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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: 2003-22 Bradley M. Bell
// ----------------------------------------------------------------------------
/*
{xrst_begin json_comp_op.cpp}
Json Comparison Operators: Example and Test
###########################################
Source Code
***********
{xrst_literal
// BEGIN C++
// END C++
}
{xrst_end json_comp_op.cpp}
*/
// BEGIN C++
# include <cppad/cppad.hpp>
bool comp_op(void)
{ bool ok = true;
using CppAD::vector;
using CppAD::AD;
double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
//
// AD graph example
// node_1 : p[0]
// node_2 : x[0]
// : x[0] < p[0]
// node_3 : p[0] - x[0]
// node_4 : log( p[0] - x[0] )
// y[0] = log( p[0] - x[0] )
// use single quote to avoid having to escape double quote
std::string json =
"{\n"
" 'function_name' : 'comp_op example',\n"
" 'op_define_vec' : [ 3, [\n"
" { 'op_code':1, 'name':'comp_lt' } ,\n"
" { 'op_code':2, 'name':'sub', 'n_arg':2 } ,\n"
" { 'op_code':3, 'name':'log', 'n_arg':1 } ]\n"
" ],\n"
" 'n_dynamic_ind' : 1,\n"
" 'n_variable_ind' : 1,\n"
" 'constant_vec' : [ 0, [ ] ],\n"
" 'op_usage_vec' : [ 3, [\n"
" [ 1, 0, 2, [2, 1 ] ] ,\n" // x[0] < p[0]
" [ 2, 1, 2 ] ,\n" // p[0] - x[0]
" [ 3, 3 ] ]\n" // log( p[0] - x[0] )
" ],\n"
" 'dependent_vec' : [ 1, [4] ] \n"
"}\n";
// Convert the single quote to double quote
for(size_t i = 0; i < json.size(); ++i)
if( json[i] == '\'' ) json[i] = '"';
//
// f(x, p) = log( p[0] - x[0] )
CppAD::ADFun<double> f;
f.from_json(json);
ok &= f.Domain() == 1;
ok &= f.Range() == 1;
ok &= f.size_dyn_ind() == 1;
//
// set independent variables and parameters
vector<double> p(1), x(1);
p[0] = 0.3;
x[0] = 0.2;
//
// compute y = f(x, p)
f.new_dynamic(p);
vector<double> y = f.Forward(0, x);
//
// x[0] < p[0] so comparison should not have changed
ok &= f.compare_change_number() == 0;
//
// check result
double check = std::log( p[0] - x[0] );
ok &= CppAD::NearEqual(y[0], check, eps99, eps99);
//
// case where comparison is false
f.check_for_nan(false); // suppress checking for nan for this test
x[0] = 0.4;
y = f.Forward(0, x);
ok &= f.compare_change_number() == 1;
//
// -----------------------------------------------------------------------
// Convert to Json graph and back again
json = f.to_json();
// std::cout << json;
f.from_json(json);
// -----------------------------------------------------------------------
//
// compute y = f(x, p)
f.new_dynamic(p);
x[0] = 0.2;
y = f.Forward(0, x);
//
// check result
ok &= CppAD::NearEqual(y[0], check, eps99, eps99);
//
// case where comparison is false
x[0] = 0.4;
y = f.Forward(0, x);
ok &= f.compare_change_number() == 1;
//
return ok;
}
// END C++
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