\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)

base_require.cpp

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Using a User Defined AD Base Type: Example and Test

// suppress conversion warnings before other includes
# include <cppad/wno_conversion.hpp>
//
# include "base_alloc.hpp"
# include <cppad/cppad.hpp>

bool base_require(void)
{  bool ok = true;
   using CppAD::thread_alloc;
   typedef CppAD::AD<base_alloc> ad_base_alloc;

   // check the amount of memory inuse by this thread (thread zero)
   size_t thread = thread_alloc::thread_num();
   ok &= thread == 0;

   // y = x^2
   size_t n = 1, m = 1;
   CPPAD_TESTVECTOR(ad_base_alloc) a_x(n), a_y(m);
   a_x[0] = ad_base_alloc(1.);
   CppAD::Independent(a_x);
   a_y[0] = a_x[0] * a_x[0];
   CppAD::ADFun<base_alloc> f(a_x, a_y);

   // check function value f(x) = x^2
   CPPAD_TESTVECTOR(base_alloc) x(n), y(m);
   base_alloc eps =
      base_alloc(100.) * CppAD::numeric_limits<base_alloc>::epsilon();
   x[0] = base_alloc(3.);
   y    = f.Forward(0, x);
   ok  &= CppAD::NearEqual(y[0], x[0] * x[0], eps, eps);

   // check derivative value f'(x) = 2 * x
   CPPAD_TESTVECTOR(base_alloc) dy(m * n);
   dy   = f.Jacobian(x);
   ok  &= CppAD::NearEqual(dy[0], base_alloc(2.) * x[0], eps, eps);

   // check the abs function
   ok  &= abs( - a_x[0] ) == abs( a_x[0] );

   return ok;
}

Purpose

The type base_alloc , defined in base_alloc.hpp , meets the requirements specified by base_require for Base in AD < Base > . The program below is an example use of AD<base_alloc> .