# LineLegend is behaving erratically

The top one is fine, but if I change Red into dashed version, it behaves erratically.

• Use Directive[Blue,Dashed] instead of {Blue, Dashed}. – Szabolcs Feb 20 '16 at 0:36
• Problem solved. Thank you so much! It seems that only changing one of it in your way is sufficient. – Wendy Feb 20 '16 at 0:40
• Since version 6, Directive should always be used instead of {...} when specifying a list of styles... (like in legends, PlotStyle, etc.) Lists are ambiguous and cause problems. – Szabolcs Feb 20 '16 at 0:43

I think the behavior of LineLegend exhibited in the question, if not a bug, is within an epsilon of a bug. Consider that the following all succeed ...

LineLegend[{{Red, Dashed}, Green, Blue}, {"r", "g", "b"}]

LineLegend[{{Red, Dashed}, {Green, Dashed}, Blue}, {"r", "g", "b"}]

LineLegend[{Directive[Red, Dashed], {Green, Dashed}, {Blue, Dashed}}, {"r", "g", "b"}]

LineLegend[{{Red, Dashed}, Directive[Green, Dashed], {Blue, Dashed}}, {"r", "g", "b"}]

LineLegend[{{Red, Dashed}, {Green, Dashed}, Directive[Blue, Dashed]}, {"r", "g", "b"}]


... and that this is the only failure case.

LineLegend[{{Red, Dashed}, {Green, Dashed}, {Blue, Dashed}}, {"r", "g", "b"}]


The singleton nature of the failure strikes me as indicating there is some edge case that has been missed in the Mathematica code underlying the evaluation or internal use of the 1st argument of LineLegend.

• It's an "internal" use to make it compatible with ChartLegends, see the output of BarChart with multiple data sets. – rcollyer Aug 9 '16 at 13:03