I would like to have a variant on the tikz dashed line style that begins with dashes spread far apart, and as the line continues to plot, the spacing between dashes reduces, perhaps to zero at the very end. Is it possible to do this with something simple like a line style? Perhaps just in the narrow context of an \addplot command with a domain? Or would it need to be complicated along the lines of this similar question?
My motivation is to plot one-sided asymptotes of function plots, like with arctangent. Personally I feel the horizontal asymptotes are only important in one direction or the other, so I tend to draw them as rays taking up maybe a quarter of the graph width. Some colleagues feel the entire horizontal line should be plotted though. I think what I described might meet both camps' preferences.
