Android センサーの TYPE_PRESSURE + kivy.garden.graph

気圧のグラフったって、大したもんを描こうってんではない。

元ネタ:

ので、

android.txt – お約束
environmental_sensors.py – Android Environmental sensors…

参照

geographiclib_web.py – Android センサーの TYPE_PRESSURE で少し遊ぶ参照
libs/garden/garden.graph/__init__.py – kivyLauncher 環境でグラフ (+ kivy garden について) 参照
main.py – ここで扱うもの

てことで。

Pressure Altitude の NOAA による計算式再掲:

\(
\displaystyle (1-(\frac{P_a}{1013.25})^{.190284})*145366.45
\)

この曲線と現在気圧をグラフで見ると面白いかなと。うん、どーせ面白いのはアタシだけだ、けど知るもんか。

main.py

  1 # -*- coding: utf-8 -*-
  2 import math
  3 from kivy.lang import Builder
  4 from kivy.app import App
  5 from kivy.clock import Clock, mainthread
  6 from kivy.properties import StringProperty
  7 from kivy.uix.boxlayout import BoxLayout
  8 from plyer import gps
  9 from environmental_sensors import pressureSensor
 10 from geographiclib_web import query_geoid_eval
 11 from kivy.garden.graph import Graph, LinePlot
 12 
 13 kv = '''
 14 <VariousAltitudeDemo>:
 15     orientation: 'vertical'
 16 
 17     RstDocument:
 18         id: result
 19         text: root.result
 20 
 21     Graph:
 22         id: graph_plot
 23         background_color: (0.5, 0.5, 0.5, 1)
 24         xlabel: 'Pressure'
 25         ylabel: 'Altitude'
 26         x_grid: True
 27         y_grid: True
 28         x_grid_label: True
 29         y_grid_label: True
 30 '''
 31 Builder.load_string(kv)
 32 
 33 
 34 def calc_pressure_altitude(P):
 35     # NOAA formula (in feet)
 36     # (see https://en.wikipedia.org/wiki/Pressure_altitude)
 37     pres_alt = (1.0 - math.pow((P / 1013.25), 0.190284)) * 145366.45
 38     pres_alt *= 0.3048  # in metre
 39     return pres_alt
 40 
 41 
 42 class VariousAltitudeDemo(BoxLayout):
 43     result = StringProperty()
 44     lon = None
 45     lat = None
 46     alt = None
 47 
 48     def __init__(self):
 49         super(VariousAltitudeDemo, self).__init__()
 50         pressureSensor.enable()
 51         gps.configure(on_location=self.on_location,
 52                            on_status=self.on_status)
 53         gps.start()
 54 
 55         self.graph = self.ids.graph_plot
 56 
 57         P = pressureSensor.value
 58         while not P:
 59             import time
 60             time.sleep(0.5)
 61             P = pressureSensor.value
 62         self.plot_ISA_P = LinePlot(color=[0, 0, 1, 1], line_width=2)
 63         _PRNG = 5
 64         self.plot_ISA_P.points = [
 65             (p, calc_pressure_altitude(p))
 66             for p in range(int(P) - _PRNG, int(P) + _PRNG, 1)
 67             ]
 68         self.graph.xmin = int(P) - _PRNG
 69         self.graph.xmax = int(P) + _PRNG
 70         self.graph.ymin = int(calc_pressure_altitude(P + _PRNG))
 71         self.graph.ymax = int(calc_pressure_altitude(P - _PRNG))
 72         self.graph.x_ticks_major = 5
 73         self.graph.x_ticks_minor = 1
 74         self.graph.y_ticks_major = 10
 75         self.graph.y_ticks_minor = 5
 76         self.plot_PA = LinePlot(color=[1, 0, 0, 1], line_width=2)
 77         self.graph.add_plot(self.plot_ISA_P)
 78         self.graph.add_plot(self.plot_PA)
 79         
 80         Clock.schedule_interval(self.do_interval, 1.)
 81 
 82     @mainthread
 83     def on_location(self, **kwargs):
 84         self.lon = float(kwargs['lon'])
 85         self.lat = float(kwargs['lat'])
 86         self.alt = float(kwargs['altitude'])
 87 
 88     @mainthread
 89     def on_status(self, stype, status):
 90         pass
 91 
 92     def do_interval(self, *args, **kwargs):
 93         geoid = {}
 94         if self.lon:
 95             geoid = query_geoid_eval(self.lon, self.lat)
 96 
 97         P = pressureSensor.value
 98         pres_alt = calc_pressure_altitude(P)
 99         plot = self.plot_PA
100         plot.points = [
101             (P, 0),
102             (P, pres_alt),
103             (0, pres_alt),
104             ]
105 
106         self.result = """
107 GPS
108 ===
109 * alt: {} [m]
110 
111 World Geoid Model
112 =================
113 * EGM2008: {} [m]
114 * EGM96: {} [m]
115 * EGM84: {} [m]
116 
117 Pressure Altitude
118 =================
119 * Pressure: {} [hPa]
120 * Pressure altitude: {} [m]
121 
122 """.format(self.alt,
123            geoid.get('EGM2008'), geoid.get('EGM96'), geoid.get('EGM84'),
124            P, pres_alt)
125 
126 
127 class VariousAltitudeDemoApp(App):
128     def build(self):
129         return VariousAltitudeDemo()
130 
131 
132 if __name__ == '__main__':
133     VariousAltitudeDemoApp().run()