R/fTheta.R

In solaR: Solar Photovoltaic Systems

 # Copyright (C) 2010, 2009 Oscar Perpiñán Lamigueiro
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
 # as published by the Free Software Foundation; either version 2
 # of the License, or (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #/
fTheta<-function(sol, beta, alfa=0, modeTrk='fixed', betaLim=90, 
                 BT=FALSE, struct, dist){

  stopifnot(modeTrk %in% c('two','horiz','fixed'))
  if (!missing(struct)) {stopifnot(is.list(struct))}
  if (!missing(dist)) {stopifnot(is.data.frame(dist))}

  betaLim=d2r(betaLim)
  lat=getLat(sol, 'rad')
  signLat=ifelse(sign(lat)==0, 1, sign(lat)) ##Cuando lat=0, sign(lat)=0. Lo cambio a sign(lat)=1

  solI<-as.data.frameI(sol, complete=TRUE, day=TRUE)
  AlS=solI$AlS
  AzS=solI$AzS
  decl=solI$decl
  w<-solI$w

  aman<-solI$aman

  Beta<-switch(modeTrk,
               two = {Beta2x=pi/2-AlS
                                        #if (BT==TRUE) {Beta=	
                      Beta=Beta2x+(betaLim-Beta2x)*(Beta2x>betaLim)},
               fixed = rep(d2r(beta), length(w)), 
               horiz={BetaHoriz0=atan(abs(sin(AzS)/tan(AlS)))
                      if (BT){lew=dist$Lew/struct$L
                              Longitud=lew*cos(BetaHoriz0)
                              Cond=(Longitud>=1)
                              Longitud[Cond]=1
                                        #Cuando Cond==TRUE Longitud=1 
                                        #y por tanto asin(Longitud)=pi/2,
                                        #de forma que BetaHoriz=BetaHoriz0
                              BetaHoriz=BetaHoriz0+asin(Longitud)-pi/2
                                        #=ifelse(Cond, 
                                        #BetaHoriz0,#No hay sombra
                                        #BetaHoriz0+asin(Longitud)-pi/2)
                            } else {
                              BetaHoriz=BetaHoriz0
                              rm(BetaHoriz0)}
                      Beta=ifelse(BetaHoriz>betaLim,betaLim,BetaHoriz)}
               )
  is.na(Beta) <- (!aman)

  Alfa<-switch(modeTrk,
               two = AzS,
               fixed = rep(d2r(alfa), length(w)),
               horiz=pi/2*sign(AzS))
  is.na(Alfa) <- (!aman)

  cosTheta<-switch(modeTrk,
                   two=cos(Beta-(pi/2-AlS)),
                   horiz={
                     t1=sin(decl)*sin(lat)*cos(Beta)      
                     t2=cos(decl)*cos(w)*cos(lat)*cos(Beta)   
                     t3=cos(decl)*abs(sin(w))*sin(Beta)   
                     cosTheta=t1+t2+t3
                     rm(t1,t2,t3)
                     cosTheta
                   },
                   fixed={
                     t1=sin(decl)*sin(lat)*cos(Beta)      
                     t2=-signLat*sin(decl)*cos(lat)*sin(Beta)*cos(Alfa) 
                     t3=cos(decl)*cos(w)*cos(lat)*cos(Beta)   
                     t4=signLat*cos(decl)*cos(w)*sin(lat)*sin(Beta)*cos(Alfa) 
                     t5=cos(decl)*sin(w)*sin(Alfa)*sin(Beta)   
                     cosTheta=t1+t2+t3+t4+t5
                     rm(t1,t2,t3,t4,t5)
                     cosTheta
                   }
                   )
  is.na(cosTheta) <- (!aman)
  cosTheta=cosTheta*(cosTheta>0) #cuando cosTheta<0, Theta es mayor de 90º, y por tanto el Sol está detras del panel.
    
  result<-zoo(data.frame(Beta, Alfa, cosTheta), order.by=indexI(sol))   
}