plotting implicit functions



On 01/16/2013 04:18 PM, Michele Minelli wrote:
> What I was trying to do is plotting a function which is defined as 
> implicit, such as x^2+y^2=1.
> I searched the web and found a method, which is:
>
> load(draw)
> draw2d(implicit(x^2+y^2=1, x, -2, 2, y, -2, 2))
>
> and this works nicely. Anyway I would like a higher precision since 
> the function is plotted with some angles and straight lines.
> Is there a way to obtain this? 
Hi,
I know two other ways; the first one will probably have the same 
problems as the first:

load (implicit_plot);
implicit_plot (x^2+y^2-1,[x,-2,2],[y,-2,2]);

the second one, which I have not documented in the manual yet :( is the 
following:

ploteq (x^2+y^2, [x,-2,2], [y,-2,2]);

You will not get the plot yet, just a box with a menu. In the menu, 
click on the "tools" button (the one with a screwdriver and a wrench); 
then, in the box that says "Trajectory at", write down:
1 0
and press enter and click in the OK button.

Best regards,
Jaime