Question from customer:

Is there any way to mix a line and a single symbol in a legend? You can reduce the number of symbol by setting the SAMPLE_WIDTH to zero, but then the line will disappear.

Possible Answer:

Unfortunately, I think the only way to reduce the number of symbols is by adjusting the SAMPLE_WIDTH. You can then use the POLYLINE routine to manually draw the line onto the legend:

IDL> theory = SIN(2.0*FINDGEN(201)*!PI/25.0)*EXP(-0.02*FINDGEN(201))
IDL> observed = theory + RANDOMU(seed,201)*0.4-0.2
IDL> plot1 = PLOT(observed, 'b2', NAME='Observed', symbol='star')
IDL> plot2 = PLOT(theory, /OVERPLOT, 'r2', NAME='Theory')
IDL> leg = LEGEND(TARGET=[plot1,plot2], POSITION=[185,0.9],/DATA, /AUTO_TEXT_COLOR, SAMPLE_WIDTH=0.0)
IDL> p = polyline([.73,.75], [.62,.62],/NORMAL, COLOR='red')

NOTE: I figured out the location of the POLYLINE empirically.

-David
Harris GS