def get_data_from_WU():
###array to store the reports
wu_weather_reports = []
## today and last 6 days definition
day1 = now - datetime.timedelta(days=6)
day2 = now - datetime.timedelta(days=5)
day3 = now - datetime.timedelta(days=4)
day4 = now - datetime.timedelta(days=3)
day5 = now - datetime.timedelta(days=2)
day6 = now - datetime.timedelta(days=1)
day7 = now
#### convert dates to WU required format
days = {
'day1': day1.strftime('%Y%m%d'),
'day2': day2.strftime('%Y%m%d'),
'day3': day3.strftime('%Y%m%d'),
'day4': day4.strftime('%Y%m%d'),
'day5': day5.strftime('%Y%m%d'),
'day6': day6.strftime('%Y%m%d'),
'day7': day7.strftime('%Y%m%d')
}
### make API wather hisotry call for each day
for day in days:
url = 'http://api.wunderground.com/api/7c2ab99a0ccee978/history_{0}/q/95316.json'.format(days[day])
headers = {'content-type': 'application/JSON; charset=utf8'}
response = requests.get(url, headers=headers)
data = json.loads(response.text)
#ETo calculation for the day using FAO-56 Penman-Monteith method
lat = pyeto.deg2rad(37.585652)
altitude = 38
julian_day = datetime.datetime.strptime(days.get(day), '%Y%m%d').timetuple().tm_yday
sol_dec = pyeto.sol_dec(julian_day)
sha = pyeto.sunset_hour_angle(lat, sol_dec)
ird = pyeto.inv_rel_dist_earth_sun(julian_day)
### net radiation calculator
net_rad = pyeto.et_rad(lat, sol_dec, sha, ird)
temp_c = float(data["history"]["observations"][1]["tempm"])
temp_k = float(data["history"]["observations"][1]["tempi"])
humidity = float(data["history"]["observations"][1]["hum"])
dew_point = float(data["history"]["observations"][1]["dewptm"])
ws = float(data["history"]["observations"][1]["wspdm"])
#actual and saturated vapour pressure in kPH
svp = pyeto.svp_from_t(temp_c)
avp = pyeto.avp_from_tdew(dew_point)
delta_svp = pyeto.delta_svp(temp_c)
atm_pressure = pyeto.atm_pressure(altitude)
psy = pyeto.psy_const(atm_pressure)
#### the ETo plugin retun results in mm, it was converted to inched
ETo_in_mm = pyeto.fao56_penman_monteith(net_rad, temp_k, ws, svp, avp, delta_svp, psy, shf=0.0)
ETo = ETo_in_mm * 0.039370
## insert eto value to day weather report
data["history"]["observations"][1].update({"ETo": "{0:.2f}".format(ETo)})
###add report to report collector array
wu_weather_reports.append(data["history"]["observations"][1])
#return all reports
return wu_weather_reports
tmin = 37 tmax = 53 coastal = True altitude = 147 rh_min = 13 rh_max = 88 ws = 1.3 tmean = pyeto.daily_mean_t(tmin, tmax) atmos_pres = pyeto.atm_pressure(altitude) psy = pyeto.psy_const(atmos_pres) # Humidity svp_tmin = pyeto.svp_from_t(tmin) svp_tmax = pyeto.svp_from_t(tmax) delta_svp = pyeto.delta_svp(tmean) svp = pyeto.mean_svp(tmin, tmax) avp = pyeto.avp_from_rhmin_rhmax(svp_tmin, svp_tmax, rh_min, rh_max) # Radiation sol_dec = pyeto.sol_dec(day_of_year) sha = pyeto.sunset_hour_angle(latitude, sol_dec) ird = pyeto.inv_rel_dist_earth_sun(day_of_year) et_rad = pyeto.et_rad(latitude, sol_dec, sha, ird) cs_rad = pyeto.cs_rad(altitude, et_rad) sol_rad = pyeto.sol_rad_from_t(et_rad, cs_rad, tmin, tmax, coastal) ni_sw_rad = pyeto.net_in_sol_rad(sol_rad) no_lw_rad = pyeto.net_out_lw_rad(pyeto.celsius2kelvin(tmin), pyeto.celsius2kelvin(tmax), sol_rad, cs_rad, avp) net_rad = pyeto.net_rad(ni_sw_rad, no_lw_rad) eto = pyeto.fao56_penman_monteith(net_rad, pyeto.celsius2kelvin(tmean), ws, svp, avp, delta_svp, psy)
def test_delta_svp(self):
# Test based on example 17, p.111 of FAO paper
dh = pyeto.delta_svp(30.2)
self.assertAlmostEqual(dh, 0.246, 3)
