()

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