R/zhr.plot.R

In MetFns: Analysis of Visual Meteor Data

zhr.plot<-function(zhrdata,xlim1,xlim2,xinc,ylim1,ylim2,yinc,dlim1=NULL,dlim2=NULL,dinc=NULL,dunit=NULL)
{
 if(!is.data.frame(zhrdata))
      stop("Invalid input parameter specification: check data")
      
 if(!("sollong"%in%names(zhrdata))|| !("ZHR"%in%names(zhrdata)) || !("st.error"%in%names(zhrdata)))
      stop("Error: zhrdata does not contain columns named sollong, ZHR and st.error")
 
 
 year<-year(zhrdata$date[1])
 
 if(is.null(dlim1) || is.null(dlim2) || is.null(dinc) || is.null(dunit)){
 solvals<-seq(xlim1,xlim2,by=xinc)
 dates<-solar.long_date(solvals,year)
 }else{
   date1<-tryCatch(as.POSIXct(dlim1,tz="UTC"),error=function(e){return(NA)})
   date2<-tryCatch(as.POSIXct(dlim2,tz="UTC"),error=function(e){return(NA)})
   
   if(is.na(date1) || is.na(date2))
     stop("Invalid input parameter specification: check dlim1/dlim2 format")
   
   if(date1>date2)
     stop("Error:dlim2 must be greater than dlim1")
   
   if(any(c(year(date1),year(date2))!=year))
     stop("Year in start and end dates have to match data year")
   
   if(!is.numeric(dinc))
     stop("Invalid input parameter specification: check dinc format")
   
   if(!dunit%in%c("min","h","day"))
     stop("Invalid input parameter specification: check dunit format")
   
   dstep<-function(dinc,dunit)
   {switch(dunit,min=60*dinc,h=3600*dinc,day=86400*dinc)
   }
   dates<-seq(date1,date2,by=dstep(dinc,dunit))
   solvals<-solar.long(dates)
   
 }
 
 if(!is.null(dunit) && dunit=="day")
 {xlab2<-paste(day(dates),month.abb[month(dates)],sep="")
 }else{
 xlab2<-paste(day(dates),month.abb[month(dates)]," ",strftime(dates,format="%H:%M",tz="UTC"),sep="")}
 
 ind<-!is.na(zhrdata$ZHR)
 
 par(mar=c(5,4,6,3))
 graph.data(zhrdata$sollong[ind],zhrdata$ZHR[ind],zhrdata$st.error[ind],"ZHR(Corrected hourly meteor rate)",xlim1,xlim2,xinc,ylim1,ylim2,yinc)
 axis(3,solvals,labels=F,tcl=0.4)
 text(solvals,par("usr")[4]+0.1*yinc,srt=45,xpd=TRUE,pos=4,offset=-0.1,labels=xlab2)
 mtext(paste("Time (UT,",year,")",sep=""),side=3,line=4,cex=1.2)
 
}