Incident angle modifiers

iam.physical(aoi[, n, K, L, n_ar])	Determine the incidence angle modifier using refractive index n, extinction coefficient K, glazing thickness L and refractive index n_ar of an optional anti-reflective coating.
iam.ashrae(aoi[, b])	Determine the incidence angle modifier using the ASHRAE transmission model.
iam.martin_ruiz(aoi[, a_r])	Determine the incidence angle modifier (IAM) using the Martin and Ruiz incident angle model.
iam.martin_ruiz_diffuse(surface_tilt[, a_r, ...])	Determine the incidence angle modifiers (iam) for diffuse sky and ground-reflected irradiance using the Martin and Ruiz incident angle model.
iam.sapm(aoi, module[, upper])	Determine the incidence angle modifier (IAM) using the SAPM model.
iam.interp(aoi, theta_ref, iam_ref[, ...])	Determine the incidence angle modifier (IAM) by interpolating a set of reference values, which are usually measured values.
iam.marion_diffuse(model, surface_tilt, **kwargs)	Determine diffuse irradiance incidence angle modifiers using Marion's method of integrating over solid angle.
iam.marion_integrate(function, surface_tilt, ...)	Integrate an incidence angle modifier (IAM) function over solid angle to determine a diffuse irradiance correction factor using Marion's method.
iam.schlick(aoi)	Determine incidence angle modifier (IAM) for direct irradiance using the Schlick approximation to the Fresnel equations.
iam.schlick_diffuse(surface_tilt)	Determine the incidence angle modifiers (IAM) for diffuse sky and ground-reflected irradiance on a tilted surface using the Schlick incident angle model.
iam.convert(source_name, source_params, ...)	Convert a source IAM model to a target IAM model.
iam.fit(measured_aoi, measured_iam, model_name)	Find model parameters that best fit the data.