def first_solar_spectral_loss(self, pw, airmass_absolute):
if '<STR_LIT>' inself.module_parameters.keys():<EOL><INDENT>coefficients =self.module_parameters['<STR_LIT>']<EOL>module_type = None<EOL><DEDENT>else:<EOL><INDENT>module_type = self._infer_cell_type()<EOL>coefficients = None<EOL><DEDENT>return atmosphere.first_solar_spectral_correction(pw,<EOL>airmass_absolute,<EOL>module_type,<EOL>coefficients)<EOL>
Use the :py:func:`first_solar_spectral_correction` function to
calculate the spectral loss modifier. The model coefficients are
specific to the module's cell type, and are determined by searching
for one of the following keys in self.module_parameters (in order):
    'first_solar_spectral_coefficients' (user-supplied coefficients)
    'Technology' - a string describing the cell type, can be read from
    the CEC module parameter database
    'Material' - a string describing the cell type, can be read from
    the Sandia module database.

Parameters
----------
pw : array-like
    atmospheric precipitable water (cm).

airmass_absolute : array-like
    absolute (pressure corrected) airmass.

Returns
-------
modifier: array-like
    spectral mismatch factor (unitless) which can be multiplied
    with broadband irradiance reaching a module's cells to estimate
    effective irradiance, i.e., the irradiance that is converted to
    electrical current.