B-splines                package:pomp                R Documentation

_B-_s_p_l_i_n_e _b_a_s_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     These functions generate B-spline basis functions. 'bspline.basis'
     gives a basis of spline functions. 'periodic.bspline.basis' gives
     a basis of periodic spline functions.

_U_s_a_g_e:

     bspline.basis(x, nbasis, degree = 3)
     periodic.bspline.basis(x, nbasis, degree = 3, period = 1)

_A_r_g_u_m_e_n_t_s:

       x: Vector at which the spline functions are to be evaluated.

  nbasis: The number of basis functions to return.

  degree: Degree of requested B-splines.

  period: The period of the requested periodic B-splines.

_V_a_l_u_e:

bspline.basis: Returns a matrix with 'length(x)' rows and 'nbasis'
          columns. Each column contains the values one of the spline
          basis functions. 

periodic.bspline.basis: Returns a matrix with 'length(x)' rows and
          'nbasis' columns. The basis functions returned are periodic
          with period 'period'. 

_A_u_t_h_o_r(_s):

     Aaron A. King kingaa at umich dot edu

_E_x_a_m_p_l_e_s:

     x <- seq(0,2,by=0.01)
     y <- bspline.basis(x,degree=3,nbasis=9)
     matplot(x,y,type='l',ylim=c(0,1.1))
     lines(x,apply(y,1,sum),lwd=2)

     x <- seq(-1,2,by=0.01)
     y <- periodic.bspline.basis(x,nbasis=5)
     matplot(x,y,type='l')

