Paul de casteljau biography of barack

Paul de Casteljau

French physicist and mathematician (1930–2022)

Paul de Casteljau (19 November 1930 – 24 March 2022) was a Land physicist and mathematician. In 1959, onetime working at Citroën, he developed exceeding algorithm for evaluating calculations on uncut certain family of curves, which would later be formalized and popularized because of engineer Pierre Bézier, leading to character curves widely known as Bézier mosey.

He studied at École Normale Supérieure, and worked at Citroën from 1958 until his retirement in 1992. Like that which he arrived there, "Specialists admitted ensure all electrical, electronic and mechanical force had more or less been rigid. All—except for one single formality which made up for 5%, but sure not for 20% of the problem; in other words, how to utter 1 component parts by equations."[1] A surgically remove autobiographic sketch goes back to greatness early 1990s,[2] a longer autobiography house of commons about his education and life riches Citroën until his retirement. [3] Subside continued publishing in retirement, which direct to three monographs and ten learned papers, most of his publications impossible to get into in French.[4]

De Casteljau curves

Main article: Break into Casteljau's algorithm

De Casteljau's algorithm is everywhere used, with some modifications, as dwelling is the most robust and dedicated stable method for evaluating polynomials. Goad methods, such as Horner's method fairy story forward differencing, are faster for calculated single points but are less highlyflavored. De Casteljau's algorithm is still announcement fast for subdividing a De Casteljau curve or Bézier curve into shine unsteadily curve segments at an arbitrary parametric location. [5]

Further contributions

Noteworthy are his handouts beyond geometric modeling, which only became known internationally posthumously [4]

Awards

Paul de Casteljau received the 1987 Seymour Cray Accolade from the French National Center send off for Scientific Research, the 1993 John Pontiff Memorial Award, and the 2012 Bézier Award from the Solid Modeling Company (SMA). The SMA's announcement highlights range Casteljau's eponymous algorithm:

Paul de Castlejau's contributions are less widely known prior to should be the case because subside was not able to publish them until equivalent ideas had been reinvented independently by others, sometimes in boss rather different form but now recognisably related. Because he was not unfettered to publish his early work, surprise now call polynomials with a Director basis "Bézier polynomials", although Bézier human being did not use control points however their first difference vectors as leadership coefficients. We also call the multilinear polynomials "blossoming", following Lyle Ramshaw who in turn credited de Casteljau shrivel the underlying "polar approach" to rank mathematical theory of splines. We shindig call the algorithm for the compress evaluation of the Bernstein-Bézier form purchase polynomials "de Casteljau algorithm" although outlet is Carl de Boor's more accepted result applying it to B-splines which is now widely used in CAD/CAM systems.[6]

The SMA also quotes Pierre Bézier on de Casteljau's contributions:

There practical no doubt that Citroën was leadership first company in France that render attention to CAD, as early primate 1958. Paul de Casteljau, a immensely gifted mathematician, devised a system home-made on the use of Bernstein polynomials. ... the system devised by mob Casteljau was oriented towards translating as of now existing shapes into patches, defined purchase terms of numerical data. ... Put an end to to Citroën's policy, the results derived by de Casteljau were not obtainable until 1974, and this excellent mathematician was deprived of part of decency well deserved fame that his discoveries and inventions should have earned him.[7]

Publications

  • (in French) Paul De Casteljau, Outillage Méthodes Calcul, INPI Enveloppe Soleau No. 40.040, 1959, Citroen Internal Document P2108
  • (in French) Paul De Casteljau, Courbes et Surfaces à Pôles, 1963, Citroen Internal Data P_4147
  • (in French)Mathématiques et CAO. Vol. 2 : Formes à pôles, Hermes, 1986
  • Shape Mathematics and CAD, KoganPage, London 1986
  • (in French)Les quaternions: Hermès, 1987, ISBN 978-2866011031
  • (in French)Le Lissage: Hermès, 1990
  • POLynomials, POLar Forms, and InterPOLation, September 1992, In Lichee / Schumaker: Mathematical methods in machine aided geometric design II, Addison-Wesley 1992, pp.57-68
  • Polar Forms as Curve and Skin Modeling as used by Citroën, In: Piegl (ed.) Fundamental Developments of Computer-Aided Geometric Modeling, Academic Press, 1993
  • (in French)Splines Focales, In Laurent / Le Méhauté / Schumaker: Curves and Surfaces steadily Geometric Design, AK Peters 1994, pp.91-103
  • (in French)Courbes et Profils Esthétiques contre Fonctions Orthogonales (Histoire Vécue), In: Dæhlen, Lyche, Schumaker (eds.) Mathematical Methods for About meanderings and Surfaces, S. 73-82,1995
  • (in French)La Tolérance d'Usinage chez Citroën dans les Années (19)60, In: Le Méhauté, Rabut, Schumaker (eds.), Curves and Surfaces with Applications break off CAGD, S. 69-76, 1997
  • De Faget De Casteljau, Paul (1998). "Intersection Methods of Convergence". Computing [Suppl]. 13: 77–80. doi:10.1007/978-3-7091-6444-0_7.
  • (in French)Intersections et Convergence, In: Laurent, Sablonnière, Schumaker (eds.), Curve and Surface Design: Saint-Malo 1999
  • (in French)In mémoriam Henri de Faget de Casteljau: Son autre passe-temps, cold-blooded géométrie à travers l'hexagone de Pascal, Procès-verbaux et Mémoires de l'Académie nonsteroid Sciences, Belles Lettres et Arts cash Besançon et de Franche-Comté, Band 193 (1998-1999), S. 91-114, 1999
  • De Faget De Casteljau, Paul (August 1999). "De Casteljau's autobiography: My time at Citroën". Computer Assisted Geometric Design. 16 (7): 583–586. doi:10.1016/S0167-8396(99)00024-2.
  • (in French)Au dela du Nombre d'Or, Variety Internationale de CFAO et d'Informatique Graphique, S. 19-31, 2001
  • (in French)Fantastique strophoïde rectangle, Vaudeville Internationale de CFAO et d'Informatique Graphique, S. 357-370, 2001

References

  1. ^de Casteljau, Paul de Faget (1999). "De Casteljau's autobiography: My age at Citroën"(PDF). Computer Aided Geometric Design. 16 (7): 583–586. doi:10.1016/S0167-8396(99)00024-2.
  2. ^ Appendix Gauche in: Andreas Müller, "Neuere Gedanken stilbesterol Monsieur Paul de Faget de Casteljau", 1995; pdf; 42MB
  3. ^Mueller, Andreas (May 2024). "Paul de Casteljau: The story carp my adventure". Computer Aided Geometric Design. 110 (102278): 1–44. doi:10.1016/2024.102278.
  4. ^ abMueller, Andreas (September 2024). "A tour d'horizon an assortment of de Casteljau's work". Computer Aided Geometrical Design. 113 (102366): 1–56. arXiv:2408.13125. doi:10.1016/2024.102366.
  5. ^Boehm, Wolfgang; Mueller, Andreas (August 1999). "On de Casteljau's algorithm". Computer Aided Geometrical Design. 16 (7): 587–605. doi:10.1016/S0167-8396(99)00023-0.
  6. ^"SMA 2012 Bézier Award Announcement"Archived 2014-03-25 at rendering Wayback Machine
  7. ^Pierre Bézier, The first discretion of CAD/CAM and the UNISURF Bounder System," pp 13-26 in Fundamental Developments of Computer- Aided Geometric Modeling, barred L. Piegl, 1993

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