plot domains from table

[larsbuntemeyer]

import cartopy.crs as ccrs
import geopandas as gpd
import pandas as pd
from pyproj import CRS
from shapely.geometry import Polygon

df = pd.read_csv(
    "https://raw.githubusercontent.com/WCRP-CORDEX/domain-tables/main/rotated-latitude-longitude.csv",
    index_col="domain_id",
)

def create_polygon(domain_id):
    """create polygon in rotated pole coords"""
    data = df.loc[domain_id].to_dict()
    coords = [
        [data["ll_lon"], data["ll_lat"]],
        [data["ur_lon"], data["ll_lat"]],
        [data["ur_lon"], data["ur_lat"]],
        [data["ll_lon"], data["ur_lat"]],
    ]
    return Polygon(coords)

def get_ccrs(domain_id):
    data = df.loc[domain_id].to_dict()
    return ccrs.RotatedPole(data["pollon"], data["pollat"])

def get_crs(domain_id):
    data = df.loc[domain_id].to_dict()
    return CRS.from_cf(
        {
            "grid_mapping_name": "rotated_latitude_longitude",
            "grid_north_pole_longitude": data["pollon"],
            "grid_north_pole_latitude": data["pollat"],
        }
    )

def get_geodataframe(domain_id):
    polygon = create_polygon(domain_id)
    crs = get_crs(domain_id)
    return gpd.GeoDataFrame(index=[0], crs=crs, geometry=[polygon])

def get_center(domain_id):
    data = df.loc[domain_id].to_dict()
    return (
        0.5 * (data["ur_lon"] + data["ll_lon"]),
        0.5 * (data["ur_lat"] + data["ll_lat"]),
    )

def transform_center(cenlon, cenlat, transform, proj=None):
    if proj is None:
        proj = ccrs.PlateCarree()
    return plate.transform_point(cenlon, cenlat, transform)

def plot_domain(domain_id, figsize=None):
    import matplotlib.pyplot as plt

    if figsize is None:
        figsize=(20,10)
    polygon = create_polygon(domain_id)
    rotated = get_ccrs(domain_id)
    cenlon, cenlat = transform_center(*get_center(domain_id), rotated)
    print(cenlon, cenlat)
    #projection = ccrs.NearsidePerspective(
    #    central_longitude=cenlon, central_latitude=cenlat, globe=None, satellite_height = 10000000
    #)
    projection = ccrs.Orthographic(
        central_longitude=cenlon, central_latitude=cenlat, globe=None
    )
    # https://stackoverflow.com/questions/59020032/how-to-plot-a-filled-polygon-on-a-map-in-cartopy
    projection._threshold /= 100.0

    plt.figure(figsize=figsize)
    ax = plt.axes(projection=projection)
    ax.stock_img()

    ax.gridlines(
        draw_labels=True,
        linewidth=0.8,
        color="gray",
        xlocs=range(-180, 180, 15),
        ylocs=range(-90, 90, 15),
    )
    ax.coastlines(resolution="50m", linewidth=0.3, color="black")

    ax.add_geometries(
        [create_polygon(domain_id)],
        crs=get_ccrs(domain_id),
        facecolor="none",
        edgecolor="red",
        alpha=1.0,
        lw=2.0,
    )

    return

plot_domain("EUR-11", figsize=(10,10))