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yap-6.3/packages/yap-lbfgs/yap_lbfgs.c

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#include <string.h>
#include "YapInterface.h"
#include <lbfgs.h>
#include <stdio.h>
/*
This file is part of YAP-LBFGS.
Copyright (C) 2009 Bernd Gutmann
YAP-LBFGS is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
YAP-LBFGS 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 YAP-LBFGS. If not, see <http://www.gnu.org/licenses/>.
*/
// These constants describe the internal state
#define OPTIMIZER_STATUS_NONE 0
#define OPTIMIZER_STATUS_INITIALIZED 1
#define OPTIMIZER_STATUS_RUNNING 2
#define OPTIMIZER_STATUS_CB_EVAL 3
#define OPTIMIZER_STATUS_CB_PROGRESS 4
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void init_lbfgs_predicates( void ) ;
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int optimizer_status=OPTIMIZER_STATUS_NONE; // the internal state
int n; // the size of the parameter vector
lbfgsfloatval_t *x; // pointer to the parameter vector x[0],...,x[n-1]
lbfgsfloatval_t *g; // pointer to the gradient vector g[0],...,g[n-1]
lbfgs_parameter_t param; // the parameters used for lbfgs
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YAP_Functor fcall3, fprogress8;
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static lbfgsfloatval_t evaluate(
void *instance,
const lbfgsfloatval_t *x,
lbfgsfloatval_t *g_tmp,
const int n,
const lbfgsfloatval_t step
)
{
YAP_Term call;
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YAP_Term a1;
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YAP_Bool result;
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YAP_Int s1;
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YAP_Term t[3];
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t[0] = YAP_MkVarTerm();
t[1] = YAP_MkIntTerm(n);
t[2] = YAP_MkFloatTerm(step);
call = YAP_MkApplTerm(fcall3, 3, t);
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g=g_tmp;
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s1 = YAP_InitSlot(call);
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optimizer_status=OPTIMIZER_STATUS_CB_EVAL;
result=YAP_CallProlog(call);
optimizer_status=OPTIMIZER_STATUS_RUNNING;
if (result==FALSE) {
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printf("ERROR: the evaluate call failed in YAP.\n");
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// Goal did not succeed
return FALSE;
}
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call = YAP_GetFromSlot( s1 );
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a1 = YAP_ArgOfTerm(1,call);
if (YAP_IsFloatTerm(a1)) {
YAP_ShutdownGoal( TRUE );
return (lbfgsfloatval_t) YAP_FloatOfTerm(a1);
} else if (YAP_IsIntTerm(a1)) {
YAP_ShutdownGoal( TRUE );
return (lbfgsfloatval_t) YAP_IntOfTerm(a1);
}
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YAP_ShutdownGoal( TRUE );
fprintf(stderr, "ERROR: The evaluate call back function did not return a number as first argument.\n");
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return 0;
}
static int progress(
void *instance,
const lbfgsfloatval_t *local_x,
const lbfgsfloatval_t *local_g,
const lbfgsfloatval_t fx,
const lbfgsfloatval_t xnorm,
const lbfgsfloatval_t gnorm,
const lbfgsfloatval_t step,
int n,
int k,
int ls
)
{
YAP_Term call;
YAP_Bool result;
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YAP_Int s1;
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YAP_Term t[8];
t[0] = YAP_MkFloatTerm(fx);
t[1] = YAP_MkFloatTerm(xnorm);
t[2] = YAP_MkFloatTerm(gnorm);
t[3] = YAP_MkFloatTerm(step);
t[4] = YAP_MkIntTerm(n);
t[5] = YAP_MkIntTerm(k);
t[6] = YAP_MkIntTerm(ls);
t[7] = YAP_MkVarTerm();
call = YAP_MkApplTerm( fprogress8, 8, t);
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s1 = YAP_InitSlot(call);
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optimizer_status=OPTIMIZER_STATUS_CB_PROGRESS;
result=YAP_CallProlog(call);
optimizer_status=OPTIMIZER_STATUS_RUNNING;
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call = YAP_GetFromSlot( s1 );
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if (result==FALSE) {
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printf("ERROR: the progress call failed in YAP.\n");
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// Goal did not succeed
return FALSE;
}
if (YAP_IsIntTerm(YAP_ArgOfTerm(8,call))) {
return YAP_IntOfTerm(YAP_ArgOfTerm(8,call));
}
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YAP_ShutdownGoal( TRUE );
fprintf(stderr, "ERROR: The progress call back function did not return an integer as last argument\n");
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return 1;
}
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/** @pred optimizer_set_x(+I,+X)
Set the current value for `x[I]`. Only possible when the optimizer is
initialized but not running.
*/
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static YAP_Bool set_x_value(void) {
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YAP_Term t1=YAP_ARG1;
YAP_Term t2=YAP_ARG2;
int i=0;
if (optimizer_status!=OPTIMIZER_STATUS_INITIALIZED) {
printf("ERROR: set_x_value/2 can be called only when the optimizer is initialized and not running.\n");
return FALSE;
}
if (YAP_IsIntTerm(t1)) {
i=YAP_IntOfTerm(t1);
} else {
return FALSE;
}
if (i<0 || i>=n) {
printf("ERROR: invalid index for set_x_value/2.\n");
return FALSE;
}
if (YAP_IsFloatTerm(t2)) {
x[i]=(lbfgsfloatval_t) YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
x[i]=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
return TRUE;
}
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/** @pred optimizer_get_x(+I,-X)
Get the current value for `x[I]`. Only possible when the optimizer is
initialized or running.
*/
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static YAP_Bool get_x_value(void) {
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YAP_Term t1=YAP_ARG1;
YAP_Term t2=YAP_ARG2;
int i=0;
if (optimizer_status==OPTIMIZER_STATUS_NONE) {
printf("ERROR: set_x_value/2 can be called only when the optimizer is initialized.\n");
return FALSE;
}
if (YAP_IsIntTerm(t1)) {
i=YAP_IntOfTerm(t1);
} else {
return FALSE;
}
if (i<0 || i>=n) {
printf("ERROR: invalid index for set_x_value/2.\n");
return FALSE;
}
return YAP_Unify(t2,YAP_MkFloatTerm(x[i]));
}
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/** @pred optimizer_set_g(+I,+G) Set the current value for `g[I]` (the
partial derivative of _F_ with respect to `x[I]`). Can only be called
from the evaluate call back predicate.
*/
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static YAP_Bool set_g_value(void) {
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YAP_Term t1=YAP_ARG1;
YAP_Term t2=YAP_ARG2;
int i=0;
if (optimizer_status != OPTIMIZER_STATUS_CB_EVAL) {
printf("ERROR: optimizer_set_g/2 can only be called by the evaluation call back function.\n");
return FALSE;
}
if (YAP_IsIntTerm(t1)) {
i=YAP_IntOfTerm(t1);
} else {
return FALSE;
}
if (i<0 || i>=n) {
return FALSE;
}
if (YAP_IsFloatTerm(t2)) {
g[i]=(lbfgsfloatval_t) YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
g[i]=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
return TRUE;
}
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/** @pred optimizer_get_g(+I,-G)
Get the current value for `g[I]` (the partial derivative of _F_ with respect to `x[I]`). Only possible when the optimizer is
initialized or running.
*/
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static YAP_Bool get_g_value(void) {
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YAP_Term t1=YAP_ARG1;
YAP_Term t2=YAP_ARG2;
int i=0;
if (optimizer_status != OPTIMIZER_STATUS_RUNNING && optimizer_status != OPTIMIZER_STATUS_CB_EVAL && optimizer_status != OPTIMIZER_STATUS_CB_PROGRESS) {
printf("ERROR: optimizer_get_g/2 can only be called while the optimizer is running.\n");
return FALSE;
}
if (YAP_IsIntTerm(t1)) {
i=YAP_IntOfTerm(t1);
} else {
return FALSE;
}
if (i<0 || i>=n) {
return FALSE;
}
return YAP_Unify(t2,YAP_MkFloatTerm(g[i]));
}
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/** @pred optimizer_initialize(+N,+Module,+Evaluate,+Progress)
Create space to optimize a function with _N_ variables (_N_ has to be
integer).
+ _Module</span>_ is the name of the module where the call back
predicates can be found,
+ _Evaluate_ is the call back predicate (arity 3)
to evaluate the function math <span class="math">_F</span>_,
+ _Progress_ is the call back predicate invoked
(arity 8) after every iteration
Example
~~~~
optimizer_initialize(1,user,evaluate,progress)</span>
~~~~
The evaluate call back predicate has to be of the type
`evaluate(-F,+N,+Step)`. It has to calculate the current function
value _F_. _N_ is the
size of the parameter vector (the value which was used to initialize
LBFGS) and _Step_ is the current state of the
line search. The call back predicate can access the current values of
`x[i]` by calling `optimizer_get_x(+I,-Xi)`. Finally, the call back
predicate has to calculate the gradient of _F</span>_
and set its value by calling `optimizer_set_g(+I,+Gi)` for every `1<=I<=N`.
The progress call back predicate has to be of the type
`progress(+F,+X_Norm,+G_Norm,+Step,+N,+Iteration,+LS,-Continue)`. It
is called after every iteration. The call back predicate can access
the current values of _X_ and of the gradient by calling
`optimizer_get_x(+I,-Xi)` and `optimizer_get_g`(+I,-Gi)`
respectively. However, it must not call the setter predicates for <span
class="code"_X_ or _G_. If it tries to do so, the optimizer will
terminate with an error. If _Continue_ is set to 0 (int) the
optimization process will continue for one more iteration, any other
value will terminate the optimization process.
*/
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static YAP_Bool optimizer_initialize(void) {
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YAP_Term t1 = YAP_ARG1;
int temp_n=0;
if (optimizer_status!=OPTIMIZER_STATUS_NONE) {
printf("ERROR: Optimizer has already been initialized. Please call optimizer_finalize/0 first.\n");
return FALSE;
}
if (! YAP_IsIntTerm(t1)) {
return FALSE;
}
temp_n=YAP_IntOfTerm(t1);
if (temp_n<1) {
return FALSE;
}
x = lbfgs_malloc(temp_n);
if (x == NULL) {
printf("ERROR: Failed to allocate a memory block for variables.\n");
return FALSE;
}
n=temp_n;
optimizer_status=OPTIMIZER_STATUS_INITIALIZED;
return TRUE;
}
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/** @pred optimizer_run(-F,-Status)
Runs the optimization, _F is the best (minimal) function value and
Status (int) is the status code returned by libLBFGS. Anything except
0 indicates an error, see the documentation of libLBFGS for the
meaning.
*/
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static YAP_Bool optimizer_run(void) {
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int ret = 0;
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YAP_Term t1 = YAP_ARG1;
YAP_Term t2 = YAP_ARG2;
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YAP_Int s1, s2;
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lbfgsfloatval_t fx;
lbfgsfloatval_t * tmp_x=x;
if (optimizer_status == OPTIMIZER_STATUS_NONE) {
printf("ERROR: Memory for parameter vector not initialized, please call optimizer_initialize/1 first.\n");
return FALSE;
}
if (optimizer_status != OPTIMIZER_STATUS_INITIALIZED) {
printf("ERROR: Optimizer is running right now. Please wait till it is finished.\n");
return FALSE;
}
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// both arguments have to be variables
if (! YAP_IsVarTerm(t1) || ! YAP_IsVarTerm(t2)) {
return FALSE;
}
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s1 = YAP_InitSlot(t1);
s2 = YAP_InitSlot(t2);
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optimizer_status = OPTIMIZER_STATUS_RUNNING;
ret = lbfgs(n, x, &fx, evaluate, progress, NULL, &param);
x=tmp_x;
optimizer_status = OPTIMIZER_STATUS_INITIALIZED;
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YAP_Unify(YAP_GetFromSlot(s1),YAP_MkFloatTerm(fx));
YAP_Unify(YAP_GetFromSlot(s2),YAP_MkIntTerm(ret));
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return TRUE;
}
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static YAP_Bool optimizer_finalize( void ) {
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if (optimizer_status == OPTIMIZER_STATUS_NONE) {
printf("Error: Optimizer is not initialized.\n");
return FALSE;
}
if (optimizer_status == OPTIMIZER_STATUS_INITIALIZED) {
lbfgs_free(x);
x=NULL;
n=0;
optimizer_status = OPTIMIZER_STATUS_NONE;
return TRUE;
}
printf("ERROR: Optimizer is running right now. Please wait till it is finished.\n");
return FALSE;
}
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/** @pred optimizer_set_parameter(+Name,+Value)
Set the parameter Name to Value. Only possible while the optimizer
is not running.
*/
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static YAP_Bool optimizer_set_parameter( void ) {
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YAP_Term t1 = YAP_ARG1;
YAP_Term t2 = YAP_ARG2;
if (optimizer_status != OPTIMIZER_STATUS_NONE && optimizer_status != OPTIMIZER_STATUS_INITIALIZED){
printf("ERROR: Optimizer is running right now. Please wait till it is finished.\n");
return FALSE;
}
if (! YAP_IsAtomTerm(t1)) {
return FALSE;
}
const char* name=YAP_AtomName(YAP_AtomOfTerm(t1));
if ((strcmp(name, "m") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.m = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "epsilon") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.epsilon=v;
} else if ((strcmp(name, "past") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.past = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "delta") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.delta=v;
} else if ((strcmp(name, "max_iterations") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.max_iterations = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "linesearch") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.linesearch = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "max_linesearch") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.max_linesearch = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "min_step") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.min_step=v;
} else if ((strcmp(name, "max_step") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.max_step=v;
} else if ((strcmp(name, "ftol") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.ftol=v;
} else if ((strcmp(name, "gtol") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.gtol=v;
} else if ((strcmp(name, "xtol") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.xtol=v;
} else if ((strcmp(name, "orthantwise_c") == 0)) {
lbfgsfloatval_t v;
if (YAP_IsFloatTerm(t2)) {
v=YAP_FloatOfTerm(t2);
} else if (YAP_IsIntTerm(t2)) {
v=(lbfgsfloatval_t) YAP_IntOfTerm(t2);
} else {
return FALSE;
}
param.orthantwise_c=v;
} else if ((strcmp(name, "orthantwise_start") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.orthantwise_start = YAP_IntOfTerm(t2);
} else if ((strcmp(name, "orthantwise_end") == 0)) {
if (! YAP_IsIntTerm(t2)) {
return FALSE;
}
param.orthantwise_end = YAP_IntOfTerm(t2);
} else {
printf("ERROR: The parameter %s is unknown.\n",name);
return FALSE;
}
return TRUE;
}
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/** @pred optimizer_get_parameter(+Name,-Value)</h3>
Get the current Value for Name
*/
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static YAP_Bool optimizer_get_parameter( void ) {
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YAP_Term t1 = YAP_ARG1;
YAP_Term t2 = YAP_ARG2;
if (! YAP_IsAtomTerm(t1)) {
return FALSE;
}
const char* name=YAP_AtomName(YAP_AtomOfTerm(t1));
if ((strcmp(name, "m") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.m));
} else if ((strcmp(name, "epsilon") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.epsilon));
} else if ((strcmp(name, "past") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.past));
} else if ((strcmp(name, "delta") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.delta));
} else if ((strcmp(name, "max_iterations") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.max_iterations));
} else if ((strcmp(name, "linesearch") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.linesearch));
} else if ((strcmp(name, "max_linesearch") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.max_linesearch));
} else if ((strcmp(name, "min_step") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.min_step));
} else if ((strcmp(name, "max_step") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.max_step));
} else if ((strcmp(name, "ftol") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.ftol));
} else if ((strcmp(name, "gtol") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.gtol));
} else if ((strcmp(name, "xtol") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.xtol));
} else if ((strcmp(name, "orthantwise_c") == 0)) {
return YAP_Unify(t2,YAP_MkFloatTerm(param.orthantwise_c));
} else if ((strcmp(name, "orthantwise_start") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.orthantwise_start));
} else if ((strcmp(name, "orthantwise_end") == 0)) {
return YAP_Unify(t2,YAP_MkIntTerm(param.orthantwise_end));
}
printf("ERROR: The parameter %s is unknown.\n",name);
return FALSE;
}
void init_lbfgs_predicates( void )
{
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fcall3 = YAP_MkFunctor(YAP_LookupAtom("$lbfgs_callback_evaluate"), 3);
fprogress8 = YAP_MkFunctor(YAP_LookupAtom("$lbfgs_callback_progress"), 8);
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//Initialize the parameters for the L-BFGS optimization.
lbfgs_parameter_init(&param);
YAP_UserCPredicate("optimizer_reserve_memory",optimizer_initialize,1);
YAP_UserCPredicate("optimizer_run",optimizer_run,2);
YAP_UserCPredicate("optimizer_free_memory",optimizer_finalize,0);
YAP_UserCPredicate("optimizer_set_x",set_x_value,2);
YAP_UserCPredicate("optimizer_get_x",get_x_value,2);
YAP_UserCPredicate("optimizer_set_g",set_g_value,2);
YAP_UserCPredicate("optimizer_get_g",get_g_value,2);
YAP_UserCPredicate("optimizer_set_parameter",optimizer_set_parameter,2);
YAP_UserCPredicate("optimizer_get_parameter",optimizer_get_parameter,2);
}