Hi, if you don't know the bounds for x and y you don't have enough info to plot some shape, easiest would be to prepare setings of your axis. You can use similar command:
axis([xmin xmax ymin ymax zmin zmax cmin cmax]) % sets the x-, y-, and z-axis limits and the color scaling limits (see caxis help for more info) of the current axes.
so if we use ezplot3 for now instead plot3
figure
ezplot3('sin(t)','cos(t)','t',[0,6*pi])
with what you want, it might be like this:
%zmin=0; %min of z
%zmax=pi; %max of z
%xmin=min(x); %not specified
%xmax=max(x); %x >=y
%ymin=min(y); %not specified
%ymax=max(x); %x >=y
%axis([xmin xmax ymin ymax zmin zmax])
but we need some real values now, so lets say x=0->1 y=0->2 z=0->3
axis([0 1 0 2 0 3])
and we will get:
