"""
io.py
This module provides functions to read and parse MoorDyn output files.
The main function read_moordyn takes as input the path to a MoorDyn output file and optionally
the path to a MoorDyn input file. It reads the data from the output file, stores it in an
xarray dataset, and then if provided, parses the input file for additional metadata to store
as attributes in the dataset.
The helper function _moordyn_input is used to parse the MoorDyn output file. It loops through
each line in the output file, parses various sets of properties and parameters, and stores
them as attributes in the provided dataset.
Typical usage example:
dataset = read_moordyn(filepath="FAST.MD.out", input_file="FAST.MD.input")
"""
import os
import pandas as pd
[docs]def read_moordyn(filepath, input_file=None):
"""
Reads in MoorDyn OUT files such as "FAST.MD.out" and
"FAST.MD.Line1.out" and stores inside xarray. Also allows for
parsing and storage of MoorDyn input file as attributes inside
the xarray.
Parameters
----------
filepath : str
Path to MoorDyn OUT file
inputfile : str (optional)
Path to MoorDyn input file
Returns
-------
xr.Dataset
Dataset containing parsed MoorDyn OUT file
Raises
------
TypeError
Checks for correct input types for filepath and input_file
"""
if not isinstance(filepath, str):
raise TypeError('filepath must be of type str')
if input_file:
if not isinstance(input_file, str):
raise TypeError('input_file must be of type str')
if not os.path.isfile(filepath):
raise FileNotFoundError(f"No file found at provided path: {filepath}")
data = pd.read_csv(filepath, header=0, skiprows=[
1], sep=' ', skipinitialspace=True, index_col=0)
data = data.dropna(axis=1)
dataset = data.to_xarray()
if input_file:
dataset = _moordyn_input(input_file, dataset)
return dataset
def _moordyn_input(input_file, dataset):
"""
Internal function used to parse MoorDyn input file and write attributes.
Parameters
----------
input_file : str
Path to moordyn input file
dataset : xr.Dataset
xarray Dataset to be written to
Returns
-------
xr.Dataset
return Dataset that includes input file parameters as attributes
"""
with open(input_file, 'r', encoding='utf-8') as moordyn_file:
for line in moordyn_file: # loop through each line in the file
# get line type property sets
if line.count('---') > 0 and (line.upper().count('LINE DICTIONARY') > 0 or
line.upper().count('LINE TYPES') > 0):
linetypes = dict()
# skip this header line, plus channel names and units lines
line = next(moordyn_file)
variables = line.split()
line = next(moordyn_file)
units = line.split()
line = next(moordyn_file)
while line.count('---') == 0:
entries = line.split()
linetypes[entries[0]] = dict()
for x in range(1, len(entries)):
linetypes[entries[0]][variables[x]] = entries[x]
line = next(moordyn_file)
linetypes['units'] = units[1:]
dataset.attrs['LINE_TYPES'] = linetypes
# get properties of each Point
if line.count('---') > 0 and (line.upper().count('POINTS') > 0
or line.upper().count('POINT LIST') > 0
or line.upper().count('POINT PROPERTIES') > 0):
# skip this header line, plus channel names and units lines
line = next(moordyn_file)
variables = line.split()
line = next(moordyn_file)
units = line.split()
line = next(moordyn_file)
points = dict()
while line.count('---') == 0:
entries = line.split()
points[entries[0]] = dict()
for x in range(1, len(entries)):
points[entries[0]][variables[x]] = entries[x]
line = next(moordyn_file)
points['units'] = units[1:]
dataset.attrs['POINTS'] = points
# get properties of each line
if line.count('---') > 0 and (line.upper().count('LINES') > 0
or line.upper().count('LINE LIST') > 0
or line.upper().count('LINE PROPERTIES') > 0):
# skip this header line, plus channel names and units lines
line = next(moordyn_file)
variables = line.split()
line = next(moordyn_file)
units = line.split()
line = next(moordyn_file)
lines = {}
while line.count('---') == 0:
entries = line.split()
lines[entries[0]] = dict()
for x in range(1, len(entries)):
lines[entries[0]][variables[x]] = entries[x]
line = next(moordyn_file)
lines['units'] = units[1:]
dataset.attrs['LINES'] = lines
# get options entries
if line.count('---') > 0 and "options" in line.lower():
line = next(moordyn_file) # skip this header line
options = {}
while line.count('---') == 0:
entries = line.split()
options[entries[1]] = entries[0]
line = next(moordyn_file)
dataset.attrs['OPTIONS'] = options
moordyn_file.close()
return dataset