#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Wed Nov 22 14:04:14 2017

@author: dandrea
"""

import matplotlib.pyplot as plt
import numpy as np    
from mpl_toolkits.basemap import Basemap


def cylmap_BM(lat,lon,field, *args, **kwargs):

    
    ''' Plots a contour map of the array in "field" over a map of the Earth with coastlines
        and latitude longitude grid. Contours are couloured and filled, a colorbar is shown.
        
        "lat" and "lon" are vectors specifying the latitude and longitude of the map. 
        They must have dimensions compatible with "field". 
        
        Optional parameters:
            levels : array_like
                an array containing the contour levels for the map, 
                default is nlev levels between the minimum 
                and the maximum of field
            nlev   : int
                number of levels, default 10, if levels is specified, nlev is overridden
            title  : str
                plot title, default "no title"
            
  
      '''

    titles = kwargs.get('titl',"")
    nlev  = kwargs.get('nlev',10)

#    plt.figure(figsize=(10, 8))

    # llcrnrlat,llcrnrlon,urcrnrlat,urcrnrlon
    # are the lat/lon values of the lower left and upper right corners
    # of the map.
    # resolution = 'c' means use crude resolution coastlines.
    m = Basemap(projection='cyl',llcrnrlat=lat[-1],urcrnrlat=lat[0],\
                llcrnrlon=lon[0],urcrnrlon=lon[-1],resolution='c')
    m.drawcoastlines()
#    m.fillcontinents(color='coral',lake_color='aqua')
    # draw parallels and meridians.
    m.drawparallels(np.arange(-90.,91.,30.))
    m.drawmeridians(np.arange(-180.,181.,60.))
    m.drawmapboundary(fill_color='aqua')
    if titles : plt.title(titles)

    x,y=np.meshgrid(lon, lat)  
    lev=(np.linspace((field.min()), (field.max()),nlev))  # DEFAULT LEVELS
    lev = kwargs.get('levels',lev)
    m.contourf(x,y,field,levels=lev)