Source code for metpy.plots.declarative

#  Copyright (c) 2018,2019 MetPy Developers.
#  Distributed under the terms of the BSD 3-Clause License.
#  SPDX-License-Identifier: BSD-3-Clause
"""Declarative plotting tools."""

from datetime import datetime

try:
    import cartopy.crs as ccrs
    DEFAULT_LAT_LON = ccrs.PlateCarree()
except ImportError:
    DEFAULT_LAT_LON = None
import matplotlib.pyplot as plt
import numpy as np
from traitlets import (Any, Bool, Float, HasTraits, Instance, Int, List, observe, Tuple,
                       Unicode, Union)

from . import ctables
from ..cbook import is_string_like
from ..package_tools import Exporter
from ..units import units

exporter = Exporter(globals())

_areas = {
    '105': (-129.3, -22.37, 17.52, 53.78),
    'local': (-92., -64., 28.5, 48.5),
    'wvaac': (120.86, -15.07, -53.6, 89.74),
    'tropsfc': (-100., -55., 8., 33.),
    'epacsfc': (-155., -75., -20., 33.),
    'ofagx': (-100., -80., 20., 35.),
    'ahsf': (-105., -30., -5., 35.),
    'ehsf': (-145., -75., -5., 35.),
    'shsf': (-125., -75., -20., 5.),
    'tropful': (-160., 0., -20., 50.),
    'tropatl': (-115., 10., 0., 40.),
    'subtrop': (-90., -20., 20., 60.),
    'troppac': (-165., -80., -25., 45.),
    'gulf': (-105., -70., 10., 40.),
    'carib': (-100., -50., 0., 40.),
    'sthepac': (-170., -70., -60., 0.),
    'opcahsf': (-102., -20., 0., 45.),
    'opcphsf': (175., -70., -28., 45.),
    'wwe': (-106., -50., 18., 54.),
    'world': (-24., -24., -90., 90.),
    'nwwrd1': (-180., 180., -90., 90.),
    'nwwrd2': (0., 0., -90., 90.),
    'afna': (-135.02, -23.04, 10.43, 40.31),
    'awna': (-141.03, -18.58, 7.84, 35.62),
    'medr': (-178., -25., -15., 5.),
    'pacsfc': (129., -95., -5., 18.),
    'saudi': (4.6, 92.5, -13.2, 60.3),
    'natlmed': (-30., 70., 0., 65.),
    'ncna': (-135.5, -19.25, 8., 37.7),
    'ncna2': (-133.5, -20.5, 10., 42.),
    'hpcsfc': (-124., -26., 15., 53.),
    'atlhur': (-96., -6., 4., 3.),
    'nam': (-134., 3., -4., 39.),
    'sam': (-120., -20., -60., 20.),
    'samps': (-148., -36., -28., 12.),
    'eur': (-16., 80., 24., 52.),
    'afnh': (-155.19, 18.76, -6.8, -3.58),
    'awnh': (-158.94, 15.35, -11.55, -8.98),
    'wwwus': (-127.7, -59., 19.8, 56.6),
    'ccfp': (-130., -65., 22., 52.),
    'llvl': (-119.6, -59.5, 19.9, 44.5),
    'llvl2': (-125., -32.5, 5., 46.),
    'llvl_e': (-89., -59.5, 23.5, 44.5),
    'llvl_c': (-102.4, -81.25, 23.8, 51.6),
    'llvl_w': (-119.8, -106.5, 19.75, 52.8),
    'ak_artc': (163.7, -65.3, 17.5, 52.6),
    'fxpswna': (-80.5, 135., -1., 79.),
    'fxpsnna': (-80.5, 54., -1., 25.5),
    'fxpsna': (-72.6, 31.4, -3.6, 31.),
    'natl_ps': (-80.5, 54., -1., 25.5),
    'fxpsena': (-45., 54., 11., 25.5),
    'fxpsnp': (155.5, -106.5, 22.5, 47.),
    'npac_ps': (155.5, -106.5, 22.5, 47.),
    'fxpsus': (-120., -59., 20., 44.5),
    'fxmrwrd': (58., 58., -70., 70.),
    'fxmrwr2': (-131., -131., -70., 70.),
    'nwmrwrd': (70., 70., -70., 70.),
    'wrld_mr': (58., 58., -70., 70.),
    'fxmr110': (-180., -110., -20., 50.5),
    'fxmr180': (110., -180., -20., 50.5),
    'fxmrswp': (97.5, -147.5, -36., 45.5),
    'fxmrus': (-162.5, -37.5, -28., 51.2),
    'fxmrea': (-40., 20., -20., 54.2),
    'fxmrjp': (100., -160., 0., 45.),
    'icao_a': (-137.4, -12.6, -54., 67.),
    'icao_b': (-52.5, -16., -62.5, 77.5),
    'icao_b1': (-125., 40., -45.5, 62.7),
    'icao_c': (-35., 70., -45., 75.),
    'icao_d': (-15., 132., -27., 63.),
    'icao_e': (25., 180., -54., 40.),
    'icao_f': (100., -110., -52.7, 50.),
    'icao_g': (34.8, 157.2, -0.8, 13.7),
    'icao_h': (-79.1, 56.7, 1.6, 25.2),
    'icao_i': (166.24, -60.62, -6.74, 33.32),
    'icao_j': (106.8, -101.1, -27.6, 0.8),
    'icao_k': (3.3, 129.1, -11.1, 6.7),
    'icao_m': (100., -110., -10., 70.),
    'icao_eu': (-21.6, 68.4, 21.4, 58.7),
    'icao_me': (17., 70., 10., 44.),
    'icao_as': (53., 108., 00., 36.),
    'icao_na': (-54.1, 60.3, 17.2, 50.7),
    'nhem': (-135., 45., -15., -15.),
    'nhem_ps': (-135., 45., -15., -15.),
    'nhem180': (135., -45., -15., -15.),
    'nhem155': (160., -20., -15., -15.),
    'nhem165': (150., -30., -15., -15.),
    'nh45_ps': (-90., 90., -15., -15.),
    'nhem0': (-45., 135., -15., -15.),
    'shem_ps': (88., -92., 30., 30.),
    'hfo_gu': (160., -130., -30., 40.),
    'natl': (-110., 20.1, 15., 70.),
    'watl': (-84., -38., 25., 46.),
    'tatl': (-90., -15., -10., 35.),
    'npac': (102., -110., -12., 60.),
    'spac': (102., -70., -60., 20.),
    'tpac': (-165., -75., -10., 40.),
    'epac': (-134., -110., 12., 75.),
    'wpac': (130., -120., 0., 63.),
    'mpac': (128., -108., 15., 71.95),
    'opcsfp': (128.89, -105.3, 3.37, 16.77),
    'opcsfa': (-55.5, 75., -8.5, 52.6),
    'opchur': (-99., -15., 1., 50.05),
    'us': (-119., -56., 19., 47.),
    'spcus': (-116.4, -63.9, 22.1, 47.2),
    'afus': (-119.04, -63.44, 23.1, 44.63),
    'ncus': (-124.2, -40.98, 17.89, 47.39),
    'nwus': (-118., -55.5, 17., 46.5),
    'awips': (-127., -59., 20., 50.),
    'bwus': (-124.6, -46.7, 13.1, 43.1),
    'usa': (-118., -62., 22.8, 45.),
    'usnps': (-118., -62., 18., 51.),
    'uslcc': (-118., -62., 20., 51.),
    'uswn': (-129., -45., 17., 53.),
    'ussf': (-123.5, -44.5, 13., 32.1),
    'ussp': (-126., -49., 13., 54.),
    'whlf': (-123.8, -85.9, 22.9, 50.2),
    'chlf': (-111., -79., 27.5, 50.5),
    'centus': (-105.4, -77., 24.7, 47.6),
    'ehlf': (-96.2, -62.7, 22., 49.),
    'mehlf': (-89.9, -66.6, 23.8, 49.1),
    'bosfa': (-87.5, -63.5, 34.5, 50.5),
    'miafa': (-88., -72., 23., 39.),
    'chifa': (-108., -75., 34., 50.),
    'dfwfa': (-106.5, -80.5, 22., 40.),
    'slcfa': (-126., -98., 29.5, 50.5),
    'sfofa': (-129., -111., 30., 50.),
    'g8us': (-116., -58., 19., 56.),
    'wsig': (155., -115., 18., 58.),
    'esig': (-80., -30., 25., 51.),
    'eg8': (-79., -13., 24., 52.),
    'west': (-125., -90., 25., 55.),
    'cent': (-107.4, -75.3, 24.3, 49.7),
    'east': (-100.55, -65.42, 24.57, 47.2),
    'nwse': (-126., -102., 38.25, 50.25),
    'swse': (-126., -100., 28.25, 40.25),
    'ncse': (-108., -84., 38.25, 50.25),
    'scse': (-108.9, -84., 24., 40.25),
    'nese': (-89., -64., 37.25, 47.25),
    'sese': (-90., -66., 28.25, 40.25),
    'afwh': (170.7, 15.4, -48.6, 69.4),
    'afeh': (-9.3, -164.6, -48.6, 69.4),
    'afpc': (80.7, -74.6, -48.6, 69.4),
    'ak': (-179., -116.4, 49., 69.),
    'ak2': (-180., -106., 42., 73.),
    'nwak': (-180., -110., 50., 60.),
    'al': (-95., -79., 27., 38.),
    'ar': (-100.75, -84.75, 29.5, 40.5),
    'ca': (-127.75, -111.75, 31.5, 42.5),
    'co': (-114., -98., 33.5, 44.5),
    'ct': (-81.25, -65.25, 36., 47.),
    'dc': (-85., -69., 33.35, 44.35),
    'de': (-83.75, -67.75, 33.25, 44.25),
    'fl': (-90., -74., 23., 34.),
    'ga': (-92., -76., 27.5, 38.5),
    'hi': (-161.5, -152.5, 17., 23.),
    'nwxhi': (-166., -148., 14., 26.),
    'ia': (-102., -86., 36.5, 47.5),
    'id': (-123., -107., 39.25, 50.25),
    'il': (-97.75, -81.75, 34.5, 45.5),
    'in': (-94.5, -78.5, 34.5, 45.5),
    'ks': (-106.5, -90.5, 33.25, 44.25),
    'ky': (-93., -77., 31.75, 42.75),
    'la': (-100.75, -84.75, 25.75, 36.75),
    'ma': (-80.25, -64.25, 36.75, 47.75),
    'md': (-85.25, -69.25, 33.75, 44.75),
    'me': (-77.75, -61.75, 39.5, 50.5),
    'mi': (-93., -77., 37.75, 48.75),
    'mn': (-102., -86., 40.5, 51.5),
    'mo': (-101., -85., 33., 44.),
    'ms': (-98., -82., 27., 38.),
    'mt': (-117., -101., 41.5, 52.5),
    'nc': (-87.25, -71.25, 30., 41.),
    'nd': (-107.5, -91.5, 42.25, 53.25),
    'ne': (-107.5, -91.5, 36.25, 47.25),
    'nh': (-79.5, -63.5, 38.25, 49.25),
    'nj': (-82.5, -66.5, 34.75, 45.75),
    'nm': (-114.25, -98.25, 29., 40.),
    'nv': (-125., -109., 34., 45.),
    'ny': (-84., -68., 37.25, 48.25),
    'oh': (-91., -75., 34.5, 45.5),
    'ok': (-105.25, -89.25, 30.25, 41.25),
    'or': (-128., -112., 38.75, 49.75),
    'pa': (-86., -70., 35.5, 46.5),
    'ri': (-79.75, -63.75, 36., 47.),
    'sc': (-89., -73., 28.5, 39.5),
    'sd': (-107.5, -91.5, 39., 50.),
    'tn': (-95., -79., 30., 41.),
    'tx': (-107., -91., 25.4, 36.5),
    'ut': (-119., -103., 34., 45.),
    'va': (-86.5, -70.5, 32.25, 43.25),
    'vt': (-80.75, -64.75, 38.25, 49.25),
    'wi': (-98., -82., 38.5, 49.5),
    'wv': (-89., -73., 33., 44.),
    'wy': (-116., -100., 37.75, 48.75),
    'az': (-119., -103., 29., 40.),
    'wa': (-128., -112., 41.75, 52.75),
    'abrfc': (-108., -88., 30., 42.),
    'ab10': (-106.53, -90.28, 31.69, 40.01),
    'cbrfc': (-117., -103., 28., 46.),
    'cb10': (-115.69, -104.41, 29.47, 44.71),
    'lmrfc': (-100., -77., 26., 40.),
    'lm10': (-97.17, -80.07, 28.09, 38.02),
    'marfc': (-83.5, -70., 35.5, 44.),
    'ma10': (-81.27, -72.73, 36.68, 43.1),
    'mbrfc': (-116., -86., 33., 53.),
    'mb10': (-112.8, -89.33, 35.49, 50.72),
    'ncrfc': (-108., -76., 34., 53.),
    'nc10': (-104.75, -80.05, 35.88, 50.6),
    'nerfc': (-84., -61., 39., 49.),
    'ne10': (-80.11, -64.02, 40.95, 47.62),
    'nwrfc': (-128., -105., 35., 55.),
    'nw10': (-125.85, -109.99, 38.41, 54.46),
    'ohrfc': (-92., -75., 34., 44.),
    'oh10': (-90.05, -77.32, 35.2, 42.9),
    'serfc': (-94., -70., 22., 40.),
    'se10': (-90.6, -73.94, 24.12, 37.91),
    'wgrfc': (-112., -88., 21., 42.),
    'wg10': (-108.82, -92.38, 23.99, 39.18),
    'nwcn': (-133.5, -10.5, 32., 56.),
    'cn': (-120.4, -14., 37.9, 58.6),
    'ab': (-119.6, -108.2, 48.6, 60.4),
    'bc': (-134.5, -109., 47.2, 60.7),
    'mb': (-102.4, -86.1, 48.3, 60.2),
    'nb': (-75.7, -57.6, 42.7, 49.6),
    'nf': (-68., -47., 45., 62.),
    'ns': (-67., -59., 43., 47.5),
    'nt': (-131.8, -33.3, 57.3, 67.8),
    'on': (-94.5, -68.2, 41.9, 55.),
    'pe': (-64.6, -61.7, 45.8, 47.1),
    'qb': (-80., -49.2, 44.1, 60.9),
    'sa': (-111.2, -97.8, 48.5, 60.3),
    'yt': (-142., -117., 59., 70.5),
    'ag': (-80., -53., -56., -20.),
    'ah': (60., 77., 27., 40.),
    'afrca': (-25., 59.4, -36., 41.),
    'ai': (-14.3, -14.1, -8., -7.8),
    'alba': (18., 23., 39., 43.),
    'alge': (-9., 12., 15., 38.),
    'an': (10., 25., -20., -5.),
    'antl': (-70., -58., 11., 19.),
    'antg': (-86., -65., 17., 25.),
    'atg': (-62., -61.6, 16.9, 17.75),
    'au': (101., 148., -45., -6.5),
    'azor': (-27.6, -23., 36., 41.),
    'ba': (-80.5, -72.5, 22.5, 28.5),
    'be': (-64.9, -64.5, 32.2, 32.6),
    'bel': (2.5, 6.5, 49.4, 51.6),
    'bf': (113., 116., 4., 5.5),
    'bfa': (-6., 3., 9., 15.1),
    'bh': (-89.3, -88.1, 15.7, 18.5),
    'bi': (29., 30.9, -4.6, -2.2),
    'bj': (0., 5., 6., 12.6),
    'bn': (50., 51., 25.5, 27.1),
    'bo': (-72., -50., -24., -8.),
    'bots': (19., 29.6, -27., -17.),
    'br': (-62.5, -56.5, 12.45, 13.85),
    'bt': (71.25, 72.6, -7.5, -5.),
    'bu': (22., 30., 40., 45.),
    'bv': (3., 4., -55., -54.),
    'bw': (87., 93., 20.8, 27.),
    'by': (19., 33., 51., 60.),
    'bz': (-75., -30., -35., 5.),
    'cais': (-172., -171., -3., -2.),
    'nwcar': (-120., -50., -15., 35.),
    'cari': (-103., -53., 3., 36.),
    'cb': (13., 25., 7., 24.),
    'ce': (14., 29., 2., 11.5),
    'cg': (10., 20., -6., 5.),
    'ch': (-80., -66., -56., -15.),
    'ci': (85., 145., 14., 48.5),
    'cm': (7.5, 17.1, 1., 14.),
    'colm': (-81., -65., -5., 14.),
    'cr': (-19., -13., 27., 30.),
    'cs': (-86.5, -81.5, 8.2, 11.6),
    'cu': (-85., -74., 19., 24.),
    'cv': (-26., -22., 14., 18.),
    'cy': (32., 35., 34., 36.),
    'cz': (8.9, 22.9, 47.4, 52.4),
    'dj': (41.5, 44.1, 10.5, 13.1),
    'dl': (4.8, 16.8, 47., 55.),
    'dn': (8., 11., 54., 58.6),
    'do': (-61.6, -61.2, 15.2, 15.8),
    'dr': (-72.2, -68., 17.5, 20.2),
    'eg': (24., 37., 21., 33.),
    'eq': (-85., -74., -7., 3.),
    'er': (50., 57., 22., 26.6),
    'es': (-90.3, -87.5, 13., 14.6),
    'et': (33., 49., 2., 19.),
    'fa': (-8., -6., 61., 63.),
    'fg': (-55., -49., 1., 7.),
    'fi': (20.9, 35.1, 59., 70.6),
    'fj': (176., -179., 16., 19.),
    'fk': (-61.3, -57.5, -53., -51.),
    'fn': (0., 17., 11., 24.),
    'fr': (-5., 11., 41., 51.5),
    'gb': (-17.1, -13.5, 13., 14.6),
    'gc': (-82.8, -77.6, 17.9, 21.1),
    'gh': (-4.5, 1.5, 4., 12.),
    'gi': (-8., -4., 35., 38.),
    'gl': (-56.7, 14., 58.3, 79.7),
    'glp': (-64.2, -59.8, 14.8, 19.2),
    'gm': (144.5, 145.1, 13., 14.),
    'gn': (2., 16., 3.5, 15.5),
    'go': (8., 14.5, -4.6, 3.),
    'gr': (20., 27.6, 34., 42.),
    'gu': (-95.6, -85., 10.5, 21.1),
    'gw': (-17.5, -13.5, 10.8, 12.8),
    'gy': (-62., -55., 0., 10.),
    'ha': (-75., -71., 18., 20.),
    'he': (-6.1, -5.5, -16.3, -15.5),
    'hk': (113.5, 114.7, 22., 23.),
    'ho': (-90., -83., 13., 16.6),
    'hu': (16., 23., 45.5, 49.1),
    'ic': (43., 45., -13.2, -11.),
    'icel': (-24.1, -11.5, 63., 67.5),
    'ie': (-11.1, -4.5, 50., 55.6),
    'inda': (67., 92., 4.2, 36.),
    'indo': (95., 141., -8., 6.),
    'iq': (38., 50., 29., 38.),
    'ir': (44., 65., 25., 40.),
    'is': (34., 37., 29., 34.),
    'iv': (-9., -2., 4., 11.),
    'iw': (34.8, 35.6, 31.2, 32.6),
    'iy': (6.6, 20.6, 35.6, 47.2),
    'jd': (34., 39.6, 29., 33.6),
    'jm': (-80., -76., 16., 19.),
    'jp': (123., 155., 24., 47.),
    'ka': (131., 155., 1., 9.6),
    'kash': (74., 78., 32., 35.),
    'kb': (172., 177., -3., 3.2),
    'khm': (102., 108., 10., 15.),
    'ki': (105.2, 106.2, -11., -10.),
    'kn': (32.5, 42.1, -6., 6.),
    'kna': (-62.9, -62.4, 17., 17.5),
    'ko': (124., 131.5, 33., 43.5),
    'ku': (-168., -155., -24.1, -6.1),
    'kw': (46.5, 48.5, 28.5, 30.5),
    'laos': (100., 108., 13.5, 23.1),
    'lb': (34.5, 37.1, 33., 35.),
    'lc': (60.9, 61.3, 13.25, 14.45),
    'li': (-12., -7., 4., 9.),
    'ln': (-162.1, -154.9, -4.2, 6.),
    'ls': (27., 29.6, -30.6, -28.),
    'lt': (9.3, 9.9, 47., 47.6),
    'lux': (5.6, 6.6, 49.35, 50.25),
    'ly': (8., 26., 19., 35.),
    'maar': (-63.9, -62.3, 17., 18.6),
    'made': (-17.3, -16.5, 32.6, 33.),
    'mala': (100., 119.6, 1., 8.),
    'mali': (-12.5, 6., 8.5, 25.5),
    'maur': (57.2, 57.8, -20.7, -19.9),
    'maut': (-17.1, -4.5, 14.5, 28.1),
    'mc': (-13., -1., 25., 36.),
    'mg': (43., 50.6, -25.6, -12.),
    'mh': (160., 172., 4.5, 12.1),
    'ml': (14.3, 14.7, 35.8, 36.),
    'mmr': (92., 102., 7.5, 28.5),
    'mong': (87.5, 123.1, 38.5, 52.6),
    'mr': (-61.2, -60.8, 14.3, 15.1),
    'mu': (113., 114., 22., 23.),
    'mv': (70.1, 76.1, -6., 10.),
    'mw': (32.5, 36.1, -17., -9.),
    'mx': (-119., -83., 13., 34.),
    'my': (142.5, 148.5, 9., 25.),
    'mz': (29., 41., -26.5, -9.5),
    'nama': (11., 25., -29.5, -16.5),
    'ncal': (158., 172., -23., -18.),
    'ng': (130., 152., -11., 0.),
    'ni': (2., 14.6, 3., 14.),
    'nk': (-88., -83., 10.5, 15.1),
    'nl': (3.5, 7.5, 50.5, 54.1),
    'no': (3., 35., 57., 71.5),
    'np': (80., 89., 25., 31.),
    'nw': (166.4, 167.4, -1., 0.),
    'nz': (165., 179., -48., -33.),
    'om': (52., 60., 16., 25.6),
    'os': (9., 18., 46., 50.),
    'pf': (-154., -134., -28., -8.),
    'ph': (116., 127., 4., 21.),
    'pi': (-177.5, -167.5, -9., 1.),
    'pk': (60., 78., 23., 37.),
    'pl': (14., 25., 48.5, 55.),
    'pm': (-83., -77., 7., 10.),
    'po': (-10., -4., 36.5, 42.5),
    'pr': (-82., -68., -20., 5.),
    'pt': (-130.6, -129.6, -25.56, -24.56),
    'pu': (-67.5, -65.5, 17.5, 18.5),
    'py': (-65., -54., -32., -17.),
    'qg': (7., 12., -2., 3.),
    'qt': (50., 52., 24., 27.),
    'ra': (60., -165., 25., 55.),
    're': (55., 56., -21.5, -20.5),
    'riro': (-18., -12., 17.5, 27.5),
    'ro': (19., 31., 42.5, 48.5),
    'rw': (29., 31., -3., -1.),
    'saud': (34.5, 56.1, 15., 32.6),
    'sb': (79., 83., 5., 10.),
    'seyc': (55., 56., -5., -4.),
    'sg': (-18., -10., 12., 17.),
    'si': (39.5, 52.1, -4.5, 13.5),
    'sk': (109.5, 119.3, 1., 7.),
    'sl': (-13.6, -10.2, 6.9, 10.1),
    'sm': (-59., -53., 1., 6.),
    'sn': (10., 25., 55., 69.6),
    'so': (156., 167., -12., -6.),
    'sp': (-10., 6., 35., 44.),
    'sr': (103., 105., 1., 2.),
    'su': (21.5, 38.5, 3.5, 23.5),
    'sv': (30.5, 33.1, -27.5, -25.3),
    'sw': (5.9, 10.5, 45.8, 48.),
    'sy': (35., 42.6, 32., 37.6),
    'tanz': (29., 40.6, -13., 0.),
    'td': (-62.1, -60.5, 10., 11.6),
    'tg': (-0.5, 2.5, 5., 12.),
    'th': (97., 106., 5., 21.),
    'ti': (-71.6, -70.6, 21., 22.),
    'tk': (-173., -171., -11.5, -7.5),
    'to': (-178.5, -170.5, -22., -15.),
    'tp': (6., 7.6, 0., 2.),
    'ts': (7., 13., 30., 38.),
    'tu': (25., 48., 34.1, 42.1),
    'tv': (176., 180., -11., -5.),
    'tw': (120., 122., 21.9, 25.3),
    'ug': (29., 35., -3.5, 5.5),
    'uk': (-11., 5., 49., 60.),
    'ur': (24., 41., 44., 55.),
    'uy': (-60., -52., -35.5, -29.5),
    'vanu': (167., 170., -21., -13.),
    'vi': (-65.5, -64., 16.6, 19.6),
    'vk': (13.8, 25.8, 46.75, 50.75),
    'vn': (-75., -60., -2., 14.),
    'vs': (102., 110., 8., 24.),
    'wk': (166.1, 167.1, 18.8, 19.8),
    'ye': (42.5, 54.1, 12.5, 19.1),
    'yg': (13.5, 24.6, 40., 47.),
    'za': (16., 34., -36., -22.),
    'zb': (21., 35., -20., -7.),
    'zm': (170.5, 173.5, -15., -13.),
    'zr': (12., 31.6, -14., 6.),
    'zw': (25., 34., -22.9, -15.5)
}


def lookup_projection(projection_code):
    """Get a Cartopy projection based on a short abbreviation."""
    import cartopy.crs as ccrs

    projections = {'lcc': ccrs.LambertConformal(central_latitude=40, central_longitude=-100,
                                                standard_parallels=[30, 60]),
                   'ps': ccrs.NorthPolarStereo(central_longitude=-100),
                   'mer': ccrs.Mercator()}
    return projections[projection_code]


def lookup_map_feature(feature_name):
    """Get a Cartopy map feature based on a name."""
    import cartopy.feature as cfeature
    from . import cartopy_utils

    name = feature_name.upper()
    try:
        feat = getattr(cfeature, name)
        scaler = cfeature.AdaptiveScaler('110m', (('50m', 50), ('10m', 15)))
    except AttributeError:
        feat = getattr(cartopy_utils, name)
        scaler = cfeature.AdaptiveScaler('20m', (('5m', 5), ('500k', 1)))
    return feat.with_scale(scaler)


class Panel(HasTraits):
    """Draw one or more plots."""


[docs]@exporter.export class PanelContainer(HasTraits): """Collects panels and set complete figure related settings (e.g., figsize).""" size = Union([Tuple(Int(), Int()), Instance(type(None))], default_value=None) size.__doc__ = """This trait takes a tuple of (width, height) to set the size of the figure. This trait defaults to None and will assume the default `matplotlib.pyplot.figure` size. """ panels = List(Instance(Panel)) panels.__doc__ = """A list of panels to plot on the figure. This trait must contain at least one panel to plot on the figure.""" @property def panel(self): """Provide simple access for a single panel.""" return self.panels[0] @panel.setter def panel(self, val): self.panels = [val] @observe('panels') def _panels_changed(self, change): for panel in change.new: panel.parent = self panel.observe(self.refresh, names=('_need_redraw')) @property def figure(self): """Provide access to the underlying figure object.""" if not hasattr(self, '_fig'): self._fig = plt.figure(figsize=self.size) return self._fig
[docs] def refresh(self, _): """Refresh the rendering of all panels.""" # First make sure everything is properly constructed self.draw() # Trigger the graphics refresh self.figure.canvas.draw() # Flush out interactive events--only ok on Agg for newer matplotlib try: self.figure.canvas.flush_events() except NotImplementedError: pass
[docs] def draw(self): """Draw the collection of panels.""" for panel in self.panels: with panel.hold_trait_notifications(): panel.draw()
[docs] def save(self, *args, **kwargs): """Save the constructed graphic as an image file. This method takes a string for saved file name. Additionally, the same arguments and keyword arguments that `matplotlib.pyplot.savefig` does. """ self.draw() self.figure.savefig(*args, **kwargs)
[docs] def show(self): """Show the constructed graphic on the screen.""" self.draw() self.figure.show()
[docs]@exporter.export class MapPanel(Panel): """Set figure related elements for an individual panel. Parameters that need to be set include collecting all plotting types (e.g., contours, wind barbs, etc.) that are desired to be in a given panel. Additionally, traits can be set to plot map related features (e.g., coastlines, borders), projection, graphics area, and title. """ parent = Instance(PanelContainer) layout = Tuple(Int(), Int(), Int(), default_value=(1, 1, 1)) layout.__doc__ = """A tuple that contains the description (nrows, ncols, index) of the panel position; default value is (1, 1, 1). This trait is set to describe the panel position and the default is for a single panel. For example, a four-panel plot will have two rows and two columns with the tuple setting for the upper-left panel as (2, 2, 1), upper-right as (2, 2, 2), lower-left as (2, 2, 3), and lower-right as (2, 2, 4). For more details see the documentation for `matplotlib.figure.Figure.add_subplot`. """ plots = List(Any()) plots.__doc__ = """A list of handles that represent the plots (e.g., `ContourPlot`, `FilledContourPlot`, `ImagePlot`) to put on a given panel. This trait collects the different plots, including contours and images, that are intended for a given panel. """ _need_redraw = Bool(default_value=True) area = Union([Unicode(), Tuple(Float(), Float(), Float(), Float())], allow_none=True, default_value=None) area.__doc__ = """A tuple or string value that indicates the graphical area of the plot. The tuple value coresponds to longitude/latitude box based on the projection of the map with the format (west-most longitude, east-most longitude, south-most latitude, north-most latitude). This tuple defines a box from the lower-left to the upper-right corner. This trait can also be set with a string value associated with the named geographic regions within MetPy. The tuples associated with the names are based on a PlatteCarree projection. For a CONUS region, the following strings can be used: 'us', 'spcus', 'ncus', and 'afus'. For regional plots, US state postal codes can be used. """ projection = Union([Unicode(), Instance('cartopy.crs.Projection')], default_value='data') projection.__doc__ = """A string for a pre-defined projection or a Cartopy projection object. There are three pre-defined projections that can be called with a short name: Lambert conformal conic ('lcc'), Mercator ('mer'), or polar-stereographic ('ps'). Additionally, this trait can be set to a Cartopy projection object. """ layers = List(Union([Unicode(), Instance('cartopy.feature.Feature')]), default_value=['coastline']) layers.__doc__ = """A string for a pre-defined feature layer or a Cartopy Feature object. Like the projection, there are a couple of pre-defined feature layers that can be called using a short name. The pre-defined layers are: 'coastline', 'states', 'borders', 'lakes', 'land', 'ocean', and 'rivers'. Additionally, this trait can be set using a Cartopy Feature object. """ title = Unicode() title.__doc__ = """A string to set a title for the figure. This trait sets a user-defined title that will plot at the top center of the figure. """ @observe('plots') def _plots_changed(self, change): """Handle when our collection of plots changes.""" for plot in change.new: plot.parent = self plot.observe(self.refresh, names=('_need_redraw')) self._need_redraw = True @observe('parent') def _parent_changed(self, _): """Handle when the parent is changed.""" self.ax = None @property def _proj_obj(self): """Return the projection as a Cartopy object. Handles looking up a string for the projection, or if the projection is set to ``'data'`` looks at the data for the projection. """ if is_string_like(self.projection): if self.projection == 'data': if isinstance(self.plots[0].griddata, tuple): return self.plots[0].griddata[0].metpy.cartopy_crs else: return self.plots[0].griddata.metpy.cartopy_crs else: return lookup_projection(self.projection) else: return self.projection @property def _layer_features(self): """Iterate over all map features and return as Cartopy objects. Handle converting names of maps to auto-scaling map features. """ for item in self.layers: if is_string_like(item): feat = lookup_map_feature(item) else: feat = item yield feat @observe('area') def _set_need_redraw(self, _): """Watch traits and set the need redraw flag as necessary.""" self._need_redraw = True @property def ax(self): """Get the :class:`matplotlib.axes.Axes` to draw on. Creates a new instance if necessary. """ # If we haven't actually made an instance yet, make one with the right size and # map projection. if getattr(self, '_ax', None) is None: self._ax = self.parent.figure.add_subplot(*self.layout, projection=self._proj_obj) return self._ax @ax.setter def ax(self, val): """Set the :class:`matplotlib.axes.Axes` to draw on. Clears existing state as necessary. """ if getattr(self, '_ax', None) is not None: self._ax.cla() self._ax = val
[docs] def refresh(self, changed): """Refresh the drawing if necessary.""" self._need_redraw = changed.new
[docs] def draw(self): """Draw the panel.""" # Only need to run if we've actually changed. if self._need_redraw: # Draw all of the plots. for p in self.plots: with p.hold_trait_notifications(): p.draw() # Add all of the maps for feat in self._layer_features: self.ax.add_feature(feat) # Set the extent as appropriate based on the area. One special case for 'global' if self.area == 'global': self.ax.set_global() elif self.area is not None: # Try to look up if we have a string if is_string_like(self.area): area = _areas[self.area] # Otherwise, assume we have a tuple to use as the extent else: area = self.area self.ax.set_extent(area, DEFAULT_LAT_LON) # Use the set title or generate one. title = self.title or ',\n'.join(plot.name for plot in self.plots) self.ax.set_title(title) self._need_redraw = False
[docs]@exporter.export class Plots2D(HasTraits): """The highest level class related to plotting 2D data. This class collects all common methods no matter whether plotting a scalar variable or vector. Primary settings common to all types of 2D plots are time and level. """ parent = Instance(Panel) _need_redraw = Bool(default_value=True) level = Union([Int(allow_none=True, default_value=None), Instance(units.Quantity)]) level.__doc__ = """The level of the field to be plotted. This is a value with units to choose the desired plot level. For example, selecting the 850-hPa level, set this parameter to ``850 * units.hPa`` """ time = Instance(datetime, allow_none=True) time.__doc__ = """Set the valid time to be plotted as a datetime object. If a forecast hour is to be plotted the time should be set to the valid future time, which can be done using the `~datetime.datetime` and `~datetime.timedelta` objects from the Python standard library. """ @property def _cmap_obj(self): """Return the colormap object. Handle convert the name of the colormap to an object from matplotlib or metpy. """ try: return ctables.registry.get_colortable(self.colormap) except KeyError: return plt.get_cmap(self.colormap) @property def _norm_obj(self): """Return the normalization object. Converts the tuple image range to a matplotlib normalization instance. """ return plt.Normalize(*self.image_range)
[docs] def clear(self): """Clear the plot. Resets all internal state and sets need for redraw. """ if getattr(self, 'handle', None) is not None: if getattr(self.handle, 'collections', None) is not None: self.clear_collections() else: self.clear_handle() self._need_redraw = True
[docs] def clear_handle(self): """Clear the handle to the plot instance.""" self.handle.remove() self.handle = None
[docs] def clear_collections(self): """Clear the handle collections to the plot instance.""" for col in self.handle.collections: col.remove() self.handle = None
@observe('parent') def _parent_changed(self, _): """Handle setting the parent object for the plot.""" self.clear() @observe('level', 'time') def _update_data(self, _=None): """Handle updating the internal cache of data. Responds to changes in various subsetting parameters. """ self._griddata = None self.clear() # Can't be a Traitlet because notifications don't work with arrays for traits # notification never happens @property def data(self): """Xarray dataset that contains the field to be plotted.""" return self._data @data.setter def data(self, val): self._data = val self._update_data() @property def name(self): """Generate a name for the plot.""" if isinstance(self.field, tuple): ret = '' ret += ' and '.join(f for f in self.field) else: ret = self.field if self.level is not None: ret += '@{:d}'.format(self.level) return ret
[docs]@exporter.export class PlotScalar(Plots2D): """Defines the common elements of 2D scalar plots for single scalar value fields. Most of the other traits here are for one or more of the specific plots. Currently this allows too many options for `ContourPlot` since it does not user image_range, for example. Similar issues for `ImagePlot` and `FilledContourPlot`. """ field = Unicode() field.__doc__ = """Name of the field to be plotted. This is the name of the variable from the dataset that is to be plotted. An example, from a model grid file that uses the THREDDS convention for naming would be `Geopotential_height_isobaric` or `Temperature_isobaric`. For GOES-16/17 satellite data it might be `Sectorized_CMI`. To check for the variables available within a dataset, list the variables with the following command assuming the dataset was read using xarray as `ds`, `list(ds)` """ @observe('field') def _update_data(self, _=None): """Handle updating the internal cache of data. Responds to changes in various subsetting parameters. """ self._griddata = None self.clear() @property def griddata(self): """Return the internal cached data.""" if getattr(self, '_griddata', None) is None: if self.field: data = self.data.metpy.parse_cf(self.field) elif not hasattr(self.data.metpy, 'x'): # Handles the case where we have a dataset but no specified field raise ValueError('field attribute has not been set.') else: data = self.data subset = {'method': 'nearest'} if self.level is not None: subset[data.metpy.vertical.name] = self.level if self.time is not None: subset[data.metpy.time.name] = self.time self._griddata = data.metpy.sel(**subset).squeeze() return self._griddata @property def plotdata(self): """Return the data for plotting. The data array, x coordinates, and y coordinates. """ x = self.griddata.metpy.x y = self.griddata.metpy.y if 'degree' in x.units: x, y, _ = self.griddata.metpy.cartopy_crs.transform_points(DEFAULT_LAT_LON, *np.meshgrid(x, y)).T x = x[:, 0] % 360 y = y[0, :] return x, y, self.griddata
[docs] def draw(self): """Draw the plot.""" if self._need_redraw: if getattr(self, 'handle', None) is None: self._build() if getattr(self, 'colorbar', None) is not None: self.parent.ax.figure.colorbar( self.handle, orientation=self.colorbar, pad=0, aspect=50) self._need_redraw = False
class ContourTraits(HasTraits): """Represents common contour traits.""" contours = Union([List(Float()), Int()], default_value=25) contours.__doc__ = """A list of values to contour or an integer number of contour levels. This parameter sets contour or colorfill values for a plot. Values can be entered either as a list of values or as an integer with the number of contours to be plotted (as per matplotlib documentation). A list can be generated by using square brackets or creating a numpy 1D array and converting it to a list with the `~numpy.ndarray.tolist` method. """ clabels = Bool(default_value=False) clabels.__doc__ = """A boolean (True/False) on whether to plot contour labels. To plot contour labels set this trait to ``True``, the default value is ``False``. """ class ColorfillTraits(HasTraits): """Represent common colorfill traits.""" colormap = Unicode(allow_none=True, default_value=None) colormap.__doc__ = """The string name for a Matplolib or MetPy colormap. For example, the Blue-Purple colormap from Matplotlib can be accessed using 'BuPu'. """ image_range = Union([Tuple(Int(allow_none=True), Int(allow_none=True)), Instance(plt.Normalize)], default_value=(None, None)) image_range.__doc__ = """A tuple of min and max values that represent the range of values to color the rasterized image. The min and max values entered as a tuple will be converted to a `matplotlib.colors.Normalize` instance for plotting. """ colorbar = Unicode(default_value=None, allow_none=True) colorbar.__doc__ = """A boolean (True/False) on whether to add a colorbar to the plot. To add a colorbar associated with the plot data set the trait to ``True``, the default values is ``False``. """
[docs]@exporter.export class ImagePlot(PlotScalar, ColorfillTraits): """Make raster image using `~matplotlib.pyplot.imshow` for satellite or colored image.""" @observe('colormap', 'image_range') def _set_need_redraw(self, _): """Handle changes to attributes that just need a simple redraw.""" if hasattr(self, 'handle'): self.handle.set_cmap(self._cmap_obj) self.handle.set_norm(self._norm_obj) self._need_redraw = True @observe('colorbar') def _set_need_rebuild(self, _): """Handle changes to attributes that need to regenerate everything.""" # Because matplotlib doesn't let you just change these properties, we need # to trigger a clear and re-call of contour() self.clear() @property def plotdata(self): """Return the data for plotting. The data array, x coordinates, and y coordinates. """ x = self.griddata.metpy.x y = self.griddata.metpy.y # At least currently imshow with cartopy does not like this if 'degree' in x.units: x = x.data x[x > 180] -= 360 return x, y, self.griddata def _build(self): """Build the plot by calling any plotting methods as necessary.""" x, y, imdata = self.plotdata # We use min/max for y and manually figure out origin to try to avoid upside down # images created by images where y[0] > y[-1] extents = (x[0], x[-1], y.min(), y.max()) origin = 'upper' if y[0] > y[-1] else 'lower' self.handle = self.parent.ax.imshow(imdata, extent=extents, origin=origin, cmap=self._cmap_obj, norm=self._norm_obj, transform=imdata.metpy.cartopy_crs)
[docs]@exporter.export class ContourPlot(PlotScalar, ContourTraits): """Make contour plots by defining specific traits.""" linecolor = Unicode('black') linecolor.__doc__ = """A string value to set the color of plotted contours; default is black. This trait can be set to any Matplotlib color (https://matplotlib.org/3.1.0/gallery/color/named_colors.html) """ linewidth = Int(2) linewidth.__doc__ = """An integer value to set the width of plotted contours; default value is 2. This trait changes the thickness of contour lines with a higher value plotting a thicker line. """ linestyle = Unicode('solid', allow_none=True) linestyle.__doc__ = """A string value to set the linestyle (e.g., dashed); default is solid. The valid string values are those of Matplotlib which are solid, dashed, dotted, and dashdot. """ @observe('contours', 'linecolor', 'linewidth', 'linestyle', 'clabels') def _set_need_rebuild(self, _): """Handle changes to attributes that need to regenerate everything.""" # Because matplotlib doesn't let you just change these properties, we need # to trigger a clear and re-call of contour() self.clear() def _build(self): """Build the plot by calling any plotting methods as necessary.""" x, y, imdata = self.plotdata self.handle = self.parent.ax.contour(x, y, imdata, self.contours, colors=self.linecolor, linewidths=self.linewidth, linestyles=self.linestyle, transform=imdata.metpy.cartopy_crs) if self.clabels: self.handle.clabel(inline=1, fmt='%.0f', inline_spacing=2, use_clabeltext=True)
[docs]@exporter.export class FilledContourPlot(PlotScalar, ColorfillTraits, ContourTraits): """Make color-filled contours plots by defining appropriate traits.""" @observe('contours', 'colorbar', 'colormap') def _set_need_rebuild(self, _): """Handle changes to attributes that need to regenerate everything.""" # Because matplotlib doesn't let you just change these properties, we need # to trigger a clear and re-call of contour() self.clear() def _build(self): """Build the plot by calling any plotting methods as necessary.""" x, y, imdata = self.plotdata self.handle = self.parent.ax.contourf(x, y, imdata, self.contours, cmap=self._cmap_obj, norm=self._norm_obj, transform=imdata.metpy.cartopy_crs)
[docs]@exporter.export class PlotVector(Plots2D): """Defines common elements for 2D vector plots. This class collects common elements including the field trait, which is a tuple argument accepting two strings, for plotting 2D vector fields. """ field = Tuple(Unicode(), Unicode()) field.__doc__ = """A tuple containing the two components of the vector field from the dataset in the form (east-west component, north-south component). For a wind barb plot each component of the wind must be specified and should be of the form (u-wind, v-wind). """ pivot = Unicode('middle') pivot.__doc__ = """A string setting the pivot point of the vector. Default value is 'middle'. This trait takes the values of the keyword argument from `matplotlin.pyplot.barbs`: 'tip' or 'middle'. """ skip = Tuple(Int(), Int(), default_value=(1, 1)) skip.__doc__ = """A tuple of integers to indicate the number of grid points to skip between plotting vectors. Default is (1, 1). This trait is to be used to reduce the number of vectors plotted in the (east-west, north-south) components. The two values can be set to the same or different integer values depending on what is desired. """ earth_relative = Bool(default_value=True) earth_relative.__doc__ = """A boolean value to indicate whether the vector to be plotted is earth- or grid-relative. Default value is `True`, indicating that vectors are earth-relative. Common gridded meteorological datasets including GFS and NARR output contain wind components that are earth-relative. The primary expection is NAM output with wind components that are grid-relative. For any grid-relative vectors set this trait to `False`. """ color = Unicode(default_value='black') color.__doc__ = """A string value that controls the color of the vectors. Default value is black. This trait can be set to any named color from `Matplotlibs Colors <https://matplotlib.org/3.1.0/gallery/color/named_colors.html>` """ @observe('field') def _update_data(self, _=None): """Handle updating the internal cache of data. Responds to changes in various subsetting parameters. """ self._griddata_u = None self._griddata_v = None self.clear() @property def griddata(self): """Return the internal cached data.""" if getattr(self, '_griddata_u', None) is None: if self.field[0]: u = self.data.metpy.parse_cf(self.field[0]) v = self.data.metpy.parse_cf(self.field[1]) else: raise ValueError('field attribute not set correctly') subset = {'method': 'nearest'} if self.level is not None: subset[u.metpy.vertical.name] = self.level if self.time is not None: subset[u.metpy.time.name] = self.time self._griddata_u = u.metpy.sel(**subset).squeeze() self._griddata_v = v.metpy.sel(**subset).squeeze() return (self._griddata_u, self._griddata_v) @property def plotdata(self): """Return the data for plotting. The data array, x coordinates, and y coordinates. """ x = self.griddata[0].metpy.x y = self.griddata[0].metpy.y if self.earth_relative: x, y, _ = DEFAULT_LAT_LON.transform_points(self.griddata[0].metpy.cartopy_crs, *np.meshgrid(x, y)).T x = x.T y = y.T else: if 'degree' in x.units: x, y, _ = self.griddata[0].metpy.cartopy_crs.transform_points( DEFAULT_LAT_LON, *np.meshgrid(x, y)).T x = x.T % 360 y = y.T if x.ndim == 1: xx, yy = np.meshgrid(x, y) else: xx, yy = x, y return xx, yy, self.griddata[0], self.griddata[1]
[docs] def draw(self): """Draw the plot.""" if self._need_redraw: if getattr(self, 'handle', None) is None: self._build() self._need_redraw = False
[docs]@exporter.export class BarbPlot(PlotVector): """Make plots of wind barbs on a map with traits to refine the look of plotted elements.""" barblength = Float(default_value=7) barblength.__doc__ = """A float value that changes the length of the wind barbs. Default value is 7. This trait corresponds to the keyword length in `matplotlib.pyplot.barbs`. """ @observe('barblength', 'pivot', 'skip', 'earth_relative', 'color') def _set_need_rebuild(self, _): """Handle changes to attributes that need to regenerate everything.""" # Because matplotlib doesn't let you just change these properties, we need # to trigger a clear and re-call of contour() self.clear() def _build(self): """Build the plot by calling needed plotting methods as necessary.""" x, y, u, v = self.plotdata if self.earth_relative: transform = DEFAULT_LAT_LON else: transform = u.metpy.cartopy_crs wind_slice = (slice(None, None, self.skip[0]), slice(None, None, self.skip[1])) self.handle = self.parent.ax.barbs( x[wind_slice], y[wind_slice], u.values[wind_slice], v.values[wind_slice], color=self.color, pivot=self.pivot, length=self.barblength, transform=transform)