Looking for curve fit program



 Dear Netters,
 	I need a program to do an arbitrary curve fit for over twenty
 parameters.  It would be best if it can ran on the UNIX system and
 show a 3D picture in X window.  Do you have any idea to obtain this kind
 of program?
 	Thanks in advance.
 						Jian Wang
 						jwang' at \`ac.dal.ca