dataframe: A dataframe that contains the text variable and optionally the grouping.var and tot variables.
text.var: The text variable (character string).
grouping.var: The grouping variables to color by. Default NULL
colors everything in "black". Also takes a single grouping variable or a list of 1 or more grouping variables.
facet.vars: An optional single vector or list of 1 or 2 to facet by.
tot: The turn of talk variable (character string). May be TRUE
(assumes "tot" is the variable name), FALSE (use row numbers), or a character string of the turn of talk column.
transform: logical. If TRUE the repeated facets will be transformed from stacked to side by side.
ncol: number of columns. gantt_wrap uses facet_wrap
rather than facet_grid.
ylab: Optional y label.
xlab: Optional x label.
bar.space: The amount space between bars (ranging between 1 and 0).
scale: Should scales be fixed ("fixed", the default), free ("free"), or free in one dimension ("free_x", "free_y")
space: If "fixed", the default, all panels have the same size. If "free_y" their height will be proportional to the length of the y scale; if "free_x" their width will be proportional to the length of the x scale; or if "free" both height and width will vary. This setting has no effect unless the appropriate scales also vary.
plot: logical. If TRUE the plot will automatically plot. The user may wish to set to FALSE for use in knitr, sweave, etc. to add additional plot layers.