BUFR, Geopoints - Coloured Observation Values

# (C) Copyright 2017- ECMWF.
#
# This software is licensed under the terms of the Apache Licence Version 2.0
# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
#
# In applying this licence, ECMWF does not waive the privileges and immunities
# granted to it by virtue of its status as an intergovernmental organisation
# nor does it submit to any jurisdiction.
#

import metview as mv

# read BUFR data
filename = "temp.bufr"
if mv.exist(filename):
    temp = mv.read(filename)
else:
    temp = mv.gallery.load_dataset(filename)

# filter just the 500 hPa temperature from the obs data (Geopoints)
gpt = mv.obsfilter(
    output="geopoints",
    parameter="airTemperature",
    level="single",
    first_level=500,
    data=temp,
)

# convert values to C units
gpt = gpt - 273.16

# define coloured value (as number) plotting
sym = mv.msymb(
    legend="on",
    symbol_table_mode="advanced",
    symbol_format="(F3.1)",
    symbol_advanced_table_selection_type="interval",
    symbol_advanced_table_interval=1,
    symbol_advanced_table_max_level_colour="red",
    symbol_advanced_table_min_level_colour="lavender",
    symbol_advanced_table_colour_director="clockwise",
    symbol_advanced_table_text_font_size=0.6,
)

# shaded land and sea
coast = mv.mcoast(
    map_coastline_land_shade="on",
    map_coastline_land_shade_colour="RGB(0.29,0.29,0.29)",
    map_coastline_sea_shade="on",
    map_coastline_sea_shade_colour="RGB(0.49,0.49,0.49)",
    map_coastline_colour="RGB(0.59,0.59,0.59)",
    map_grid_latitude_increment=10,
    map_grid_longitude_increment=20,
    map_grid_colour="RGB(0.25,0.25,0.25)",
)

# adjust the legend
legend = mv.mlegend(legend_text_font_size=0.3)

# define title
title = mv.mtext(text_lines="Radiosonde - Temperature at 500 hPa", text_font_size=0.4)

# set the view area
view = mv.geoview(
    map_area_definition="corners", area=[7, -105, 35, -55], coastlines=coast
)

# define the output plot file
mv.setoutput(mv.pdf_output(output_name="coloured_obs_values"))

# plot the data with the style
mv.plot(view, gpt, sym, legend, title)