Re: How to draw several contours for one function, while

*To*: mathgroup at smc.vnet.net*Subject*: [mg127680] Re: How to draw several contours for one function, while*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Wed, 15 Aug 2012 03:30:45 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120814082402.2D8BD6862@smc.vnet.net>

Without knowing the functions it is difficult to guess the best way to show what you might want to see. Manipulate may be a better way than Animate to examine what is going on. Manipulate[ pts = {x, y} /. Solve[{ f[x, y, a] == intersect, g[x, y, a] == 0}, {x, y}, Reals]; Show[ ContourPlot[f[x, y, a], {x, -8, 8}, {y, -8, 8}, Contours -> Range[0, 75, 15], ContourStyle -> Hue /@ (.7 Range[0, 1, 15/75] + .15), ContourShading -> None, ContourLabels -> All], ContourPlot[g[x, y, a] == 0, {x, -8, 8}, {y, -8, 8}, ContourShading -> None, ContourLabels -> All], Graphics[{Red, AbsolutePointSize[4], Tooltip[Point[#], #] & /@ pts}], PlotRange -> {{-8, 8}, {-7, 8}}], {{a, 0}, -5, 5, .5, Appearance -> "Labeled"}, {{intersect, 0}, 0, 75, 5, Appearance -> "Labeled"}, Initialization :> { f[x_, y_, a_] = (x - a/2)^2 + (y - a/4)^2 - 2, g[x_, y_, a_] = x + y - a}] Bob Hanlon On Tue, Aug 14, 2012 at 4:24 AM, <loveinla at gmail.com> wrote: > Dear all, > > Suppose I have two implicit functions, say, F(x, y) and G(x, y); both involve a parameter a. > > In one Animate, I need: > (1) several contours for function F(x, y) with its Max and Min values; > (2) only one contour for function G(x, y)==0. > (3) because I need to see how they change as parameter a changes, I want to use Animate to generate animation. > > Can anybody help? Thanks. >

**References**:**How to draw several contours for one function, while only one contour***From:*loveinla@gmail.com