I want to plot the function:
f(x,y) = x^2 + y^2 +x*y - 3600, bounded with f(x,y) <=0;
Just like the graph shown below:
The figure is plotted with ezplot in Matlab.
So far I haven't figured out an alternative in Mathcad that can do this.
Could you help me with some ideas?
Thank you very much!
Solved! Go to Solution.
Hi Shawn Fan,
your function is a quadric which can be plotted as follows:
the 2D plot looks like the intersection of the quadric with a plane parallel to the xy plane (z=f(x,y)=a).
For me this is the most simple and basic method ...
Thank you Valery!
This is very helpful!
Could you give me some hint on how you apply the approximate equal?
I use a Greek beta letter to substitute your approximate equal sign since I don't know how to input it in Prime.
When I type f(x,y) and the beta sign, Mathcad will always place a "." in between the two terms, making that beta a variable rather than an operator.
Unfortunately I am using Mathcad Prime now and it appears that Prime cancels the infix operator (so sad)
I would use the convergence of say f(x,y) <= 0 to generate a solid(with many points) circle then.
So sad Prime cancels this useful function that looks like a devolve.
Considering Matlab recommends fplot over the old ezplot, while fplot does not come with the same function as ezplot, I feel a little bit better, LOL...
Still, thank you Valery, thank you FM!
An ingenious method implemented by Viacheslav N. Mezentsev to do implicit 2D and 3D plots (even for Prime) can be found here:
Here is a way to simulate it in Prime
Its a pity its not possible to do it the way it works in real Mathcad
Alas - its Prime - what did we expect?