Ronald Rousseau:


Highly cited researcher (2014) 





The YNOT formula

This formula gives an approximation for the perimeter of an ellipse.


The perimeter of an ellipse with half-axes a and b is obtained as:

                                    4 ( ay + by)1/y

with y = ln(2)/ln(pi/2) ~ 1.534928536...(y is called the YNOT-constant)

Rewritten as a function of a and the excentricity,e, this formula becomes:

                                    4a ( 1 + (1-eČ)y/2)1/y

This approximation formula, first proposed by Roger Maertens, makes an error of at most 0.4%.


Doctoraat 022

Dilruba Mahbuba (Ruba) and her doctoral jury: December 17, 2012

Profs. Colpaert, Engels, Nyssen, Delsaerdt, dr. Mahbuba and me