Files
galvani/BioLogic.py
Chris Kerr d909305b74 Added a class to read in .mpt files as numpy record arrays
Realised that comparing numpy arrays read in from the binary .mpr
files to a csv.DictReader would be more work than just writing a
new function to read in a record array.
2013-11-30 11:35:44 +00:00

122 lines
4.4 KiB
Python

# -*- coding: utf-8 -*-
"""Code to read in data files from Bio-Logic instruments"""
__all__ = ['MPTfileCSV', 'MPTfile']
import re
import csv
import numpy as np
def fieldname_to_dtype(fieldname):
"""Converts a column header from the MPT file into a tuple of
canonical name and appropriate numpy dtype"""
if fieldname == 'mode':
return ('mode', np.uint8)
elif fieldname in ("ox/red", "error", "control changes", "Ns changes",
"counter inc."):
return (fieldname, np.bool_)
elif fieldname in ("time/s", "Ewe/V", "P/W", "(Q-Qo)/mA.h", "x"):
return (fieldname, np.float_)
elif fieldname in ("dq/mA.h", "dQ/mA.h"):
return ("dQ/mA.h", np.float_)
elif fieldname in ("I/mA", "<I>/mA"):
return ("I/mA", np.float_)
elif fieldname in ("control/V", "control/V/mA"):
return ("control/V/mA", np.float_)
else:
raise ValueError("Invalid column header: %s" % fieldname)
def MPTfile(file_or_path):
"""Opens .mpt files as numpy record arrays
Checks for the correct headings, skips any comments and returns a
numpy record array object and a list of comments
"""
if isinstance(file_or_path, str):
mpt_file = open(file_or_path, 'rb')
else:
mpt_file = file_or_path
magic = next(mpt_file)
if magic != b'EC-Lab ASCII FILE\r\n':
raise ValueError("Bad first line for EC-Lab file: '%s'" % magic)
nb_headers_match = re.match(b'Nb header lines : (\d+)\s*$', next(mpt_file))
nb_headers = int(nb_headers_match.group(1))
if nb_headers < 3:
raise ValueError("Too few header lines: %d" % nb_headers)
## The 'magic number' line, the 'Nb headers' line and the column headers
## make three lines. Every additional line is a comment line.
comments = [next(mpt_file) for i in range(nb_headers - 3)]
fieldnames = next(mpt_file).decode('ascii').strip().split('\t')
expected_fieldnames = (
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V/mA", "Ewe/V", "dq/mA.h",
"P/W", "<I>/mA", "(Q-Qo)/mA.h", "x"],
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V", "Ewe/V", "I/mA",
"dQ/mA.h", "P/W"],
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V", "Ewe/V", "<I>/mA",
"dQ/mA.h", "P/W"])
if fieldnames not in expected_fieldnames:
raise ValueError("Unrecognised headers for MPT file format %s" %
fieldnames)
record_type = np.dtype(list(map(fieldname_to_dtype, fieldnames)))
mpt_array = np.loadtxt(mpt_file, dtype=record_type)
return mpt_array, comments
def MPTfileCSV(file_or_path):
"""Simple function to open MPT files as csv.DictReader objects
Checks for the correct headings, skips any comments and returns a
csv.DictReader object and a list of comments
"""
if isinstance(file_or_path, str):
mpt_file = open(file_or_path, 'r')
else:
mpt_file = file_or_path
magic = next(mpt_file)
if magic != 'EC-Lab ASCII FILE\n':
raise ValueError("Bad first line for EC-Lab file: '%s'" % magic)
nb_headers_match = re.match('Nb header lines : (\d+)\s*$', next(mpt_file))
nb_headers = int(nb_headers_match.group(1))
if nb_headers < 3:
raise ValueError("Too few header lines: %d" % nb_headers)
## The 'magic number' line, the 'Nb headers' line and the column headers
## make three lines. Every additional line is a comment line.
comments = [next(mpt_file) for i in range(nb_headers - 3)]
mpt_csv = csv.DictReader(mpt_file, dialect='excel-tab')
expected_fieldnames = (
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V/mA", "Ewe/V", "dq/mA.h",
"P/W", "<I>/mA", "(Q-Qo)/mA.h", "x"],
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V", "Ewe/V", "I/mA",
"dQ/mA.h", "P/W"],
["mode", "ox/red", "error", "control changes", "Ns changes",
"counter inc.", "time/s", "control/V", "Ewe/V", "<I>/mA",
"dQ/mA.h", "P/W"])
if mpt_csv.fieldnames not in expected_fieldnames:
raise ValueError("Unrecognised headers for MPT file format")
return mpt_csv, comments