BUG: fix contrib.gen_coeffs Isat2 temperature dependence (#89)

* BUG: fix contrib.gen_coeffs Isat2 temperature dependence

* in residual, assume "isat2" in x is at STC, ie "isat2_t0" and calculate
isat2 using `diode.isat_t()`
* also fix all documentation in gen_coeffs to render okay
* make example a callable script, allow user to specify whether they want
to fit just STC or all IEC61853, show generated coeffs, and save figure
* futurize Bennet's module mismatch simulator for py36
* add contrib, gen_coeffs, and module mismatch simulator to docs in new
api section called contrib
* add example output figures
* fix intersphinx, must use https, leave off trailing slash
* don't ignore git conflict files, so they can be removed without hiding
* ignore the new .pytest_cache folder, move python3 __pycache__ folder to
#build
* fix underline in README.rst, should be as long as the title

* fix NoneType has no method upper()

* scale STC values by cells in series and parallel

in RMSE relative to STC

* fix RMSE, show Isc, Voc on plots

.gitignore

@@ -10,14 +10,14 @@ pvmismatch.sublime-workspace
 
 # files
 *.pyc
-*.orig
 
 # build
 dist/
 pvmismatch.egg-info/
 build/
 Makefile
 version.py
+__pycache__/
 
 # docs
 !docs/_templates/
@@ -28,7 +28,7 @@ testPV/
 benchmark_*/
 .coverage
 .cache/
-__pycache__/
+.pytest_cache/
 
 # virtualenv
 venv/

README.rst

@@ -35,6 +35,6 @@ history is also on `GitHub <https://github.com/SunPower/releases/>`__.
    :target: https://travis-ci.org/SunPower/PVMismatch
 
 Other Projects that use PVMismatch
------
+----------------------------------
 System level mismatch loss calculator using PVMismatch tool (STC and Annual energy loss)
 https://github.com/SunPower/MismatchLossStudy 

pvmismatch/contrib/gen_coeffs/__init__.py

@@ -11,25 +11,37 @@
 # IEC 61853 test matrix
 TC_C = [15.0, 25.0, 50.0, 75.0]
 IRR_W_M2 = [100.0, 200.0, 400.0, 600.0, 800.0, 1000.0, 1100.0]
-TEST_MAT = np.meshgrid(TC_C, IRR_W_M2)
+TEST_MAT = np.meshgrid(TC_C, IRR_W_M2)  #: IEC61853 test matrix
 
 def gen_iec_61853_from_sapm(pvmodule):
     """
     Generate an IEC 61853 test from Sandia Array Performance Model (sapm).
 
-    :param pvmodule: PV module to be tested
-    :type pvmodule: dict
+    :param dict pvmodule: PV module to be tested
+    :returns: a pandas dataframe with columns ``i_mp``, ``v_mp``, ``i_sc``, and
+        ``v_oc`` and rows corresponding to the IEC61853 test conditions
 
-    Module is a dictionary according to :def:`pvlib.pvsystem.sapm`.
+    Module is a dictionary according to ``pvlib.pvsystem.sapm``.
     """
     tc, irr = TEST_MAT
     return sapm(irr / 1000.0, tc, pvmodule)
 
 
 def gen_two_diode(isc, voc, imp, vmp, nseries, nparallel,
-                  tc, x0 = None, *args, **kwargs):
+                  tc, x0=None, *args, **kwargs):
     """
-    Generate two-diode model parameters for ``pvcell`` given 
+    Generate two-diode model parameters for ``pvcell`` given.
+
+    :param numeric isc: short circuit current [A]
+    :param numeric voc: open circuit voltage [V]
+    :param numeric imp: max power current [A]
+    :param numeric vmp: max power voltage [V]
+    :param int nseries: number of cells in series
+    :param int nparallel: number of parallel substrings in PV module
+    :param numeric tc: cell temperature [C]
+    :param x0: optional list of initial guesses, default is ``None``
+    :returns: tuple ``(isat1, isat2, rs, rsh)`` of generated coefficients and
+        the solver output
     """
     isc_cell = isc / nparallel
     voc_cell = voc / nseries
@@ -78,17 +90,17 @@ def gen_sapm(iec_61853):
     return isc0, alpha_isc
 
 
-
 def residual_two_diode(x, isc, voc, imp, vmp, tc):
     """
     Objective function to solve 2-diode model.
-    :param x: parameters isat1, isat2, rs and rsh
-    :param isc: short circuit current [A] at tc [C]
-    :param voc: open circuit voltage [V] at tc [C]
-    :param imp: max power current [A] at tc [C]
-    :param vmp: max power voltage [V] at tc [C]
+
+    :param x: parameters ``isat1``, ``isat2``, ``rs``, and ``rsh``
+    :param isc: short circuit current [A] at ``tc`` [C]
+    :param voc: open circuit voltage [V] at ``tc`` [C]
+    :param imp: max power current [A] at ``tc`` [C]
+    :param vmp: max power voltage [V] at ``tc`` [C]
     :param tc: cell temperature [C]
-    :return: norm of the residuals its sensitivity
+    :returns: norm of the residuals and the Jacobian matrix
     """
     # Constants
     q = diode.QE  # [C/electron] elementary electric charge
@@ -99,11 +111,12 @@ def residual_two_diode(x, isc, voc, imp, vmp, tc):
     vt = kb * tck / q  # [V] thermal voltage
     # Rescale Variables
     isat1_t0 = np.exp(x[0])
-    isat2 = np.exp(x[1])
+    isat2_t0 = np.exp(x[1])
     rs = x[2] ** 2.0
     rsh = x[3] ** 2.0
     # first diode saturation current
     isat1 = diode.isat_t(tc, isat1_t0)
+    isat2 = diode.isat_t(tc, isat2_t0)
     # Short Circuit
     vd_isc, _ = diode.fvd(vc=0.0, ic=isc, rs=rs)
     id1_isc, _ = diode.fid(isat=isat1, vd=vd_isc, m=1.0, vt=vt)

pvmismatch/contrib/gen_coeffs/example.py

@@ -1,7 +1,14 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
 """
 Generate coefficients example.
 """
 
+from __future__ import (
+    absolute_import, division, print_function, unicode_literals)
+import os
+import sys
 from pvmismatch.contrib import gen_coeffs
 from pvmismatch import *
 from matplotlib import pyplot as plt
@@ -22,60 +29,89 @@
 
 iec61853 = gen_coeffs.gen_iec_61853_from_sapm(gen_coeffs.PVMODULES[PROD_NAME])
 iec61853['i_mp'] = iec61853['p_mp'] / iec61853['v_mp']
-#isc0, alpha_isc = gen_coeffs.gen_sapm(iec61853)
-#x, sol = gen_coeffs.gen_two_diode(ISC0, VOC0, IMP0, VMP0, NS, NP, T0)
-x, sol = gen_coeffs.gen_two_diode(
-    iec61853['i_sc'], iec61853['v_oc'], iec61853['i_mp'],
-    iec61853['v_mp'], NS, NP, tc=TC, method='lm',
-    x0=(2.25e-11, 1.5e-6, 0.004, 10.0)
-)
-isat1, isat2, rs, rsh = x
-
-pvc = pvcell.PVcell(
-    Rs=rs, Rsh=rsh, Isat1_T0=isat1, Isat2_T0=isat2,
-    Isc0_T0=ISC0/NP, alpha_Isc=AISC
-)
-f1 = plt.figure()
+isc0, alpha_isc = gen_coeffs.gen_sapm(iec61853)
+assert np.isclose(isc0, ISC0)
+assert np.isclose(alpha_isc, AISC)
 
-for m, _tc in enumerate(gen_coeffs.TC_C):
-    pvc.Tcell = _tc + 273.15
-    plt.subplot(2, 2, m+1)
-    plt.xlim([0, 0.8])
-    plt.ylim([0, 8])
-    res_norm = 0
-    for n, _irr in enumerate(gen_coeffs.IRR_W_M2):
-        pvc.Ee = _irr / 1000.0
-        plt.plot(pvc.Vcell, pvc.Icell, '-', pvc.Vcell, pvc.Pcell, ':')
-        plt.plot(
-            iec61853['v_mp'][n][m]/NS, iec61853['i_mp'][n][m]/NP, 'x',
-            iec61853['v_oc'][n][m]/NS, 0.0, 'x',
-            0.0, iec61853['i_sc'][n][m]/NP, 'x',
-            iec61853['v_mp'][n][m]/NS, iec61853['p_mp'][n][m]/NS/NP, 'o',
+if __name__ == '__main__':
+    test_cond = 'STC'
+    if len(sys.argv) > 1:
+        test_cond = sys.argv[1]
+    if test_cond.upper() == 'STC':
+        x, sol = gen_coeffs.gen_two_diode(ISC0, VOC0, IMP0, VMP0, NS, NP, T0)
+    else:
+        x, sol = gen_coeffs.gen_two_diode(
+            iec61853['i_sc'], iec61853['v_oc'], iec61853['i_mp'],
+            iec61853['v_mp'], NS, NP, tc=TC, method='lm',
+            x0=(2.25e-11, 1.5e-6, 0.004, 10.0)
         )
-        res_norm += (
-            pvc.calcIcell(iec61853['v_mp'][n][m]/NS)
-            - iec61853['i_mp'][n][m]/NP
-        )**2 / (iec61853['i_mp'][n][m]/NP)**2
-        res_norm += (
-            pvc.calcVcell(iec61853['i_mp'][n][m]/NP)
-            - iec61853['v_mp'][n][m]/NS
-        )**2 / (iec61853['v_mp'][n][m]/NS)**2
-        res_norm += (
-            pvc.calcVcell(0.0) - iec61853['v_oc'][n][m]/NS
-        )**2 / (iec61853['v_oc'][n][m]/NS)**2
-        res_norm += (
-            pvc.calcIcell(0.0) - iec61853['i_sc'][n][m]/NP
-        )**2 / (iec61853['i_sc'][n][m]/NP)**2
-        rel_diff = (pvc.Pcell.max()*NS*NP - iec61853['p_mp'][n][m]) / PMP0
-        plt.annotate('$\Delta_{rel}$ = %.2g%%' % (rel_diff*100),
-                     (0.65, iec61853['p_mp'][n][m]/NS/NP))
-    plt.annotate('norm of residuals = %g' % np.sqrt(res_norm / (7*4)),
-                 (0.5, 7.5))
-    plt.grid(True)
-    plt.title(
-        'PVMismatch Generated Coefficients for %s at Tc = %g' % (PROD_NAME, _tc)
+    isat1, isat2, rs, rsh = x
+
+    pvc = pvcell.PVcell(
+        Rs=rs, Rsh=rsh, Isat1_T0=isat1, Isat2_T0=isat2,
+        Isc0_T0=ISC0/NP, alpha_Isc=AISC,
+        pvconst=pvconstants.PVconstants(npts=1001)
     )
-    plt.xlabel('voltage')
-    plt.ylabel('current [A]')
-    plt.xlabel('voltage [V]')
-f1.show()
+    f1 = plt.figure(figsize=(16, 10))
+
+    for m, _tc in enumerate(gen_coeffs.TC_C):
+        pvc.Tcell = _tc + 273.15
+        plt.subplot(2, 2, m+1)
+        plt.xlim([0, 0.8])
+        plt.ylim([0, 8])
+        res_norm = 0
+        for n, _irr in enumerate(gen_coeffs.IRR_W_M2):
+            pvc.Ee = _irr / 1000.0
+            plt.plot(pvc.Vcell, pvc.Icell, '-', pvc.Vcell, pvc.Pcell, ':')
+            plt.plot(
+                iec61853['v_mp'][n][m]/NS, iec61853['i_mp'][n][m]/NP, 'x',
+                iec61853['v_oc'][n][m]/NS, 0.0, 'x',
+                0.0, iec61853['i_sc'][n][m]/NP, 'x',
+                iec61853['v_mp'][n][m]/NS, iec61853['p_mp'][n][m]/NS/NP, 'o',
+            )
+            mpp = np.argmax(pvc.Pcell)
+            res_norm += (
+                pvc.Icell[mpp] - iec61853['i_mp'][n][m]/NP
+            )**2 / (IMP0/NP)**2
+            res_norm += (
+                pvc.Vcell[mpp] - iec61853['v_mp'][n][m]/NS
+            )**2 / (VMP0/NS)**2
+            voc = pvc.calcVcell(0.0)
+            res_norm += (
+                voc - iec61853['v_oc'][n][m]/NS
+            )**2 / (VOC0/NS)**2
+            isc = pvc.calcIcell(0.0)
+            res_norm += (
+                isc - iec61853['i_sc'][n][m]/NP
+            )**2 / (ISC0/NP)**2
+            rel_diff = (pvc.Pcell[mpp]*NS*NP - iec61853['p_mp'][n][m]) / PMP0
+            plt.annotate('$\Delta_{STC}$ = %.2g%%' % (rel_diff*100),
+                         (0.65, iec61853['p_mp'][n][m]/NS/NP))
+            plt.annotate(
+                '$E_e$ = %.2g[suns], $V_{oc}$ = %.2g[V}, $I_{sc}$ = %.g[A]' % (_irr/1000, voc, isc),
+                (0.05, 0.05+iec61853['i_sc'][n][m]/NP))
+        plt.annotate('STC RMSE = %.2g%%' % (np.sqrt(res_norm / (7*4))*100),
+                     (0.65, 7.5))
+        plt.annotate('$I_{sat,1}$ = %.4g' % isat1,
+                     (0.65, 7.2))
+        plt.annotate('$I_{sat,2}$ = %.4g' % isat2,
+                     (0.65, 6.9))
+        plt.annotate('$R_s$ = %.4g' % rs,
+                     (0.65, 6.6))
+        plt.annotate('$R_{sh}$ = %.4g' % rsh,
+                     (0.65, 6.3))
+
+        plt.grid(True)
+        plt.title(
+            'PVMismatch Generated Coefficients for %s at Tc = %g' % (PROD_NAME, _tc)
+        )
+        plt.xlabel('voltage')
+        plt.ylabel('current [A], power [W]')
+        plt.xlabel('voltage [V]')
+        plt.tight_layout()
+        if len(sys.argv) > 2:
+            test_save_dir = sys.argv[2]
+            os.makedirs(test_save_dir, exist_ok=True)
+            f1.savefig(os.path.join(test_save_dir, sys.argv[1]))
+        else:
+            f1.show()

pvmismatch/contrib/module_mismatch_simulator.py

@@ -2,27 +2,33 @@
 
 '''
 Created on Mar 29, 2013
+
 This script allows the user to dynamically investigate the IV and PV
 characteristics of a single module. The user chooses the modules size--72 or 96
-cells. A UI is then generated that allows the user to change the size, location,
+cells. A GUI is then generated that allows the user to change the size, location,
 and irradiance level of a single "shade rectangle". Outputs include cell,
 substring, and module level IV and PV curves as well as a module diagram showing
 the shade location, any reverse biased cells, and any active diodes.
+
 @author: bmeyers
 '''
 # ==============================================================================
 # Importing standard libraries
 # ==============================================================================
 
-import matplotlib.pyplot as plt
-import matplotlib.gridspec as gridspec
+from __future__ import (
+    absolute_import, division, unicode_literals, print_function)
+import json
+from functools import partial
+from copy import deepcopy
+import os
 import numpy as np
 from scipy.interpolate import interp1d
+import matplotlib.pyplot as plt
+import matplotlib.gridspec as gridspec
 from matplotlib.widgets import Slider
 from matplotlib.widgets import Button
-import json
-from functools import partial
-from copy import deepcopy
+from past.builtins import raw_input, xrange
 
 # ==============================================================================
 # Import PVmismatch items
@@ -32,8 +38,8 @@
     from pvmismatch import PVsystem, PVmodule, PVcell, PVconstants
     from pvmismatch.pvmismatch_lib.pvmodule import STD72, STD96, STD128
 except ImportError:
-    print "PVMismatch not found on path! Please use 'pip install -e path/to/pvmismatch'"
-    print "or 'export PYTHONPATH=path/to/pvmismatch:$PYTHONPATH' first."
+    print("PVMismatch not found on path! Please use 'pip install -e path/to/pvmismatch'")
+    print("or 'export PYTHONPATH=path/to/pvmismatch:$PYTHONPATH' first.")
     import sys
     sys.exit(-1)
 
@@ -74,8 +80,8 @@ class ShadeObj(object):
     def __init__(self, pershade=90, shd_width=1, shd_height=1, shd_x=4,
                  shd_y=6, numberCells=96):
         modHeight = modheight(numberCells)
-        module = np.empty([numberCells / modHeight, modHeight], dtype=int)
-        for n in range(numberCells / modHeight):
+        module = np.empty([numberCells // modHeight, modHeight], dtype=int)
+        for n in range(numberCells // modHeight):
             if n % 2 == 0:
                 module[n] = np.arange(n * modHeight, (n + 1) * modHeight, 1)
             else:
@@ -155,8 +161,8 @@ def plotting_calcs(pvmod, ivp=None):
     reversebias = [n for n in range(len(ivp.Icell.T))
                    if -np.interp(-ivp.Imp, -ivp.Icell.T[n], -ivp.Vcell.T[n]) < 0]
     boolindx = np.array(reversebias)
-    module = np.empty([pvmod.numberCells / ivp.modHeight, ivp.modHeight], dtype=int)
-    for n in range(pvmod.numberCells / ivp.modHeight):
+    module = np.empty([pvmod.numberCells // ivp.modHeight, ivp.modHeight], dtype=int)
+    for n in range(pvmod.numberCells // ivp.modHeight):
         if n % 2 == 0:
             module[n] = np.arange(n * ivp.modHeight, (n + 1) * ivp.modHeight, 1)
         else:
@@ -427,24 +433,26 @@ def full_update(val, output=None, ivp0=None, plotobjs=None):
                 output['ax12'], output['ax03'], output['ax_4'], output['x'], output['y'])
     plt.draw()
     t1 = (sw * sh, s_ps.val, ivp0.Pmp, 100 * ivp0.Pmp / Pmp0)
-    print '{0:^6} {1:^6,.2f} {2:^6,.2f} {3:^7,.2f}'.format(*t1)
+    print('{0:^6} {1:^6,.2f} {2:^6,.2f} {3:^7,.2f}'.format(*t1))
 
 
 def set_the_shade(val):
     ivp0.shade.insert(0, ivp0.shade[-1])
 
 
 def save_the_shade(val):
+    this_dir = os.getcwd()
+    save_dir = os.path.join(this_dir, 'JSONshade')
+    os.makedirs(save_dir, exist_ok=True)
     dicts = []
     for shd in ivp0.shade:
         dicts.append({'ps': shd.pershade, 'sw': shd.sw, 'sh': shd.sh,
                       'sy': shd.sy, 'sx': shd.sx,
                       'numberCells': pvmod1.numberCells})
     filename = raw_input("File name? ")
-    filename = 'JSONshade/' + filename + '.json'
-    fo = open(filename, 'w')
-    shades_json = json.dump(dicts, fo, sort_keys=True, indent=2)
-    fo.close()
+    filename = os.path.join(save_dir, filename + '.json')
+    with open(filename, 'w') as fo:
+        json.dump(dicts, fo, sort_keys=True, indent=2)
 
 
 def clear_last_full(val, update=None):
@@ -465,10 +473,10 @@ def clear_last_full(val, update=None):
     plotobjs = PlotObjs()
     update = partial(full_update, output=output, ivp0=ivp0, plotobjs=plotobjs)
     ClearLast = partial(clear_last_full, update=update)
-    print "Pmp0: {}".format(Pmp0)
-    print ""
-    print '{0:6} {1:^6} {2:^6} {3:^7}'.format('#Cells', '%Shade', 'Pmp', '%ofPmp0')
-    print '----------------------------'
+    print("Pmp0: {}".format(Pmp0))
+    print("")
+    print('{0:6} {1:^6} {2:^6} {3:^7}'.format('#Cells', '%Shade', 'Pmp', '%ofPmp0'))
+    print('----------------------------')
     ps0 = 90
     sw0 = 1
     sh0 = 1