handle plot line when there is only one point

close #126 (closed)

if sample number is one, even if the setup of the plot is to plot line, still plot a dot with the same color (if not, nothing will be plotted)

assigned to @ldam

requested review from @kienle

approved this merge request

changed the description

added 3 commits

• 1965e1ab...9c9382b0 - 2 commits from branch master
• 4caa5692 - Merge branch 'master' into i126_plot_line_w_one_point

Compare with previous version

merged

mentioned in commit e3a121ae