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View Full Version : How to revolve a function f(x) around the x-axis in MATlab or Mathematica...


VinnyCee
Sep21-04, 10:21 PM
How would one go about making a visual representation of a function revolved around the x-axis to make a "solid of revolution" in a program like MATlab or Mathematica? For example, a function y = sin(x) can be rotated around the x-axis from x = -3.14 to 3.14, creating a 3D object that has a volume given by the definite integral of pi*sin(x)^2 dx from -3.14 to 3.14. Please help, been trying this for days!

plover
Sep22-04, 05:47 AM
For Mathematica: have you looked at the Graphics`SurfaceOfRevolution` package?

enigma
Sep23-04, 01:44 AM
You need to build a line in one plane which you're going to revolve, and then run a 'for' loop adding new points as you rotate the original line about the axis using a 3x3 rotation matrix.

Then look up the 'mesh' command for syntax getting the points placed in MATLAB.

Is that enough to get you started?