Hi I have a function, which is cylindrical symmetric given by [tex] f(x, y, z) = \exp(-x^2-z^2) [/tex] For a given [itex]y[/itex], the function [itex]\exp(-x^2-z^2) = c[/itex] traces out a circle (where c is a constant). A contourplot of [itex]f(x, 0, z)[/itex] is attached. However, this is for [itex]y=0[/itex] (currently, I get the same plot for an arbitrary value of y). I am interested in constructing a function, which is identical to [itex]f[/itex], but where the center of the above circle increases linearly with y. In other words, at [itex]y=y'[/itex] I want my function to have the same contour plot as attached, but its center should be at [itex]y=y'[/itex]. Is it possible to construct such a function? I guess this is merely a tube, which is tilted.