simplex

LP: postive reduced costs corresponding to positive variables?

由 谁说我不能喝 提交于 2021-02-08 06:16:38
问题 I have the next LP problem Maximize 1000 x1 + 500 x2 - 500 x5 - 250 x6 Subject To c1: x1 + x2 - x3 - x4 = 0 c2: - x3 + x5 = 0 c3: - x4 + x6 = 0 With these Bounds 0 <= x1 <= 10 0 <= x2 <= 15 0 <= x5 <= 15 0 <= x6 <= 5 By solving this problem with Cplex dual algorithm I get an optimal solution of 6250. But checking the reduced costs of the variables I get the next results Variable value reduced cost 1 10.0 500.0 1 0.0 -0.0 2 5.0 -0.0 3 5.0 -0.0 4 5.0 -0.0 5 5.0 250.0 Is it possible to have a

LP: postive reduced costs corresponding to positive variables?

由 心不动则不痛 提交于 2021-02-08 06:16:26
问题 I have the next LP problem Maximize 1000 x1 + 500 x2 - 500 x5 - 250 x6 Subject To c1: x1 + x2 - x3 - x4 = 0 c2: - x3 + x5 = 0 c3: - x4 + x6 = 0 With these Bounds 0 <= x1 <= 10 0 <= x2 <= 15 0 <= x5 <= 15 0 <= x6 <= 5 By solving this problem with Cplex dual algorithm I get an optimal solution of 6250. But checking the reduced costs of the variables I get the next results Variable value reduced cost 1 10.0 500.0 1 0.0 -0.0 2 5.0 -0.0 3 5.0 -0.0 4 5.0 -0.0 5 5.0 250.0 Is it possible to have a

zmq: can multiple threads PUSH in a simple PUSH-PULL pattern

由 泄露秘密 提交于 2020-01-22 14:56:09
问题 I have two processes: a producer which pushes messages via ZMQ to a consumer in a simple PULL-PUSH point-to-point pattern. The producer has several internal threads that send() via zmq. However, 0MQ's docs suggest not to share sockets between threads . Must I use a single thread to send? Assuming there is no strict requirement for keeping the sending order between the threads, doesn't the fact that the socket is a one-directional simplex allow multiple threads to use it without introducing

zmq: can multiple threads PUSH in a simple PUSH-PULL pattern

由 感情迁移 提交于 2020-01-22 14:56:04
问题 I have two processes: a producer which pushes messages via ZMQ to a consumer in a simple PULL-PUSH point-to-point pattern. The producer has several internal threads that send() via zmq. However, 0MQ's docs suggest not to share sockets between threads . Must I use a single thread to send? Assuming there is no strict requirement for keeping the sending order between the threads, doesn't the fact that the socket is a one-directional simplex allow multiple threads to use it without introducing

Choosing the initial simplex in the Nelder-Mead optimization algorithm

由 谁都会走 提交于 2019-12-20 12:36:29
问题 What's the best way to initialize a simplex for use in a Nelder-Mead simplex search from a user's 'guess' vertex? 回答1: I'm not sure if there is a best way to choose the initial simplex in the Nelder-Mead method, but the following is what is done in common practice. The construction of the initial simplex S is obtained from generating n+1 vertices x0,..,xn around what you call a user's "guess" vertex xin in a N dimensional space. The most frequent choice is x0=xin and the remaining n vertices

Solid Noise Generation in C++

由 浪子不回头ぞ 提交于 2019-12-18 18:39:44
问题 So I have been using my Google'ing skills to study Perlin and Simplex noise, and have come across a lot of articles that are a bit math heavy for myself. I've also come across a lot of code, but it seems to be either in C# or Java, neither of which I am familiar enough to be able to extrapolate how the noise is actually generated. My goal is to find some code that will generate solid noise, similar to the "Render Clouds" function in GIMP, as shown below: Now it doesn't have to be anything

Alter Simplex Algorithm to Minimize on objective function NOT maximize [closed]

由 泄露秘密 提交于 2019-12-11 19:43:51
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I have created the following Simplex Algorithm that maximises on the objective function. I want the opposite to happen. In this example there are two variables and the algorithm must figure out what to multiply these two variables here (13.0 and 23.0) by in order to get the maximum possible result within the

Simplex solver in Z3

由 牧云@^-^@ 提交于 2019-12-11 03:05:14
问题 I'm aware that there is a simplex solver implemented in z3. Is it possible to use the solver for linear optimization? Where is the interface for the solver located in the z3 source code? 回答1: Yes, Z3 has a solver based on the Simplex method. It is implemented in the files src\smt\theory_arith* . The main files are src\smt\theory_arith.h and src\smt\theory_arith_core.h . This solver has very basic support for optimization in the file src\smt\theory_arith_aux.h . This functionality is not

How to determine simplex time complexity (ie Max flow)

由 梦想与她 提交于 2019-12-04 18:13:26
问题 Simplex algorithm is said to have exponential worst case time complexity. Yet it is still often used in practice. How can you determine the average time complexity for a certain problem (being solved with simplex). For example, what is the average time complexity of the maximum flow problem being solved with simplex algorithm. (Wiki has time complexity for all other algorithms) Thank you for your time. 回答1: The average case complexity is rather difficult to analyze and it depends on the

How to determine simplex time complexity (ie Max flow)

由 南楼画角 提交于 2019-12-03 12:48:43
Simplex algorithm is said to have exponential worst case time complexity. Yet it is still often used in practice. How can you determine the average time complexity for a certain problem (being solved with simplex). For example, what is the average time complexity of the maximum flow problem being solved with simplex algorithm. (Wiki has time complexity for all other algorithms) Thank you for your time. The average case complexity is rather difficult to analyze and it depends on the distribution of your linear program. I believe that it was worked out to be polynomial time under some common
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