ivcurve¶

Module author: Adam Gagorik <adam.gagorik@gmail.com>

class ivcurve.IVCurve(i, v, a, ierr=None)[source]¶

A class to analyze IV curves.

Attr	Description
i	current
v	voltage
p	power
a	area
j	current density
r	irradiance

See also

IVCurveSolar

Construct IV curve.

Parameters:	i (numpy.ndarray) – current v (numpy.ndarray) – voltage a (numpy.ndarray or float) – area ierr – std of current

>>> v = np.linspace(0, 100, 10)
>>> i = np.tanh(v)
>>> a = 1024 * 256
>>> ivcurve = lm.ivcurve.IVCurve(i, v, a)

See also

IVCurve.from_dataframe() IVCurve.from_panel() IVCurve.load_pkl() IVCurve.load_pkls()

classmethod from_dataframe(frame)[source]¶

Construct IV curve from pandas DataFrame.

Parameters:	frame (pandas.DataFrame) – dataframe object

>>> frame = lm.common.load_pkl('calculated.pkl.gz')
>>> ivcurve = lm.ivcurve.IVCurve(frame)

See also

IVCurve.load_pkl()

classmethod from_panel(panel)[source]¶

Construct IV curve from pandas Panel.

Parameters:	panel (pandas.Panel) – panel object

>>> pkls = lm.find.pkls('.', stub='gathered*', r=True)
>>> panel = lm.analyze.create_panel(lm.common.load_pkls(pkls))
>>> ivcurve = lm.ivcurve.IVCurve.from_panel(panel)

See also

IVCurve.load_pkls()

classmethod load_pkl(pkl)[source]¶

Construct IV curve from pkl file.

Parameters:	pkl (str) – name of file

>>> ivcurve = lm.ivcurve.IVCurve.load_pkl('gathered.pkl.gz')

classmethod load_pkls(pkls)[source]¶

Construct IV curve from a list of pkl files.

Parameters:	pkls (list) – list of filenames.

>>> pkls = lm.find.pkls('.', stub='gathered*', r=True)
>>> ivcurve = lm.ivcurve.IVCurve.load_pkls(pkls)

to_dict()[source]¶

Get data as dict.

to_dataframe()[source]¶

Convert data into a pandas.DataFrame

save_csv(handle, **kwargs)[source]¶

Save data to a CSV file.

Parameters:	handle (str) – filename

summary()[source]¶

Get summary of all calculated results as a dictionary.

to_series()[source]¶

Convert data into a pandas.Series

save_pkl(handle)[source]¶

Save results and data to a PKL file.

Parameters:	handle (str) – filename

class ivcurve.IVCurveSolar(i, v, a, ierr=None, v_shift=1.5, **kwargs)[source]¶

A class to analyze IV curves for solar cells. Calculates the fill factor.

Attr	Description
v_oc	open circuit voltage
v_mp	voltage at max power
i_sc	short circuit current
i_mp	current at max power
p_th	theoretical power
p_mp	max power
fill	fill factor

Construct IV curve. See arguments for IVCurve.

Parameters:	v_shift (float) – amount to shift voltage axis by

>>> v = np.linspace(0, 100, 10)
>>> i = np.tanh(v)
>>> a = 1024 * 256
>>> ivcurve = lm.ivcurve.IVCurveSolar(i, v, a)

summary()[source]¶

Get summary of all calculated results as a dictionary.

calculate(mode='interp1d', recycle=False, guess=None, **kwargs)[source]¶

Calculate fill factor. kwargs are passed to fitting functions.

Parameters:	mode (str) – fitting mode (tanh, power, interp1d, spline, erf) recycle (bool) – recycle fit parameters when guessing guess (float) – guess for v_oc (default=shift)

Mode	Option
power	order=8
tanh
erf
interp1d	kind=’cubic’
spline	k=5

>>> ivcurve = lm.ivcurve.IVCurve.load_pkl('gathered.pkl.gz')
>>> ivcurve.calculate(mode='interp1d', kind='linear')
>>> print ivcurve.fill