[Ipopt] Defining a Global Variable in IPOPT and Using This Global Variable From IPOPT Matlab Interface

[Senses,Begum]

Good morning!!

Ok I am trying this once again I typed everything this time. Hopefully 
it will work.


Hello everyone,

I am using IPOPT with MATLAB interface. I am trying to send an array 
from IPOPT Matlab interface to the MA57 interface. In order to be able 
to do that first I edited option.cpp file in the 
../CoinIpopt/Ipopt/contrib/MatlabInterface/src directory. In the 
options.cpp file I added the following code under Options::Options(const 
Iterate& x, Ipopt::IpoptApplication& app, const mxArray* ptr)


Options::Options(const Iterate& x, Ipopt::IpoptApplication& app, const 
mxArray* ptr)

{

.
. There are some other ipopt mexhfile code here
.

// I want to use gpops_descriptor in MA57 interface and I want to 
obtain this array of integers from IPOPT Matlab interface.

gpops_descriptor = NULL;
const mxArray* gpops_mxArray = mxGetField(ptr, 0, "gpops_descriptor");

if (gpops_mxArray)

   {
      \\ The MATLAB options.gpops_descriptor exists and has been passed 
into the IPOPT mex function interface
      \\ It is a double vector of length gpops_len.

      int gpops_len = mxGetNumberOfElements(gpops_mxArray);

      if (gpops_len>0)

          {

             // Allocate an extern int array for IPOPT's copy of 
options.gpops_descriptor.
             // Note that this array is not explicitly freed (yet), 
since we are trying to minimize the changes
             // to the IPOPT mexFunction. Matlab will free it for us 
when this mexFunction returns to Matlab.

             gpops_descriptor = (int*) mxMalloc(gpops_len * 
sizeof(int));

             // Copy the Matlab options.gpops_descriptor into the IPOPT 
options object
             double *gpops_double = mxGetPr(gpops_mxArray);

             for (int 0; i< gpops_len; i++)

             {

              gpops_descriptor[i] = (int) gpops_double[i];

              // Print out gpops_descriptor for test purposes
              printf("gpops[%d]: %d\n, i, gpops_descriptor[i]);


             }


           }
    }

    if (gpops_descriptor == NULL)

     {

      printf("options.gpops_descriptor is not present\n");

     }

}

I did not change anything in options.hpp file. Maybe I need to change 
something in that file too???

Following this step, I wanted to declare the global variable in a .hpp 
and .cpp file that can be seen by both Ipopt and ipopt matlab interface. 
When I check ipopt.cpp file in the 
../CoinIpopt/Ipopt/contrib/MatlabInterface/src directory I realized that 
it includes "IpJournalist.hpp". This file is also included in the main 
IPOPT files. Therefore, I edited IpJournalist.hpp and IpJournalist.cpp 
files which are in the ../CoinIpopt/Ipopt/src/Common directory. I added 
a line of code for global variable decleration in IpJournalist.hpp file 
right before namespace Ipopt.


extern int*gpops_descriptor

namespace Ipopt

   {


    .

    .

    .

   }

Next, I added a line of code in IpJournalist.cpp file again right 
before namespace Ipopt.

int *gpops_descriptor;

namespace Ipopt

{

   .
   .
   .


}

After all these configure, make and make install commands worked in the 
CoinIpopt main directory but when I try to compile the mexFile by using 
the make command in the CoinIpopt/Ipopt/contrib/MatlabInterface/src 
directory it gave me the following error.

Undefined symbolds for architecture x86_64:
   "_gpops_descriptor", referenced from:
     Options::Options(const Iterate& x, Ipopt::IpoptApplication&, 
mxArray_tag const*) in options.o
ld: symbol(s) not found for architecture x86_64:
clang: error: linker command failed with exit code 1(use -v to see 
invocation)

   mex: link of "ipopt.mexmaci64" failed.

make: ***[ipopt.mexmaci64] Error 1

Does anyone have any suggestions to fix this error? In case somebody 
wants to see what happens in my terminal after I run the make command 
you can find it in the attachments.

Thank you
Begum