From b60973fd62813393f05ad4547b4591a99d142ccf Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Wed, 19 Jul 2023 18:43:54 -0700
Subject: [PATCH 1/9] bishop88 works with pandas.Series of length one

---
 pvlib/singlediode.py            | 58 ++++++++++++++++++++-------------
 pvlib/tests/test_singlediode.py | 12 +++++++
 2 files changed, 47 insertions(+), 23 deletions(-)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index cfc63f3591..5226d5464e 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -319,11 +319,9 @@ def vd_from_brent(voc, v, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, voltage, *args)
     elif method == 'newton':
-        # make sure all args are numpy arrays if max size > 1
-        # if voltage is an array, then make a copy to use for initial guess, v0
-        args, v0, method_kwargs = \
-            _prepare_newton_inputs((voltage,), args, voltage, method_kwargs)
-        vd = newton(func=lambda x, *a: fv(x, voltage, *a), x0=v0,
+        x0, (voltage, *args), method_kwargs = \
+            _prepare_newton_inputs(voltage, [voltage, *args], method_kwargs)
+        vd = newton(func=lambda x, *a: fv(x, voltage, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[4],
                     args=args,
                     **method_kwargs)
@@ -454,11 +452,9 @@ def vd_from_brent(voc, i, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, current, *args)
     elif method == 'newton':
-        # make sure all args are numpy arrays if max size > 1
-        # if voc_est is an array, then make a copy to use for initial guess, v0
-        args, v0, method_kwargs = \
-            _prepare_newton_inputs((current,), args, voc_est, method_kwargs)
-        vd = newton(func=lambda x, *a: fi(x, current, *a), x0=v0,
+        x0, (current, *args), method_kwargs = \
+            _prepare_newton_inputs(voc_est, [current, *args], method_kwargs)
+        vd = newton(func=lambda x, *a: fi(x, current, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[3],
                     args=args,
                     **method_kwargs)
@@ -584,10 +580,10 @@ def fmpp(x, *a):
     elif method == 'newton':
         # make sure all args are numpy arrays if max size > 1
         # if voc_est is an array, then make a copy to use for initial guess, v0
-        args, v0, method_kwargs = \
-            _prepare_newton_inputs((), args, voc_est, method_kwargs)
+        x0, args, method_kwargs = \
+            _prepare_newton_inputs(voc_est, args, method_kwargs)
         vd = newton(
-            func=fmpp, x0=v0,
+            func=fmpp, x0=x0,
             fprime=lambda x, *a: bishop88(x, *a, gradients=True)[7], args=args,
             **method_kwargs)
     else:
@@ -627,22 +623,38 @@ def _get_size_and_shape(args):
     return size, shape
 
 
-def _prepare_newton_inputs(i_or_v_tup, args, v0, method_kwargs):
-    # broadcast arguments for newton method
-    # the first argument should be a tuple, eg: (i,), (v,) or ()
-    size, shape = _get_size_and_shape(i_or_v_tup + args)
-    if size > 1:
-        args = [np.asarray(arg) for arg in args]
-    # newton uses initial guess for the output shape
-    # copy v0 to a new array and broadcast it to the shape of max size
+def _prepare_newton_inputs(x0, args, method_kwargs):
+    """
+    Make inputs compatible with Scipy's newton by:
+    - converting all arugments (`x0` and `args`) into numpy.ndarrays if any
+      argument has size greater than 1 or is a pandas.Series.
+    - broadcasting the initial guess `x0` to the shape of the argument with
+      the greatest size.
+
+    Parameters
+    ----------
+    x0: numeric
+        Initial guess for newton.
+    args: Iterable(numeric)
+        Iterable of additional arguments to use in SciPy's newton.
+    method_kwargs: dict
+        Options to pass to newton.
+
+    Returns
+    -------
+        tuple containing the updated initial guess, arguments, and options
+        for newton.
+    """
+    shape = _get_size_and_shape(args)[1]
     if shape is not None:
-        v0 = np.broadcast_to(v0, shape).copy()
+        args = list(map(np.asarray, args))
+        x0 = np.broadcast_to(x0, shape)
 
     # set abs tolerance and maxiter from method_kwargs if not provided
     # apply defaults, but giving priority to user-specified values
     method_kwargs = {**NEWTON_DEFAULT_PARAMS, **method_kwargs}
 
-    return args, v0, method_kwargs
+    return x0, args, method_kwargs
 
 
 def _lambertw_v_from_i(current, photocurrent, saturation_current,
diff --git a/pvlib/tests/test_singlediode.py b/pvlib/tests/test_singlediode.py
index 16b93cbf77..7d4dbe7025 100644
--- a/pvlib/tests/test_singlediode.py
+++ b/pvlib/tests/test_singlediode.py
@@ -1,6 +1,7 @@
 """
 testing single-diode methods using JW Bishop 1988
 """
+import itertools
 
 import numpy as np
 import pandas as pd
@@ -557,3 +558,14 @@ def test_bishop88_full_output_kwarg(method, bishop88_arguments):
     assert isinstance(ret_val[1], tuple)  # second is output from optimizer
     # any root finder returns at least 2 elements with full_output=True
     assert len(ret_val[1]) >= 2
+
+
+@pytest.mark.parametrize('method', ['newton', 'brentq'])
+def test_bishop88_pdSeries_len_one(method, bishop88_arguments):
+    for k, v in bishop88_arguments.items():
+        bishop88_arguments[k] = pd.Series([v])
+
+    # should not raise error
+    bishop88_i_from_v(pd.Series([0]), **bishop88_arguments, method=method)
+    bishop88_v_from_i(pd.Series([0]), **bishop88_arguments, method=method)
+    bishop88_mpp(**bishop88_arguments, method=method)

From 5e2e109818c17592591b2dfea7365e10c1a5f928 Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Wed, 19 Jul 2023 19:41:06 -0700
Subject: [PATCH 2/9] fix to many cases when arguments would be converted

---
 pvlib/singlediode.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index 5226d5464e..39bfbb189d 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -3,6 +3,7 @@
 """
 
 import numpy as np
+import pandas as pd
 from pvlib.tools import _golden_sect_DataFrame
 
 from scipy.optimize import brentq, newton
@@ -645,8 +646,8 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
         tuple containing the updated initial guess, arguments, and options
         for newton.
     """
-    shape = _get_size_and_shape(args)[1]
-    if shape is not None:
+    size, shape = max(((np.size(a), np.shape(a)) for a in args), key=lambda a: a[0])
+    if size > 1 or any(isinstance(a, pd.Series) for a in args):
         args = list(map(np.asarray, args))
         x0 = np.broadcast_to(x0, shape)
 

From 4e24a8b2aa96fe20a60054a2986401da32231c4f Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Tue, 1 Aug 2023 15:19:59 -0700
Subject: [PATCH 3/9] converting all newton numeric args if not np.isscalar

---
 pvlib/singlediode.py | 63 +++++++++++++++++++++++---------------------
 1 file changed, 33 insertions(+), 30 deletions(-)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index 39bfbb189d..f9641e8f41 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -288,9 +288,10 @@ def bishop88_i_from_v(voltage, photocurrent, saturation_current,
     ...     method_kwargs={'full_output': True})
     """
     # collect args
-    args = (photocurrent, saturation_current, resistance_series,
-            resistance_shunt, nNsVth, d2mutau, NsVbi,
-            breakdown_factor, breakdown_voltage, breakdown_exp)
+    args_numeric = (photocurrent, saturation_current, resistance_series,
+                    resistance_shunt, nNsVth, d2mutau, NsVbi)
+    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
+    args = args_numeric + args_scalar
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -320,12 +321,13 @@ def vd_from_brent(voc, v, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, voltage, *args)
     elif method == 'newton':
-        x0, (voltage, *args), method_kwargs = \
-            _prepare_newton_inputs(voltage, [voltage, *args], method_kwargs)
+        x0, (voltage, *args_numeric), method_kwargs = \
+            _prepare_newton_inputs(voltage, [voltage, *args_numeric],
+                                   method_kwargs)
+        args = tuple(args_numeric) + args_scalar
         vd = newton(func=lambda x, *a: fv(x, voltage, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[4],
-                    args=args,
-                    **method_kwargs)
+                    args=args, **method_kwargs)
     else:
         raise NotImplementedError("Method '%s' isn't implemented" % method)
 
@@ -421,9 +423,10 @@ def bishop88_v_from_i(current, photocurrent, saturation_current,
     ...     method_kwargs={'full_output': True})
     """
     # collect args
-    args = (photocurrent, saturation_current, resistance_series,
-            resistance_shunt, nNsVth, d2mutau, NsVbi, breakdown_factor,
-            breakdown_voltage, breakdown_exp)
+    args_numeric = (photocurrent, saturation_current, resistance_series,
+                    resistance_shunt, nNsVth, d2mutau, NsVbi)
+    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
+    args = args_numeric + args_scalar
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -453,12 +456,13 @@ def vd_from_brent(voc, i, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, current, *args)
     elif method == 'newton':
-        x0, (current, *args), method_kwargs = \
-            _prepare_newton_inputs(voc_est, [current, *args], method_kwargs)
+        x0, (current, *args_numeric), method_kwargs = \
+            _prepare_newton_inputs(voc_est, [current, *args_numeric],
+                                   method_kwargs)
+        args = tuple(args_numeric) + args_scalar
         vd = newton(func=lambda x, *a: fi(x, current, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[3],
-                    args=args,
-                    **method_kwargs)
+                    args=args, **method_kwargs)
     else:
         raise NotImplementedError("Method '%s' isn't implemented" % method)
 
@@ -552,9 +556,10 @@ def bishop88_mpp(photocurrent, saturation_current, resistance_series,
     ...     method='newton', method_kwargs={'full_output': True})
     """
     # collect args
-    args = (photocurrent, saturation_current, resistance_series,
-            resistance_shunt, nNsVth, d2mutau, NsVbi, breakdown_factor,
-            breakdown_voltage, breakdown_exp)
+    args_numeric = (photocurrent, saturation_current, resistance_series,
+                    resistance_shunt, nNsVth, d2mutau, NsVbi)
+    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
+    args = args_numeric + args_scalar
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -581,12 +586,12 @@ def fmpp(x, *a):
     elif method == 'newton':
         # make sure all args are numpy arrays if max size > 1
         # if voc_est is an array, then make a copy to use for initial guess, v0
-        x0, args, method_kwargs = \
-            _prepare_newton_inputs(voc_est, args, method_kwargs)
-        vd = newton(
-            func=fmpp, x0=x0,
-            fprime=lambda x, *a: bishop88(x, *a, gradients=True)[7], args=args,
-            **method_kwargs)
+        x0, args_numeric, method_kwargs = \
+            _prepare_newton_inputs(voc_est, args_numeric, method_kwargs)
+        args = tuple(args_numeric) + args_scalar
+        vd = newton(func=fmpp, x0=x0,
+                    fprime=lambda x, *a: bishop88(x, *a, gradients=True)[7],
+                    args=args, **method_kwargs)
     else:
         raise NotImplementedError("Method '%s' isn't implemented" % method)
 
@@ -628,7 +633,7 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
     """
     Make inputs compatible with Scipy's newton by:
     - converting all arugments (`x0` and `args`) into numpy.ndarrays if any
-      argument has size greater than 1 or is a pandas.Series.
+      argument is not a scalar.
     - broadcasting the initial guess `x0` to the shape of the argument with
       the greatest size.
 
@@ -643,13 +648,11 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
 
     Returns
     -------
-        tuple containing the updated initial guess, arguments, and options
-        for newton.
+    tuple
+        The updated initial guess, arguments, and options for newton.
     """
-    size, shape = max(((np.size(a), np.shape(a)) for a in args), key=lambda a: a[0])
-    if size > 1 or any(isinstance(a, pd.Series) for a in args):
-        args = list(map(np.asarray, args))
-        x0 = np.broadcast_to(x0, shape)
+    if not (np.isscalar(x0) and all(map(np.isscalar, args))):
+        x0, *args = np.broadcast_arrays(x0, *args)
 
     # set abs tolerance and maxiter from method_kwargs if not provided
     # apply defaults, but giving priority to user-specified values

From 7acf63e9242b0963f8715f0b97d63ef61284adc7 Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Tue, 1 Aug 2023 15:25:03 -0700
Subject: [PATCH 4/9] remove used imports

---
 pvlib/singlediode.py            | 1 -
 pvlib/tests/test_singlediode.py | 2 --
 2 files changed, 3 deletions(-)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index f9641e8f41..2ae0e47eb5 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -3,7 +3,6 @@
 """
 
 import numpy as np
-import pandas as pd
 from pvlib.tools import _golden_sect_DataFrame
 
 from scipy.optimize import brentq, newton
diff --git a/pvlib/tests/test_singlediode.py b/pvlib/tests/test_singlediode.py
index 7d4dbe7025..bd3b33776a 100644
--- a/pvlib/tests/test_singlediode.py
+++ b/pvlib/tests/test_singlediode.py
@@ -1,8 +1,6 @@
 """
 testing single-diode methods using JW Bishop 1988
 """
-import itertools
-
 import numpy as np
 import pandas as pd
 import scipy

From 4c0f2c59b8b59a7ae6d286ce896426a3dec1fd82 Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Tue, 1 Aug 2023 15:26:42 -0700
Subject: [PATCH 5/9] add back newline

---
 pvlib/tests/test_singlediode.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pvlib/tests/test_singlediode.py b/pvlib/tests/test_singlediode.py
index bd3b33776a..8e0d05668e 100644
--- a/pvlib/tests/test_singlediode.py
+++ b/pvlib/tests/test_singlediode.py
@@ -1,6 +1,7 @@
 """
 testing single-diode methods using JW Bishop 1988
 """
+
 import numpy as np
 import pandas as pd
 import scipy

From cc3700d39dda7a437602d43b8b5e196c90382dce Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Wed, 2 Aug 2023 11:07:56 -0700
Subject: [PATCH 6/9] update whatsnew

---
 docs/sphinx/source/whatsnew/v0.10.2.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/docs/sphinx/source/whatsnew/v0.10.2.rst b/docs/sphinx/source/whatsnew/v0.10.2.rst
index 7259f6a566..b0a2462693 100644
--- a/docs/sphinx/source/whatsnew/v0.10.2.rst
+++ b/docs/sphinx/source/whatsnew/v0.10.2.rst
@@ -21,6 +21,9 @@ Bug fixes
 ~~~~~~~~~
 * :py:func:`~pvlib.iotools.get_psm3` no longer incorrectly returns clear-sky
   DHI instead of clear-sky GHI when requesting ``ghi_clear``. (:pull:`1819`)
+* :py:func:`pvlib.singlediode.bishop88` with `method='newton'` no longer
+  crashes when passed `pandas.Series` of length one.
+  (:issue:`1787`, :pull:`1822`)
 
 Testing
 ~~~~~~~

From bc6646b1eeaa3de0ab19af830cc612027ab96aa7 Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Thu, 3 Aug 2023 10:47:22 -0700
Subject: [PATCH 7/9] _prepare_newton_inputs only changes shape of x0;
 refactoring to remove singlediode._get_size_and_shape

---
 pvlib/pvsystem.py    | 46 ++++++++++--------------------
 pvlib/singlediode.py | 66 ++++++++++++++------------------------------
 2 files changed, 34 insertions(+), 78 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 4fb0dc5772..9144106e79 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -2651,28 +2651,19 @@ def v_from_i(current, photocurrent, saturation_current, resistance_series,
        parameters of real solar cells using Lambert W-function", Solar
        Energy Materials and Solar Cells, 81 (2004) 269-277.
     '''
+    args = (current, photocurrent, saturation_current,
+            resistance_series, resistance_shunt, nNsVth)
     if method.lower() == 'lambertw':
-        return _singlediode._lambertw_v_from_i(
-            current, photocurrent, saturation_current, resistance_series,
-            resistance_shunt, nNsVth
-        )
+        return _singlediode._lambertw_v_from_i(*args)
     else:
         # Calculate points on the IV curve using either 'newton' or 'brentq'
         # methods. Voltages are determined by first solving the single diode
         # equation for the diode voltage V_d then backing out voltage
-        args = (current, photocurrent, saturation_current,
-                resistance_series, resistance_shunt, nNsVth)
         V = _singlediode.bishop88_v_from_i(*args, method=method.lower())
-        # find the right size and shape for returns
-        size, shape = _singlediode._get_size_and_shape(args)
-        if size <= 1:
-            if shape is not None:
-                V = np.tile(V, shape)
-        if np.isnan(V).any() and size <= 1:
-            V = np.repeat(V, size)
-            if shape is not None:
-                V = V.reshape(shape)
-        return V
+        if all(map(np.isscalar, args)):
+            return V
+        shape = _singlediode._shape_of_max_size(*args)
+        return np.broadcast_to(V, shape)
 
 
 def i_from_v(voltage, photocurrent, saturation_current, resistance_series,
@@ -2742,28 +2733,19 @@ def i_from_v(voltage, photocurrent, saturation_current, resistance_series,
        parameters of real solar cells using Lambert W-function", Solar
        Energy Materials and Solar Cells, 81 (2004) 269-277.
     '''
+    args = (voltage, photocurrent, saturation_current,
+            resistance_series, resistance_shunt, nNsVth)
     if method.lower() == 'lambertw':
-        return _singlediode._lambertw_i_from_v(
-            voltage, photocurrent, saturation_current, resistance_series,
-            resistance_shunt, nNsVth
-        )
+        return _singlediode._lambertw_i_from_v(*args)
     else:
         # Calculate points on the IV curve using either 'newton' or 'brentq'
         # methods. Voltages are determined by first solving the single diode
         # equation for the diode voltage V_d then backing out voltage
-        args = (voltage, photocurrent, saturation_current, resistance_series,
-                resistance_shunt, nNsVth)
         current = _singlediode.bishop88_i_from_v(*args, method=method.lower())
-        # find the right size and shape for returns
-        size, shape = _singlediode._get_size_and_shape(args)
-        if size <= 1:
-            if shape is not None:
-                current = np.tile(current, shape)
-        if np.isnan(current).any() and size <= 1:
-            current = np.repeat(current, size)
-            if shape is not None:
-                current = current.reshape(shape)
-        return current
+        if all(map(np.isscalar, args)):
+            return current
+        shape = _singlediode._shape_of_max_size(*args)
+        return np.broadcast_to(current, shape)
 
 
 def scale_voltage_current_power(data, voltage=1, current=1):
diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index 2ae0e47eb5..a00554f49e 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -287,10 +287,9 @@ def bishop88_i_from_v(voltage, photocurrent, saturation_current,
     ...     method_kwargs={'full_output': True})
     """
     # collect args
-    args_numeric = (photocurrent, saturation_current, resistance_series,
-                    resistance_shunt, nNsVth, d2mutau, NsVbi)
-    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
-    args = args_numeric + args_scalar
+    args = (photocurrent, saturation_current,
+            resistance_series, resistance_shunt, nNsVth, d2mutau, NsVbi,
+            breakdown_factor, breakdown_voltage, breakdown_exp)
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -320,10 +319,8 @@ def vd_from_brent(voc, v, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, voltage, *args)
     elif method == 'newton':
-        x0, (voltage, *args_numeric), method_kwargs = \
-            _prepare_newton_inputs(voltage, [voltage, *args_numeric],
-                                   method_kwargs)
-        args = tuple(args_numeric) + args_scalar
+        x0, (voltage, *args), method_kwargs = \
+            _prepare_newton_inputs(voltage, (voltage, *args), method_kwargs)
         vd = newton(func=lambda x, *a: fv(x, voltage, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[4],
                     args=args, **method_kwargs)
@@ -422,10 +419,9 @@ def bishop88_v_from_i(current, photocurrent, saturation_current,
     ...     method_kwargs={'full_output': True})
     """
     # collect args
-    args_numeric = (photocurrent, saturation_current, resistance_series,
-                    resistance_shunt, nNsVth, d2mutau, NsVbi)
-    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
-    args = args_numeric + args_scalar
+    args = (photocurrent, saturation_current,
+            resistance_series, resistance_shunt, nNsVth, d2mutau, NsVbi,
+            breakdown_factor, breakdown_voltage, breakdown_exp)
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -455,10 +451,8 @@ def vd_from_brent(voc, i, iph, isat, rs, rsh, gamma, d2mutau, NsVbi,
         vd_from_brent_vectorized = np.vectorize(vd_from_brent)
         vd = vd_from_brent_vectorized(voc_est, current, *args)
     elif method == 'newton':
-        x0, (current, *args_numeric), method_kwargs = \
-            _prepare_newton_inputs(voc_est, [current, *args_numeric],
-                                   method_kwargs)
-        args = tuple(args_numeric) + args_scalar
+        x0, (current, *args), method_kwargs = \
+            _prepare_newton_inputs(voc_est, (current, *args), method_kwargs)
         vd = newton(func=lambda x, *a: fi(x, current, *a), x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[3],
                     args=args, **method_kwargs)
@@ -555,10 +549,9 @@ def bishop88_mpp(photocurrent, saturation_current, resistance_series,
     ...     method='newton', method_kwargs={'full_output': True})
     """
     # collect args
-    args_numeric = (photocurrent, saturation_current, resistance_series,
-                    resistance_shunt, nNsVth, d2mutau, NsVbi)
-    args_scalar = (breakdown_factor, breakdown_voltage, breakdown_exp)
-    args = args_numeric + args_scalar
+    args = (photocurrent, saturation_current,
+            resistance_series, resistance_shunt, nNsVth, d2mutau, NsVbi,
+            breakdown_factor, breakdown_voltage, breakdown_exp)
     method = method.lower()
 
     # method_kwargs create dict if not provided
@@ -585,9 +578,8 @@ def fmpp(x, *a):
     elif method == 'newton':
         # make sure all args are numpy arrays if max size > 1
         # if voc_est is an array, then make a copy to use for initial guess, v0
-        x0, args_numeric, method_kwargs = \
-            _prepare_newton_inputs(voc_est, args_numeric, method_kwargs)
-        args = tuple(args_numeric) + args_scalar
+        x0, args, method_kwargs = \
+            _prepare_newton_inputs(voc_est, args, method_kwargs)
         vd = newton(func=fmpp, x0=x0,
                     fprime=lambda x, *a: bishop88(x, *a, gradients=True)[7],
                     args=args, **method_kwargs)
@@ -604,28 +596,9 @@ def fmpp(x, *a):
         return bishop88(vd, *args)
 
 
-def _get_size_and_shape(args):
-    # find the right size and shape for returns
-    size, shape = 0, None  # 0 or None both mean scalar
-    for arg in args:
-        try:
-            this_shape = arg.shape  # try to get shape
-        except AttributeError:
-            this_shape = None
-            try:
-                this_size = len(arg)  # try to get the size
-            except TypeError:
-                this_size = 0
-        else:
-            this_size = arg.size  # if it has shape then it also has size
-            if shape is None:
-                shape = this_shape  # set the shape if None
-        # update size and shape
-        if this_size > size:
-            size = this_size
-            if this_shape is not None:
-                shape = this_shape
-    return size, shape
+def _shape_of_max_size(*args):
+    return max(((np.size(a), np.shape(a)) for a in args),
+               key=lambda t: t[0])[1]
 
 
 def _prepare_newton_inputs(x0, args, method_kwargs):
@@ -651,7 +624,8 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
         The updated initial guess, arguments, and options for newton.
     """
     if not (np.isscalar(x0) and all(map(np.isscalar, args))):
-        x0, *args = np.broadcast_arrays(x0, *args)
+        args = tuple(map(np.asarray, args))
+        x0 = np.broadcast_to(x0, _shape_of_max_size(x0, *args))
 
     # set abs tolerance and maxiter from method_kwargs if not provided
     # apply defaults, but giving priority to user-specified values

From 7b396738bb23e2be3ac6c42e369a9f51fc857ace Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Thu, 3 Aug 2023 11:23:16 -0700
Subject: [PATCH 8/9] remove _shape_of_max_size, np.broadcast_shapes handles
 this

---
 pvlib/pvsystem.py    | 4 ++--
 pvlib/singlediode.py | 7 +------
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index 9144106e79..a8fc0c7258 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -2662,7 +2662,7 @@ def v_from_i(current, photocurrent, saturation_current, resistance_series,
         V = _singlediode.bishop88_v_from_i(*args, method=method.lower())
         if all(map(np.isscalar, args)):
             return V
-        shape = _singlediode._shape_of_max_size(*args)
+        shape = np.broadcast_shapes(*map(np.shape, args))
         return np.broadcast_to(V, shape)
 
 
@@ -2744,7 +2744,7 @@ def i_from_v(voltage, photocurrent, saturation_current, resistance_series,
         current = _singlediode.bishop88_i_from_v(*args, method=method.lower())
         if all(map(np.isscalar, args)):
             return current
-        shape = _singlediode._shape_of_max_size(*args)
+        shape = np.broadcast_shapes(*map(np.shape, args))
         return np.broadcast_to(current, shape)
 
 
diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index a00554f49e..c82a69bb53 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -596,11 +596,6 @@ def fmpp(x, *a):
         return bishop88(vd, *args)
 
 
-def _shape_of_max_size(*args):
-    return max(((np.size(a), np.shape(a)) for a in args),
-               key=lambda t: t[0])[1]
-
-
 def _prepare_newton_inputs(x0, args, method_kwargs):
     """
     Make inputs compatible with Scipy's newton by:
@@ -625,7 +620,7 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
     """
     if not (np.isscalar(x0) and all(map(np.isscalar, args))):
         args = tuple(map(np.asarray, args))
-        x0 = np.broadcast_to(x0, _shape_of_max_size(x0, *args))
+        x0 = np.broadcast_to(x0, np.broadcast_shapes(*map(np.shape, args)))
 
     # set abs tolerance and maxiter from method_kwargs if not provided
     # apply defaults, but giving priority to user-specified values

From 54462679cb6407464337f7169d126d65afde3d46 Mon Sep 17 00:00:00 2001
From: Taos Transue <spacechips@rocketmail.com>
Date: Thu, 3 Aug 2023 11:40:59 -0700
Subject: [PATCH 9/9] np.broadcast_shapes not available for Python 3.7 conda
 -min

This reverts commit 7b396738bb23e2be3ac6c42e369a9f51fc857ace.
---
 pvlib/pvsystem.py    | 4 ++--
 pvlib/singlediode.py | 7 ++++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/pvlib/pvsystem.py b/pvlib/pvsystem.py
index a8fc0c7258..9144106e79 100644
--- a/pvlib/pvsystem.py
+++ b/pvlib/pvsystem.py
@@ -2662,7 +2662,7 @@ def v_from_i(current, photocurrent, saturation_current, resistance_series,
         V = _singlediode.bishop88_v_from_i(*args, method=method.lower())
         if all(map(np.isscalar, args)):
             return V
-        shape = np.broadcast_shapes(*map(np.shape, args))
+        shape = _singlediode._shape_of_max_size(*args)
         return np.broadcast_to(V, shape)
 
 
@@ -2744,7 +2744,7 @@ def i_from_v(voltage, photocurrent, saturation_current, resistance_series,
         current = _singlediode.bishop88_i_from_v(*args, method=method.lower())
         if all(map(np.isscalar, args)):
             return current
-        shape = np.broadcast_shapes(*map(np.shape, args))
+        shape = _singlediode._shape_of_max_size(*args)
         return np.broadcast_to(current, shape)
 
 
diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index c82a69bb53..a00554f49e 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -596,6 +596,11 @@ def fmpp(x, *a):
         return bishop88(vd, *args)
 
 
+def _shape_of_max_size(*args):
+    return max(((np.size(a), np.shape(a)) for a in args),
+               key=lambda t: t[0])[1]
+
+
 def _prepare_newton_inputs(x0, args, method_kwargs):
     """
     Make inputs compatible with Scipy's newton by:
@@ -620,7 +625,7 @@ def _prepare_newton_inputs(x0, args, method_kwargs):
     """
     if not (np.isscalar(x0) and all(map(np.isscalar, args))):
         args = tuple(map(np.asarray, args))
-        x0 = np.broadcast_to(x0, np.broadcast_shapes(*map(np.shape, args)))
+        x0 = np.broadcast_to(x0, _shape_of_max_size(x0, *args))
 
     # set abs tolerance and maxiter from method_kwargs if not provided
     # apply defaults, but giving priority to user-specified values