curvation

From Latin curvatio, equivalent to curve +‎ -ation.

curvation (countable and uncountable, plural curvations)

1. The act of curving or bending, or the shape of the resulting curve; curvature.
   • 1840, François Marie Guyonneau de Pambour, A Practical Treatise on Locomotive Engines Upon Railways:

     Knowing, then, the conical form and the diameter of the wheels, as well as the average velocity of the motion and the breadth of the way, this expression will give the surplus of elevation y that suits the radius of curvation r.

   • 1899, "Rectangle" (pseudonym of T. Winship.), Zetetic Cosmogony, page 125:

     According to the calculated rate of curvation of a spherical body of 25,000 miles in circumference, a straight line running at right angles with the perpendicular at the transmitting stations, Mount Uncompahgre, would run as a tangent from the line of curvation so that in the distance of 183 miles, the curvation would place Mount Ellen downward from the tangent line, below the line of vision nearly 3¾ miles!

   • 1900, Mrs. Mary Olmstead Stanton, The Encyclopedia of Face and Form Reading, page 57:

     Imperfect curvation, or crookedness of the features, the head, the limbs, the organs, and body, producing malformations of the organs of speech, hearing, and sight.

   • 1909, Byron Robinson, “Conclusions in Regard to Uro-Ureter due to Nephroptosia”, in Henry G. Spooner, editor, The American Journal of Urology and Sexology, volume 5, page 182:

     Nephroptosia is the most fruitful cause of uro-ureter. It offers numerous opportunities for flexion, curvation and torsion of the ureter.

   • 2011, Margaret R Colyar, Assessment Of The School-Age Child and Adolescent, page 120:

     Note the curvation of the ankles. If spontaneous movement corrects curvation, then there is no problem.·

2. A measure of how much a curve deviates from a straight line.
   • 1850, Samuel Wright Mifflin, Methods of Location:

     Divide this angle by the degree of curvation and the result 2.6/4 = .65 is the length of the chord EV.

   • 2001, M Y H Bangash, Manual of Numerical Methods in Concrete, page 872:

     The ductility of a concrete cross-section will be defined as the ratio of the ultimate curvation and the yield curvation.

   • 2006, Günter Wilkening, ‎Ludger Koenders, Nanoscale Calibration Standards and Methods:

     The curvation can also be considered as the angle enclosed by two tangents on the endpoints of an infinitesimal small interval of the polynomial.