Missing data types for Python

[nicsalv]

Hi everyone, I am trying to use the Python bindings of the GPS Toolkit, in particular the PRSolution class. I followed the swig/examples/example4.py in order to read my RINEX files and to compute the position solutions, and everything was fine. Now, I would like to use the PRSolution.PreparePRSolution method so as to obtain the corrected pseudoranges without computing the position solution. However, I can not call this method because the argument types do not match.

In particular, the call is

raimSolver.PreparePRSolution(time, satVector, syss, rangeVector, ephStore, SVP)

and the error that raises is

TypeError: in method 'PRSolution_PreparePRSolution', argument 4 of type 'std::vector< gpstk::SatID::SatelliteSystem,std::allocator< gpstk::SatID::SatelliteSystem > > &' 

I know from the PYTHON.md file that the enumerations have been removed in the Python bindings, so I do not know how I could define the syss variable. After several trials, I tried

syss = [gpstk.SatID.systemGPS, gpstk.SatID.systemGlonass]

without success.

Then, I tried to use the PRSolution2 class; it has a similar method called PrepareAutonomousSolution that does not need the previous argument. I made the call

gpstk.PRSolution2_PrepareAutonomousSolution(time, satVector, rangeVector, ephStore, SVP)

and unfortunately another error raised

TypeError: Wrong number or type of arguments for overloaded function 'PRSolution2_PrepareAutonomousSolution'.
  Possible C/C++ prototypes are:
    gpstk::PRSolution2::PrepareAutonomousSolution(gpstk::CommonTime const &,std::vector< gpstk::SatID,std::allocator< gpstk::SatID > > &,std::vector< double,std::allocator< double > > const &,gpstk::XvtStore< gpstk::SatID > const &,Matrix< double > &,std::ostream *)
    gpstk::PRSolution2::PrepareAutonomousSolution(gpstk::CommonTime const &,std::vector< gpstk::SatID,std::allocator< gpstk::SatID > > &,std::vector< double,std::allocator< double > > const &,gpstk::XvtStore< gpstk::SatID > const &,Matrix< double > &)

I definitely think that the problem concerns the variable SVP, since the other ones have been previously used for the computation of the position solution. Always from the PYTHON.md file, I know that the Matrix class is not wrapped so I do not know how to pass this argument. I tried with a list, a numpy array and even with the gpstk.seqToVector without success. Furthermore, I do not know how the GPS Toolkit could return the filled SVP matrix since it is passed as argument. I saw that functions modifying parameters passed by reference are opportunely modified but this method still requires the matrix as an argument.

Looking at the source code of PRSolution, I came across the RAIMComputeSimple method, that is used in order to avoid using "data types not exposed in swig". Therefore, I wonder if there actually exist a way to make things work.

What am I doing wrong? Is there a way to call those functions in Python? These are the only pieces of code where I found something that corrects the measured pseudoranges. If there are other way to do this, please let me know.

Thank you for your time, and for this great library.

[UT-dave]

There were a number of SWIG issues, many of which have been resolved recently. We plan to push a major update to the GPSTk later this summer, which solves numerous of these problems.