{
private:
LinearProgram &linprog;
- unsigned index;
+ size_t index;
public:
- Row(LinearProgram &, unsigned);
+ Row(LinearProgram &, size_t);
- float &operator[](unsigned);
+ float &operator[](size_t);
float &back();
};
private:
struct Column
{
- unsigned basic;
+ size_t basic;
std::vector<float> values;
Column();
};
- unsigned n_columns = 1;
- unsigned n_rows = 1;
+ size_t n_columns = 1;
+ size_t n_rows = 1;
std::vector<Column> columns;
bool solved = false;
bool infeasible = false;
public:
- LinearProgram(unsigned);
+ LinearProgram(size_t);
Row add_row();
- Row operator[](unsigned);
+ Row operator[](size_t);
Row get_objective_row();
- float get_variable(unsigned);
+ float get_variable(size_t);
bool solve();
private:
void prepare_columns();
void add_artificial_variables();
void remove_artificial_variables();
- unsigned find_minimal_ratio(unsigned);
- void make_basic_column(unsigned, unsigned);
+ size_t find_minimal_ratio(size_t);
+ void make_basic_column(size_t, size_t);
bool pivot();
};
void Layout::update_slot_indices()
{
n_active_slots = 0;
- unsigned n_floating = 0;
+ size_t n_floating = 0;
for(Slot *s: slots)
{
if(s->widget.is_visible() || s->ghost)
remaining three are slack columns; see below for their purposes. */
LinearProgram linprog(n_active_slots*5+n_slack_vars[dir]+1);
float weight = slots.size()+1;
- unsigned k = n_active_slots*5;
+ size_t k = n_active_slots*5;
for(const Slot *s: slots)
{
if(s->index<0)
}
-Layout::LinearProgram::LinearProgram(unsigned s):
+Layout::LinearProgram::LinearProgram(size_t s):
n_columns(s),
columns(n_columns)
{ }
return Row(*this, n_rows++);
}
-Layout::LinearProgram::Row Layout::LinearProgram::operator[](unsigned r)
+Layout::LinearProgram::Row Layout::LinearProgram::operator[](size_t r)
{
if(r>=n_rows)
throw out_of_range("LinearProgram::operator[]");
return Row(*this, 0);
}
-float Layout::LinearProgram::get_variable(unsigned i)
+float Layout::LinearProgram::get_variable(size_t i)
{
if(!solved || infeasible)
throw logic_error("not solved");
if(i+1>=n_columns)
throw out_of_range("LinearProgram::get_variable");
- if(unsigned r = columns[i].basic)
+ if(size_t r = columns[i].basic)
return columns.back().values[r];
else
return 0;
if(c.values.size()>=2 && c.values.back()!=0.0f && (constants.size()<c.values.size() || c.values.back()*constants[c.values.size()-1]>=0.0f) && obj_coeff[c.values.size()-1]==0.0f)
{
bool basic = true;
- for(unsigned j=1; (basic && j+1<c.values.size()); ++j)
+ for(size_t j=1; (basic && j+1<c.values.size()); ++j)
basic = (c.values[j]==0.0f);
if(basic)
{
for(Column &c: columns)
if(!c.values.empty())
{
- for(unsigned j=0; j<c.values.size(); ++j)
+ for(size_t j=0; j<c.values.size(); ++j)
{
c.values[j] *= row_coeff[j];
c.values.front() += obj_coeff[j]*c.values[j];
void Layout::LinearProgram::add_artificial_variables()
{
- vector<unsigned> artificial_rows(n_rows-1);
- for(
unsigned i=0; i<artificial_rows.size(); ++i)
+ vector<size_t> artificial_rows(n_rows-1);
+ for(
size_t i=0; i<artificial_rows.size(); ++i)
artificial_rows[i] = i+1;
for(const Column &c: columns)
{
objective = c.values.front();
c.values.front() = 0.0f;
- for(unsigned r: artificial_rows)
+ for(size_t r: artificial_rows)
if(r<c.values.size())
c.values.front() += c.values[r];
}
columns.resize(n_columns+artificial_rows.size());
columns.back() = columns[n_columns-1];
columns[n_columns-1].values.clear();
- for(
unsigned i=0; i<artificial_rows.size(); ++i)
+ for(
size_t i=0; i<artificial_rows.size(); ++i)
columns[n_columns+i-1].basic = artificial_rows[i];
}
some of the original variables basic instead.
I don't fully understand why this is needed, but it appears to work. */
- for(unsigned i=n_columns-1; i+1<columns.size(); ++i)
+ for(size_t i=n_columns-1; i+1<columns.size(); ++i)
if(columns[i].basic && columns.back().values[columns[i].basic]==0.0f)
{
- for(unsigned j=0; j+1<n_columns; ++j)
+ for(size_t j=0; j+1<n_columns; ++j)
if(!columns[j].basic && columns[j].values[columns[i].basic]!=0.0f)
{
make_basic_column(j, columns[i].basic);
}
}
-unsigned Layout::LinearProgram::find_minimal_ratio(unsigned c)
+size_t Layout::LinearProgram::find_minimal_ratio(size_t c)
{
/* Pick the row with the minimum ratio between the constant column and the
pivot column. This ensures that when the pivot column is made basic, values
The use of n_rows instead of the true size of the column is intentional,
since the relocated objective row must be ignored in phase 1. */
float best = numeric_limits<float>::infinity();
- unsigned row = 0;
- for(unsigned i=1; i<n_rows; ++i)
+ size_t row = 0;
+ for(size_t i=1; i<n_rows; ++i)
if(columns[c].values[i]>0)
{
float ratio = columns.back().values[i]/columns[c].values[i];
return row;
}
-void Layout::LinearProgram::make_basic_column(unsigned c, unsigned r)
+void Layout::LinearProgram::make_basic_column(size_t c, size_t r)
{
/* Perform row transfer operations to make the pivot column basic,
containing a 1 on the pivot row. */
- for(unsigned i=0; i<columns.size(); ++i)
+ for(size_t i=0; i<columns.size(); ++i)
if(i!=c && (columns[i].basic==r || (!columns[i].basic && columns[i].values[r])))
{
if(columns[i].basic)
float scale = columns[i].values[r]/columns[c].values[r];
columns[i].values[r] = scale;
- for(unsigned j=0; j<columns[i].values.size(); ++j)
+ for(size_t j=0; j<columns[i].values.size(); ++j)
if(j!=r)
columns[i].values[j] -= scale*columns[c].values[j];
}
/* Pick a nonbasic column and make it basic. Requiring a positive objective
coefficient ensures that the objective function's value will decrease in the
process. */
- for(unsigned i=0; i+1<columns.size(); ++i)
+ for(size_t i=0; i+1<columns.size(); ++i)
if(!columns[i].basic && columns[i].values.front()>0)
- if(unsigned row = find_minimal_ratio(i))
+ if(size_t row = find_minimal_ratio(i))
{
make_basic_column(i, row);
return true;
}
-Layout::LinearProgram::Row::Row(LinearProgram &lp, unsigned i):
+Layout::LinearProgram::Row::Row(LinearProgram &lp, size_t i):
linprog(lp),
index(i)
{ }
-float &Layout::LinearProgram::Row::operator[](unsigned c)
+float &Layout::LinearProgram::Row::operator[](size_t c)
{
if(c>=linprog.n_columns)
throw out_of_range("Row::operator[]");
projects / libs / gltk.git / blobdiff