PLearn 0.1
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cost = - sum_i {target_i * log(output_i) + (1-target_i) * log(1-output_i)} More...
#include <CrossEntropyVariable.h>
Public Member Functions | |
CrossEntropyVariable () | |
Default constructor for persistence. | |
CrossEntropyVariable (Variable *netout, Variable *target) | |
virtual string | classname () const |
virtual OptionList & | getOptionList () const |
virtual OptionMap & | getOptionMap () const |
virtual RemoteMethodMap & | getRemoteMethodMap () const |
virtual CrossEntropyVariable * | deepCopy (CopiesMap &copies) const |
virtual void | build () |
Post-constructor. | |
virtual void | recomputeSize (int &l, int &w) const |
Recomputes the length l and width w that this variable should have, according to its parent variables. | |
virtual void | fprop () |
compute output given input | |
virtual void | bprop () |
Static Public Member Functions | |
static string | _classname_ () |
CrossEntropyVariable. | |
static OptionList & | _getOptionList_ () |
static RemoteMethodMap & | _getRemoteMethodMap_ () |
static Object * | _new_instance_for_typemap_ () |
static bool | _isa_ (const Object *o) |
static void | _static_initialize_ () |
static const PPath & | declaringFile () |
Static Public Attributes | |
static StaticInitializer | _static_initializer_ |
Protected Member Functions | |
void | build_ () |
This does the actual building. | |
Private Types | |
typedef BinaryVariable | inherited |
cost = - sum_i {target_i * log(output_i) + (1-target_i) * log(1-output_i)}
Definition at line 53 of file CrossEntropyVariable.h.
typedef BinaryVariable PLearn::CrossEntropyVariable::inherited [private] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 55 of file CrossEntropyVariable.h.
PLearn::CrossEntropyVariable::CrossEntropyVariable | ( | ) | [inline] |
Definition at line 56 of file CrossEntropyVariable.cc.
References build_().
string PLearn::CrossEntropyVariable::_classname_ | ( | ) | [static] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
OptionList & PLearn::CrossEntropyVariable::_getOptionList_ | ( | ) | [static] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
RemoteMethodMap & PLearn::CrossEntropyVariable::_getRemoteMethodMap_ | ( | ) | [static] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
Object * PLearn::CrossEntropyVariable::_new_instance_for_typemap_ | ( | ) | [static] |
Reimplemented from PLearn::Object.
Definition at line 54 of file CrossEntropyVariable.cc.
StaticInitializer CrossEntropyVariable::_static_initializer_ & PLearn::CrossEntropyVariable::_static_initialize_ | ( | ) | [static] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
void PLearn::CrossEntropyVariable::bprop | ( | ) | [virtual] |
Implements PLearn::Variable.
Definition at line 102 of file CrossEntropyVariable.cc.
References PLearn::fast_exact_is_equal(), PLearn::Variable::gradientdata, i, PLearn::BinaryVariable::input1, PLearn::BinaryVariable::input2, and PLERROR.
{ real gr = *gradientdata; for (int i=0; i<input1->size(); i++) { real output = input1->valuedata[i]; real target = input2->valuedata[i]; #ifdef BOUNDCHECK if (fast_exact_is_equal(output, target)) PLERROR("CrossEntropyVariable::bprop: model output is either exactly " "0.0 or 1.0; cannot compute bprop"); #endif input1->gradientdata[i] += gr*(-target/output + (1.0-target)/(1.0-output)); } }
void PLearn::CrossEntropyVariable::build | ( | ) | [virtual] |
Post-constructor.
The normal implementation should call simply inherited::build(), then this class's build_(). This method should be callable again at later times, after modifying some option fields to change the "architecture" of the object.
Reimplemented from PLearn::BinaryVariable.
Definition at line 63 of file CrossEntropyVariable.cc.
References PLearn::BinaryVariable::build(), and build_().
{ inherited::build(); build_(); }
void PLearn::CrossEntropyVariable::build_ | ( | ) | [protected] |
This does the actual building.
Reimplemented from PLearn::BinaryVariable.
Definition at line 70 of file CrossEntropyVariable.cc.
References PLearn::BinaryVariable::input1, PLearn::BinaryVariable::input2, and PLERROR.
Referenced by build(), and CrossEntropyVariable().
{ // input1 and input2 are (respectively) netout and target from constructor if (input1 && input2 && (input1->size() != input2->size())) PLERROR("In CrossEntropyVariable: netout and target must have the same size"); }
string PLearn::CrossEntropyVariable::classname | ( | ) | const [virtual] |
Reimplemented from PLearn::Object.
Definition at line 54 of file CrossEntropyVariable.cc.
static const PPath& PLearn::CrossEntropyVariable::declaringFile | ( | ) | [inline, static] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 62 of file CrossEntropyVariable.h.
: void build_();
CrossEntropyVariable * PLearn::CrossEntropyVariable::deepCopy | ( | CopiesMap & | copies | ) | const [virtual] |
Reimplemented from PLearn::BinaryVariable.
Definition at line 54 of file CrossEntropyVariable.cc.
void PLearn::CrossEntropyVariable::fprop | ( | ) | [virtual] |
compute output given input
Implements PLearn::Variable.
Definition at line 81 of file CrossEntropyVariable.cc.
References PLearn::fast_exact_is_equal(), i, PLearn::BinaryVariable::input1, PLearn::BinaryVariable::input2, pl_log, PLASSERT, PLERROR, and PLearn::Variable::valuedata.
{ real cost = 0.0; for (int i=0; i<input1->size(); i++) { real output = input1->valuedata[i]; real target = input2->valuedata[i]; PLASSERT( fast_exact_is_equal(target, 0) || fast_exact_is_equal(target, 1) ); PLASSERT( output >= 0 && output <= 1 ); if ((fast_exact_is_equal(output,0) && !fast_exact_is_equal(target,0)) || (fast_exact_is_equal(output,1) && !fast_exact_is_equal(target,1))) PLERROR("CrossEntropyVariable::fprop: model output is either exactly " "0.0 or 1.0; cannot compute cost function"); if (!fast_exact_is_equal(output,0) && !fast_exact_is_equal(output,1)) { cost += target*pl_log(output) + (1.0-target)*pl_log(1.0-output); } } valuedata[0] = -cost; }
OptionList & PLearn::CrossEntropyVariable::getOptionList | ( | ) | const [virtual] |
Reimplemented from PLearn::Object.
Definition at line 54 of file CrossEntropyVariable.cc.
OptionMap & PLearn::CrossEntropyVariable::getOptionMap | ( | ) | const [virtual] |
Reimplemented from PLearn::Object.
Definition at line 54 of file CrossEntropyVariable.cc.
RemoteMethodMap & PLearn::CrossEntropyVariable::getRemoteMethodMap | ( | ) | const [virtual] |
Reimplemented from PLearn::Object.
Definition at line 54 of file CrossEntropyVariable.cc.
Recomputes the length l and width w that this variable should have, according to its parent variables.
This is used for ex. by sizeprop() The default version stupidly returns the current dimensions, so make sure to overload it in subclasses if this is not appropriate.
Reimplemented from PLearn::Variable.
Definition at line 78 of file CrossEntropyVariable.cc.
{ l=1, w=1; }
Reimplemented from PLearn::BinaryVariable.
Definition at line 62 of file CrossEntropyVariable.h.