# Metview Macro
# **************************** 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)
my_data1 = read("./t850.grb")
my_data2 = read("./z500.grb")
# set up the geographical view
my_view = 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 = 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 = 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= mcoast(map_coastline_resolution : "HIGH",
map_grid_colour : "CHARCOAL",
map_grid : "ON",
map_coastline_colour : "CHARCOAL")
# set up the title
my_title = 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 = 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
setoutput(pdf_output(output_name : 'legend3'))
# plot the map
plot(my_view,my_data1,my_contour1,my_data2,my_contour2,my_coast,my_title,my_legend)
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