Source code for pygmt.src.solar

"""
solar - Plot day-night terminators and twilight.
"""

from typing import Literal

import pandas as pd
from pygmt.clib import Session
from pygmt.exceptions import GMTInvalidInput
from pygmt.helpers import build_arg_list, fmt_docstring, kwargs_to_strings, use_alias

__doctest_skip__ = ["solar"]


@fmt_docstring
@use_alias(
    B="frame",
    G="fill",
    J="projection",
    R="region",
    V="verbose",
    W="pen",
    c="panel",
    p="perspective",
    t="transparency",
)
@kwargs_to_strings(R="sequence", c="sequence_comma", p="sequence")
def solar(
    self,
    terminator: Literal["astronomical", "civil", "day_night", "nautical"] = "day_night",
    terminator_datetime=None,
    **kwargs,
):
    r"""
    Plot day-light terminators or twilights.

    This function plots the day-night terminator. Alternatively, it can plot the
    terminators for civil twilight, nautical twilight, or astronomical twilight.

    Full option list at :gmt-docs:`solar.html`

    {aliases}

    Parameters
    ----------
    terminator
        Set the type of terminator displayed, which can be set with either the full name
        or the first letter of the name. Available options are:

        - ``"astronomical"``: Astronomical twilight
        - ``"civil"``: Civil twilight
        - ``"day_night"``: Day/night terminator
        - ``"nautical"``: Nautical twilight

        Refer to https://en.wikipedia.org/wiki/Twilight for the definitions of different
        types of twilight.
    terminator_datetime : str or datetime object
        Set the UTC date and time of the displayed terminator [Default is the current
        UTC date and time]. It can be passed as a string or Python datetime object.
    {region}
    {projection}
    {frame}
    fill : str
        Set color or pattern for filling terminators [Default is no fill].
    pen : str
        Set pen attributes for lines [Default is ``"0.25p,black,solid"``].
    {verbose}
    {panel}
    {perspective}
    {transparency}

    Example
    -------
    >>> # import the Python module "datetime"
    >>> import datetime
    >>> import pygmt
    >>> # create a datetime object at 8:52:18 on June 24, 1997 (time in UTC)
    >>> date = datetime.datetime(
    ...     year=1997, month=6, day=24, hour=8, minute=52, second=18
    ... )
    >>> # create a new plot with pygmt.Figure()
    >>> fig = pygmt.Figure()
    >>> # create a map of the Earth with the coast method
    >>> fig.coast(land="darkgreen", water="lightblue", projection="W10c", region="d")
    >>> fig.solar(
    ...     # set the terminator to "day_night"
    ...     terminator="day_night",
    ...     # pass the datetime object
    ...     terminator_datetime=date,
    ...     # fill the night-section with navyblue at 75% transparency
    ...     fill="navyblue@75",
    ...     # draw the terminator with a 1-point black line
    ...     pen="1p,black",
    ... )
    >>> # show the plot
    >>> fig.show()
    """
    kwargs = self._preprocess(**kwargs)
    if kwargs.get("T") is not None:
        msg = "Use 'terminator' and 'terminator_datetime' instead of 'T'."
        raise GMTInvalidInput(msg)

    valid_terminators = ["day_night", "civil", "nautical", "astronomical"]
    if terminator not in valid_terminators and terminator not in "dcna":
        msg = (
            f"Unrecognized solar terminator type '{terminator}'. "
            f"Valid values are {valid_terminators}."
        )
        raise GMTInvalidInput(msg)
    kwargs["T"] = terminator[0]
    if terminator_datetime:
        try:
            datetime_string = pd.to_datetime(terminator_datetime).strftime(
                "%Y-%m-%dT%H:%M:%S.%f"
            )
        except ValueError as verr:
            msg = "Unrecognized datetime format."
            raise GMTInvalidInput(msg) from verr
        kwargs["T"] += f"+d{datetime_string}"
    with Session() as lib:
        lib.call_module(module="solar", args=build_arg_list(kwargs))