def SimulateSpan(latitude_deg,
longitude_deg,
start_utc_datetime,
end_utc_datetime,
step_minutes,
elevation=0,
temperature_celsius=25,
pressure_millibars=1013.25):
'''Simulate the motion of the sun over a time span and location of your choosing.
The start and end points are set by datetime objects, which can be created with
the standard Python datetime module like this:
import datetime
start = datetime.datetime(2008, 12, 23, 23, 14, 0)
'''
time_list = BuildTimeList(start_utc_datetime, end_utc_datetime,
step_minutes)
angles_list = [(time,
solar.GetAltitude(latitude_deg, longitude_deg, time,
elevation, temperature_celsius,
pressure_millibars),
solar.GetAzimuth(latitude_deg, longitude_deg, time,
elevation)) for time in time_list]
power_list = [(time, alt, az, radiation.GetRadiationDirect(time, alt))
for (time, alt, az) in angles_list]
print power_list
def ComparePysolarToUSNO(datum):
alt = solar.GetAltitude(float(datum.latitude), float(datum.longitude),
datum.timestamp, datum.elevation)
pysolar_alt = (90.0 - alt)
az = solar.GetAzimuth(float(datum.latitude), float(datum.longitude),
datum.timestamp, datum.elevation)
pysolar_az = (180.0 - az) % 360.0
# print pysolar_alt
# print pysolar_az
pysolar = Ephemeris(datum.timestamp, datum.latitude, datum.longitude,
datum.elevation, pysolar_az, pysolar_alt)
c = EphemerisComparison('pysolar', pysolar, 'usno', datum)
return c
def calculateSolarAngles(self,timeDatetimeFormat):
# solar altitude, sometimes called solar angle
self.solarAltitudeDegrees=solar.GetAltitude(self.latitudeFloatingPoint,self.longitudeFloatingPoint,timeDatetimeFormat)
self.solarAltitudeRadians=math.radians(self.solarAltitudeDegrees)
# azimuth: west is -90 degrees, north is -180 degrees, east is -270 degrees
self.solarAzimuthDegrees=solar.GetAzimuth(self.latitudeFloatingPoint,self.longitudeFloatingPoint,timeDatetimeFormat)
self.solarAzimuthRadians=0.0-math.radians(self.solarAzimuthDegrees)
# solarAzimuthRadiansConverted: north is 0, east is 0.5 pi, south is pi, west is 1.5 pi
if self.solarAzimuthRadians < math.pi:
self.solarAzimuthRadiansConverted=self.solarAzimuthRadians+math.pi
else:
self.solarAzimuthRadiansConverted=self.solarAzimuthRadians-math.pi
if self.reduceRunTime:
self.solarCritAngle=self.horizontanFromList(self.solarAzimuthRadiansConverted)
else:
self.solarCritAngle=horizontan(self.extendedDem,self.solarAzimuthRadiansConverted)
def addSunPaths(im, latitude_deg, longitude_deg, horizon, d):
pix = im.load()
alt_zero = getAltitudeZero()
az_zero = getAzimuthZero()
for m in range(24 * 60):
alt = solar.GetAltitude(latitude_deg, longitude_deg,
d + dt.timedelta(minutes=m))
az = solar.GetAzimuth(latitude_deg, longitude_deg,
d + dt.timedelta(minutes=m))
x = az_zero + int(az * 1944.0 / 360.0)
y = alt_zero - int(alt_zero * sin(radians(alt)))
if y < horizon[x]:
pix[x % 1944, y] = (255, 193, 37)
return im
def from_time_and_location(self, lat, long, datetimestring, view_z,
view_a):
"""Sets the user-defined geometry to a given view zenith and azimuth, and a solar zenith and azimuth calculated from the lat, long and date given.
Uses the PySolar module for the calculations.
Arguments:
* ``lat`` -- The latitude of the location (0-90 degrees)
* ``long`` -- The longitude of the location
* ``datetimestring`` -- Any string that can be parsed to produce a date/time object. All that is really needed is a time - eg. "14:53"
* ``view_z`` -- The view zenith angle
* ``view_a`` -- The view azimuth angle
"""
# Try and import the PySolar module, if it fails give an error message
try:
import solar
except:
raise ExecutionError(
"To set the geometry from a time and location you must have the PySolar module installed.\nTo install this, run 'pip install pysolar' at the command line."
)
dt = dateutil.parser.parse(datetimestring, dayfirst=True)
self.solar_z = solar.GetAltitude(lat, long, dt)
az = solar.GetAzimuth(lat, long, dt)
if az < 0:
self.solar_a = abs(az) + 180
else:
self.solar_a = abs(az - 180)
self.solar_a = self.solar_a % 360
self.day = dt.day
self.month = dt.month
self.view_z = view_z
self.view_a = view_a
def ShadeTest():
latitude_deg = 42.364908
longitude_deg = -71.112828
width = 100
height = 200
area = width * height
d = datetime.datetime.utcnow()
thirty_minutes = datetime.timedelta(hours=0.5)
times = []
powers = []
shade_x = []
shade_y = []
shaded_powers = []
for i in range(48):
timestamp = d.ctime()
altitude_deg = solar.GetAltitude(latitude_deg, longitude_deg, d)
azimuth_deg = solar.GetAzimuth(latitude_deg, longitude_deg, d)
power = radiation.GetRadiationDirect(d, altitude_deg)
xs = shade.GetXShade(width, 120, azimuth_deg)
ys = shade.GetYShade(height, 120, altitude_deg)
shaded_area = xs * ys
shaded_percentage = shaded_area / area
if (altitude_deg > 0):
times.append(float(d.hour) + (float(d.minute) / 60) -
5) # - 5 to adjust to EST
powers.append(power)
shade_x.append(xs)
shade_y.append(ys)
shaded_powers.append(power * (1 - shaded_percentage))
#print timestamp, "UTC", altitude_deg, azimuth_deg, power
d = d + thirty_minutes
print times
print powers
print shade_x
pylab.plot(
times, shaded_powers, times, powers
) # plot ends up with a line across it because x values wrap around
pylab.show() # could fix that with sort function below
