Originally posted by: brown_rice

Hi,

I'm trying to avoid CPLEX to use barrier method to solve my LP due to the low quality solution that it produces. I set cplex.lpmethod !=4 but it does not work. CPLEX still solves my model via barrier method. 

To which value did you set lpmethod? Barrier method may be used if the parameter is set to either 0 or 4. Can you show the CPLEX log output and the code that sets the parameter?

Originally posted by: brown_rice

Daniel,

I just used cplex.lpmethod !=4  to prevent CPLEX from using Barrier method, but it looks like since the method is used while the parameter is 0, what I did was not enough. The log output was just saying that my model is solved via Barrier method.

However, I changed my algorithm and no longer need this. 

Thanks for your attention. 

For clarification: Like I said (and like is explained in the documentation), setting the lpmethod to 0 means "automatic" which  allows CPLEX to do whatever it pleases. That usually means to throw barrier into the mix. You have to set lpmethod to a value different from 0 or 4. There is no way to specify "run concurrentopt with everything but barrier".