#!/usr/bin/env python
# coding: utf-8

# # Using Exotic Map Projections: `use_crs="provided"`
# 
# Value "provided" tells Lets-Plot that the input GeoDataframe already contains coordinates in the desired CRS and should not be reprojected any further.
# 
# This is a workaround for the case when the desired CRS is not naturally supported by Lets-Plot.
# 
# For example, if you try to use the **Robinson** projection (EPSG:54030): `use_crs="EPSG:54030"`, then Lets-Plot will return an error: 
# > CRSError: Invalid projection: EPSG:54030: (Internal Proj Error: proj_create: crs not found)
# 
# Let's see how can we still plot a map in the **Robinsons** projection in Lets-Plot.

# In[1]:


from lets_plot import *
from lets_plot.geo_data import *


# In[2]:


LetsPlot.setup_html()


# #### 1. Default Presentation

# In[3]:


world = geocode_countries().inc_res().get_boundaries()

ggplot() + geom_map(map=world)


# #### 2. Project "World"  to the Robinson's

# In[4]:


from cartopy import crs as ccrs

# Define the CartoPy CRS object.
crs = ccrs.Robinson()

# This can be converted into a `proj4` string/dict compatible with GeoPandas
crs_proj4 = crs.proj4_init
world_robinson = world.to_crs(crs_proj4)

ggplot() + geom_map(map=world_robinson, use_crs="provided")


# #### 3. Options

# In[5]:


(ggplot() + 
 geom_polygon(map=world_robinson, use_crs="provided", color="white") + 
 theme_void() + theme(plot_title=element_text(face="bold-italic")) + flavor_solarized_light() + 
 ggsize(2048, 1096) + 
 xlim(-13E6, None) + 
 ggtitle("World in the Robinson Projection")
)