The cubic Hermite spline with values y and slopes m at the points x, as a function of x and the order of
derivative (0 to 3; a fraction is truncated, as R does); linear outside the data. Equivalent to R's splinefunH().
Except for the third derivative: on [x_i, x_{i+1}] it is the exact (6 m_i + 6 m_{i+1} - 12 delta) / h^2, with
h = x_{i+1} - x_i and delta = (y_{i+1} - y_i) / h, where R divides by h only once (the two agree when h = 1). The
order of derivative is the second argument of the function or its option deriv (SplineFunction).
The cubic Hermite spline with values
yand slopesmat the pointsx, as a function ofxand the order of derivative (0 to 3; a fraction is truncated, as R does); linear outside the data. Equivalent to R'ssplinefunH(). Except for the third derivative: on [x_i, x_{i+1}] it is the exact (6 m_i + 6 m_{i+1} - 12 delta) / h^2, with h = x_{i+1} - x_i and delta = (y_{i+1} - y_i) / h, where R divides by h only once (the two agree when h = 1). The order of derivative is the second argument of the function or its optionderiv(SplineFunction).