DERIV Function
Performs numerical differentiation using three-point Lagrangian interpolation.
Usage
result = DERIV([x,] y)
Input Parameters
y—Variable to be differentiated.
x—Differentiates with respect to variable x. This parameter is used for unequal point spacing. If omitted, assumes unit spacing for y, i.e., x(i)=i.
Returned Value
result—Derivative of y.
Discussion
See Hildebrand (1956, p. 82).
