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// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
// SPDX-FileCopyrightText: Bradley M. Bell <bradbell@seanet.com>
// SPDX-FileContributor: 2003-24 Bradley M. Bell
// ----------------------------------------------------------------------------
/*
{xrst_begin from_json.cpp}
Convert Jason Graph to an ADFun Object: Example and Test
########################################################
Source Code
***********
{xrst_literal
// BEGIN C++
// END C++
}
{xrst_end from_json.cpp}
*/
// BEGIN C++
# include <cppad/cppad.hpp>
bool from_json(void)
{ bool ok = true;
using CppAD::vector;
//
// An AD graph example
// node_1 : p[0]
// node_2 : x[0]
// node_3 : x[1]
// node_4 : -2.0
// node_5 : p[0] + x[0] + x[1]
// node_6 : (p[0] + x[0] + x[1]) * (p[0] + x[0] + x[1])
// y[0] = (p[0] + x[0] + x[1]) * (p[0] + x[0] + x[1])
// use single quote to avoid having to escape double quote
std::string json =
"{\n"
" 'function_name' : 'from_json example',\n"
" 'op_define_vec' : [ 3, [\n"
" { 'op_code':1, 'name':'add', 'n_arg':2 } ,\n"
" { 'op_code':2, 'name':'mul', 'n_arg':2 } ,\n"
" { 'op_code':3, 'name':'sum' } ]\n"
" ],\n"
" 'n_dynamic_ind' : 1,\n"
" 'n_variable_ind' : 2,\n"
" 'constant_vec' : [ 1, [ -2.0 ] ],\n"
" 'op_usage_vec' : [ 2, [\n"
" [ 3, 1, 3, [1, 2, 3 ] ] ,\n"
" [ 2, 5, 5 ] ] \n"
" ],\n"
" 'dependent_vec' : [ 1, [6] ] \n"
"}\n";
// Convert the single quote to double quote
for(size_t i = 0; i < json.size(); ++i)
if( json[i] == '\'' ) json[i] = '"';
//
CppAD::ADFun<double> fun;
fun.from_json(json);
//
// Compute function value
vector<double> p(1), x(2);
p[0] = 1.0;
x[0] = 2.0;
x[1] = 3.0;
fun.new_dynamic(p);
vector<double> y = fun.Forward(0, x);
ok &= y[0] == (p[0] + x[0] + x[1]) * (p[0] + x[0] + x[1]);
//
// Conpute derivative value
vector<double> jac = fun.Jacobian(x);
ok &= jac[0] == 2.0 * (p[0] + x[0] + x[1]);
ok &= jac[1] == 2.0 * (p[0] + x[0] + x[1]);
//
return ok;
}
// END C++
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