Re: Re: Draw a 3D surface

*To*: mathgroup at smc.vnet.net*Subject*: [mg100743] Re: [mg100694] Re: Draw a 3D surface*From*: Syd Geraghty <sydgeraghty at me.com>*Date*: Fri, 12 Jun 2009 05:46:01 -0400 (EDT)*References*: <h0pjhq$538$1@smc.vnet.net> <200906111108.HAA21241@smc.vnet.net>

Hi, This is a question inspired by Jens's use of RegionFunction below. In the documentation for RegionFunction there is an example where RegionFunction isa pure function is called with a slot number: SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#6 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]] Here I was perplexed to know what #6 was (and still cannot figure it out). How do I get to see what #6 is? I then tried different values for the slot number: {SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#1 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#2 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#3 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#4 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#5 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (#6 > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]]} and the result was an interesting sequence of 3D objects (note that there are only 6 slots valid - #7 fails) As a further enquiry I tried a Table version of the above: Table[SphericalPlot3D[1 + Sin[5 =CE=B8] Sin[5 =CF=86]/5, {=CE=B8, 0, Pi}, {=CF=86, 0, 2 Pi}, Mesh -> None, RegionFunction -> (# i > 0.95 &), PlotStyle -> FaceForm[Orange, Yellow]], {i, 1, 6, 1}] To my surprise the resulting 3D objects were different after #1. I would appreciate any enlightenment here regarding slots and valid Table increments for slots. Thanks in advance .... Syd Syd Geraghty B.Sc, M.Sc. sydgeraghty at mac.com Mathematica 7.0.1 for Mac OS X x86 (64 - bit) (18th February 2009) MacOS X V 10.5.6 MacBook Pro 2.33 GHz Intel Core 2 Duo 2GB RAM On Jun 11, 2009, at 4:08 AM, Jens-Peer Kuska wrote: > Hi, > > g[y_] := y^2 - 2 > > Plot3D[Exp[-x^2 - y^2], {x, -3, 3}, {y, -3, 3}, PlotRange -> All, > RegionFunction -> Function[{x, y, z}, x < g[y]]] > > > ? > > Regards > Jens > > jl_03824 at yahoo.com wrote: >> I intend to draw a 3D surface, which is defined in a tricky way. >> Given >> function f(x, y), the values of f are known but the range is >> determined by a function of y, g(y). I need to plot x as a function >> of >> y and f within the range determined by g(y). Can anybody help? >> Appreciate! >> >> Jun Lin >> >

**References**:**Re: Draw a 3D surface***From:*Jens-Peer Kuska <kuska@informatik.uni-leipzig.de>