# Quick hack to graph last 500 greenhouse temperatures from weather database. import mariadb import matplotlib.pyplot as plt conn = mariadb.connect(user="pi",password="password",host="localhost",database="weather") cur = conn.cursor() tempIN = [] tempOUT = [] timestamps = [] # Get the most recent 500 records. cur.execute("SELECT greenhouse_temperature, ambient_temperature, created FROM WEATHER_MEASUREMENT ORDER BY created DESC LIMIT 500") for i in cur: tempIN.append(i[0]) tempOUT.append(i[1]) timestamps.append(i[2]) conn.close() plt.figure(figsize=(14, 6)) plt.title(label="Greenhouse and outside temperature up to "+str(timestamps[0])) plt.xlabel("Date and time") plt.ylabel("Temperature in Celsius") plt.plot(timestamps, tempIN, label='Greenhouse temperature') plt.plot(timestamps, tempOUT, label='Outside temperature') plt.axhline(y=5.0, color='r', linestyle='-.') plt.legend() plt.savefig("/var/www/html/GHtemp.jpg") plt.show()
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