Re: How to plot the surface of revolution graphics

*To*: mathgroup at smc.vnet.net*Subject*: [mg49283] Re: How to plot the surface of revolution graphics*From*: mathma18 at hotmail.com (Narasimham G.L.)*Date*: Sun, 11 Jul 2004 02:16:16 -0400 (EDT)*References*: <ccg4la$osp$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Firstly,you have to rotate axes if surface of revolution about an axis other than x-axis is desired. I have given below for straight line generators 4 sides of a rectangle, you see four cones. The four points at rectangle corners are: {(0,4),(3,0),(11,6),(8,10)} which I assumed for convenience. The four parts are same except choice of line extreme points.[Hope someone suggests how to avoid repetition]. The meridian has to be modified for other sections. HTH Clear[r,z,r1,z1,r2,z2]; z1= 3; r1=0; z2=0; r2=4; z= (r-r1) (z2-z1)/(r2-r1)+z1 ; one=ParametricPlot3D[{r Cos[th],r Sin[th],z},{r,r1,r2},{th,0,Pi*1.5}]; Clear[r,z,r1,z1,r2,z2]; z1= 3; r1=0; z2=11; r2=6; z= (r-r1) (z2-z1)/(r2-r1)+z1 ; two=ParametricPlot3D[{r Cos[th],r Sin[th],z},{r,r1,r2},{th,0,Pi*1.5}]; Clear[r,z,r1,z1,r2,z2]; z1= 0; r1=4 ; z2=8; r2=10; z= (r-r1) (z2-z1)/(r2-r1)+z1 ; three=ParametricPlot3D[{r Cos[th],r Sin[th],z},{r,r1,r2},{th,0,Pi*1.5}]; Clear[r,z,r1,z1,r2,z2]; z1= 8; r1=10; z2=11; r2=6; z= (r-r1) (z2-z1)/(r2-r1)+z1 ; four=ParametricPlot3D[{r Cos[th],r Sin[th],z},{r,r1,r2},{th,0,Pi*1.5}]; Show[{one,two,three,four},ViewPoint->{1.5,-1.5,1}, PlotRange->{{-12,12},{0,12},{-4,12}}]; "CYSTERNA++" <e_cysterna at wp.pl> wrote in message news:<ccg4la$osp$1 at smc.vnet.net>... > I would like to make graphics with many surfaces. All surfaces are surfaces > of revolution. They are created through rotate specified countur about > certain line. I cannot make these graphics. > I have rectangle which is represented through 4 points which have following > coordinates : (2,2), (6,6), (7,5), 3,1). This rectangle is rotated about > line y(x) = x and is created cylindrical surface. How to create graph with > this surface. I know this is a simple problem and I can used > ParametricPlot3D[] function or another but in the real I have countours more > complicated than rectangle and I would like use specified function to make > graph surface of revolution. > > Thanks for all