本文整理汇总了Python中pyscipopt.Model.getPrimalbound方法的典型用法代码示例。如果您正苦于以下问题：Python Model.getPrimalbound方法的具体用法？Python Model.getPrimalbound怎么用？Python Model.getPrimalbound使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类pyscipopt.Model的用法示例。
在下文中一共展示了Model.getPrimalbound方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: test_string_poly
# 需要导入模块: from pyscipopt import Model [as 别名]
# 或者: from pyscipopt.Model import getPrimalbound [as 别名]
def test_string_poly():
PI = 3.141592653589793238462643
NWIRES = 11
DIAMETERS = [0.207, 0.225, 0.244, 0.263, 0.283, 0.307, 0.331, 0.362, 0.394, 0.4375, 0.500]
PRELOAD = 300.0
MAXWORKLOAD = 1000.0
MAXDEFLECT = 6.0
DEFLECTPRELOAD = 1.25
MAXFREELEN = 14.0
MAXCOILDIAM = 3.0
MAXSHEARSTRESS = 189000.0
SHEARMOD = 11500000.0
m = Model()
coil = m.addVar('coildiam')
wire = m.addVar('wirediam')
defl = m.addVar('deflection', lb=DEFLECTPRELOAD / (MAXWORKLOAD - PRELOAD), ub=MAXDEFLECT / PRELOAD)
ncoils = m.addVar('ncoils', vtype='I')
const1 = m.addVar('const1')
const2 = m.addVar('const2')
volume = m.addVar('volume')
y = [m.addVar('wire%d' % i, vtype='B') for i in range(NWIRES)]
obj = 1.0 * volume
m.setObjective(obj, 'minimize')
m.addCons(PI/2*(ncoils + 2)*coil*wire**2 - volume == 0, name='voldef')
# defconst1: coil / wire - const1 == 0.0
m.addCons(coil - const1*wire == 0, name='defconst1')
# defconst2: (4.0*const1 - 1.0) / (4.0*const1 - 4.0) + 0.615 / const1 - const2 == 0.0
d1 = (4.0*const1 - 4.0)
d2 = const1
m.addCons((4.0*const1 - 1.0)*d2 + 0.615*d1 - const2*d1*d2 == 0, name='defconst2')
m.addCons(8.0*MAXWORKLOAD/PI*const1*const2 - MAXSHEARSTRESS*wire**2 <= 0.0, name='shear')
# defdefl: 8.0/shearmod * ncoils * const1^3 / wire - defl == 0.0
m.addCons(8.0/SHEARMOD*ncoils*const1**3 - defl*wire == 0.0, name="defdefl")
m.addCons(MAXWORKLOAD*defl + 1.05*ncoils*wire + 2.1*wire <= MAXFREELEN, name='freel')
m.addCons(coil + wire <= MAXCOILDIAM, name='coilwidth')
m.addCons(quicksum(c*v for (c,v) in zip(DIAMETERS, y)) - wire == 0, name='defwire')
m.addCons(quicksum(y) == 1, name='selectwire')
m.optimize()
assert abs(m.getPrimalbound() - 1.6924910128) < 1.0e-5示例2: test_gastrans
# 需要导入模块: from pyscipopt import Model [as 别名]
# 或者: from pyscipopt.Model import getPrimalbound [as 别名]
#.........这里部分代码省略.........
("Petange", None, -1.919, 25.0, 66.2, 0.0 ), # 12
("Peronnes", 0.0, 0.96, 0.0, 66.2, 1.68 ), # 13
("Sinsin", 0.0, 0.0, 0.0, 63.0, 0.0 ), # 14
("Voeren", 20.344, 22.012, 50.0, 66.2, 1.68 ), # 15
("Wanze", 0.0, 0.0, 0.0, 66.2, 0.0 ), # 16
("Warnand", 0.0, 0.0, 0.0, 66.2, 0.0 ), # 17
("Zeebrugge", 8.87, 11.594, 0.0, 77.0, 2.28 ), # 18
("Zomergem", 0.0, 0.0, 0.0, 80.0, 0.0 ) # 19
]
arcs = [
# node1 node2 diameter length active */
( 18, 6, 890.0, 4.0, False ),
( 18, 6, 890.0, 4.0, False ),
( 6, 5, 890.0, 6.0, False ),
( 6, 5, 890.0, 6.0, False ),
( 5, 19, 890.0, 26.0, False ),
( 9, 1, 590.1, 43.0, False ),
( 1, 7, 590.1, 29.0, False ),
( 7, 19, 590.1, 19.0, False ),
( 19, 13, 890.0, 55.0, False ),
( 15, 3, 890.0, 5.0, True ),
( 15, 3, 395.0, 5.0, True ),
( 3, 8, 890.0, 20.0, False ),
( 3, 8, 395.0, 20.0, False ),
( 8, 17, 890.0, 25.0, False ),
( 8, 17, 395.0, 25.0, False ),
( 17, 11, 890.0, 42.0, False ),
( 11, 0, 890.0, 40.0, False ),
( 0, 13, 890.0, 5.0, False ),
( 13, 10, 890.0, 10.0, False ),
( 10, 4, 890.0, 25.0, False ),
( 17, 16, 395.5, 10.5, False ),
( 16, 14, 315.5, 26.0, True ),
( 14, 2, 315.5, 98.0, False ),
( 2, 12, 315.5, 6.0, False )
]
scip = Model()
# create flow variables
flow = {}
for arc in arcs:
flow[arc] = scip.addVar("flow_%s_%s"%(nodes[arc[0]][0],nodes[arc[1]][0]), # names of nodes in arc
lb = 0.0 if arc[4] else None) # no lower bound if not active
# pressure difference variables
pressurediff = {}
for arc in arcs:
pressurediff[arc] = scip.addVar("pressurediff_%s_%s"%(nodes[arc[0]][0],nodes[arc[1]][0]), # names of nodes in arc
lb = None)
# supply variables
supply = {}
for node in nodes:
supply[node] = scip.addVar("supply_%s"%(node[0]), lb = node[1], ub = node[2], obj = node[5])
# square pressure variables
pressure = {}
for node in nodes:
pressure[node] = scip.addVar("pressure_%s"%(node[0]), lb = node[3]**2, ub = node[4]**2)
# node balance constrains, for each node i: outflows - inflows = supply
for nid, node in enumerate(nodes):
# find arcs that go or end at this node
flowbalance = 0
for arc in arcs:
if arc[0] == nid: # arc is outgoing
flowbalance += flow[arc]
elif arc[1] == nid: # arc is incoming
flowbalance -= flow[arc]
else:
continue
scip.addCons(flowbalance == supply[node], name="flowbalance%s"%node[0])
# pressure difference constraints: pressurediff[node1 to node2] = pressure[node1] - pressure[node2]
for arc in arcs:
scip.addCons(pressurediff[arc] == pressure[nodes[arc[0]]] - pressure[nodes[arc[1]]], "pressurediffcons_%s_%s"%(nodes[arc[0]][0],nodes[arc[1]][0]))
# pressure loss constraints:
# active arc: flow[arc]^2 + coef * pressurediff[arc] <= 0.0
# regular pipes: flow[arc] * abs(flow[arc]) - coef * pressurediff[arc] == 0.0
# coef = 96.074830e-15*diameter(i)^5/(lambda*compressibility*temperatur*length(i)*density)
# lambda = (2*log10(3.7*diameter(i)/rugosity))^(-2)
from math import log10
for arc in arcs:
coef = 96.074830e-15 * arc[2]**5 * (2.0*log10(3.7*arc[2]/RUGOSITY))**2 / COMPRESSIBILITY / GASTEMP / arc[3] / DENSITY
if arc[4]: # active
scip.addCons(flow[arc]**2 + coef * pressurediff[arc] <= 0.0, "pressureloss_%s_%s"%(nodes[arc[0]][0],nodes[arc[1]][0]))
else:
scip.addCons(flow[arc]*abs(flow[arc]) - coef * pressurediff[arc] == 0.0, "pressureloss_%s_%s"%(nodes[arc[0]][0],nodes[arc[1]][0]))
scip.setRealParam('limits/time', 5)
scip.optimize()
if scip.getStatus() == 'timelimit':
pytest.skip()
assert abs(scip.getPrimalbound() - 89.08584) < 1.0e-9