make_cheb_matrix_only_x¶
- rubin_sim.moving_objects.make_cheb_matrix_only_x(n_points, n_poly)¶
Compute C1^(-1)C2 using Newhall89 approach without dx/dt
Compute xMultiplier using only the equality constraint of the x-values at the endpoints. To be used when first derivatives are not available. If chebyshev approximations are strung together piecewise only the x-values and not the first derivatives will be continuous at the boundaries. Multiplying this matrix by the x-values to be fit produces the chebyshev coefficients. This function need only be called once for a given polynomial degree and number of points. See Newhall, X. X. 1989, Celestial Mechanics, 45, p. 305-310.