static void add_constraint(int col,int idx,int next_expr(int))
{int i,nextexpr;
for(i=0;idx>=0;i++){
nextexpr=next_expr(i);
xassert(nextexpr==0);
if(entropy_expr.type == ent_Markov){
if(idx>entropy_expr.n-3){ idx -= entropy_expr.n-2; continue; }
int v1,v2,v; int j;
// add idx-th Markov equality
v=v1=v2=0; for(j=0;j<entropy_expr.n;j++){
if(j<idx+1) v1 |= entropy_expr.item[j].var;
else if(j>idx+1) v2 |= entropy_expr.item[j].var;
else v=entropy_expr.item[j].var;
} // (v1,v2|v)=0
row_idx[1]=varidx(v1|v); row_val[1]=1.0;
row_idx[2]=varidx(v2|v); row_val[2]=1.0;
row_idx[3]=varidx(v1|v2|v); row_val[3]=-1.0;
row_idx[4]=varidx(v); row_val[4]=-1.0;
add_column(col,4,GLP_FR);
return;
} else if(idx>0) { idx--; continue; }
else { // add this constraint
int j;
for(j=0;j<entropy_expr.n;j++){
row_idx[j+1]=varidx(entropy_expr.item[j].var);
row_val[j+1]=entropy_expr.item[j].coeff;
}
add_column(col,entropy_expr.n, entropy_expr.type==ent_eq?GLP_FR : GLP_LO);
return;
}
}
xassert(idx!=idx);
}
BString VisionApp::ParseAlias(const char* cmd, const BString& channel)
{
BString command(GetWord(cmd, 1).ToUpper());
BString newcmd = fAliases[command];
const char* parse = newcmd.String();
int32 replidx(0);
int32 varidx(0);
newcmd.ReplaceAll("$C", channel.String());
while (*parse != '\0') {
if (*parse != '$') {
++parse;
continue;
} else {
replidx = parse - newcmd.String();
++parse;
if (isdigit(*parse)) {
varidx = atoi(parse);
BString replString = "$";
replString << varidx;
if (*(parse + replString.Length() - 1) != '-') {
newcmd.ReplaceAll(replString.String(), GetWord(cmd, varidx + 1).String());
} else {
replString += "-";
newcmd.ReplaceAll(replString.String(), RestOfString(cmd, varidx + 1).String());
}
}
}
}
return newcmd;
}
char *call_lp(int next_expr(int))
{int i,constraints; expr_type_t goal_type;
char *retval, *retval2;
/* initially the expression to be checked is in entropy_expr.
determine first the variables */
init_var_assignment(); /* start collecting variables */
add_expr_variables(); /* variables in the expression to be checked */
constraints=0;
for(i=0;next_expr(i)==0;i++){ /* go over all constraints */
constraints++;
// Markov constraints give several cols
if(entropy_expr.type==ent_Markov){
constraints+=entropy_expr.n-3;
}
add_expr_variables();
}
/* figure out final variables, rows, cols, number of Shannon */
if(do_variable_assignment()){ // number of variables is less than 2
return "number of final random variables is less than 2";
}
/* get memory for row and column permutation */
cols += constraints;
rowperm=malloc((rows+1)*sizeof(int));
colperm=malloc((cols+1)*sizeof(int));
if(!rowperm || !colperm){
if(rowperm){ free(rowperm); rowperm=NULL; }
if(colperm){ free(colperm); colperm=NULL; }
return "the problem is too large, not enough memory";
}
for(i=0;i<=rows;i++) rowperm[i]=i; perm_array(rows+1,rowperm);
for(i=0;i<=cols;i++) colperm[i]= i-1; perm_array(cols+1,colperm);
/* the expression to be checked, this will be the goal */
if(constraints) next_expr(-1);
goal_type=entropy_expr.type; // ent_eq, ent_ge
create_glp(); // create a new glp instance
for(i=0;i<entropy_expr.n;i++){
row_idx[i+1]=varidx(entropy_expr.item[i].var);
row_val[i+1]=entropy_expr.item[i].coeff;
}
add_goal(entropy_expr.n); // right hand side value
// go over the columns add them to the lp instance
for(i=1;i<=cols;i++){
int colct=colperm[i];
if(add_shannon(i,colct)){ // this is a constraint
add_constraint(i,colct-(shannon+var_no),next_expr);
}
}
/* call the lp */
init_glp_parameters();
if(parm.presolve!=GLP_ON) // generate the first basis
glp_adv_basis(P,0);
retval=invoke_lp();
// call again with -1.0 when checking for ent_eq
if(goal_type==ent_eq && (retval==EXPR_TRUE || retval==EXPR_FALSE)){
next_expr(-1); // reload the problem
for(i=0;i<entropy_expr.n;i++){
row_idx[i+1]=varidx(entropy_expr.item[i].var);
row_val[i+1]=-entropy_expr.item[i].coeff;
}
add_goal(entropy_expr.n); // right hand side value
retval2=invoke_lp();
if(retval2==EXPR_TRUE){
if(retval==EXPR_FALSE) retval=EQ_LE_ONLY;
} else if(retval2==EXPR_FALSE){
if(retval==EXPR_TRUE) retval=EQ_GE_ONLY;
} else {
retval=retval2;
}
}
/* release allocated memory */
release_glp();
if(rowperm){ free(rowperm); rowperm=NULL; }
if(colperm){ free(colperm); colperm=NULL; }
return retval;
}
