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# Metview Example

#  **************************** LICENSE START ***********************************
# 
#  Copyright 2015 ECMWF. This software is distributed under the terms
#  of the Apache License version 2.0. In applying this license, ECMWF does not
#  waive the privileges and immunities granted to it by virtue of its status as
#  an Intergovernmental Organization or submit itself to any jurisdiction.
# 
#  ***************************** LICENSE END ************************************

# ------------------------------------------------------------------
# Tags: contour,legend
# Title: Positional and Histogram Legend
# Description: Demonstrates how to combine two fields into a single plot
#              using contour and shade. A histogram legend is used for one
#              of the fields.
# See also:
# https://software.ecmwf.int/magics/Legend+examples+legend3
# ------------------------------------------------------------------

# read the input grib files (temperature and geopotential)

import metview as mv

my_data1 = mv.read("./t850.grb")
my_data2 = mv.read("./z500.grb")

# set up the geographical view
my_view = mv.geoview(map_area_definition = "CORNERS",
                  map_projection         = "POLAR_STEREOGRAPHIC",
                  area                   = [21.51,-37.27,51.28,65.00])

# set up a shade contour with legend for the temperature field
my_contour1 = mv.mcont(contour_level_selection_type   = "LEVEL_LIST",
                    contour_level_list                = [-10.0,-8.0,-6.0,-4.0,-2.0,0.0,2.0,4.0,6.0,8.0,10.0],
                    contour                           = "OFF",
                    contour_label                     = "OFF",
                    contour_hilo                      = "OFF",
                    legend                            = "ON",
                    contour_shade                     = "ON",
                    contour_shade_method              = "AREA_FILL",  
                    contour_shade_colour_direction    = "CLOCKWISE",
                    contour_shade_max_level_colour    = "RED",
                    contour_shade_min_level_colour    = "BLUE")

# set up a black contour line for the geopotential field
my_contour2 = mv.mcont(contour_level_selection_type = "INTERVAL",
                    contour_line_colour             = "BLACK",
                    contour_line_thickness          = 1,
                    contour_hilo_height             = 0.25,
                    contour_interval                = 5.00,
                    contour_hilo                    = "ON",
                    contour_hilo_quality            = "HIGH",
                    contour_highlight_colour        = "BLACK",
                    contour_highlight_thickness     = 2,
                    contour_label                   = "OFF",
                    legend                          = "OFF")

# set up the coastlines
my_coast= mv.mcoast(map_coastline_resolution = "HIGH",
                 map_grid_colour             = "CHARCOAL",
                 map_grid                    = "ON",
                 map_coastline_colour        = "CHARCOAL")

# set up the title
my_title = mv.mtext(text_font_size  = 0.60,
                 text_lines         = ["Positional and histogram legend","","","","","",""],
                 text_justification = "LEFT",
                 text_colour        = "CHARCOAL")

# set up an histogram legend for the temperature field
my_legend =  mv.mlegend(legend_box_mode          = "POSITIONAL",
                     legend_box_x_position       = 1.00,
                     legend_box_x_length         = 27.00,
                     legend_box_y_position       = 16.00,
                     legend_box_y_length         = 3.00,
                     legend_display_type         = "HISTOGRAM",
                     legend_histogram_max_value = "ON",
                     legend_label_frequency      = 1,
                     legend_text_font_size       = 0.40,
                     legend_text_colour          = "BLACK",
                     legend_title                = "ON",
                     legend_title_text           = "Temperature at 850 hPa")


# define the output plot file
mv.setoutput(mv.pdf_output(output_name = 'legend3'))

# plot the map
mv.plot(my_view,my_data1,my_contour1,my_data2,my_contour2,my_coast,my_title,my_legend)