Constant Latitude Line in Matlab

Question

I'm new to mapping and would like to plot a line of constant latitude at -68 with longitude extending from -80 to -65. If I use linem or plotm with the four coordinates I just get a single point. The only way I can kind of create a fake lat line is to use a track2 great circle. But this line is not rounded the way a true latitude line would be. Does anyone have a solution?

Here's what I'm using: Mapping Toolbox Version 2.6 (R2007b) 02-Aug-2007

This code snippet is working but the line is not curved and I have to write the numbers in plotm in odd format.

LATMIN = -70; LATMAX = -65 ; LONMIN = -80; LONMAX = -65;

[map,maplegend] = tbase(1,[LATMIN LATMAX],[LONMIN LONMAX]);

figure(1); 
clf
ham = axesm('MapProjection','eqdconic','MapParallels',[],'MapLatLimit',...
            [LATMIN LATMAX],'MapLonLimit',[LONMIN LONMAX]); 
setm(ham,'MLineLocation',LONMIN:5:LONMAX,... 
     'MLabelLocation',(ceil(LONMIN/10)10+10):10:(floor(LONMAX/10)10),...
     'MeridianLabel','on',...
     'PLineLocation',LATMIN:1:LATMAX,...
     'PLabelLocation',LATMIN:5:(LATMAX-5),...
     'ParallelLabel','on',...
     'LabelFormat','signed',...
     'flinewidth',0.1);

hold on;

plotm([-68.58455; -68.58455],[-80.0; 360-65.0],'mo-');

hf = framem;

Answer 1

You're on the right track with using track2 (pun intended.) You'll just have to use many waypoints along the great circle line, then use plotm to plot this array of waypoints.