Mosaic plots display
tiles that correspond to the crosstabulation table cells. The areas
of the tiles are proportional to the frequencies of the table cells.
The column variable is displayed on the X axis, and the tile widths
are proportional to the relative frequencies of the column variable
levels. The row variable is displayed on the Y axis, and the tile
heights are proportional to the relative frequencies of the row levels
within column levels. For more information, see Friendly (2000).