• Uses a psExtra object to make a tree graph structure from the taxonomic table.

  • Then adds statistical results stored in "taxatree_stats" of psExtra data

  • You must use taxatree_models() first to generate statistical model results.

  • You can adjust p-values with taxatree_stats_p_adjust()

taxatree_plots(
  data,
  colour_stat = "estimate",
  palette = "Green-Brown",
  reverse_palette = FALSE,
  colour_lims = NULL,
  colour_oob = scales::oob_squish,
  colour_trans = "abs_sqrt",
  size_stat = list(prevalence = prev),
  node_size_range = c(1, 4),
  edge_width_range = node_size_range * 0.8,
  size_guide = "legend",
  size_trans = "identity",
  sig_stat = "p.value",
  sig_threshold = 0.05,
  sig_shape = "circle filled",
  sig_size = 0.75,
  sig_stroke = 0.75,
  sig_colour = "white",
  edge_alpha = 0.7,
  vars = "term",
  var_renamer = identity,
  title_size = 10,
  layout = "tree",
  layout_seed = NA,
  circular = identical(layout, "tree"),
  node_sort = NULL,
  add_circles = isTRUE(circular),
  drop_ranks = TRUE,
  l1 = if (palette == "Green-Brown") 10 else NULL,
  l2 = if (palette == "Green-Brown") 85 else NULL,
  colour_na = "grey35"
)

Arguments

data

psExtra with taxatree_stats, e.g. output of taxatree_models2stats()

colour_stat

name of variable to scale colour/fill of nodes and edges

palette

diverging hcl colour palette name from colorspace::hcl_palettes("diverging")

reverse_palette

reverse direction of colour palette?

colour_lims

limits of colour and fill scale, NULL will infer lims from range of all data

colour_oob

scales function to handle colour_stat values outside of colour_lims (default simply squishes "out of bounds" values into the given range)

colour_trans

name of transformation for colour scale: default is "abs_sqrt", the square-root of absolute values, but you can use the name of any transformer from the scales package, such as "identity" or "exp"

size_stat

named list of length 1, giving function calculated for each taxon, to determine the size of nodes (and edges). Name used as size legend title.

node_size_range

min and max node sizes, decrease to avoid node overlap

edge_width_range

min and max edge widths

size_guide

guide for node sizes, try "none", "legend" or ggplot2::guide_legend()

size_trans

transformation for size scale you can use (the name of) any transformer from the scales package, such as "identity", "log1p", or "sqrt"

sig_stat

name of variable indicating statistical significance

sig_threshold

value of sig_stat variable indicating statistical significance (below this)

sig_shape

fixed shape for significance marker

sig_size

fixed size for significance marker

sig_stroke

fixed stroke width for significance marker

sig_colour

fixed colour for significance marker (used as fill for filled shapes)

edge_alpha

fixed alpha value for edges

vars

name of column indicating terms in models (one plot made per term)

var_renamer

function to rename variables for plot titles

title_size

font size of title

layout

any ggraph layout, default is "tree"

layout_seed

any numeric, required if a stochastic igraph layout is named

circular

should the layout be circular?

node_sort

sort nodes by "increasing" or "decreasing" size? NULL for no sorting. Use tax_sort() before taxatree_plots() for finer control.

add_circles

add faint concentric circles to plot, behind each rank?

drop_ranks

drop ranks from tree if not included in stats dataframe

l1

Luminance value at the scale endpoints, NULL for palette's default

l2

Luminance value at the scale midpoint, NULL for palette's default

colour_na

colour for NA values in tree. (if unused ranks are not dropped, they will have NA values for colour_stat)

Value

list of ggraph ggplots

Details

taxatree_plotkey plots same layout as taxatree_plots, but in a fixed colour

See website article for more examples of use: https://david-barnett.github.io/microViz/articles/web-only/modelling-taxa.html

Uses ggraph, see help for main underlying graphing function with ?ggraph::ggraph

It is possible to provide multiple significance markers for multiple thresholds, by passing vectors to the sig_shape, sig_threshold, etc. arguments. It is critically important that the thresholds are provided in decreasing order of severity, e.g. sig_threshold = c(0.001, 0.01, 0.1) and you must provide a shape value for each of them.

See also

taxatree_models() to calculate statistical models for each taxon

taxatree_plotkey() to plot the corresponding labelled key

taxatree_plot_labels() and taxatree_label() to add labels

taxatree_stats_p_adjust() to adjust p-values

Examples

# Limited examples, see website article for more

library(dplyr)
library(ggplot2)

data(dietswap, package = "microbiome")
ps <- dietswap

# create some binary variables for easy visualisation
ps <- ps %>% ps_mutate(
  female = if_else(sex == "female", 1, 0, NaN),
  african = if_else(nationality == "AFR", 1, 0, NaN)
)

# This example dataset has some taxa with the same name for phylum and family...
# We can fix problems like this with the tax_prepend_ranks function
# (This will always happen with Actinobacteria!)
ps <- tax_prepend_ranks(ps)

# filter out rare taxa
ps <- ps %>% tax_filter(
  min_prevalence = 0.5, prev_detection_threshold = 100
)
#> Proportional min_prevalence given: 0.5 --> min 111/222 samples.

# delete the Family rank as we will not use it for this small example
# this is necessary as taxatree_plots can only plot consecutive ranks
ps <- ps %>% tax_mutate(Family = NULL)

# specify variables used for modelling
models <- taxatree_models(
  ps = ps, type = corncob::bbdml, ranks = c("Phylum", "Genus"),
  formula = ~ female + african, verbose = TRUE
)
#> 2024-04-03 12:21:34.745328 - modelling at rank: Phylum
#> Modelling: P: Bacteroidetes
#> Modelling: P: Firmicutes
#> 2024-04-03 12:21:34.967797 - modelling at rank: Genus
#> Modelling: G: Allistipes et rel.
#> Modelling: G: Bacteroides vulgatus et rel.
#> Modelling: G: Butyrivibrio crossotus et rel.
#> Modelling: G: Clostridium cellulosi et rel.
#> Modelling: G: Clostridium orbiscindens et rel.
#> Modelling: G: Clostridium symbiosum et rel.
#> Modelling: G: Faecalibacterium prausnitzii et rel.
#> Modelling: G: Oscillospira guillermondii et rel.
#> Modelling: G: Prevotella melaninogenica et rel.
#> Modelling: G: Prevotella oralis et rel.
#> Modelling: G: Ruminococcus obeum et rel.
#> Modelling: G: Sporobacter termitidis et rel.
#> Modelling: G: Subdoligranulum variable at rel.
# models list stored as attachment in psExtra
models
#> psExtra object - a phyloseq object with extra slots:
#> 
#> phyloseq-class experiment-level object
#> otu_table()   OTU Table:         [ 13 taxa and 222 samples ]
#> sample_data() Sample Data:       [ 222 samples by 10 sample variables ]
#> tax_table()   Taxonomy Table:    [ 13 taxa by 2 taxonomic ranks ]
#> 
#> 
#> taxatree_models list:
#> Ranks: Phylum/Genus

# get stats from models
stats <- taxatree_models2stats(models, param = "mu")
stats
#> psExtra object - a phyloseq object with extra slots:
#> 
#> phyloseq-class experiment-level object
#> otu_table()   OTU Table:         [ 13 taxa and 222 samples ]
#> sample_data() Sample Data:       [ 222 samples by 10 sample variables ]
#> tax_table()   Taxonomy Table:    [ 13 taxa by 2 taxonomic ranks ]
#> 
#> 
#> taxatree_stats dataframe:
#> 15 taxa at 2 ranks: Phylum, Genus 
#> 2 terms: female, african

plots <- taxatree_plots(
  data = stats, colour_trans = "identity",
  size_stat = list(mean = mean),
  size_guide = "legend", node_size_range = c(1, 6)
)

# if you change the size_stat for the plots, do the same for the key!!
key <- taxatree_plotkey(
  data = stats,
  rank == "Phylum" | p.value < 0.05, # labelling criteria
  .combine_label = all, # label only taxa where criteria met for both plots
  size_stat = list(mean = mean),
  node_size_range = c(2, 7), size_guide = "none",
  taxon_renamer = function(x) {
    stringr::str_remove_all(x, "[PG]: | [ae]t rel.")
  }
)

# cowplot is powerful for arranging trees and key and colourbar legend
legend <- cowplot::get_legend(plots[[1]])
#> Warning: Multiple components found; returning the first one. To return all, use `return_all = TRUE`.
plot_col <- cowplot::plot_grid(
  plots[[1]] + theme(legend.position = "none"),
  plots[[2]] + theme(legend.position = "none"),
  ncol = 1
)
cowplot::plot_grid(key, plot_col, legend, nrow = 1, rel_widths = c(4, 2, 1))