Search code examples
rggplot2vegan

ggplot2 boxplot with labelled rug


Can I make such a plot with ggplot2?

# data
require(vegan)
data(dune)
data(dune.env)

# RDA
RDA <- rda(dune ~ A1, data = dune.env)

# extract species scores
df <- data.frame(spec_scores = scores(RDA)$species[ , 1], 
                 taxa = rownames(scores(RDA)$species))
df <- df[abs(df$spec_scores) > 0.05, ]

# plot
par(mar = c(5,4,4,8))
# boxplot of sites-scores along A1-axis
boxplot(scores(RDA)$sites[ , 1] ~ dune.env$Management)
abline(h = 0, lty = "dotted")

# add species scores to plot
rug(df$spec_scores, side=4)
linestack(df$spec_scores, labels=df$taxa, at = par("usr")[2], add = TRUE, hoff = 1)

enter image description here

Basicly I am looking for a way how to plot a labelled rug beneath the boxplot.

Any hints or suggestions?


Solution

  • This is solution only using ggplot2, so it won't be most elegant one.

    I started with first steps as suggested by @Eric Fail.

    require(vegan)
    data(dune)
    data(dune.env)
    
    # RDA
    RDA <- rda(dune ~ A1, data = dune.env)
    
    # extract species scores
    df1 <- data.frame(RDA.scores = scores(RDA)$sites[ , 1], Management = dune.env$Management)
    df2 <- data.frame(y = scores(RDA)$species[ , 1], taxa = rownames(scores(RDA)$species))
    # Order data according to species scores
    df2<-df2[order(df2$y),]
    
    # define values for rugs (segments). 4.9 and 5.0 used because data has 4 levels (+1)
    df2$x=4.9
    df2$xend=5
    
    # define coordinates for names (30 is number of species)
    df2$yend2<-seq(min(df1$RDA.scores),max(df1$RDA.scores),length.out=30)
    df2$xend2=5.3
    
    # plot
    P <- ggplot(data = df1, aes( x = Management, y = RDA.scores) ) + 
         geom_segment(y=0,yend=0,x=0,xend=5, lty=2, size = I(0.3)) + 
         geom_boxplot() + 
         #add extra levels to get space
         scale_x_discrete(limits=c("BF", "HF", "NM", "SF", "","")) + 
         #set y scale
         scale_y_continuous(limits=c(-3,5),expand=c(0,0)) +
         #add rugs as segments and add segments connecting rugs and texts
         geom_segment(data= df2, mapping=aes(x=x,xend=xend,y=y,yend=y), size = I(0.3)) +
         geom_segment(data= df2, mapping=aes(x=xend,xend=xend2,y=y,yend=yend2), size = I(0.4)) +
         #add texts
         geom_text(data=df2,mapping=aes(x=xend2+0.1,y=yend2,label=taxa),hjust=0, size=3) +
         #add rectangular to imitate box around plot
         geom_rect(xmax=5,xmin=0.4,ymax=5,ymin=-3,colour="black",fill=NA)
    
    # Final adjustments of plot
    P+theme(axis.line=element_blank(),
            panel.grid=element_blank(),
            panel.background=element_blank())
    

    ggplot2 boxplot