internal pep8 changes

Author: wholmgren

docs/sphinx/source/whatsnew/v0.3.0.txt

@@ -33,6 +33,9 @@ API changes
   variable conventions.
 * ``irradiance.total_irrad`` now follows the variable conventions.
   (:issue:`105`)
+* ``atmosphere.relativeairmass`` now raises a ValueError instead of
+  assuming ``'kastenyoung1989'`` if an invalid model is supplied.
+  (:issue:`119`)
 
 
 Enhancements

pvlib/atmosphere.py

@@ -1,7 +1,6 @@
 """
-The ``atmosphere`` module contains methods to calculate
-relative and absolute airmass and to determine
-pressure from altitude or vice versa.
+The ``atmosphere`` module contains methods to calculate relative and
+absolute airmass and to determine pressure from altitude or vice versa.
 """
 
 from __future__ import division
@@ -48,14 +47,12 @@ def pres2alt(pressure):
 
     "A Quick Derivation relating altitude to air pressure" from Portland
     State Aerospace Society, Version 1.03, 12/22/2004.
-
     '''
 
     alt = 44331.5 - 4946.62 * pressure ** (0.190263)
     return alt
 
 
-
 def alt2pres(altitude):
     '''
     Determine site pressure from altitude.
@@ -97,17 +94,16 @@ def alt2pres(altitude):
     return press
 
 
-
 def absoluteairmass(airmass_relative, pressure=101325.):
     '''
     Determine absolute (pressure corrected) airmass from relative
     airmass and pressure
 
-    Gives the airmass for locations not at sea-level (i.e. not at standard
-    pressure). The input argument "AMrelative" is the relative airmass. The
-    input argument "pressure" is the pressure (in Pascals) at the location
-    of interest and must be greater than 0. The calculation for
-    absolute airmass is
+    Gives the airmass for locations not at sea-level (i.e. not at
+    standard pressure). The input argument "AMrelative" is the relative
+    airmass. The input argument "pressure" is the pressure (in Pascals)
+    at the location of interest and must be greater than 0. The
+    calculation for absolute airmass is
 
     .. math::
         absolute airmass = (relative airmass)*pressure/101325
@@ -129,8 +125,8 @@ def absoluteairmass(airmass_relative, pressure=101325.):
     References
     ----------
     [1] C. Gueymard, "Critical analysis and performance assessment of
-    clear sky solar irradiance models using theoretical and measured data,"
-    Solar Energy, vol. 51, pp. 121-138, 1993.
+    clear sky solar irradiance models using theoretical and measured
+    data," Solar Energy, vol. 51, pp. 121-138, 1993.
 
     '''
 
@@ -143,35 +139,38 @@ def relativeairmass(zenith, model='kastenyoung1989'):
     '''
     Gives the relative (not pressure-corrected) airmass.
 
-    Gives the airmass at sea-level when given a sun zenith angle
-    (in degrees).
-    The ``model`` variable allows selection of different airmass models
-    (described below). If ``model`` is not
-    included or is not valid, the default model is 'kastenyoung1989'.
+    Gives the airmass at sea-level when given a sun zenith angle (in
+    degrees). The ``model`` variable allows selection of different
+    airmass models (described below). If ``model`` is not included or is
+    not valid, the default model is 'kastenyoung1989'.
 
     Parameters
     ----------
 
     zenith : float or Series
-        Zenith angle of the sun in degrees.
-        Note that some models use the apparent (refraction corrected)
-        zenith angle, and some models use the true
-        (not refraction-corrected) zenith angle.
-        See model descriptions to determine which type of zenith
-        angle is required.
-        Apparent zenith angles must be calculated at sea level.
+        Zenith angle of the sun in degrees. Note that some models use
+        the apparent (refraction corrected) zenith angle, and some
+        models use the true (not refraction-corrected) zenith angle. See
+        model descriptions to determine which type of zenith angle is
+        required. Apparent zenith angles must be calculated at sea level.
 
     model : String
         Available models include the following:
 
         * 'simple' - secant(apparent zenith angle) -
           Note that this gives -inf at zenith=90
-        * 'kasten1966' - See reference [1] - requires apparent sun zenith
-        * 'youngirvine1967' - See reference [2] - requires true sun zenith
-        * 'kastenyoung1989' - See reference [3] - requires apparent sun zenith
-        * 'gueymard1993' - See reference [4] - requires apparent sun zenith
-        * 'young1994' - See reference [5] - requries true sun zenith
-        * 'pickering2002' - See reference [6] - requires apparent sun zenith
+        * 'kasten1966' - See reference [1] -
+          requires apparent sun zenith
+        * 'youngirvine1967' - See reference [2] -
+          requires true sun zenith
+        * 'kastenyoung1989' - See reference [3] -
+          requires apparent sun zenith
+        * 'gueymard1993' - See reference [4] -
+          requires apparent sun zenith
+        * 'young1994' - See reference [5] -
+          requries true sun zenith
+        * 'pickering2002' - See reference [6] -
+          requires apparent sun zenith
 
     Returns
     -------
@@ -183,27 +182,27 @@ def relativeairmass(zenith, model='kastenyoung1989'):
     ----------
 
     [1] Fritz Kasten. "A New Table and Approximation Formula for the
-    Relative Optical Air Mass". Technical Report 136, Hanover, N.H.: U.S.
-    Army Material Command, CRREL.
+    Relative Optical Air Mass". Technical Report 136, Hanover, N.H.:
+    U.S. Army Material Command, CRREL.
 
-    [2] A. T. Young and W. M. Irvine, "Multicolor Photoelectric Photometry
-    of the Brighter Planets," The Astronomical Journal, vol. 72,
-    pp. 945-950, 1967.
+    [2] A. T. Young and W. M. Irvine, "Multicolor Photoelectric
+    Photometry of the Brighter Planets," The Astronomical Journal, vol.
+    72, pp. 945-950, 1967.
 
-    [3] Fritz Kasten and Andrew Young. "Revised optical air mass tables and
-    approximation formula". Applied Optics 28:4735-4738
+    [3] Fritz Kasten and Andrew Young. "Revised optical air mass tables
+    and approximation formula". Applied Optics 28:4735-4738
 
     [4] C. Gueymard, "Critical analysis and performance assessment of
-    clear sky solar irradiance models using theoretical and measured data,"
-    Solar Energy, vol. 51, pp. 121-138, 1993.
+    clear sky solar irradiance models using theoretical and measured
+    data," Solar Energy, vol. 51, pp. 121-138, 1993.
 
     [5] A. T. Young, "AIR-MASS AND REFRACTION," Applied Optics, vol. 33,
     pp. 1108-1110, Feb 1994.
 
     [6] Keith A. Pickering. "The Ancient Star Catalog". DIO 12:1, 20,
 
-    [7] Matthew J. Reno, Clifford W. Hansen and Joshua S. Stein,
-    "Global Horizontal Irradiance Clear Sky Models: Implementation and Analysis"
+    [7] Matthew J. Reno, Clifford W. Hansen and Joshua S. Stein, "Global
+    Horizontal Irradiance Clear Sky Models: Implementation and Analysis"
     Sandia Report, (2012).
     '''
 
@@ -213,33 +212,33 @@ def relativeairmass(zenith, model='kastenyoung1989'):
     model = model.lower()
 
     if 'kastenyoung1989' == model:
-        AM = ( 1.0 / (np.cos(zenith_rad) +
-            0.50572*(((6.07995 + (90 - z)) ** - 1.6364))) )
+        am = (1.0 / (np.cos(zenith_rad) +
+              0.50572*(((6.07995 + (90 - z)) ** - 1.6364))))
     elif 'kasten1966' == model:
-        AM = 1.0 / (np.cos(zenith_rad) + 0.15*((93.885 - z) ** - 1.253))
+        am = 1.0 / (np.cos(zenith_rad) + 0.15*((93.885 - z) ** - 1.253))
     elif 'simple' == model:
-        AM = 1.0 / np.cos(zenith_rad)
+        am = 1.0 / np.cos(zenith_rad)
     elif 'pickering2002' == model:
-        AM = ( 1.0 / (np.sin(np.radians(90 - z +
-            244.0 / (165 + 47.0 * (90 - z) ** 1.1)))) )
+        am = (1.0 / (np.sin(np.radians(90 - z +
+              244.0 / (165 + 47.0 * (90 - z) ** 1.1)))))
     elif 'youngirvine1967' == model:
-        AM = ( (1.0 / np.cos(zenith_rad)) *
-            (1 - 0.0012*( (1.0 / np.cos(zenith_rad)) ** 2) - 1) )
+        am = ((1.0 / np.cos(zenith_rad)) *
+              (1 - 0.0012*((1.0 / np.cos(zenith_rad)) ** 2) - 1))
     elif 'young1994' == model:
-        AM = ( (1.002432*((np.cos(zenith_rad)) ** 2) +
-            0.148386*(np.cos(zenith_rad)) + 0.0096467) /
-            (np.cos(zenith_rad) ** 3 +
-            0.149864*(np.cos(zenith_rad) ** 2) +
-            0.0102963*(np.cos(zenith_rad)) + 0.000303978) )
+        am = ((1.002432*((np.cos(zenith_rad)) ** 2) +
+              0.148386*(np.cos(zenith_rad)) + 0.0096467) /
+              (np.cos(zenith_rad) ** 3 +
+              0.149864*(np.cos(zenith_rad) ** 2) +
+              0.0102963*(np.cos(zenith_rad)) + 0.000303978))
     elif 'gueymard1993' == model:
-        AM = ( 1.0 / (np.cos(zenith_rad) +
-            0.00176759*(z)*((94.37515 - z) ** - 1.21563)) )
+        am = (1.0 / (np.cos(zenith_rad) +
+              0.00176759*(z)*((94.37515 - z) ** - 1.21563)))
     else:
         raise ValueError('%s is not a valid model for relativeairmass', model)
 
     try:
-        AM[z > 90] = np.nan
+        am[z > 90] = np.nan
     except TypeError:
-        AM = np.nan if z > 90 else AM
+        am = np.nan if z > 90 else am
 
-    return AM
+    return am