#88 Change point style in a scatter plot accord to a third column

[Zewei Song]

This feature will be handy to many biologists who use multivariate analysis and draw 2-D coordination plots. In many cases, the points in the scatter plot can be assigned to several treatments, which can be saved in a third column, and some one would like the points to have different color according to the third column. Even better, it would be able to also change shapes according to a fourth column, and sizes according to a fifth column.