pvlib.iam.interp¶
-
pvlib.iam.
interp
(aoi, theta_ref, iam_ref, method='linear', normalize=True)[source]¶ Determine the incidence angle modifier (IAM) by interpolating a set of reference values, which are usually measured values.
Parameters: - aoi (numeric) – The angle of incidence between the module normal vector and the sun-beam vector [degrees].
- theta_ref (numeric) – Vector of angles at which the IAM is known [degrees].
- iam_ref (numeric) – IAM values for each angle in
theta_ref
[unitless]. - method (str, default 'linear') – Specifies the interpolation method. Useful options are: ‘linear’, ‘quadratic’, ‘cubic’. See scipy.interpolate.interp1d for more options.
- normalize (boolean, default True) – When true, the interpolated values are divided by the interpolated
value at zero degrees. This ensures that
iam=1.0
at normal incidence.
Returns: iam (numeric) – The incident angle modifier(s) [unitless]
Notes
theta_ref
must have two or more points and may span any range of angles. Typically there will be a dozen or more points in the range 0-90 degrees. Beyond the range oftheta_ref
, IAM values are extrapolated, but constrained to be non-negative.The sign of
aoi
is ignored; only the magnitude is used.See also
iam.physical()
,iam.ashrae()
,iam.martin_ruiz()
,iam.sapm()