cplex

TSP implementation in docplex python

由 久未见 提交于 2020-04-18 02:34:12
问题 Is there any python implementation available of TSP using the IBM cplex tool, with Dantzig-Fulkerson-Johnson formulation. If there is any can I get the link for it? 回答1: The exact same question was asked here. Here is my (slightly modified) answer from there: The distribution does not have an example implementation in Python, but there is one in OPL: opl/examples/opl/models/TravelingSalesmanProblem/tsp.mod in your installation. This could serve as a good starting point when implementing

Cplex Error: Adding trivial infeasible linear constraint

由 杀马特。学长 韩版系。学妹 提交于 2020-04-17 19:05:31
问题 I want to solve an integer programming model with cplex python. I have this model: a and h are matrixes with 0s and 1s. p is a set of numbers. here is a part of my cplex code for this model: p=[i for i in range (len(h))] x=mdl.binary_var_dict(p,name='x') #objective mdl.minimize(0) #constraints #1 mdl.add_constraints(mdl.sum(h[i][k]*x[i] for i in p)==4 for k in T) #2 mdl.add_constraints(mdl.sum(a[i][k]*x[i] for i in p)==4 for k in T) mdl.print_information() Solution = mdl.solve(log_output

『实践』Yalmip+Ipopt+Cplex使用手册

由 て烟熏妆下的殇ゞ 提交于 2020-03-27 02:42:03
Yalmip+Ipopt+Cplex使用手册 1.软件版本 Cplex 12.6.2，Matlab R2014a， Ipopt 3.12.9， Yalmip 2.Cplex添加方法 官方下载地址: http://www-01.ibm.com/software/websphere/products/optimization/cplex-studio-community-edition/ 破解版下载地址： http://www.0daydown.com/02/140054.html 其中community-edition可以免费试用，但最多只能计算1000个变量或1000个约束条件的优化问题。 点击 安装，安装步骤默认操作即可。 点击Matlab中的 ，点击 ，找到 路径并将其添加，最后点击 即可。 然后在Matlab命令行窗口输入 ，出现帮助文档，代表添加成功。 3.Ipopt添加方法 需要的组件：VC_redist.x64和ww_ifort_redist_intel64_2017.0.109.msi (组件下载地址链接：链接1：https://pan.baidu.com/s/1f-J5PBu1WsJO8uxyZzbcTQ 密码：crxv ) 链接2： 在打开的界面中选择图1-1即可。 图1 Ipopt下载地址： https://www.inverseproblem.co.nz

Getting the number of branch and bound nodes explored CPLEX

由 大憨熊 提交于 2020-03-25 15:18:52
问题 So I'm curious how to get the number of branch and bounds nodes explored. I was interested in this to gage how hard solving my IP is - if there is a better metric for this please feel free to share. I tried to use my_prob.solution.MIP.get_incumbent_node() which from the CPLEX documentation gives the node number which the solution was found - which I would think would be a good gage of number of nodes explored. But it always returns 0, I attached an example where the input (guess) solution and

Getting the number of branch and bound nodes explored CPLEX

由 匆匆过客 提交于 2020-03-25 15:17:33
问题 So I'm curious how to get the number of branch and bounds nodes explored. I was interested in this to gage how hard solving my IP is - if there is a better metric for this please feel free to share. I tried to use my_prob.solution.MIP.get_incumbent_node() which from the CPLEX documentation gives the node number which the solution was found - which I would think would be a good gage of number of nodes explored. But it always returns 0, I attached an example where the input (guess) solution and

Cplex Studio Does not support dvar float

由 自作多情 提交于 2020-02-06 07:57:11
问题 I am trying to use a variable to record the local timings of an object. As I could not find any way to define a variable in the Cplex, I tried using "dvar float" to define the variable. But, Cplex says that the algorithm does not support "dvar float". I tried simply define the variable as float Z[i][r][k] and also tried using CP, both did not solve the issue. May I have some help or guidance please? i = 0..3; r = 0..1; j = 0..3; s = 0..1; k = 1; float U[1..3][1..1] = ...; float T[i][r][j][s]

How to initiate the interval variable bounds in docplex (python)?

由 ￡可爱￡侵袭症＋ 提交于 2020-02-06 07:43:10
问题 I have the following OPL code and need to implement it in docplex (python), i'm newbie in that field... using CP; dvar interval I1 in 0..20; dvar interval I2 in 0..20; dvar interval I3 in 0..20; dvar int over1; dvar int start1; dvar int end1; dvar interval artificialInterval; maximize over1; subject to { over1==overlapLength(I1,I2); start1==maxl(startOf(I1),startOf(I2)); end1==minl(endOf(I1),endOf(I2)); startOf(artificialInterval)==start1; endOf(artificialInterval)==end1; over1==overlapLength

Access violation writing location 0xfdfdfdfd

由 ￡可爱￡侵袭症＋ 提交于 2020-01-30 13:29:46
问题 I have been having this problem for a few days now and I can find nothing on how to fix it. I have never had an error like this one : Unhandled exception at 0x00511e0e (msvcr100d.dll) in myproject.exe: 0xC0000005: Access violation writing location 0xfdfdfdfd. I really am at a loss of what to do. Any help? 回答1: 0xfdfdfdfd is a magic value in the MSVC debug heap implementation (details here) that's put as a canary directly before and behind an allocated region of storage. Somehow you're using

Access violation writing location 0xfdfdfdfd

由 旧时模样 提交于 2020-01-30 13:29:12
问题 I have been having this problem for a few days now and I can find nothing on how to fix it. I have never had an error like this one : Unhandled exception at 0x00511e0e (msvcr100d.dll) in myproject.exe: 0xC0000005: Access violation writing location 0xfdfdfdfd. I really am at a loss of what to do. Any help? 回答1: 0xfdfdfdfd is a magic value in the MSVC debug heap implementation (details here) that's put as a canary directly before and behind an allocated region of storage. Somehow you're using

Analysing solution (.sol) file in pyomo

由 眉间皱痕 提交于 2020-01-21 10:35:28
问题 I have a model in pyomo in say machine 1 and I have the CPLEX solver in machine 2. I convert the pyomo model ( ConcreteModel ) into a problem.lp file with function model.write("problem.lp") in machine 1. Then I transfer this file to machine 2 and get the solution.sol file from the CPLEX solver. But names of the variables in the solution file is different from the names of the variables of the model. This is causing a problem in analysis of the solution. Is there any way to convert or map the
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