R/betacar.R

In marcog77/divalt:

#' Function for calculating beta diversity between altitudinal bands following the
#' methods of Carvalho et al. (2012)
#'  
#' @ indat = matrix containing community data
#' @ alt = character vector indicating column name for altitude values
#' @ group =character vector indicating column name for site IDs (if there is more than one site )
#' 

betacar<- function(indat=NULL,alt=NULL,group=NULL) {
    results <- NULL    
    if(is.null(group)){
        alt.l<-sort(unique(indat[,alt]))    
        for (y in 1:(length(alt.l)- 1)){
            d1<-indat[indat[,alt] %in% alt.l[y],] 
            d2<-indat[indat[,alt] %in% alt.l[y+ 1],] 
            Btotal <- NULL
            Brepl <- NULL
            Brich <- NULL
            for (z in 1:dim(d1)[1]) {
                d1<-d1[,!names(d1) %in% alt] 
                d2<-d2[,!names(d2) %in% alt]  
                commBoth <- as.matrix(rbind(d1,d2)) 
                betaValues <- betaObs(comm = commBoth, func = "jaccard", abund = FALSE)
                Btotal[z] <- betaValues$Btotal
                Brepl[z] <- betaValues$Brepl
                Brich[z] <- betaValues$Brich
            } 
            res <- data.frame(Btotal = mean(Btotal), Brepl = mean(Brepl),Brich = mean(Brich), Altitude=paste(alt.l[y],alt.l[y+1],sep="-"),Altitude.midpoint=((alt.l[y]+alt.l[y+1])/2)) 
            results <- rbind(res, results)
        } 
        results.l<-melt(results,id.vars=c("Altitude","Altitude.midpoint"))  
        plot.results<-ggplot(results.l,aes(x=Altitude.midpoint,y=value,colour=variable))+
            geom_line(size=0.5)+geom_point(size=1.5)+theme_bw()+ylab("Beta Diversity")+
            xlab("Altitude")+theme(legend.title=element_blank())+theme(strip.text.x = element_text(size=9, face="bold"),strip.text.y = element_text(size=9, face="bold"))
        results1<-list(results,plot.results)
    } else {
        results <- NULL
        site.l<-unique(indat[,group]) 
        for (i in 1:length(site.l)){  
            indat1<-indat[indat[,group] %in% site.l[i],] 
            colsdel<-c(alt,group) 
            indat.tmp<-indat1[, !colnames(indat1) %in% colsdel]
            totalsp <- colSums(indat.tmp)
            cols <- names(totalsp[totalsp > 0])
            cols1 <- c(alt,group,cols)
            indat2 <- indat1[, cols1]
            alt.l<-sort(unique(indat2[,alt]))     
            for (y in 1:(length(alt.l)- 1)){
                d1<-indat2[indat2[,alt] %in% alt.l[y],] 
                d2<-indat2[indat2[,alt] %in% alt.l[y+ 1],] 
                Btotal <- NULL
                Brepl <- NULL
                Brich <- NULL
                for (z in 1:dim(d1)[1]) {
                    d1<-d1[,!names(d1) %in% alt]   
                    d2<-d2[,!names(d2) %in% alt]  
                    commBoth <- as.matrix(rbind(d1,d2)) 
                    betaValues <- betaObs(comm = commBoth, func = "jaccard", abund = FALSE)
                    Btotal[z] <- betaValues$Btotal
                    Brepl[z] <- betaValues$Brepl
                    Brich[z] <- betaValues$Brich
                } 
                res <- data.frame(site=site.l[i],Btotal = mean(Btotal), Brepl = mean(Brepl),Brich = mean(Brich), Altitude=paste(alt.l[y],alt.l[y+1],sep="-"),Altitude.midpoint=((alt.l[y]+alt.l[y+1])/2))
                results <- rbind(res, results) 
            } 
        }  
        results.l<-melt(results,id.vars=c(group,"Altitude","Altitude.midpoint"))  
        plot.results<-ggplot(results.l,aes(x=Altitude.midpoint,y=value,colour=variable))+
            geom_line(size=0.5)+geom_point(size=1.5)+theme_bw()+ylab("Beta Diversity")+
            xlab("Altitude")+theme(legend.title=element_blank())+theme(strip.text.x = element_text(size=9, face="bold"),strip.text.y = element_text(size=9, face="bold"))+facet_wrap(~site)
        results1<-list(results,plot.results)       
    }
    return(results1)
}