Fortran Toolkit

`ces`

function ces(x1,x2,a,b) result(u)
  implicit none
  real(kind=8) :: x1,x2,a,b
  real(kind=8) :: u

This function aggregates x1 and x2with a CES function:

\[u = \begin{cases} \left( a\,x_1^b + (1-a)\,x_2^b\right)^{1/b} & \text{ if } b>0 \\ \\ x_1^a \,x_2^{1-a} & \text{ if } b\approx 0 \end{cases}\]

Internal dependencies: none