Hi All

> I am new to Matplotlib, and was wondering if anybody knew

> of an easy way to construct a dropline from a data point in

> a plot to the x axis, i.e. a vertical line from (x1,y1) to

> (x1,0)?

ax.plot((x1, x1), (y1, 0), linestyle='-', color='black', linewidth=2)

should do it... There are some helper functions vline and

axvline you may want to look at

http://matplotlib.sourceforge.net/matplotlib.pylab.html#-axvline

http://matplotlib.sourceforge.net/matplotlib.pylab.html#-vline

The first will draw a vertical line that spans the axes vertical

extent regardless of zoom level, and the second simply draws a

vertical line at a given x from y1 to y2. vline supports many

vertical lines and for a single one as in your example, it's easy

enough to just use plot.

JDH