POLYNOMIALCURVEDERIVATIVE Compute derivative vector of a polynomial curve.

   VECT = polynomialCurveLength(T, XCOEF, YCOEF);
   XCOEF and YCOEF are row vectors of coefficients, in the form:
       [a0 a1 a2 ... an]
   VECT is a 1x2 array containing direction of derivative of polynomial
   curve, computed for position T. If T is a vector, VECT has as many rows
   as the length of T.

   VECT = polynomialCurveLength(T, COEFS);
   COEFS is either a 2xN matrix (one row for the coefficients of each
   coordinate), or a cell array.

   Example
   polynomialCurveDerivative

   See also
   polynomialCurves2d, polynomialCurveNormal, polynomialCurvePoint,
   polynomialCurveCurvature 


 ------
 Author: David Legland
 e-mail: david.legland@grignon.inra.fr
 Created: 2007-02-23
 Copyright 2007 INRA - BIA PV Nantes - MIAJ Jouy-en-Josas.

Package: matgeom