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Parser Module Documentation

This module provides parser for MB-System data files.

Functions:

Name Description
mbs_read_fnv

Read MB-System fnv files and return a nav_structtype object.

Read MB-System fnv files and return a nav_structtype object.

Parameters:

Name Type Description Default
files str or list of str

Path to the fnv files. If a string is passed, it is converted to a list.

 required
processed_files bool

If True, the function looks for processed files with suffix "p.mb89.fnv" or "p.fnv". If False, it looks for raw files with suffix ".mb89.fnv" or ".fnv". Default is True.

 True

Returns:

Name Type Description
fnv_nav nav_structtype

A nav_structtype object containing the navigation data.

Raises:

Type Description
TypeError

If files is not a string or a list of strings.
FileNotFoundError

If any of the files do not exist.
ValueError

If no files are found with the specified suffix.
Source code in navlib/mbsystem/parsers.py 
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def mbs_read_fnv(files: Union[str, List[str]], processed_files=True) -> nav_structtype:
    """
    Read MB-System fnv files and return a nav_structtype object.

    Args:
        files (str or list of str): Path to the fnv files. If a string is passed, it is converted to a list.
        processed_files (bool): If True, the function looks for processed files with suffix "p.mb89.fnv" or "p.fnv".
            If False, it looks for raw files with suffix ".mb89.fnv" or ".fnv". Default is True.

    Returns:
        fnv_nav (nav_structtype): A nav_structtype object containing the navigation data.

    Raises:
        TypeError: If files is not a string or a list of strings.
        FileNotFoundError: If any of the files do not exist.
        ValueError: If no files are found with the specified suffix.
    """
    # Check typing
    if not isinstance(files, (str, list)):
        raise TypeError("files must be a string or a list of strings")

    # Convert to list if a string is passed
    files = files if isinstance(files, list) else [files]

    for file in files:
        if not isinstance(file, str):
            raise TypeError("files must be a string or a list of strings")
    if not isinstance(processed_files, bool):
        raise TypeError("processed_files must be a boolean")

    # Check if files exist
    for file in files:
        if not os.path.isfile(file):
            raise FileNotFoundError(f"File {file} does not exist")

    # Parse the files
    # Initialize the variable to store the data
    fnv = None

    # Define suffixes to look for
    if processed_files:
        # Processed files: "p.mb89.fnv" or "p.fnv"
        suffixes = ["p.mb89.fnv", "p.fnv"]
    else:
        # Raw files: ".mb89.fnv" or ".fnv"
        suffixes = [".mb89.fnv", ".fnv"]

    # Filter files by suffix
    filtered_files = []
    for file in files:
        if any(file.endswith(suffix) for suffix in suffixes):
            filtered_files.append(file)
        else:
            warn(f"File {file} rejected: does not end with any of {suffixes}")

    if not filtered_files:
        raise ValueError(f"No files found with suffixes {suffixes}")

    # Process the files
    for file in filtered_files:
        # Check if the file is empty
        with open(file, "r") as f:
            content = f.read().strip()
        if not content:
            warn(
                f"File {file} is empty or contains only whitespace and will be skipped"
            )
            continue

        # Read the file and concatenate the data
        try:
            data = np.genfromtxt(file)
        except ValueError as e:
            warn(f"Error reading file {file}: {e}")
            continue

        data = np.atleast_2d(data)
        if data.shape[1] != 19:
            warn(
                f"File {file} has an unexpected number of columns: {data.shape[1]} (expected 19)"
            )
            continue

        # Concatenate the data
        if fnv is None:
            fnv = data
        else:
            fnv = np.concatenate([fnv, data], axis=0)

    # Check if fnv is empty
    if fnv is None or fnv.size == 0:
        raise ValueError("No valid data found in the files")

    nav = nav_structtype()
    nav.utime = fnv[:, 6]
    nav.longitude = fnv[:, 7]
    nav.latitude = fnv[:, 8]
    nav.heading = fnv[:, 9]
    nav.speed = fnv[:, 10]
    nav.sonardepth = fnv[:, 11]
    nav.roll = fnv[:, 12]
    nav.pitch = fnv[:, 13]
    nav.heave = fnv[:, 14]
    nav.portlon = fnv[:, 15]
    nav.portlat = fnv[:, 16]
    nav.stbdlon = fnv[:, 17]
    nav.stbdlat = fnv[:, 18]

    return nav