Hello,

Are there callback functions available in the C API to access the incoming nonbasic variable ( entering arc in a basis tree in a call to CPXNETprimopt() ) and the outgoing basic variable ( leaving arc in a basis tree ) during each iteration of the primal network simplex optimizer of CPLEX?

I ask because none of the advanced C API callbacks available https://www.ibm.com/docs/en/icos/22.1.2?topic=bbticclcarm-advanced-routines-in-cplex-callable-library-c-api seem to mention the network simplex optimizer. 

lpex4.c illustrates a normal simplex optimizer callback and accesses a few information in an information callback. The example does not seem to cover being able to query the incoming variable and the outgoing variable into/from the basis.

netex1.c and netex2.c, while they illustrate how to build a network simplex model for CPLEX, do not contain any callback implementation for accessing the inner workings of the network simplex code. Hence this post.

Thanks.