Ordering legend the same way data is ordered in donut plot

[thbt.m...@gmail.com]

Hi,

I'm starting using ggplot and I have a problem to order the legend the same way data is ordered in the donut plot I'm trying to generate.

I saw similar questions on the forum but unfortunately answers did not help me.

Here is my code:

abundances <- c(11.42, 8.71, 8.36, 6.72, 6.46, 5.24, 5.24, 3.13, 2.48, 2.22, 40.02)

microbes   <- c("Bacteroides vulgatus", "Bacteroides uniformis", "Bacteroides fragilis", "Bacteroides eggerthii", "[Eubacterium] eligens", "Bacteroides cellulosilyticus", 

                "Faecalibacterium prausnitzii", "Bacteroides intestinalis", "Roseburia intestinalis", "Bacteroides salyersiae", "Other organisms")  

dat <- data.frame(abundances=abundances, microbes=microbes, stringsAsFactors=FALSE) 

dat = dat[order(dat$abundances), ]      # order dataframe by abundances

dat$ymax  = cumsum(dat$abundances)      # create ymax column (similar to abundances)

dat$ymin  = c(0, head(dat$ymax, n=-1))  # create ymin column (f)

dat$ymean = (dat$ymin + dat$ymax) / 2

# Make the plot

p1 = ggplot(dat, aes(fill=microbes, xmin=3, xmax=4, ymin=ymin, ymax=ymax)) + 

    geom_rect(colour="grey30") +

    xlim(c(0, 4)) +

    geom_text(data=dat, aes(x=3.5, y=ymean, label=abundances), size=3) +

    coord_polar(theta="y") +                      # to obtain ring plot

    theme_bw() +                                  # ggplot theme

    theme(  panel.grid=element_blank()) +         # to hide grid

    theme(   axis.text=element_blank()) +         # to hide axis text

    theme(axis.title.x=element_blank()) +         # to hide x axis title

    theme(axis.title.y=element_blank()) +         # to hide y axis title

    theme(  axis.ticks=element_blank()) +         # to hide axis ticks

    labs(title="Top10 microbes") +                # title

    scale_fill_discrete(name = "Microbes") +      # Change legend title

    theme(plot.title = element_text(hjust = 0.5)) # Center plot title

p1

As you can see, organism in the legend are ordered alphabetically and not based on their abundances like on the donut plot.

Do you have an idea to order the legend the same way the abundances are?

Or maybe do you have an idea to generate differently a similar donut plot?

Thank you in advance for your answers!

Best,

Thibaut

[Pete St Marie]

Using the forcats package, you might try using fct_reorder().

For instance, p1 = ggplot(dat, aes(fill=fct_reorder(microbes, abundances), xmin=3, xmax=4, ymin=ymin, ymax=ymax))

--pete

[thbt.m...@gmail.com]

A HUGE THANK YOU!

Thibaut