paradiseo/eo/contrib/mathsym/eval/MultiFunction.cpp
2005-11-24 09:35:34 +00:00

341 lines
7.6 KiB
C++

#include <vector.h>
#include "MultiFunction.h"
#include "Sym.h"
#include "FunDef.h"
using namespace std;
typedef vector<double>::const_iterator data_ptr;
typedef vector<data_ptr> data_ptrs;
typedef data_ptrs::const_iterator arg_ptr;
#include "MultiFuncs.cpp"
typedef double (*fptr)( arg_ptr );
string print_function( fptr f) {
if (f == multi_function::plus) return "+";
if (f == multi_function::mult) return "*";
if (f == multi_function::min) return "-";
if (f == multi_function::inv) return "/";
if (f == multi_function::exp) return "e";
return "unknown";
}
struct Function {
fptr function;
arg_ptr args;
double operator()() const { return function(args); }
};
static vector<Function> token_2_function;
Sym make_binary(Sym sym) {
if (sym.args().size() == 2) return sym;
SymVec args = sym.args();
Sym an = args.back();
args.pop_back();
Sym nw = make_binary( Sym( sym.token(), args) );
args.resize(2);
args[0] = nw;
args[1] = an;
return Sym(sym.token(), args);
}
class Compiler {
public:
enum func_type {constant, variable, function};
typedef pair<func_type, unsigned> entry;
#if USE_TR1
typedef std::tr1::unordered_map<Sym, entry, HashSym> HashMap;
#else
typedef hash_map<Sym, entry, HashSym> HashMap;
#endif
HashMap map;
vector<double> constants;
vector<unsigned> variables;
vector< fptr > functions;
vector< vector<entry> > function_args;
unsigned total_args;
vector<entry> outputs;
Compiler() : total_args(0) {}
entry do_add(Sym sym) {
HashMap::iterator it = map.find(sym);
if (it == map.end()) { // new entry
token_t token = sym.token();
if (is_constant(token)) {
constants.push_back( get_constant_value(token) ); // set value
entry e = make_pair(constant, constants.size()-1);
map.insert( make_pair(sym, e) );
return e;
} else if (is_variable(token)) {
unsigned idx = get_variable_index(token);
variables.push_back(idx);
entry e = make_pair(variable, variables.size()-1);
map.insert( make_pair(sym, e) );
return e;
} // else
fptr f;
vector<entry> vec;
const SymVec& args = sym.args();
switch (token) {
case sum_token:
{
if (args.size() == 0) {
return do_add( SymConst(0.0));
}
if (args.size() == 1) {
return do_add(args[0]);
}
if (args.size() == 2) {
vec.push_back(do_add(args[0]));
vec.push_back(do_add(args[1]));
f = multi_function::plus;
//cout << "Adding + " << vec[0].second << ' ' << vec[1].second << endl;
break;
} else {
return do_add( make_binary(sym) );
}
}
case prod_token:
{
if (args.size() == 0) {
return do_add( SymConst(1.0));
}
if (args.size() == 1) {
return do_add(args[0]);
}
if (args.size() == 2) {
vec.push_back(do_add(args[0]));
vec.push_back(do_add(args[1]));
f = multi_function::mult;
//cout << "Adding * " << vec[0].second << ' ' << vec[1].second << endl;
break;
} else {
return do_add( make_binary(sym) );
}
}
case sqr_token:
{
SymVec newargs(2);
newargs[0] = args[0];
newargs[1] = args[0];
return do_add( Sym(prod_token, newargs));
}
default :
{
if (args.size() != 1) {
cerr << "Unknown function " << sym << " encountered" << endl;
exit(1);
}
vec.push_back(do_add(args[0]));
switch (token) {
case min_token: f = multi_function::min; break;
case inv_token: f = multi_function::inv; break;
case exp_token :f = multi_function::exp; break;
default :
{
cerr << "Unimplemented token encountered " << sym << endl;
exit(1);
}
}
//cout << "Adding " << print_function(f) << ' ' << vec[0].second << endl;
}
}
total_args += vec.size();
function_args.push_back(vec);
functions.push_back(f);
entry e = make_pair(function, functions.size()-1);
map.insert( make_pair(sym, e) );
return e;
}
return it->second; // entry
}
void add(Sym sym) {
entry e = do_add(sym);
outputs.push_back(e);
}
};
class MultiFunctionImpl {
public:
// input mapping
vector<unsigned> input_idx;
unsigned constant_offset;
unsigned var_offset;
// evaluation
vector<double> data;
vector<Function> funcs;
data_ptrs args;
vector<unsigned> output_idx;
MultiFunctionImpl() {}
void clear() {
input_idx.clear();
data.clear();
funcs.clear();
args.clear();
output_idx.clear();
constant_offset = 0;
}
void eval(const double* x, double* y) {
unsigned i;
// evaluate variables
for (i = constant_offset; i < constant_offset + input_idx.size(); ++i) {
data[i] = x[input_idx[i-constant_offset]];
}
for(; i < data.size(); ++i) {
data[i] = funcs[i-var_offset]();
//cout << i << " " << data[i] << endl;
}
for (i = 0; i < output_idx.size(); ++i) {
y[i] = data[output_idx[i]];
}
}
void eval(const vector<double>& x, vector<double>& y) {
eval(&x[0], &y[0]);
}
void setup(const vector<Sym>& pop) {
clear();
Compiler compiler;
for (unsigned i = 0; i < pop.size(); ++i) {
Sym sym = (expand_all(pop[i]));
compiler.add(sym);
}
// compiler is setup so get the data
constant_offset = compiler.constants.size();
var_offset = constant_offset + compiler.variables.size();
int n = var_offset + compiler.functions.size();
data.resize(n);
funcs.resize(compiler.functions.size());
args.resize(compiler.total_args);
// constants
for (unsigned i = 0; i < constant_offset; ++i) {
data[i] = compiler.constants[i];
//cout << i << ' ' << data[i] << endl;
}
// variables
input_idx = compiler.variables;
//for (unsigned i = constant_offset; i < var_offset; ++i) {
//cout << i << " x" << input_idx[i-constant_offset] << endl;
//}
// functions
unsigned which_arg = 0;
for (unsigned i = 0; i < funcs.size(); ++i) {
Function f;
f.function = compiler.functions[i];
//cout << i+var_offset << ' ' << print_function(f.function);
// interpret args
for (unsigned j = 0; j < compiler.function_args[i].size(); ++j) {
Compiler::entry e = compiler.function_args[i][j];
unsigned idx = e.second;
switch (e.first) {
case Compiler::function: idx += compiler.variables.size();
case Compiler::variable: idx += compiler.constants.size();
case Compiler::constant: {}
}
args[which_arg + j] = data.begin() + idx;
//cout << ' ' << idx << "(" << e.second << ")";
}
//cout << endl;
f.args = args.begin() + which_arg;
which_arg += compiler.function_args[i].size();
funcs[i] = f;
}
// output indices
output_idx.resize(compiler.outputs.size());
for (unsigned i = 0; i < output_idx.size(); ++i) {
output_idx[i] = compiler.outputs[i].second;
switch(compiler.outputs[i].first) {
case Compiler::function: output_idx[i] += compiler.variables.size();
case Compiler::variable: output_idx[i] += compiler.constants.size();
case Compiler::constant: {}
}
//cout << "out " << output_idx[i] << endl;
}
}
};
MultiFunction::MultiFunction(const std::vector<Sym>& pop) : pimpl(new MultiFunctionImpl) {
pimpl->setup(pop);
}
MultiFunction::~MultiFunction() { delete pimpl; }
void MultiFunction::operator()(const std::vector<double>& x, std::vector<double>& y) {
pimpl->eval(x,y);
}
void MultiFunction::operator()(const double* x, double* y) {
pimpl->eval(x,y);
}