Coverage for pyguymer3/geo/_add_urbanAreas.py: 3%

1#!/usr/bin/env python3 

2 

3# Define function ... 

4def _add_urbanAreas( 

5 ax, 

6 /, 

7 *, 

8 debug = __debug__, 

9 fov = None, 

10 onlyValid = False, 

11 repair = False, 

12 resolution = "10m", 

13): 

14 """Add urban areas to a Cartopy axis. 

15 

16 Parameters 

17 ---------- 

18 axis : cartopy.mpl.geoaxes.GeoAxesSubplot 

19 the axis to add the urban areas to 

20 debug : bool, optional 

21 print debug messages 

22 fov : None or shapely.geometry.polygon.Polygon, optional 

23 clip the plotted shapes to the provided field-of-view to work around 

24 occaisional MatPlotLib or Cartopy plotting errors when shapes much 

25 larger than the field-of-view are plotted 

26 onlyValid : bool, optional 

27 only add valid Polygons (checks for validity can take a while, if being 

28 being called often) 

29 repair : bool, optional 

30 attempt to repair invalid Polygons 

31 resolution : str, optional 

32 the resolution of the urban areas 

33 

34 Notes 

35 ----- 

36 This function uses `CSS4 named colours 

37 <https://matplotlib.org/stable/gallery/color/named_colors.html>`_ . 

38 

39 Copyright 2017 Thomas Guymer [1]_ 

40 

41 References 

42 ---------- 

43 .. [1] PyGuymer3, https://github.com/Guymer/PyGuymer3 

44 """ 

45 

46 # Import standard modules ... 

47 import pathlib 

48 import urllib 

49 

50 # Import special modules ... 

51 try: 

52 import cartopy 

53 cartopy.config.update( 

54 { 

55 "cache_dir" : pathlib.PosixPath("~/.local/share/cartopy_cache").expanduser(), 

56 } 

57 ) 

58 except: 

59 raise Exception("\"cartopy\" is not installed; run \"pip install --user Cartopy\"") from None 

60 try: 

61 import matplotlib 

62 matplotlib.rcParams.update( 

63 { 

64 "backend" : "Agg", # NOTE: See https://matplotlib.org/stable/gallery/user_interfaces/canvasagg.html 

65 "figure.dpi" : 300, 

66 "figure.figsize" : (9.6, 7.2), # NOTE: See https://github.com/Guymer/misc/blob/main/README.md#matplotlib-figure-sizes 

67 "font.size" : 8, 

68 } 

69 ) 

70 except: 

71 raise Exception("\"matplotlib\" is not installed; run \"pip install --user matplotlib\"") from None 

72 

73 # Import sub-functions ... 

74 from .extract_polys import extract_polys 

75 

76 # ************************************************************************** 

77 

78 # Create suitable colour ... 

79 facecolor = matplotlib.colors.to_rgba(matplotlib.colors.CSS4_COLORS["gold"]) 

80 if debug: 

81 print(f"INFO: \"urban_areas\" is ({facecolor[0]:.6f},{facecolor[1]:.6f},{facecolor[2]:.6f},{facecolor[3]:.6f}).") 

82 

83 # Find file containing the shapes ... 

84 try: 

85 sfile = cartopy.io.shapereader.natural_earth( 

86 resolution = resolution, 

87 category = "cultural", 

88 name = "urban_areas", 

89 ) 

90 except urllib.error.HTTPError: 

91 return 

92 if debug: 

93 print(f"INFO: \"urban_areas\" is \"{sfile}\".") 

94 

95 # Loop over records ... 

96 for record in cartopy.io.shapereader.Reader(sfile).records(): 

97 # Skip bad records ... 

98 if not hasattr(record, "geometry"): 

99 continue 

100 

101 # Create a list of Polygons to plot (taking in to account if the user 

102 # provided a field-of-view to clip them by) ... 

103 polys = [] 

104 for poly in extract_polys( 

105 record.geometry, 

106 onlyValid = onlyValid, 

107 repair = repair, 

108 ): 

109 if fov is None: 

110 polys.append(poly) 

111 continue 

112 if poly.disjoint(fov): 

113 continue 

114 polys.append(poly.intersection(fov)) 

115 

116 # Plot geometry ... 

117 ax.add_geometries( 

118 polys, 

119 cartopy.crs.PlateCarree(), 

120 edgecolor = "none", 

121 facecolor = facecolor, 

122 )