nanovna-saver/NanoVNASaver/Touchstone.py

94 wiersze
3.3 KiB
Python

# NanoVNASaver - a python program to view and export Touchstone data from a NanoVNA
# Copyright (C) 2019. Rune B. Broberg
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
import collections
from typing import List
Datapoint = collections.namedtuple('Datapoint', 'freq re im')
class Touchstone:
s11data: List[Datapoint] = []
s21data: List[Datapoint] = []
filename = ""
def __init__(self, filename):
self.filename = filename
def load(self):
self.s11data = []
self.s21data = []
factor = 1
try:
file = open(self.filename, "r")
lines = file.readlines()
parsed_header = False
for l in lines:
l = l.strip()
if l.startswith("!"):
continue
if l.startswith("#") and not parsed_header:
# Check that this is a valid header
if l == "# Hz S RI R 50":
parsed_header = True
factor = 1
continue
elif l == "# kHz S RI R 50":
parsed_header = True
factor = 10**3
continue
elif l == "# MHz S RI R 50":
parsed_header = True
factor = 10**6
continue
elif l == "# GHz S RI R 50":
parsed_header = True
factor = 10**9
continue
else:
# This is some other comment line
continue
if not parsed_header:
print("Warning: Read line without having read header: " + l)
continue
try:
values = l.split(maxsplit=5)
freq = values[0]
re11 = values[1]
im11 = values[2]
freq = int(float(freq) * factor)
re11 = float(re11)
im11 = float(im11)
self.s11data.append(Datapoint(freq, re11, im11))
if len(values) > 3:
re21 = values[3]
im21 = values[4]
re21 = float(re21)
im21 = float(im21)
self.s21data.append(Datapoint(freq, re21, im21))
except ValueError as e:
print("Error parsing line " + l + " : " + str(e))
file.close()
except IOError as e:
print("Failed to open " + self.filename)
return
def setFilename(self, filename):
self.filename = filename