paradiseo/eo/contrib/mathsym/fun/FunDef.cpp
2007-09-23 08:35:51 +00:00

891 lines
21 KiB
C++

/*
* Copyright (C) 2005 Maarten Keijzer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <sstream>
#include "Sym.h"
#include "FunDef.h"
#include <LanguageTable.h>
using namespace std;
using namespace boost::numeric;
vector<const FunDef*> language;
token_t add_function(FunDef* function) {
language.push_back(function);
return token_t(language.size()-1);
}
const FunDef& get_element(token_t token) { return *language[token]; }
/* Printing */
string c_print(const Sym& sym) {
return c_print(sym, vector<string>());
}
string c_print(const Sym& sym, const vector<string>& vars) {
const SymVec& args = sym.args();
vector<string> names(args.size());
for (unsigned i = 0; i < args.size(); ++i) {
names[i] = c_print(args[i], vars);
}
return language[sym.token()]->c_print(names, vars);
}
/* Evaluation */
double eval(const Sym& sym, const std::vector<double>& inputs) {
return language[sym.token()]->eval(sym.args(), inputs);
}
/* Interval Logic */
Interval eval(const Sym& sym, const vector<Interval>& inputs) {
const SymVec& args = sym.args();
vector<Interval> interv(args.size());
for (unsigned i = 0; i < args.size(); ++i) {
interv[i] = eval(args[i], inputs);
if (!valid(interv[i])) throw interval_error();
}
return language[sym.token()]->eval(interv, inputs);
}
/* */
void add_function_to_table(LanguageTable& table, token_t token) {
const FunDef& fundef = *language[token];
if (fundef.has_varargs() == false) {
table.add_function(token, fundef.min_arity());
} else { // sum or prod (or min or max)
table.add_function(token, 2);
}
}
// by default it is eager
double FunDef::eval(const SymVec& args, const vector<double>& inputs) const {
vector<double> values(args.size());
for (unsigned i = 0; i < args.size(); ++i) {
values[i] = ::eval(args[i], inputs);
}
return eval(values, inputs);
}
/* Variable Handling */
FunDef* make_var(int idx); // defined in FunDefs.h
static vector<token_t> var_token;
Sym SymVar(unsigned idx) {
if (var_token.size() <= idx) {
// it is new
var_token.resize(idx+1, token_t(-1));
var_token[idx] = add_function( make_var(idx) );
} else if (var_token[idx] == token_t(-1)) {
var_token[idx] = add_function( make_var(idx) );
}
return Sym(var_token[idx]);
}
/* Constant Handling */
struct HashDouble{
size_t operator()(double val) const {
unsigned long h = 0;
char* s = (char*)&val;
for (unsigned i=0 ; i<sizeof(double); ++i)
h = 5*h + s[i];
return size_t(h);
}
};
#if USE_TR1
typedef std::tr1::unordered_map<double, token_t> DoubleSet;
typedef std::tr1::unordered_map<Sym, token_t> LambdaSet;
#else
typedef hash_map<double, token_t, HashDouble> DoubleSet;
typedef hash_map<Sym, token_t, HashSym> LambdaSet;
#endif
static DoubleSet doubleSet; // for quick checking if a constant already exists
static vector<double> token_value;
static LambdaSet lambdaSet;
static vector<Sym> token_lambda;
static std::vector<token_t> free_list;
void delete_val(token_t token) { // clean up the information about this value
if (is_constant(token)) {
//cout << "Deleting constant token " << token << endl;
double value = token_value[token];
doubleSet.erase(value);
delete language[token];
language[token] = 0;
free_list.push_back(token);
}
else if (is_lambda(token)) {
//cout << "Deleting lambda token " << token << endl;
Sym expression = token_lambda[token];
lambdaSet.erase(expression);
delete language[token];
language[token] = 0;
free_list.push_back(token);
}
}
FunDef* make_const(double value);
void extend_free_list();
Sym SymConst(double value) {
DoubleSet::iterator it = doubleSet.find(value);
if (it != doubleSet.end()) {
return Sym(it->second); // already exists
}
if (free_list.empty()) { // make space for tokens;
extend_free_list();
}
token_t token = free_list.back();
free_list.pop_back();
//cout << "Creating constant with token " << token << endl;
assert(language[token] == 0);
language[token] = make_const(value);
doubleSet[value] = token;
if (token_value.size() < token) token_value.resize(token+1);
token_value[token] = value;
return Sym(token);
}
/* LanguageTable depends on this one, XXX move somewhere safe.*/
#include <utils/eoRNG.h>
extern Sym default_const() { return SymConst(rng.normal()); }
/* The functions */
namespace {
class Var : public FunDef {
public :
unsigned idx;
string default_str;
Var(unsigned _idx) : idx(_idx) {
ostringstream os;
os << "x[" << idx << ']'; // CompiledCode expects this form
default_str = os.str();
}
double eval(const vector<double>& _, const vector<double>& inputs) const { return inputs[idx]; }
double eval(const SymVec& _, const vector<double>& inputs) const { return inputs[idx]; }
string c_print(const vector<string>& _, const vector<string>& names) const {
if (names.empty()) {
return default_str;
}
return names[idx];
}
Interval eval(const vector<Interval>& _, const vector<Interval>& inputs) const {
return inputs[idx];
}
unsigned min_arity() const { return 0; }
string name() const { return "var"; }
};
class Const : public FunDef {
public:
double value;
string value_str;
Const(double _value) : value(_value) {
ostringstream os;
os.precision(17);
os.setf(ios::showpoint);
os << '(' << value << ')';
value_str = os.str();
}
double eval(const vector<double>& _, const vector<double>& inputs) const { return value; }
double eval(const SymVec& _, const vector<double>& inputs) const { return value; }
string c_print(const vector<string>& _, const vector<string>& names) const {
return value_str;
}
Interval eval(const vector<Interval>& _, const vector<Interval>& inputs) const {
return Interval(value);
}
unsigned min_arity() const { return 0; }
string name() const { return "parameter"; }
};
} // namespace
void get_constants(Sym sym, vector<double>& ret) {
token_t token = sym.token();
if (is_constant(token)) {
double val = static_cast<const Const*>(language[token])->value;
ret.push_back(val);
}
const SymVec& args = sym.args();
for (unsigned i = 0; i < args.size(); ++i) {
get_constants(args[i], ret);
}
}
double get_constant_value(token_t token) {
return static_cast<const Const*>(language[token])->value;
}
/** Get out the values for all constants in the expression */
vector<double> get_constants(Sym sym) {
vector<double> retval;
get_constants(sym, retval);
return retval;
}
/** Set the values for all constants in the expression. Vector needs to be the same size as the one get_constants returns
* The argument isn't touched, it will return a new sym with the constants set. */
Sym set_constants(Sym sym, vector<double>::const_iterator& it) {
token_t token = sym.token();
if (is_constant(token)) {
return SymConst(*it++);
}
SymVec args = sym.args();
for (unsigned i = 0; i < args.size(); ++i) {
args[i] = set_constants(args[i], it);
}
return Sym(token, args);
}
Sym set_constants(Sym sym, const vector<double>& constants) {
vector<double>::const_iterator it = constants.begin();
return set_constants(sym, it);
}
// Get functions out, excluding Const and Var
vector<const FunDef*> get_defined_functions() {
vector<const FunDef*> res;
for (unsigned i = 0; i < language.size(); ++i) {
res.push_back(language[i]);
if (is_constant(i) || is_variable(i)) {
res.back() = 0; // erase
}
}
return res;
}
FunDef* make_var(int idx) { return new Var(idx); }
FunDef* make_const(double value) { return new Const(value); }
bool is_constant(token_t token) {
const Const* cnst = dynamic_cast<const Const*>( language[token] );
return cnst != 0;
}
bool is_variable(token_t token) {
const Var* var = dynamic_cast<const Var*>( language[token] );
return var != 0;
}
unsigned get_variable_index(token_t token) {
const Var* var = static_cast<const Var*>( language[token] );
return var->idx;
}
namespace {
class Lambda : public FunDef {
public:
Sym expression;
int arity;
Lambda(Sym expr, int arity_) : expression(expr), arity(arity_) {}
double eval(const vector<double>& vals, const vector<double>& _) const {
return ::eval(expression, vals);
}
string c_print(const vector<string>& args, const vector<string>& _) const {
return string("/*f*/") + ::c_print(expression, args) + string("/*eof*/");
}
Interval eval(const vector<Interval>& args, const vector<Interval>& _) const {
return ::eval(expression, args);
}
unsigned min_arity() const { return arity; }
string name() const { return "F"; }
};
Sym normalize(Sym sym, SymVec& args) {
// check if it's a variable
token_t token = sym.token();
const Var* var = dynamic_cast< const Var*>(language[token]);
if (var != 0) {
for (unsigned i = 0; i < args.size(); ++i) {
if (sym == args[i]) {
return SymVar(i); // replace with reference to arg
}
}
// not replaced, add it
args.push_back(sym);
return SymVar(args.size()-1);
}
SymVec a = sym.args();
for (unsigned i = 0; i < a.size(); ++i) {
a[i] = normalize(a[i], args);
}
return Sym(token, a);
}
}
bool is_lambda(token_t token) {
const Lambda* lambda = dynamic_cast<const Lambda*>( language[token]);
return lambda != 0;
}
std::ostream& print_list(Sym sym, ostream& os) {
os << sym.token() << ' ';
const SymVec& args = sym.args();
for (unsigned i = 0; i < args.size(); ++i) {
print_list(args[i], os);
}
return os;
}
token_t new_lambda(Sym sym, int arity) {
// check if already present
LambdaSet::iterator it = lambdaSet.find(sym);
if (it != lambdaSet.end()) {
return it->second;
}
// new, insert
Lambda* lambda = new Lambda(sym, arity);
if (free_list.empty()) {
extend_free_list();
}
token_t token = free_list.back();
free_list.pop_back();
language[token] = lambda;
lambdaSet[sym] = token;
if (token_lambda.size() <= token) token_lambda.resize(token+1);
token_lambda[token] = sym;
return token;
}
/* Compression */
typedef hash_map<Sym, unsigned, HashSym> OccMap;
void count_occurances(Sym sym, OccMap& occ) {
occ[sym]++;
const SymVec& args = sym.args();
for (unsigned i = 0; i < args.size(); ++i) {
count_occurances(args[i], occ);
}
}
Sym create_lambda(Sym sym, OccMap& occ, unsigned nvars, vector<Sym>& args) {
unsigned o = occ[sym];
unsigned sz = sym.size();
if (o * sz > o + sz + nvars || is_variable(sym.token()) ) {
// check if it's already present
for (unsigned i = 0; i < args.size(); ++i) {
if (args[i] == sym) {
return SymVar(i);
}
}
// push_back
args.push_back(sym);
return SymVar(args.size()-1);
}
SymVec sym_args = sym.args();
for (unsigned i = 0; i < sym_args.size(); ++i) {
sym_args[i] = create_lambda(sym_args[i], occ, nvars, args);
}
return Sym(sym.token(), sym_args);
}
Sym compress(Sym sym) {
OccMap occ(sym.size());
count_occurances(sym, occ);
unsigned nvars = 0;
for (OccMap::iterator it = occ.begin(); it != occ.end(); ++it) {
if (is_variable(it->first.token())) nvars++;
}
SymVec args;
Sym body = create_lambda(sym, occ, nvars, args);
if (body.size() < sym.size()) {
// see if the body can be compressed some more
body = compress(body);
token_t token = new_lambda(body, args.size());
for (unsigned i = 0; i < args.size(); ++i) {
args[i] = compress(args[i]);
}
Sym result = Sym(token, args);
return compress(result); // see if it can be compressed some more
}
return sym;
}
Sym SymLambda(Sym expr) { return compress(expr); }
Sym expand(Sym expr, const SymVec& args) {
const Var* var = dynamic_cast<const Var*>( language[expr.token()] );
if (var != 0) {
return args[var->idx];
}
SymVec expr_args = expr.args();
for (unsigned i = 0; i < expr_args.size(); ++i) {
expr_args[i] = expand(expr_args[i], args);
}
return Sym(expr.token(), expr_args);
}
Sym SymUnlambda(Sym sym) {
Sym retval = sym;
const Lambda* lambda = dynamic_cast<const Lambda*>( language[sym.token()] );
if (lambda != 0) {
retval = expand(lambda->expression, sym.args());
}
return retval;
}
Sym expand_all(Sym sym) {
SymVec args = sym.args();
for (unsigned i = 0; i < args.size(); ++i) {
args[i] = expand_all(args[i]);
}
Sym nw = SymUnlambda( Sym(sym.token(), args) );
if (nw != sym) {
nw = expand_all(nw);
}
return nw;
}
namespace {
class Sum : public FunDef {
public :
double eval(const vector<double>& vals, const vector<double>& _) const {
double res = 0;
for (unsigned i = 0; i < vals.size(); ++i) res += vals[i];
return res;
}
string c_print(const vector<string>& args, const vector<string>& _) const {
if (args.empty()) { return "0.0"; }
ostringstream os;
os << "(" << args[0];
for (unsigned i = 1; i < args.size(); ++i) {
os << "+" << args[i];
}
os << ")";
return os.str();
}
Interval eval(const vector<Interval>& args, const vector<Interval>& inputs) const {
Interval interv(0.0);
for (unsigned i = 0; i < args.size(); ++i) {
interv += args[i];
}
return interv;
}
unsigned min_arity() const { return 0; }
bool has_varargs() const { return true; }
string name() const { return "sum"; }
};
class Prod : public FunDef {
public :
double eval(const vector<double>& vals, const vector<double>& _) const {
double res = 1;
for (unsigned i = 0; i < vals.size(); ++i) res *= vals[i];
return res;
}
string c_print(const vector<string>& args, const vector<string>& _) const {
if (args.empty()) { return "1.0"; }
ostringstream os;
os << "(" << args[0];
for (unsigned i = 1; i < args.size(); ++i) {
os << "*" << args[i];
}
os << ")";
return os.str();
}
Interval eval(const vector<Interval>& args, const vector<Interval>& inputs) const {
Interval interv(1.0);
for (unsigned i = 0; i < args.size(); ++i) {
interv *= args[i];
}
return interv;
}
unsigned min_arity() const { return 0; }
bool has_varargs() const { return true; }
string name() const { return "prod"; }
};
class Power : public FunDef {
public :
double eval(const vector<double>& vals, const vector<double>& _) const {
return pow(vals[0], vals[1]);
}
string c_print(const vector<string>& args, const vector<string>& _) const {
return "pow(" + args[0] + ',' + args[1] + ')';
}
Interval eval(const vector<Interval>& args, const vector<Interval>& _) const {
Interval first = args[0];
Interval second = args[1];
Interval lg = log(first);
if (!valid(lg)) throw interval_error();
return exp(second * lg);
}
unsigned min_arity() const { return 2; }
string name() const { return "pow"; }
};
class IsNeg : public FunDef {
public:
double eval(const vector<double>& vals, const vector<double>& _) const {
if (vals[0] < 0.0) return vals[1];
return vals[2];
}
double eval(const Sym& sym, const vector<double>& inputs) const {
const SymVec& args = sym.args();
double arg0 = ::eval(args[0], inputs);
if (arg0 < 0.0) {
return ::eval(args[1], inputs);
}
return ::eval(args[2], inputs);
}
string c_print(const vector<string>& args, const vector<string>& _) const {
return "((" + args[0] + "<0.0)?" + args[1] + ":" + args[2]+")";
}
Interval eval(const vector<Interval>& args, const vector<Interval>& _) const {
Interval a0 = args[0];
if (a0.upper() < 0.0) return args[1];
if (a0.lower() >= 0.0) return args[2];
return Interval( std::min(args[1].lower(), args[2].lower()), std::max(args[1].upper(), args[2].upper()));
}
unsigned min_arity() const { return 3; }
string name() const { return "ifltz"; }
};
template <typename Func>
class Unary : public FunDef {
Func un;
double eval(const vector<double>& vals, const vector<double>& _) const {
return un(vals[0]);
}
string c_print(const vector<string>& args, const vector<string>& _) const {
return un(args[0]);
}
Interval eval(const vector<Interval>& args, const vector<Interval>& _) const {
return un(args[0]);
}
unsigned min_arity() const { return 1; }
string name() const { return un.name(); }
};
struct Inv {
double operator()(double val) const { return 1.0 / val; }
string operator()(string v) const { return "(1./" + v + ")"; }
Interval operator()(Interval v) const { return 1.0 / v; }
string name() const { return "inv"; }
};
struct Min {
double operator()(double val) const { return -val; }
string operator()(string v) const { return "(-" + v + ")"; }
Interval operator()(Interval v) const { return -v; }
string name() const { return "min"; }
};
} // namespace
string prototypes = "double pow(double, double);";
string get_prototypes() { return prototypes; }
unsigned add_prototype(string str) { prototypes += string("double ") + str + "(double);"; return prototypes.size(); }
token_t add_function(FunDef* function, token_t where) {
if (language.size() <= where) language.resize(where+1);
language[where] = function;
return 0;
}
namespace {
#define FUNCDEF(funcname) struct funcname##_struct { \
double operator()(double val) const { return funcname(val); }\
string operator()(string val) const { return string(#funcname) + '(' + val + ')'; }\
Interval operator()(Interval val) const { return funcname(val); }\
string name() const { return string(#funcname); }\
};\
static const token_t funcname##_token_static = add_function( new Unary<funcname##_struct>, funcname##_token);\
unsigned funcname##_size = add_prototype(#funcname);
static token_t ssum_token = add_function( new Sum , sum_token);
static token_t sprod_token = add_function( new Prod, prod_token);
static token_t sinv_token = add_function( new Unary<Inv>, inv_token);
static token_t smin_token = add_function( new Unary<Min>, min_token);
static token_t spow_token = add_function( new Power, pow_token);
static token_t sifltz_token = add_function( new IsNeg, ifltz_token);
FUNCDEF(sin);
FUNCDEF(cos);
FUNCDEF(tan);
FUNCDEF(asin);
FUNCDEF(acos);
FUNCDEF(atan);
FUNCDEF(sinh);
FUNCDEF(cosh);
FUNCDEF(tanh);
FUNCDEF(asinh);
FUNCDEF(acosh);
FUNCDEF(atanh);
FUNCDEF(exp);
FUNCDEF(log);
} // namespace
double sqr(double x) { return x*x; }
namespace {
FUNCDEF(sqr);
FUNCDEF(sqrt);
const int buildInFunctionOffset = language.size();
} // namespace
void add_tokens() {
unsigned sz = language.size();
language.resize(sz + sz+1); // double
for (unsigned i = sz; i < language.size(); ++i) {
free_list.push_back(i);
}
}
void extend_free_list() {
// first check if we can clean up unused tokens;
const vector<unsigned>& refcount = Sym::token_refcount();
for (unsigned i = buildInFunctionOffset; i < refcount.size(); ++i) {
if (language[i] == 0) continue;
bool c = is_constant(i);
bool l = is_lambda(i);
if (refcount[i] == 0 && (c || l)) {
if (c) {
doubleSet.erase(token_value[i]);
}
if (l) {
lambdaSet.erase(token_lambda[i]);
}
delete language[i];
language[i] = 0;
free_list.push_back(i);
}
}
// if still empty, add new tokens
if (free_list.empty()) {
add_tokens();
}
}
/* Serialization */
void write_raw(ostream& os, const Sym& sym) {
token_t token = sym.token();
const SymVec& args = sym.args();
if (is_constant(token)) {
os << "c" << language[token]->c_print(vector<string>(), vector<string>());
} else {
const Var* var = dynamic_cast<const Var*>( language[token] );
if (var != 0) {
os << "v" << var->idx;
} else {
os << "f" << token << ' ' << args.size();
}
}
for (unsigned i = 0; i < args.size(); ++i) {
write_raw(os, args[i]);
}
}
string write_raw(const Sym& sym) {
ostringstream os;
write_raw(os, sym);
return os.str();
}
Sym read_raw(istream& is) {
char id = is.get();
switch (id) {
case 'c' :
{
double val;
is.get(); // skip '('
is >> val;
is.get(); // skip ')'
return SymConst(val);
}
case 'v' :
{
unsigned idx;
is >> idx;
return SymVar(idx);
}
case 'f' :
{
token_t token;
unsigned arity;
is >> token;
is >> arity;
SymVec args(arity);
for (unsigned i = 0; i < arity; ++i) {
args[i] = read_raw(is);
}
return Sym(token, args);
}
default : {
cerr << "Character = " << id << " Could not read formula from stream" << endl;
exit(1);
}
}
return Sym();
}
Sym read_raw(string str) {
istringstream is(str);
return read_raw(is);
}
void read_raw(istream& is, Sym& sym) {
sym = read_raw(is);
}