xmet/bin/xmet-sounding-plot

#! /usr/bin/env python3

import argparse
import cairo
import shapely

from xmet.config    import Config
from xmet.db        import Database
from xmet.sounding  import Sounding
from xmet.skew_t    import SkewTGraph, SkewTLegend
from xmet.hodograph import Hodograph

IMAGE_WIDTH  = 800
IMAGE_HEIGHT = 800

GRAPH_WIDTH  = 800 - 128
GRAPH_HEIGHT = 800 - 128

def plot_skew_t(sounding: Sounding, output: str):
    print(f"Plotting Skew-T chart of {sounding.station} sounding at {sounding.timestamp_observed} to {output}")

    with cairo.SVGSurface(output, IMAGE_WIDTH, IMAGE_HEIGHT) as surface:
        cr = cairo.Context(surface)

        cr.set_source_rgb(1, 1, 1)
        cr.rectangle(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT)
        cr.fill()

        skew_t = SkewTGraph(GRAPH_WIDTH, GRAPH_HEIGHT)
        skew_t.draw(cr, 64, 64, sounding)

        cr.set_source_rgb(0, 0, 0)
        cr.rectangle(64, 64, GRAPH_WIDTH, GRAPH_HEIGHT)
        cr.stroke()

        SkewTLegend.draw_for_graph(cr, skew_t, 64, 64)

def plot_hodograph(sounding: Sounding, output: str):
    print(f"Plotting hodograph of {sounding.station} sounding at {sounding.timestamp_observed} to {output}")

    with cairo.SVGSurface(output, IMAGE_WIDTH, IMAGE_HEIGHT) as surface:
        cr = cairo.Context(surface)

        cr.save()
        cr.set_source_rgb(1, 1, 1)
        cr.rectangle(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT)
        cr.fill()
        cr.restore()

        cr.set_source_rgb(0, 0, 0)
        cr.rectangle(64, 64, GRAPH_WIDTH, GRAPH_HEIGHT)
        cr.stroke()

        hodograph = Hodograph(GRAPH_WIDTH, GRAPH_HEIGHT)
        hodograph.draw(cr, 64, 64, sounding)

parser = argparse.ArgumentParser(
    description = 'Graph most recent valid sounding for location'
)

parser.add_argument('--skew-t',    type=str, help='Plot a Skew-T chart to the specified SVG file')
parser.add_argument('--hodograph', type=str, help='Plot a hodograph to the specified SVG file')

parser.add_argument('lat',       help='Latitude')
parser.add_argument('lon',       help='Longitude')
parser.add_argument('timestamp', help='Timestamp in YYYY-MM-DD HH:MM:SS (UTC)')

args = parser.parse_args()

config = Config.load()
db     = Database.from_config(config)

location = shapely.Point(float(args.lon), float(args.lat))
sounding = Sounding.valid_by_location(db, location, args.timestamp)

if args.skew_t is not None:
    plot_skew_t(sounding, args.skew_t)

if args.hodograph is not None:
    plot_hodograph(sounding, args.hodograph)