Example 10: Custom coastline
============================

This example demonstrates how to plot a map wwith custom coastal line with GINCCO_lib
using :func:`GINCCO_lib.map_plot.map_draw`.


Code Example
------------

Now we will import the library and the grid

.. code-block:: python

    # =========================
    # IMPORTS
    # =========================
    import numpy as np
    import GINCCO_lib as gc
    from netCDF4 import Dataset
    from datetime import *

    # =========================
    # CONFIGURATION
    # =========================
    tstart = datetime(2010, 1, 1)
    tend   = datetime(2010, 1, 10)

    path = '/work/users/tungnd/GOT271/GOT_REF5/OFFLINE/'

    # =========================
    # LOAD GRID
    # =========================
    fgrid = Dataset(path + 'grid.nc', 'r')
    lat_t = fgrid.variables['latitude_t'][:]
    lon_t = fgrid.variables['longitude_t'][:]



Now define the box to average. In this example, we will define 3 boxes

.. code-block:: python

    # ============================================================
    # EXAMPLE 10: plot with a custom coast line
    # ============================================================


    # OpenStreetMap shapefile is in a projected coordinate system (meters) instead of geographic (lat/lon)
    # and Basemap requires longitude–latitude (EPSG:4326) coordinates.
    # So we need to convert it
    # Note: it may be super slow to run this command (10 or more minutes). Please be patient when the code is running. 

    import geopandas as gpd

    # Read the Web Mercator shapefile
    gdf = gpd.read_file("/data/projects/LOTUS/tungnd/openstreetmap-coastline/lines.shp")

    # Convert to geographic coordinates (lon/lat)
    gdf = gdf.to_crs(epsg=4326)

    # Save as a new shapefile
    gdf.to_file("/data/projects/LOTUS/tungnd/openstreetmap-coastline/osm_coastline_wgs84.shp")

    # Simplified version for faster loading
    shp_simplified = gdf.simplify(tolerance=0.05)
    gdf.geometry = shp_simplified
    gdf.to_file("/data/projects/LOTUS/tungnd/openstreetmap-coastline/osm_coastline_wgs84_simple.shp")





Now import data, and draw, with full resolution coastal line

.. code-block:: python

    sal_full = gc.import_4D(path, 'sal', tstart, tend, ignore_missing='False')

    # Plot using the full coastal line
    gc.map_draw(
        lon_min=105, lon_max=111,
        lat_min=16.5, lat_max=22,
        title="Bottom salinity (example 1)",
        lon_data=lon_t,
        lat_data=lat_t,
        data_draw=sal_full[0, 0, :, :],  # day 0, level 0
        path_save="/prod/projects/data/tungnd/figure/",
        name_save="example10.1", 
        custom_coastline = "/data/projects/LOTUS/tungnd/openstreetmap-coastline/osm_coastline_wgs84", 
        layer_name= "osm_coastline_wgs84",
    )



.. image:: ../_static/example10.1_49071.png
   :width: 500px
   :align: center


Plot using the simplified coastal line

.. code-block:: python

    gc.map_draw(
        lon_min=105, lon_max=111,
        lat_min=16.5, lat_max=22,
        title="Bottom salinity (example 1)",
        lon_data=lon_t,
        lat_data=lat_t,
        data_draw=sal_full[0, 0, :, :],  # day 0, level 0
        path_save="/prod/projects/data/tungnd/figure/",
        name_save="example10.2", 
        custom_coastline = "/data/projects/LOTUS/tungnd/openstreetmap-coastline/osm_coastline_wgs84_simple", 
        layer_name= "osm_coastline_wgs84_simple",
    )


.. image:: ../_static/example10.2_76829.png
   :width: 500px
   :align: center