I think YC is asking how to place markers evenly on the curve, rather than the kind of fine tuning that AlignVertexCenters does. If that's the case ...
Consider this example:
rng default
x = randn(1,37);
x = sort(x);
y = sin(x);
plot(x,y,'-+')
Those makers show where the data points are, but they don't look very good if you're just using them to identify a particular curve. In that case, we'd like to just have markers spread evenly along the curve.
To do that, we need to use interp1 to find some evenly spaced locations:
cla
range = [min(x), max(x)];
x2 = linspace(range(1),range(2),12);
y2 = interp1(x,y,x2,'linear');
plot(x,y);
hold on
plot(x2,y2,'+');
There are a couple of problems with that. The obvious one is that the markers aren't the same color as the line. The less obvious one comes when we add a legend. There isn't a single line which the legend can point at which has both the line and the marker. I'm afraid that to solve these issues, things get a bit more involved:
cla
h1 = plot(x,y);
hold on
h2 = plot(x2,y2,'+');
h3 = plot(nan,nan,'-+');
set([h2 h3],'Color',h1.Color);
h3.Visible = 'off';
legend(h3)
We actually need 3 line objects. The first one draws the line. The second one draws the markers, with different spacing. The third one is invisible, and just exists to tell the legend what we think it should show.