【发布时间】:2020-12-30 23:56:23
【问题描述】:
以下集合和参数是在 AMPL 环境中编写的。如何将它们转换为 CPLEX?
set B; #set of all blocks
set T; #set of time periods
set BI{B}; #set of blocks that overlie a block
set BY{T}; #set of blocks that can be excavated in time period t
param C_min; #minimum processing capacity of a mill
param g{B}; #average grade for block
param x_cord{B}; #x-coordinate of a block
param r{B} symbolic;
param early{B} default 1;
var alpha{B,T} binary; # indicator for which sequencing constraint 6 won't be met
此外,以下约束是在 AMPL 环境中编写的。如何将它们转换为 CPLEX?(尤其是条件部分)
subject to processing{t in T}: C_min <= sum{b in B: early[b] <= t}(if g[b] > total[b]
then total[b] else 0)*y[b,t];
subject to sequencing{b in B, vb in B, t in T: early [b] <= t and (x_cord[b]=x_cord[vb])
and
(y_cord[b]=y_cord[vb]) and (z_cord[b] = z_cord[vb]-1)}: y[b,t] <= sum{u in
early[vb]..t}y[vb,u];
subject to logic:sum{b in B, t in T} alpha[b,t] <= card(T)*card(B)-1;
在复杂的:
forall (t in T) {
processing:
C_min<=sum(b in B: early[b] <= t)
[(g[b] > total[b])=> (total[b])(g[b] <= total[b])=>(0)]*y[b][t];
}
forall (b in B)
forall (vb in B)
forall (t in T:early [b] <= t &&
(x_cord[b]==x_cord[vb]) && (y_cord[b]==y_cord[vb]) && (z_cord[b] == z_cord[vb]-1)){
sequencing:
y[b][t]<=sum(u in early[vb]..t) y[vb][u];
}
logic:
sum(b in B)sum(t in T) alpha[b][t]<= ??;
【问题讨论】:
-
CPLEX 到底是什么意思?你是说OPL吗?或者您的意思是在编程 API 中编写这些东西?您是否查看过 CPLEX 的示例和教程?例如,请参见此处:ibm.com/support/knowledgecenter/SSSA5P_12.10.0/…。
-
我的意思是 OPL。我以前读过 CPLEX 指南,我知道 CPLEX。我只是在转换上述限制时遇到了麻烦。
-
您必须显示
C_min、alpha和g是什么。它们是决策变量还是参数?还请显示您目前拥有的 OPL 模型。对于您的条件中的if,您是否检查了“隐含”运算符=>? -
请求的参数和变量以及约束已在 CPLEX 环境中提交。