Merge commit '8ed11759775913dce2d559da19418d2c93320348' into new-master

Merges develop-solarposition-integration.

Also brings in pvl_tools small fix, extraradiation DF output, pvsystem
small fixes. Also brings in a change to the default spa calculator,
and I will change this back next.

Author: wholmgren

pvlib/__init__.py

@@ -1,5 +1,14 @@
 
-import pvl_tools
+import logging
+logging.basicConfig()
+
+from . import atmosphere
+from . import clearsky
+from . import irradiance
+from . import location
+from . import pvl_tools
+from . import solarposition
+from . import tmy
 
 # '''
 # Irradiance and atmosperhic functions

pvlib/docs/tutorials/TS_2_Irradiance_functions.ipynb

@@ -3,6 +3,7 @@
 import numpy as np
 import pvl_tools 
 import pandas as pd 
+import pdb
 
 def extraradiation(doy):
   '''
@@ -123,8 +124,7 @@ def globalinplane(SurfTilt,SurfAz,AOI,DNI,In_Plane_SkyDiffuse, GR):
   Ediff = var.In_Plane_SkyDiffuse + var.GR
 
 
-
-  return E, Eb, Ediff
+  return pd.DataFrame({'E':E,'Eb':Eb,'Ediff':Ediff})
 
 
 

pvlib/irradiance.py

@@ -166,7 +166,8 @@ def parse_fcn(self, kwargs, Expect):
 
                     #Excecute proper logical operations if syntax matches regex
                     elif np.shape(re.findall(reg,string))[0]>0:
-
+                        eflag=False 
+                        
                         lambdastring='lambda x:'+re.findall(reg,string)[0]
 
                         #check df elements
@@ -182,21 +183,28 @@ def parse_fcn(self, kwargs, Expect):
                                 continue
                             try:    
                                 if not(eval(lambdastring)(kwargs[arg][~np.isnan(kwargs[arg])]).all()): #ignore NAN entries
-                                    raise Exception('Error: optional input "'+arg+' " fails on logical test " '+ re.findall(reg,string)[0]+'"')
+                                    eflag=True
+                                    
                             except:
                                 if not(eval(lambdastring)(kwargs[arg])):
-                                    raise Exception('Error: optional input "'+arg+' " fails on logical test " '+ re.findall(reg,string)[0]+'"')
+                                    eflag=True
+                                    
 
 
                         #check all other contraints
-
+                        
                         else:
                             try:    
                                 if not(eval(lambdastring)(kwargs[arg][~np.isnan(kwargs[arg])]).all()): #ignore NAN entries
-                                    raise Exception('Error: Numeric input "'+arg+' " fails on logical test " '+ re.findall(reg,string)[0]+'"')
+                                    eflag=True
+                                    
                             except:
                                 if not(eval(lambdastring)(kwargs[arg])): 
-                                    raise Exception('Error: Numeric input "'+arg+' " fails on logical test " '+ re.findall(reg,string)[0]+'"')
+                                    eflag=True
+                                    
+
+                        if eflag==True:
+                            raise Exception('Error: Numeric input "'+arg+' " fails on logical test " '+ re.findall(reg,string)[0]+'"')
 
                     #Check if any string logicals are bypassed due to poor formatting
 

pvlib/pvl_tools.py

@@ -4,6 +4,7 @@
 import os
 import pvl_tools
 import scipy 
+import urllib2
 from scipy.special import lambertw
 
 
@@ -855,8 +856,8 @@ def sapm(Module,Eb,Ediff,Tcell,AM,AOI):
   AMcoeff=[var.Module['A4'],var.Module['A3'],var.Module['A2'],var.Module['A1'],var.Module['A0']]
   AOIcoeff=[var.Module['B5'],var.Module['B4'],var.Module['B3'],var.Module['B2'],var.Module['B1'],var.Module['B0']]
 
-  F1 = Np.polyval(AMcoeff,var.AM)
-  F2 = Np.polyval(AOIcoeff,var.AOI)
+  F1 = np.polyval(AMcoeff,var.AM)
+  F2 = np.polyval(AOIcoeff,var.AOI)
   var.Ee= F1*((var.Eb*F2+var.Module['FD']*var.Ediff)/E0)
   #var['Ee']=F1*((var.Eb+var.Ediff)/E0)
   #print "Ee modifed, revert for main function"
@@ -872,9 +873,9 @@ def sapm(Module,Eb,Ediff,Tcell,AM,AOI):
   DFOut['Imp']=var.Module.ix['Impo']*((var.Module.ix['C0']*(var.Ee) + var.Module.ix['C1'] * (var.Ee ** 2)))*((1 + var.Module.ix['Aimp']*((var.Tcell - T0))))
   Bvoco=var.Module.ix['Bvoco'] + var.Module.ix['Mbvoc']*((1 - var.Ee))
   delta=var.Module.ix['N']*(k)*((var.Tcell + 273.15)) / q
-  DFOut['Voc']=(var.Module.ix['Voco'] + var.Module.ix['#Series']*(delta)*(Np.log(var.Ee)) + Bvoco*((var.Tcell - T0)))
+  DFOut['Voc']=(var.Module.ix['Voco'] + var.Module.ix['#Series']*(delta)*(np.log(var.Ee)) + Bvoco*((var.Tcell - T0)))
   Bvmpo=var.Module.ix['Bvmpo'] + var.Module.ix['Mbvmp']*((1 - var.Ee))
-  DFOut['Vmp']=(var.Module.ix['Vmpo'] + var.Module.ix['C2']*(var.Module.ix['#Series'])*(delta)*(Np.log(var.Ee)) + var.Module.ix['C3']*(var.Module.ix['#Series'])*((delta*(Np.log(var.Ee))) ** 2) + Bvmpo*((var.Tcell - T0)))
+  DFOut['Vmp']=(var.Module.ix['Vmpo'] + var.Module.ix['C2']*(var.Module.ix['#Series'])*(delta)*(np.log(var.Ee)) + var.Module.ix['C3']*(var.Module.ix['#Series'])*((delta*(np.log(var.Ee))) ** 2) + Bvmpo*((var.Tcell - T0)))
   DFOut['Vmp'][DFOut['Vmp']<0]=0
   DFOut['Pmp']=DFOut.Imp*DFOut.Vmp
   DFOut['Ix']=var.Module.ix['IXO'] * (var.Module.ix['C4']*(var.Ee) + var.Module.ix['C5']*((var.Ee) ** 2))*((1 + var.Module.ix['Aisc']*((var.Tcell - T0))))
@@ -992,7 +993,8 @@ def sapmcelltemp(E, Wspd, Tamb,modelt='Open_rack_cell_glassback',**kwargs):
 
   Tcell=Tmodule + var.E / E0*(deltaT)
 
-  return Tcell, Tmodule
+  return pd.DataFrame({'Tcell':Tcell,'Tmodule':Tmodule})
+
 def singlediode(Module,IL,I0,Rs,Rsh,nNsVth,**kwargs):
     '''
     Solve the single-diode model to obtain a photovoltaic IV curve

pvlib/pvsystem.py

@@ -15,6 +15,7 @@
 
 import numpy as np
 import pandas as pd
+import pytz
 
 try:
     from .spa_c_files.spa_py import spa_calc
@@ -28,7 +29,7 @@
 
 
 
-def get_solarposition(time, location, method='pyephem', pressure=101325, 
+def get_solarposition(time, location, method='spa', pressure=101325, 
                       temperature=12):
     """
     A convenience wrapper for the solar position calculators.
@@ -199,6 +200,183 @@ def pyephem(time, location, pressure=101325, temperature=12):
 
 
 
+def ephemeris(time, location, pressure=101325, temperature=12):
+    ''' 
+    Python-native solar position calculator.
+    The accuracy of this code is not guaranteed. 
+    Consider using the built-in spa_c code or the PyEphem library.
+
+    Parameters
+    ----------
+    time : pandas.DatetimeIndex
+    location : pvlib.Location
+
+    Other Parameters
+    ----------------
+
+    pressure : float or DataFrame
+          Ambient pressure (Pascals)
+
+    tempreature: float or DataFrame
+          Ambient temperature (C)
+      
+    Returns
+    -------
+    
+    DataFrame with the following columns
+    
+    SunEl : float of DataFrame
+        Actual elevation (not accounting for refraction)of the sun 
+        in decimal degrees, 0 = on horizon. The complement of the True Zenith
+        Angle.
+        
+    SunAz : Azimuth of the sun in decimal degrees from North. 0 = North to 270 = West
+    
+    SunZen : Solar zenith angle
+
+    ApparentSunEl : float or DataFrame
+
+        Apparent sun elevation accounting for atmospheric 
+        refraction. This is the complement of the Apparent Zenith Angle.
+
+    SolarTime : fload or DataFrame
+        Solar time in decimal hours (solar noon is 12.00).
+        
+
+    References
+    -----------
+
+    Grover Hughes' class and related class materials on Engineering 
+    Astronomy at Sandia National Laboratories, 1985.
+
+    See also
+    --------
+    pvl_makelocationstruct
+    pvl_alt2pres
+    pvl_getaoi 
+    pvl_spa
+
+    '''
+    
+    # Added by Rob Andrews (@Calama-Consulting), Calama Consulting, 2014 
+    # Edited by Will Holmgren (@wholmgren), University of Arizona, 2014 
+    
+    pvl_logger.warning('Using solarposition.ephemeris is discouraged. ' \
+                       'solarposition.pyephem and solarposition.spa are ' \
+                       'faster and more accurate.')
+    
+    pvl_logger.debug('location={}, temperature={}, pressure={}'.format(location, temperature, pressure))
+
+    Latitude = location.latitude
+    ''' the inversion of longitude is due to the fact that this code was
+    originally written for the convention that positive longitude were for
+    locations west of the prime meridian. However, the correct convention (as
+    of 2009) is to use negative longitudes for locations west of the prime
+    meridian. Therefore, the user should input longitude values under the
+    correct convention (e.g. Albuquerque is at -106 longitude), but it needs
+    to be inverted for use in the code.
+    '''
+    Latitude = location.latitude
+    Longitude=1 * location.longitude
+    Year = time.year
+    Month = time.month
+    Day = time.day
+    Hour = time.hour
+    Minute = time.minute
+    Second = time.second
+    DayOfYear = time.dayofyear
+
+    DecHours = Hour + Minute / float(60) + Second / float(3600)
+
+    Abber=20 / float(3600)
+    LatR=np.radians(Latitude)
+    
+    # this code is needed to handle the new location.tz format string
+    try:
+        utc_offset = pytz.timezone(location.tz).utcoffset(time[0]).total_seconds() / 3600.
+    except ValueError:
+        utc_offset = time.tzinfo.utcoffset(time[0]).total_seconds() / 3600.
+    pvl_logger.debug('utc_offset={}'.format(utc_offset))
+    
+    UnivDate=DayOfYear 
+    UnivHr = DecHours + utc_offset - .5 # Will H: surprised to see the 0.5 here, but moving on...
+    #+60/float(60)/2
+
+    Yr=Year - 1900
+
+    YrBegin=365 * Yr + np.floor((Yr - 1) / float(4)) - 0.5
+
+    Ezero=YrBegin + UnivDate
+    T=Ezero / float(36525)
+    GMST0=6 / float(24) + 38 / float(1440) + (45.836 + 8640184.542 * T + 0.0929 * T ** 2) / float(86400)
+    GMST0=360 * (GMST0 - np.floor(GMST0))
+    GMSTi=np.mod(GMST0 + 360 * (1.0027379093 * UnivHr / float(24)),360)
+
+    LocAST=np.mod((360 + GMSTi - Longitude),360)
+    EpochDate=Ezero + UnivHr / float(24)
+    T1=EpochDate / float(36525)
+    ObliquityR=np.radians(23.452294 - 0.0130125 * T1 - 1.64e-06 * T1 ** 2 + 5.03e-07 * T1 ** 3)
+    MlPerigee=281.22083 + 4.70684e-05 * EpochDate + 0.000453 * T1 ** 2 + 3e-06 * T1 ** 3
+    MeanAnom=np.mod((358.47583 + 0.985600267 * EpochDate - 0.00015 * T1 ** 2 - 3e-06 * T1 ** 3),360)
+    Eccen=0.01675104 - 4.18e-05 * T1 - 1.26e-07 * T1 ** 2
+    EccenAnom=MeanAnom
+    E=0
+
+    while np.max(abs(EccenAnom - E)) > 0.0001:
+        E=EccenAnom
+        EccenAnom=MeanAnom + np.degrees(Eccen)*(np.sin(np.radians(E)))
+    
+    #pdb.set_trace()     
+    TrueAnom=2 * np.mod(np.degrees(np.arctan2(((1 + Eccen) / (1 - Eccen)) ** 0.5*np.tan(np.radians(EccenAnom) / float(2)),1)),360)
+    EcLon=np.mod(MlPerigee + TrueAnom,360) - Abber
+    EcLonR=np.radians(EcLon)
+    DecR=np.arcsin(np.sin(ObliquityR)*(np.sin(EcLonR)))
+    Dec=np.degrees(DecR)
+    #pdb.set_trace()
+
+    RtAscen=np.degrees(np.arctan2(np.cos(ObliquityR)*((np.sin(EcLonR))),np.cos(EcLonR)))
+
+    HrAngle=LocAST - RtAscen
+    HrAngleR=np.radians(HrAngle)
+
+    HrAngle=HrAngle - (360*((abs(HrAngle) > 180)))
+    SunAz=np.degrees(np.arctan2(- 1 * np.sin(HrAngleR),np.cos(LatR)*(np.tan(DecR)) - np.sin(LatR)*(np.cos(HrAngleR))))
+    SunAz=SunAz + (SunAz < 0) * 360
+    SunEl=np.degrees(np.arcsin((np.cos(LatR)*(np.cos(DecR))*(np.cos(HrAngleR)) + np.sin(LatR)*(np.sin(DecR))))) #potential error
+    SolarTime=(180 + HrAngle) / float(15)
+
+    Refract=[]
+
+    for Elevation in SunEl:
+        TanEl=np.tan(np.radians(Elevation))
+        if Elevation>5 and Elevation<=85:
+            Refract.append((58.1 / float(TanEl) - 0.07 / float(TanEl ** 3) + 8.6e-05 / float(TanEl ** 5)))
+        elif Elevation > -0.575 and Elevation <=5:
+            Refract.append((Elevation*((- 518.2 + Elevation*((103.4 + Elevation*((- 12.79 + Elevation*(0.711))))))) + 1735))
+        elif Elevation> -1 and Elevation<= -0.575:
+            Refract.append(- 20.774 / float(TanEl))
+        else:
+            Refract.append(0)
+
+
+    Refract=np.array(Refract)*((283 / float(273 + temperature)))*(pressure) / float(101325) / float(3600)
+
+    SunZen = 90 - SunEl
+    #SunZen[SunZen >= 90] = 90 
+    
+    ApparentSunEl = SunEl + Refract
+
+    DFOut = pd.DataFrame({'elevation':SunEl}, index=time)
+    DFOut['azimuth'] = SunAz-180  #Changed RA Feb 18,2014 to match Duffe
+    DFOut['zenith'] = SunZen
+    DFOut['apparent_elevation'] = ApparentSunEl
+    DFOut['apparent_zenith'] = 90 - ApparentSunEl
+    DFOut['solar_time'] = SolarTime
+
+    return DFOut
+        
+        
+        
 def _localize_to_utc(time, location):
     """
     Converts or localizes a time series to UTC.