From: lily on
> % the data
> x=0:10:360;
> y=sin(pi*x/180);
> ix=randperm(numel(x));
> ix=ix(1:9);
> % the plot
> % - line #1
> ph=line(x,y,...
> 'marker','s',...
> 'markersize',20,...
> 'markerfacecolor',[0,0,0]);
> % - line #2
> line(x(ix),y(ix),...
> 'marker','o',...
> 'markersize',10,...
> 'markerfacecolor',[1,1,0],...
> 'linestyle','none');

> % the legend
> lh=legend(ph,'double legend');
> ch=findall(lh,'type','line','marker','s');
&& when change 's' as 'o', why can't get the data of line #2?
> xp=get(ch,'xdata');
> yp=get(ch,'ydata');
&& here (xp,yp) mean the points of line #1? totally 36 points?

> % - add handle props/vals from line #2
> line(xp,yp,...
> 'parent',lh,...
&& line(...) is create line object, and why legend is changed?
&& here create line #3,isn't line #3 the same as lline #1? they have the same data.
&& will line #3 cover the line #2
&& why set its marker as 'o', what needed is not the data of line #2?
&& what is the function of 'parent',lh,... here?
> 'marker','o',...
> 'markersize',10,...
> 'markerfacecolor',[1,1,0],...
> 'linestyle','none');
>
> us

Could you please explain in more detail, I have read it several times but still don't get it, especially the last two sections,thanks very much.