4 ms·

Do you have any experience with the Google Maps API? I would love to implement this.

mkl 7y ago
No I don't. All you need, though, is the ability to draw straight lines (well, great circle lines) between points. You could do the region generation once offline, in Python: import numpy as np from scipy.spatial import SphericalVoronoi import json with open('volcanos.json', 'rt') as f: volcanos = json.load(f) #There are some nulls in the data: volcanos = [v for v in volcanos if v['longitude'] != None and v['latitude'] != None] def longlat_to_xyz(longlat): longlat = longlat.reshape((-1, 2))*(np.pi/180.) r = np.cos(longlat[:, 1]) return np.column_stack((r*np.cos(longlat[:, 0]), r*np.sin(longlat[:, 0]), np.sin(longlat[:, 1]))) #go through set to remove duplicates: volcano_longlat = np.array(list(set((v['longitude'], v['latitude']) for v in volcanos))) volcano_xyz = longlat_to_xyz(volcano_longlat) sv = SphericalVoronoi(volcano_xyz) sv.sort_vertices_of_regions() #make the vertices go around each shape #find unique edges (they're shared between regions): edges = set() for region in sv.regions: region.append(region[0]) for i in range(len(region)-1): edges.add((region[i], region[i+1])) long_min = -30. long_max = 330. def xyz_to_longlat(xyz, long_min=long_min, long_max=long_max): long = np.arctan2(xyz[:, 1], xyz[:, 0])*(180./np.pi) long[long<long_min] += 360. long[long>long_max] -= 360. return np.column_stack((long, np.arcsin(xyz[:, 2])*(180./np.pi))) vertices = xyz_to_longlat(sv.vertices) #To draw the regions on Google Maps etc., save edges and vertices as JSON and load into JS. #To draw the linked map with Matplotlib (very slow for hi-res, and it was fiddly setting up the right conda environment): import matplotlib.pyplot as plt from mpl_toolkits.basemap import Basemap fig, ax = plt.subplots(figsize=(16, 10)) m = Basemap(projection='robin', lon_0=-200, resolution='h', ax=ax) m.drawcoastlines(linewidth=.1) m.drawcountries(linewidth=.1) volcano_longlat2 = xyz_to_longlat(volcano_xyz) x, y = m(volcano_longlat2[:, 0], volcano_longlat2[:, 1]) m.plot(x, y, 'ro', markersize=.5) for edge in edges: m.drawgreatcircle(vertices[edge[0], 0], vertices[edge[0], 1], vertices[edge[1], 0], vertices[edge[1], 1], color='b', linewidth=.3) fig.tight_layout() fig.savefig('volcano_voronoi.png', dpi=600)
- bonoboTP 7y ago
  You have to use "is not None" instead of "!= None"

mkl 7y ago

No I don't. All you need, though, is the ability to draw straight lines (well, great circle lines) between points. You could do the region generation once offline, in Python: import numpy as np from scipy.spatial import SphericalVoronoi import json with open('volcanos.json', 'rt') as f: volcanos = json.load(f) #There are some nulls in the data: volcanos = [v for v in volcanos if v['longitude'] != None and v['latitude'] != None] def longlat_to_xyz(longlat): longlat = longlat.reshape((-1, 2))*(np.pi/180.) r = np.cos(longlat[:, 1]) return np.column_stack((r*np.cos(longlat[:, 0]), r*np.sin(longlat[:, 0]), np.sin(longlat[:, 1]))) #go through set to remove duplicates: volcano_longlat = np.array(list(set((v['longitude'], v['latitude']) for v in volcanos))) volcano_xyz = longlat_to_xyz(volcano_longlat) sv = SphericalVoronoi(volcano_xyz) sv.sort_vertices_of_regions() #make the vertices go around each shape #find unique edges (they're shared between regions): edges = set() for region in sv.regions: region.append(region[0]) for i in range(len(region)-1): edges.add((region[i], region[i+1])) long_min = -30. long_max = 330. def xyz_to_longlat(xyz, long_min=long_min, long_max=long_max): long = np.arctan2(xyz[:, 1], xyz[:, 0])*(180./np.pi) long[long<long_min] += 360. long[long>long_max] -= 360. return np.column_stack((long, np.arcsin(xyz[:, 2])*(180./np.pi))) vertices = xyz_to_longlat(sv.vertices) #To draw the regions on Google Maps etc., save edges and vertices as JSON and load into JS. #To draw the linked map with Matplotlib (very slow for hi-res, and it was fiddly setting up the right conda environment): import matplotlib.pyplot as plt from mpl_toolkits.basemap import Basemap fig, ax = plt.subplots(figsize=(16, 10)) m = Basemap(projection='robin', lon_0=-200, resolution='h', ax=ax) m.drawcoastlines(linewidth=.1) m.drawcountries(linewidth=.1) volcano_longlat2 = xyz_to_longlat(volcano_xyz) x, y = m(volcano_longlat2[:, 0], volcano_longlat2[:, 1]) m.plot(x, y, 'ro', markersize=.5) for edge in edges: m.drawgreatcircle(vertices[edge[0], 0], vertices[edge[0], 1], vertices[edge[1], 0], vertices[edge[1], 1], color='b', linewidth=.3) fig.tight_layout() fig.savefig('volcano_voronoi.png', dpi=600)

bonoboTP 7y ago
You have to use "is not None" instead of "!= None"