max_altitude_time = gps_data['hgt'].idxmax()
max_altitude = gps_data['hgt'].max()
print "Max altitude", max_altitude, " at ", max_altitude_time
field = sys.argv[1]
# Set ascendeing and descending each to a Series of the specified field vs. time
try:
ascending = logger_data.ix[logger_data.time <= max_altitude_time, field]
descending = logger_data.ix[logger_data.time >= max_altitude_time, field]
except:
ascending = gps_data.ix[gps_data.time <= max_altitude_time , field]
descending = gps_data.ix[gps_data.time >= max_altitude_time, field]
y_label = sys.argv[len(sys.argv)-1]
# Plot specified field vs time
p = DataFrame({'Ascending': ascending, 'Descending': descending}).plot()
p.set_ylabel(y_label)
p.set_xlabel("Time")
# Plot specified field vs altitude
if field != 'hgt':
p = DataFrame({'Ascending': by_altitude(ascending, gps_data), 'Descending': by_altitude(descending, gps_data)}).plot()
p.set_ylabel(y_label)
p.set_xlabel("Altitude")
# show both plots
plt.show()
hgt = gps_data["hgt"]
# Delete the samples when the balloon was on the ground
hgt = hgt[4 : hgt.size - 15]
max_altitude_time = hgt.idxmax()
max_altitude = hgt.max()
# delta is the height difference between samples shifted by 2 minutes
delta = hgt.shift(-1, "min") - hgt.shift(1, "min")
miles = delta / 5280.0
mph = miles * 30 # delta shift is 30 periods per hour
offset = timedelta(minutes=1)
ascending = mph.ix[mph.index < max_altitude_time - offset]
descending = mph.ix[mph.index > max_altitude_time - offset]
# Plot vertical speed vs time
p = DataFrame({"Ascending": ascending, "Descending": descending}).plot()
p.set_ylabel("Vertical Speed (MPH)")
p.set_xlabel("Time")
plt.show()
# Plot descent speed vs altitude
b = by_altitude(descending, gps_data)
b = b.ix[b.index < max_altitude - 1000] # Time window causes artifacs at the altitude peak
p = b.mul(-1).plot()
p.set_ylabel("Descent Speed (MPH)")
p.set_xlabel("Altitude")
plt.show()
