Dear R experts, Did someone implemented French Curve yet? Or can anyone point me some papers that I can follow to implement it? thanks in advance for your help. Paul
>>>>> "dream" == dream home <dreamhouse at gmail.com> >>>>> on Wed, 30 Mar 2005 12:27:08 -0800 writes:dream> Dear R experts, Did someone implemented French Curve dream> yet? Or can anyone point me some papers that I can dream> follow to implement it? Are you talking about "splines" ? I vaguely remember having read that in the distant past, splines were sometimes called "French curves". There's lots of splines functionality in the basic 'stats' package, in the recommended 'mgcv' package and even more in quite a few other packages. dream> thanks in advance for your help. You're welcome, Martin Maechler, ETH Zurich
>I remember that my father had a French curve: it was a plastic template >used for drawing which had several smooth edges of varying curvature. >You could use it to draw a wide variety of curved shapes. No doubt the >French called it something else.Nobody, up and down the corridor here, of age to have used one, could think of a name, but we looked it up in a universal French dictionary on the web, and it came up with ``un pistolet''. ____________________ Ken Knoblauch Inserm U371, Cerveau et Vision Department of Cognitive Neurosciences 18 avenue du Doyen Lepine 69675 Bron cedex France tel: +33 (0)4 72 91 34 77 fax: +33 (0)4 72 91 34 61 portable: 06 84 10 64 10 http://www.lyon.inserm.fr/371/
> From: Ken Knoblauch > > > >I remember that my father had a French curve: it was a > plastic template > >used for drawing which had several smooth edges of varying curvature. > >You could use it to draw a wide variety of curved shapes. > No doubt the > >French called it something else. > > Nobody, up and down the corridor here, of age to have used one, could > think of a name, but we looked it up in a universal French dictionary > on the web, and it came up with ``un pistolet''.I recall reading: E.J. Wegman and I.W. Wright. Splines in Statistics. Journal of the American Statistical Association, vol 78, N382, 1983. which mentioned `spline' as a tool that draftsmen used to draw curves, but the description does not match the french curve I know, which _is_ a template-like piece of various curvature. (I used one of these in the year I spent in Architechture school right after high school. No, I not _that_ old... I believe they are still in common used today.) Andy> ____________________ > Ken Knoblauch > Inserm U371, Cerveau et Vision > Department of Cognitive Neurosciences > 18 avenue du Doyen Lepine > 69675 Bron cedex > France > tel: +33 (0)4 72 91 34 77 > fax: +33 (0)4 72 91 34 61 > portable: 06 84 10 64 10 > http://www.lyon.inserm.fr/371/ > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > >
Here is what my colleague dug up and his reaction to it, afterwards, and then one of mine: Pistolet, nom masculin DESSIN. Instrument de trac? permettant de dessiner les lignes courbes dans les trac?s g?om?triques. Synon. curvigraphe, virgule. Les outils de l'?crivain plumiste sont: la plume, le tire-ligne, le compas (...) le balustre pour tous les petits cercles, (...) un jeu de pistolets (CHELET, Lithogr., 1933, p.58). Un compas, un compas de r?duction, un curvigraphe, un pistolet de dessinateur, en sont des exemples (...) simples [de ?machine? ? interpolation] (RUYER, Cybern., 1954, p.43). J'aurai utilis? curvigraphe I seem to recall that when I first read about cubic splines, the splines on which they were based were flexible curves that were made to pass through knots (or ducks, I think), not at all like the rigid French curve. ken Quoting "Liaw, Andy" <andy_liaw at merck.com>:> > From: Ken Knoblauch > > > > > > >I remember that my father had a French curve: it was a > > plastic template > > >used for drawing which had several smooth edges of varying curvature. > > >You could use it to draw a wide variety of curved shapes. > > No doubt the > > >French called it something else. > > > > Nobody, up and down the corridor here, of age to have used one, could > > think of a name, but we looked it up in a universal French dictionary > > on the web, and it came up with ``un pistolet''. > > I recall reading: > > E.J. Wegman and I.W. Wright. Splines in Statistics. > Journal of the American Statistical Association, vol 78, > N382, 1983. > > which mentioned `spline' as a tool that draftsmen used to draw curves, but > the description does not match the french curve I know, which _is_ a > template-like piece of various curvature. (I used one of these in the year > I spent in Architechture school right after high school. No, I not _that_ > old... I believe they are still in common used today.) > > Andy > > > ____________________ > > Ken Knoblauch > > Inserm U371, Cerveau et Vision > > Department of Cognitive Neurosciences > > 18 avenue du Doyen Lepine > > 69675 Bron cedex > > France > > tel: +33 (0)4 72 91 34 77 > > fax: +33 (0)4 72 91 34 61 > > portable: 06 84 10 64 10 > > http://www.lyon.inserm.fr/371/ > > > > ______________________________________________ > > R-help at stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > > > > > > >------------------------------------------------------------------------------> Notice: This e-mail message, together with any attachment...{{dropped}}
Ken Knoblauch <knoblauch <at> lyon.inserm.fr> writes:> > >I remember that my father had a French curve: it was a plastic template > >used for drawing which had several smooth edges of varying curvature.Yes. These were used by graphic artists, among others. Some pictures of these are posted at http://mathworld.wolfram.com/FrenchCurve.html Along with a cute anecdote about the use of the French curve by physicist Richard Feynman. [ rest deleted ]
On Fri, 2005-04-01 at 20:07 +0100, Ted.Harding at nessie.mcc.ac.uk wrote: <snip>> I still have some, from the 1950s ... The curves in the edges > are supposed to be segments of logarithmic spirals (which > ensures a kind of self-similarity on different scales). > A nice picture is at > > http://missourifamilies.org/learningopps/ > learnmaterial/tools/frenchcurves.htm > > Splines, in the drawing-office sense, were long narrow > (about 1/4 inch wide) strips of thin springy metal with, > along their length, little flanges at right-angles to the > plane of the strip. Each little flange had a hole in it. > > The principle was that you would pinthe flanges to the > drawing-board at chosen points by pushing drawing-pins > through the holes. The metal strip then stood up at a > right-angle to the paper. > > The flanges were attached in such a way that you could > slide them along the metal strip. (Or you could use a > strip without flanges, and special pins which raised > little pillars up from the paper, against which the > spline would press.) > > The end result was that the metal strip then defined > a curve on the paper, and you could run a pencil along > it and draw a curve on the paper (taking care not to > press too hard against the metal, to avoid deforming > the curve). > > By virtue of the laws of elasticity, the curve delineated > by the metal strip had a continuous second derivative, i.e. > what modern kids call a second-derivative-continuous > piecewise cubic spline. > > We have not moved on. > > Happy whatever it is to all, > Ted.Ted, That sounds like the flexible curves that I found earlier, while Googling for an example of a French Curve and found the Mathworld link: http://www.artsupply.com/alvin/curves.htm and http://www.reuels.com/reuels/product21021.html Marc