Take advantage of plsetopt to use double buffering, making the plot smoother.
Take advantage of plsetopt to use double buffering, making the plot smoother.

svn path=/trunk/; revision=2970

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot