- dataframe
 
A data frame with plotting variable(s) and a column of start 
and end times.
- plot.var
 
A factor plotting variable (y axis).
- facet.vars
 
An optional single vector or list of 1 or 2 to facet by.
- fill.var
 
An optional variable to fill the code strips by.
- title
 
An optional title for the plot.
- ylab
 
An optional y label.
- xlab
 
An optional x label.
- rev.factor
 
logical.  If TRUE reverse the current plotting order 
so the first element in the plotting variable's levels is plotted on top.
- transform
 
logical.  If TRUE the repeated facets will be 
transformed from stacked to side by side.
- ncol
 
if an integer value is passed to this 
gantt_wrap uses facet_wrap 
rather than facet_grid.
- minor.line.freq
 
A numeric value for frequency of minor grid lines.
- major.line.freq
 
A numeric value for frequency of major grid lines.
- sig.dig.line.freq
 
An internal rounding factor for minor and major line 
freq.  Generally, default value of 1 suffices for larger range of x scale may 
need to be set to -2.
- hms.scale
 
logical.  If TRUE converts scale to h:m:s format.
Default NULL attempts to detect if object is a cm_time2long object
- 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.
- size
 
The width of the plot bars.
- rm.horiz.lines
 
logical.  If TRUE the horizontal lines will be 
removed.
- x.ticks
 
logical.  If TRUE the x ticks will be displayed.
- y.ticks
 
logical.  If TRUE the y ticks will be displayed.
- legend.position
 
The position of legends. ("left", 
"right", "bottom", "top", or two-element numeric 
vector).
- bar.color
 
Optional color to constrain all bars.
- border.color
 
The color to plot border around Gantt bars (default is 
NULL).
- border.size
 
An integer value for the size to plot borders around Gantt 
bars. Controls length (width also controlled if not specified).
- border.width
 
Controls border width around Gantt bars.  Use a numeric 
value in addition to border size if plot borders appear disproportional.
- constrain
 
logical.  If TRUE the Gantt bars touch the edge of 
the graph.
- 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.