136 lines
3.6 KiB
C++
136 lines
3.6 KiB
C++
/* ----------------------------------------------------------------------------
|
|
|
|
* GTSAM Copyright 2010, Georgia Tech Research Corporation,
|
|
* Atlanta, Georgia 30332-0415
|
|
* All Rights Reserved
|
|
* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
|
|
|
|
* See LICENSE for the license information
|
|
|
|
* -------------------------------------------------------------------------- */
|
|
|
|
/**
|
|
* @file Signature.h
|
|
* @brief signatures for conditional densities
|
|
* @author Frank Dellaert
|
|
* @date Feb 27, 2011
|
|
*/
|
|
|
|
#pragma once
|
|
#include <string>
|
|
#include <vector>
|
|
#include <boost/optional.hpp>
|
|
#include <gtsam/discrete/DiscreteKey.h>
|
|
|
|
namespace gtsam {
|
|
|
|
/**
|
|
* Signature for a discrete conditional density, used to construct conditionals.
|
|
*
|
|
* The format is (Key % string) for nodes with no parents,
|
|
* and (Key | Key, Key = string) for nodes with parents.
|
|
*
|
|
* The string specifies a conditional probability spec in the 00 01 10 11 order.
|
|
* For three-valued, it would be 00 01 02 10 11 12 20 21 22, etc...
|
|
*
|
|
* For example, given the following keys
|
|
*
|
|
* Key A("Asia"), S("Smoking"), T("Tuberculosis"), L("LungCancer"),
|
|
* B("Bronchitis"), E("Either"), X("XRay"), D("Dyspnoea");
|
|
*
|
|
* These are all valid signatures (Asia network example):
|
|
*
|
|
* A % "99/1"
|
|
* S % "50/50"
|
|
* T|A = "99/1 95/5"
|
|
* L|S = "99/1 90/10"
|
|
* B|S = "70/30 40/60"
|
|
* E|T,L = "F F F 1"
|
|
* X|E = "95/5 2/98"
|
|
* D|E,B = "9/1 2/8 3/7 1/9"
|
|
*/
|
|
class GTSAM_EXPORT Signature {
|
|
|
|
public:
|
|
|
|
/** Data type for the CPT */
|
|
typedef std::vector<double> Row;
|
|
typedef std::vector<Row> Table;
|
|
|
|
private:
|
|
|
|
/** the variable key */
|
|
DiscreteKey key_;
|
|
|
|
/** the parent keys */
|
|
DiscreteKeys parents_;
|
|
|
|
// the given CPT specification string
|
|
boost::optional<std::string> spec_;
|
|
|
|
// the CPT as parsed, if successful
|
|
boost::optional<Table> table_;
|
|
|
|
public:
|
|
|
|
/** Constructor from DiscreteKey */
|
|
Signature(const DiscreteKey& key);
|
|
|
|
/** the variable key */
|
|
const DiscreteKey& key() const {
|
|
return key_;
|
|
}
|
|
|
|
/** the parent keys */
|
|
const DiscreteKeys& parents() const {
|
|
return parents_;
|
|
}
|
|
|
|
/** All keys, with variable key first */
|
|
DiscreteKeys discreteKeys() const;
|
|
|
|
/** All key indices, with variable key first */
|
|
KeyVector indices() const;
|
|
|
|
// the CPT as parsed, if successful
|
|
const boost::optional<Table>& table() const {
|
|
return table_;
|
|
}
|
|
|
|
// the CPT as a vector of doubles, with key's values most rapidly changing
|
|
std::vector<double> cpt() const;
|
|
|
|
/** Add a parent */
|
|
Signature& operator,(const DiscreteKey& parent);
|
|
|
|
/** Add the CPT spec - Fails in boost 1.40 */
|
|
Signature& operator=(const std::string& spec);
|
|
|
|
/** Add the CPT spec directly as a table */
|
|
Signature& operator=(const Table& table);
|
|
|
|
/** provide streaming */
|
|
GTSAM_EXPORT friend std::ostream& operator <<(std::ostream &os, const Signature &s);
|
|
};
|
|
|
|
/**
|
|
* Helper function to create Signature objects
|
|
* example: Signature s = D | E;
|
|
*/
|
|
GTSAM_EXPORT Signature operator|(const DiscreteKey& key, const DiscreteKey& parent);
|
|
|
|
/**
|
|
* Helper function to create Signature objects
|
|
* example: Signature s(D % "99/1");
|
|
* Uses string parser, which requires BOOST 1.42 or higher
|
|
*/
|
|
GTSAM_EXPORT Signature operator%(const DiscreteKey& key, const std::string& parent);
|
|
|
|
/**
|
|
* Helper function to create Signature objects, using table construction directly
|
|
* example: Signature s(D % table);
|
|
*/
|
|
GTSAM_EXPORT Signature operator%(const DiscreteKey& key, const Signature::Table& parent);
|
|
|
|
}
|