Difference Contouring 1 Example

# Metview Macro

# **************************** LICENSE START ***********************************
#
# Copyright 2018 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 ************************************

# ---------------------------------------------------------------
# Description: Demonstrates how to use Rainbow contouring to
#              separately contour positive, negative and zero
#              differences, similar to the Split Contour facility
#              which existed in Metview 3.
# ---------------------------------------------------------------



# retrieve the forecast and analysis data and compute the difference
use_mars = 0
if use_mars then
    analysis_data = retrieve(param:'t', levelist: 1000, grid: [1.5,1.5], date: -10)
    forecast_data = retrieve(param:'t', levelist: 1000, grid: [1.5,1.5], date: -12, type: 'fc', step: 48)
else
    analysis_data = read('an_data_for_diff.grib')
    forecast_data = read('fc_data_for_diff.grib')
end if

difference = forecast_data - analysis_data


# define the contouring visdef
split = mcont(
    contour_line_thickness                  : 2,
    contour_line_colour_rainbow             : "on",
    contour_line_colour_rainbow_method      : "list",
    contour_line_colour_rainbow_colour_list : ["RGB(0.02,0.67,1)","RGB(0.31,0.31,0.98)","RGB(0.024,0.024,0.7)",
                                               "BLACK",
                                               "RGB(0.62,0.077,0.028)","RGB(0.77,0.019,0.019)","RED"],
    contour_line_thickness_rainbow_list     : [2,2,2,4,2,2,2],
    contour_line_style_rainbow_list         : ["dash","dash","dash","solid","solid","sold","solid"],
    contour_highlight                       : "off",
    contour_level_selection_type            : "level_list",
    contour_level_list                      : [-1,-0.5,-0.2,0,0.2,0.5,1]
)


# define the coastlines visdef and the view
land_sea_shade = mcoast(
    map_coastline_land_shade        : "on",
    map_coastline_land_shade_colour : "RGB(0.89,0.85,0.82)"
)

view = geoview(
    map_area_definition : "corners",
    area                : [37.9,-28.57,69.85,20.65],
    coastlines          : land_sea_shade
)


# define the output plot file (extension will be added automatically)
# - remove this line to get an interactive plot window
setoutput(pdf_output(output_name : 'rainbow_contour_diffs'))

# into the view, plot the difference field with the 'split' visdef
plot (view, difference, split)

# Metview Example

# **************************** LICENSE START ***********************************
#
# Copyright 2018 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 ************************************

# ---------------------------------------------------------------
# Description: Demonstrates how to use Rainbow contouring to
#              separately contour positive, negative and zero
#              differences, similar to the Split Contour facility
#              which existed in Metview 3.
# ---------------------------------------------------------------

import metview as mv

# retrieve the forecast and analysis data and compute the difference
use_mars = 0
if use_mars:
    analysis_data = mv.retrieve(param = "t", levelist = 1000, grid = [1.5,1.5], date = -10)
    forecast_data = mv.retrieve(param = "t", levelist = 1000, grid = [1.5,1.5], date = -12, type = "fc", step = 48)
else:
    analysis_data = mv.read("an_data_for_diff.grib")
    forecast_data = mv.read("fc_data_for_diff.grib")


difference = forecast_data - analysis_data


# define the contouring visdef
split = mv.mcont(
    contour_line_thickness                  = 2,
    contour_line_colour_rainbow             = "on",
    contour_line_colour_rainbow_method      = "list",
    contour_line_colour_rainbow_colour_list = ["RGB(0.02,0.67,1)","RGB(0.31,0.31,0.98)","RGB(0.024,0.024,0.7)",
                                               "BLACK",
                                               "RGB(0.62,0.077,0.028)","RGB(0.77,0.019,0.019)","RED"],
    contour_line_thickness_rainbow_list     = [2,2,2,4,2,2,2],
    contour_line_style_rainbow_list         = ["dash","dash","dash","solid","solid","sold","solid"],
    contour_highlight                       = "off",
    contour_level_selection_type            = "level_list",
    contour_level_list                      = [-1,-0.5,-0.2,0,0.2,0.5,1]
)


# define the coastlines visdef and the view
land_sea_shade = mv.mcoast(
    map_coastline_land_shade        = "on",
    map_coastline_land_shade_colour = "RGB(0.89,0.85,0.82)"
)

view = mv.geoview(
    map_area_definition = "corners",
    area                = [37.9,-28.57,69.85,20.65],
    coastlines          = land_sea_shade
)


# define the output plot file (extension will be added automatically)
# - remove this line to get an interactive plot window
mv.setoutput(mv.pdf_output(output_name = 'rainbow_contour_diffs'))

# into the view, plot the difference field with the 'split' visdef
mv.plot(view, difference, split)