corrFdKt: Correlations between the fraction of diffuse irradiation and...
In solaR: Radiation and Photovoltaic Systems

Description Usage Arguments Value Author(s) References See Also Examples

A set of correlations between the fraction of diffuse irradiation and the clearness index used by fCompD and fCompI.

## Monthly means of daily values
FdKtPage(Ktd)
FdKtLJ(Ktd)

## Daily values
FdKtCPR(Ktd)
FdKtEKDd(Ktd, sol)
FdKtCLIMEDd(Ktd)

## Intradaily values
FdKtEKDh(kt)
FdKtCLIMEDh(kt)
FdKtBRL(kt, sol)

`Ktd`	A numeric, the daily clearness index.
`kt`	A numeric, the intradaily clearness index.
`sol`	A `Sol` object provided by `calcSol` or a `zoo` object provided by `fSolD` or `fSolI`.

A numeric, the diffuse fraction.

Oscar Perpiñán Lamigueiro; The BRL model was suggested by Kevin Ummel.

Page, J. K., The calculation of monthly mean solar radiation for horizontal and inclined surfaces from sunshine records for latitudes 40N-40S. En U.N. Conference on New Sources of Energy, vol. 4, págs. 378–390, 1961.
Collares-Pereira, M. y Rabl, A., The average distribution of solar radiation: correlations between diffuse and hemispherical and between daily and hourly insolation values. Solar Energy, 22:155–164, 1979.
Erbs, D.G, Klein, S.A. and Duffie, J.A., Estimation of the diffuse radiation fraction for hourly, daily and monthly-average global radiation. Solar Energy, 28:293:302, 1982.
De Miguel, A. et al., Diffuse solar irradiation model evaluation in the north mediterranean belt area, Solar Energy, 70:143-153, 2001.
Ridley, B., Boland, J. and Lauret, P., Modelling of diffuse solar fraction with multiple predictors, Renewable Energy, 35:478-482, 2010.

fCompD, fCompI

Ktd = seq(0, 1, .01)
Monthly = data.frame(Ktd = Ktd)
Monthly$Page = FdKtPage(Ktd)
Monthly$LJ = FdKtLJ(Ktd)

xyplot(Page+LJ~Ktd, data = Monthly,
       type = c('l', 'g'), auto.key = list(space = 'right'))

Ktd = seq(0, 1, .01)
Daily = data.frame(Ktd = Ktd)
Daily$CPR = FdKtCPR(Ktd)
Daily$CLIMEDd = FdKtCLIMEDd(Ktd)

xyplot(CPR + CLIMEDd ~ Ktd, data = Daily,
       type = c('l', 'g'), auto.key = list(space = 'right'))