def _process_rhs(self, data_line: DataLine):
if len(self._rhs) != len(self.constraint_names):
self._rhs = np.zeros(len(self.constraint_names))
self._add_rhs(data_line.second_name(), data_line.first_number())
if data_line.has_third_name() and data_line.has_second_number():
self._add_rhs(data_line.third_name(), data_line.second_number())
def test_first_number_column(line, expected):
"""
The first numeric field is the 25-36 column range (inclusive).
"""
padding = " " * 24 # starts at column 25, so 24 spaces.
data_line = DataLine(padding + line)
assert_almost_equal(data_line.first_number(), expected)
def _process_scenarios(self, data_line: DataLine):
if data_line.indicator() == "SC": # new scenario
scen = Scenario(data_line.first_name(), data_line.second_name(),
data_line.third_name(), data_line.first_number())
self._current_scen = scen
return
var = data_line.first_name()
constr = data_line.second_name()
value = data_line.first_number()
assert self._current_scen is not None
self._current_scen.add_modification(constr, var, value)
if data_line.has_third_name() and data_line.has_second_number():
constr = data_line.third_name()
value = data_line.second_number()
self._current_scen.add_modification(constr, var, value)
def test_first_data_entry():
"""
Tests if the DataLine class correctly parses the first data entry.
"""
# From the sslp_5_25_50.cor file.
line = " x_1 c2 188"
data_line = DataLine(line)
assert_equal(data_line.first_name(), "x_1")
assert_equal(data_line.second_name(), "c2")
assert_almost_equal(data_line.first_number(), 188)
def _parse_column(self, data_line: DataLine):
var = data_line.first_name()
if var not in self._var2idx:
self._variable_names.append(var)
self._types.append('I' if self._parse_ints else 'C')
self._var2idx[var] = len(self._variable_names) - 1
constr = data_line.second_name()
value = data_line.first_number()
self._add_value(constr, var, value)
if data_line.has_third_name() and data_line.has_second_number():
constr = data_line.third_name()
value = data_line.second_number()
self._add_value(constr, var, value)
def _process_bounds(self, data_line: DataLine):
"""
There are a ton of bound types, but the most common are listed below,
originally due to http://lpsolve.sourceforge.net/5.5/mps-format.htm. A
bound is specified by a two-letter type and a value b.
- LO lower bound b <= x (< +inf)
- UP upper bound (0 <=) x <= b
- FX fixed variable x = b
- FR free variable -inf < x < +inf
- MI lower bound -inf -inf < x (<= 0)
- PL upper bound +inf (0 <=) x < +inf
- BV binary variable x = 0 or 1
- LI integer variable b <= x (< +inf)
- UI integer variable (0 <=) x <= b
Raises
------
ValueError
When the bound type is not understood.
"""
if len(self._lb) != len(self.variable_names) != len(self._ub):
self._lb = np.zeros(len(self.variable_names))
self._ub = np.full(len(self.variable_names), np.inf)
bound_type = data_line.indicator()
if bound_type not in _BOUNDS_TYPES:
msg = f"Bounds of type {bound_type} are not understood."
logger.error(msg)
raise ValueError(msg)
var = data_line.second_name()
idx = self._var2idx[var]
# The value is clear from the type, and need not have been specified.
# Hence we treat these separately, and then return.
if bound_type in {"FR", "MI", "PL", "BV"}:
if bound_type == "FR": # free variable
self._lb[idx] = -np.inf
self._ub[idx] = np.inf
if bound_type == "MI": # -inf lower bound
self._lb[idx] = -np.inf
if bound_type == "PL": # +inf upper bound
self._ub[idx] = np.inf
if bound_type == "BV": # binary variable
self._lb[idx] = 0
self._ub[idx] = 1
self._types[idx] = 'B'
return
value = data_line.first_number()
if bound_type == "LO": # lower bound
self._lb[idx] = value
if bound_type == "UP": # upper bound
self._ub[idx] = value
if bound_type == "FX": # fixed variable
self._lb[idx] = value
self._ub[idx] = value
if bound_type == "LI": # integer variable, lower bound
self._lb[idx] = value
self._types[idx] = 'I'
if bound_type == "UI": # integer variable, upper bound
self._ub[idx] = value
self._types[idx] = 'I'