Plot data distribution as histograms. — plot

This function takes a data table, a quantitative variable (ycol) and a grouping variable (group), if available, and plots a histogram graph using geom_histogram). Alternatives are plot_histogram, or plot_qqline.

plot_histogram(
  data,
  ycol,
  group,
  facet,
  BinSize = 30,
  c_alpha = 0.8,
  TextXAngle = 0,
  facet_scales = "fixed",
  fontsize = 20,
  linethick,
  alpha,
  ColPal = c("okabe_ito", "all_grafify", "bright", "contrast", "dark", "fishy", "kelly",
    "light", "muted", "pale", "r4", "safe", "vibrant"),
  ColSeq = TRUE,
  ColRev = FALSE,
  ...
)

Arguments

data: a data table e.g. data.frame or tibble.
ycol: name of the column containing the quantitative variable whose histogram distribution is to be plotted.
group: name of the column containing a categorical grouping variable.
facet: add another variable from the data table to create faceted graphs using ggplot2facet_wrap.
BinSize: number of distinct bins to use on X-axis, default set to 30.
c_alpha: fractional opacity of colour filled within histograms, default set to 0.8 (i.e. 80% opacity).
TextXAngle: orientation of text on X-axis; default 0 degrees. Change to 45 or 90 to remove overlapping text.
facet_scales: whether or not to fix scales on X & Y axes for all facet facet graphs. Can be fixed (default), free, free_y or free_x (for Y and X axis one at a time, respectively).
fontsize: parameter of base_size of fonts in theme_classic, default set to size 20.
linethick: thickness of symbol border, default set to fontsize/22.
alpha: deprecated old argument for c_alpha; retained for backward compatibility.
ColPal: grafify colour palette to apply, default "okabe_ito"; see graf_palettes for available palettes.
ColSeq: logical TRUE or FALSE. Default TRUE for sequential colours from chosen palette. Set to FALSE for distant colours, which will be applied using scale_fill_grafify2.
ColRev: whether to reverse order of colour within the selected palette, default F (FALSE); can be set to T (TRUE).
...: any additional arguments to pass to ggplot2geom_histogram.

Value

This function returns a ggplot2 object of class "gg" and "ggplot".

Details

Note that the function requires the quantitative Y variable first, and groups them based on a categorical variable passed on via the group argument. The grouping variable is mapped to the fill aesthetics in geom_histogram.

ColPal & ColRev options are applied to both fill and colour scales. Colours available can be seen quickly with plot_grafify_palette. Colours can be changed using ColPal, ColRev or ColSeq arguments. ColPal can be one of the following: "okabe_ito", "dark", "light", "bright", "pale", "vibrant, "muted" or "contrast". ColRev (logical TRUE/FALSE) decides whether colours are chosen from first-to-last or last-to-first from within the chosen palette. ColSeq decides whether colours are picked by respecting the order in the palette or the most distant ones using colorRampPalette.

Examples

#Basic usage
plot_histogram(data = data_t_pratio, 
ycol = Cytokine, group = Genotype, 
BinSize = 10)

#with log transformation
plot_histogram(data = data_t_pratio, 
ycol = log(Cytokine), group = Genotype, 
BinSize = 10)