xarray_matplotlib.py

#!/usr/bin/env python
"""
matplotlib with datetime64 testing
"""
import xarray
from datetime import datetime
from matplotlib.pyplot import figure, show
import matplotlib.dates as mdates
import numpy as np


def test_plot2d_datetime():
    t = np.arange("2010-05-04T12:05:00", "2010-05-04T12:05:01", dtype="datetime64[ms]")
    y = np.random.randn(t.size)

    # t = t.astype(datetime)  # Matplotlib < 2.2

    ax = figure().gca()
    ax.plot(t, y)


def test_plot2d_xarray():
    t = np.arange("2010-05-04T12:05:00", "2010-05-04T12:05:01", dtype="datetime64[ms]")
    y = np.random.randn(t.size)

    dat = xarray.DataArray(y, coords={"time": t}, dims=["time"])

    dset = xarray.Dataset({"random1Dstuff": dat})

    fg = figure()
    ax = fg.subplots(3, 1, sharex=True)

    dat.plot(ax=ax[0])

    ax[1].plot(dat.time, dat)

    dset["random1Dstuff"].plot(ax=ax[2])


def test_imshow_datetime():
    """
    keogram using matplotlib imshow
    """
    Ny = 500  # arbitrary

    t = np.arange("2010-05-04T12:05", "2010-05-04T12:06", dtype="datetime64[s]").astype(datetime)
    im = np.random.random((Ny, t.size))
    y = range(t.size)  # arbitrary

    mt = mdates.date2num((t[0], t[-1]))  # at least through Matplotlib 2.2

    fig = figure()
    ax = fig.gca()
    ax.imshow(im, extent=[mt[0], mt[1], y[0], y[-1]], aspect="auto")
    # %% datetime formatting
    ax.xaxis_date()  # like "num2date"

    # ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M:%S'))

    fig.autofmt_xdate()


if __name__ == "__main__":
    np.testing.run_module_suite()

    show()