plot level curve for higher dimensional functions

Hello everyone,

How do we plot a level curve for a function with 4 variables, knowing that I need the level curve to show 2 dimensions only. Example function:

100*(x2 - x1.^2).^2 + (1 - x1).^2 + (1 - x3).^2 + 90*(x4 - x3.^2).^2 + 10.1*((x2 - 1).^2 + (x4 - 1).^2)  + 19.8*(x2 - 1).*(x4 - 1);

Thanks

[Walter Roberson]

"level curve" -- would that be the same thing as "contour plot" ?

[Sam Alex]

Yes

[Jonathan Epperl]

How is that supposed to work? You are looking for solutions of the equation f(x1,x2,x3,x4) = C for different C. But with your one equation you only reduce the dimension by 1, and a "level curve" would still be a 3-dim object.

[Walter Roberson]

I was thinking "maybe slice() or isosurface()", but those are for 3D arrays, not for 4D arrays.