The gvisBarChart function reads a data.frame and
creates text output referring to the Google Visualisation API, which can be
included into a web page, or as a stand-alone page. The actual chart is
rendered by the web browser using SVG or
VML.
name of the character column which contains the category labels for
the x-axes.
yvar
a vector of column names of the numerical variables to be
plotted.
Each column is displayed as a separate bar/column.
options
list of configuration options for Google Bar Chart.
[object Object]
Further possible components are, taken from
https://google-developers.appspot.com/chart/interactive/docs/gallery/barchart.html#Configuration_Options:
[objec