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*Evaluate harmonics and cross-correlations of unevenly sampled and nonstationary time series, as in http://www.jstatsoft.org/v11/i02 (which has C code with interface to R). (This is now partly implemented in the [http://octave.sourceforge.net/lssa/index.html lssa] package.) | *Evaluate harmonics and cross-correlations of unevenly sampled and nonstationary time series, as in http://www.jstatsoft.org/v11/i02 (which has C code with interface to R). (This is now partly implemented in the [http://octave.sourceforge.net/lssa/index.html lssa] package.) | ||
== General purpose Finite Element library == | <!-- == General purpose Finite Element library == | ||
Octave-Forge already has a set of packages for discretizing Partial Differential operators by Finite Elements and/or Finite Volumes, | Octave-Forge already has a set of packages for discretizing Partial Differential operators by Finite Elements and/or Finite Volumes, | ||
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* create new functions specifically suited for Octave | * create new functions specifically suited for Octave | ||
* improve the efficiency of the code | * improve the efficiency of the code | ||
The main goal for the fem-fenics package is ultimately to be merged with the FEnics project itself, so that it can remain in-sync with the main library development. | The main goal for the fem-fenics package is ultimately to be merged with the FEnics project itself, so that it can remain in-sync with the main library development. --> | ||
== Implement solver for initial-boundary value problems for parabolic-elliptic PDEs in 1D == | == Implement solver for initial-boundary value problems for parabolic-elliptic PDEs in 1D == | ||
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Details on the methods to be implemented can be found in [http://dx.doi.org/10.1145/502800.502801 this paper] on bvp4c and [http://www.jnaiam.net/new/uploads/files/014dde86eef73328e7ab674d1a32aa9c.pdf this paper] on bvp5c. Further details are available in [http://books.google.it/books/about/Nonlinear_two_point_boundary_value_probl.html?id=s_pQAAAAMAAJ&redir_esc=y this book]. | Details on the methods to be implemented can be found in [http://dx.doi.org/10.1145/502800.502801 this paper] on bvp4c and [http://www.jnaiam.net/new/uploads/files/014dde86eef73328e7ab674d1a32aa9c.pdf this paper] on bvp5c. Further details are available in [http://books.google.it/books/about/Nonlinear_two_point_boundary_value_probl.html?id=s_pQAAAAMAAJ&redir_esc=y this book]. | ||
== Geometric integrators for Hamiltonian Systems == | <!-- == Geometric integrators for Hamiltonian Systems == | ||
[http://openlibrary.org/books/OL9056139M/Geometric_Numerical_Integration Geometric (AKA Symplectic) integrators] are useful for | [http://openlibrary.org/books/OL9056139M/Geometric_Numerical_Integration Geometric (AKA Symplectic) integrators] are useful for | ||
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* SHAKE, see [http://en.wikipedia.org/wiki/Constraint_algorithm here] or [http://dx.doi.org/10.1016/0021-9991(77)90098-5 here] | * SHAKE, see [http://en.wikipedia.org/wiki/Constraint_algorithm here] or [http://dx.doi.org/10.1016/0021-9991(77)90098-5 here] | ||
* RATTLE, see [http://dx.doi.org/10.1016/0021-9991(83)90014-1 here] or [http://dx.doi.org/10.1002/jcc.540161003 here] | * RATTLE, see [http://dx.doi.org/10.1016/0021-9991(83)90014-1 here] or [http://dx.doi.org/10.1002/jcc.540161003 here] | ||
--> | |||
== Matlab-compatible ODE solvers in core-Octave == | == Matlab-compatible ODE solvers in core-Octave == | ||
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* <strike> Adapt the interface of "ode45" in odepkg to be completely Matlab compatible, fix its code and documentation style and move it to Octave-core. </strike> | * <strike> Adapt the interface of "ode45" in odepkg to be completely Matlab compatible, fix its code and documentation style and move it to Octave-core. </strike> | ||
* <strike> Build Matlab compatible versions of "ode15s" and "ode15i". jwe has prototype implementations [https://savannah.gnu.org/patch/?8102 here] of these built as wrappers to "dassl" and "daspk". An initial approach could be to just improve these wrappers, but eventually it would be better to have wrappers for "IDA" from the sundials library. </strike> | * <strike> Build Matlab compatible versions of "ode15s" and "ode15i". jwe has prototype implementations [https://savannah.gnu.org/patch/?8102 here] of these built as wrappers to "dassl" and "daspk". An initial approach could be to just improve these wrappers, but eventually it would be better to have wrappers for "IDA" from the sundials library. </strike> | ||
* Improve handling of sparse Jacobians in IDE/DAE solvers | |||
** Currently, in the IDA wrapper function __ode15__ an over conservative guess for the amount of memory to be allocated when assembling a sparse jacobian is used, essentially allocating enough space for a full jacobian then freeing the excess memory, an initial patch for fixing this has been posted on the tracker, for integrating this into Octave it must be generalized to support prior versions of SUNDIALS | |||
** Currently Jacobians passed by the user in Octave's sparse matrix format are copied into SUNDIALS own sparse matrix format. Newer versions of SUNDIALS (5.x or higher) support letting the user take care of the linear algebra data structures and methods thus removing the need for the copy. Taking advantage of this feature would improve the solver performance both in terms of memory footprint and speed. | |||
** References | |||
***[https://savannah.gnu.org/bugs/?func=detailitem&item_id=55905 tracker post about memory allocation] | |||
***[https://computing.llnl.gov/projects/sundials/release-history SUNDIALS release history] | |||
* Implement Matlab compatible versions of "deval". | * Implement Matlab compatible versions of "deval". | ||
* Complete transition of ode23s into core Octave | |||
** [https://savannah.gnu.org/bugs/?57309 Bug tracker entry discussing ode23s] | |||
== High Precision Arithmetic Computation == | == High Precision Arithmetic Computation == | ||
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=GUI/IDE= | =GUI/IDE= | ||
*Søren Hauberg has suggested that we need C++ code that can: | *Søren Hauberg has suggested that we need C++ code that can: | ||
**Determine if a line of code could be fully parsed, i.e. it would return true for "plot (x, y);", but false for "while (true)". | **Determine if a line of code could be fully parsed, i.e. it would return true for "plot (x, y);", but false for "while (true)". | ||
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**Query defined variables, i.e. get a list of currently defined variables. Bonus points if it could tell you if anything had changed since the last time you checked the variables (could also be done with signals). | **Query defined variables, i.e. get a list of currently defined variables. Bonus points if it could tell you if anything had changed since the last time you checked the variables (could also be done with signals). | ||
* Create a better (G)UI for the {{manual|profile|profiler}}. This may be done with Qt, but not necessarily. | * Create a better (G)UI for the {{manual|profile|profiler}}. This may be done with Qt, but not necessarily. | ||
== GUI Variable Editor and Property Inspector == | |||
Octave has a preliminary implementation of a Variable Editor: a spreadsheet-like tool for quickly editing and visualizing variables. The initial phase of the project will be learning how the implementation was done. | |||
With the knowledge gained, the second part of the project will be to implement a Property Inspector. This is a spreadsheet like interface to the many, many graphics properties that exist and are different on a per-object basis. The goal would be not only the concise-display of the existing properties, but a reasonable user interface to change them. As examples, Boolean properties should be able to be toggled with a double-click; Radio properties should have a drop-down list of only the supported options; Other properties that can be modified should have the constraints built-in (for example, Linewidth must be a scalar, while Position must be a 1x4 vector). It would also be important to have easy access to the documentation of a property. | |||
For reference, Matlab has a similar Property Inspector (https://www.mathworks.com/help/matlab/ref/inspect.html). | |||
== Sisotool. Create a graphical design tool for tuning closed loop control system ([[Control package]])== | == Sisotool. Create a graphical design tool for tuning closed loop control system ([[Control package]])== | ||
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The paper by [http://arxiv.org/abs/cs.MS/0604006 Bateman & Adler] is good reading for understanding the sparse matrix implementation. | The paper by [http://arxiv.org/abs/cs.MS/0604006 Bateman & Adler] is good reading for understanding the sparse matrix implementation. | ||
*Improve Matlab compatibility for {{manual|sprandsym}}. | *Improve Matlab compatibility for {{manual|sprandsym}}. | ||
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**minres | **minres | ||
**symmlq | **symmlq | ||
== SPQR Interface == | |||
Octave implements QR factorization for sparse matrices, but it does so with an older "CXSPARSE" library. This has caused fundamental issues, including segfaults as recorded here (bugs {{bug|51950}} and {{bug|57033}}). The goal of this project is to program an interface to the API for the SQPR library (http://faculty.cse.tamu.edu/davis/suitesparse.html). This is the same library that Matlab uses for this purpose. | |||
*Improve QR factorization functions, using idea based on CSPARSE cs_dmsol.m | |||
*Improve QR factorization by replacing CXSPARSE code with SPQR code, and make the linear solve return 2-norm solutions for ill-conditioned matrices based on this new code | |||
=Strings= | =Strings= | ||
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=Performance= | =Performance= | ||
*A profiler for Octave would be a very useful tool. And now we have one! But it really needs a better interface. | * A profiler for Octave would be a very useful tool. And now we have one! But it really needs a better interface. | ||
*Having {{Codeline|parfor}} functioning would speed code development and execution now that multicore architectures are widespread. See [http://octave.1599824.n4.nabble.com/Parfor-td4630575.html here] and [http://stackoverflow.com/questions/24970519/how-to-use-parallel-for-loop-in-octave-or-scilab here]. Existing code from the [[Parallel package | parallel]] and [http://octave.sourceforge.net/mpi/index.html mpi] packages could perhaps be adapted for this. | * Having {{Codeline|parfor}} functioning would speed code development and execution now that multicore architectures are widespread. See [http://octave.1599824.n4.nabble.com/Parfor-td4630575.html here] and [http://stackoverflow.com/questions/24970519/how-to-use-parallel-for-loop-in-octave-or-scilab here]. Existing code from the [[Parallel package | parallel]] and [http://octave.sourceforge.net/mpi/index.html mpi] packages could perhaps be adapted for this. | ||
* Develop a performance benchmark for Octave (interpreter, load/save, plotting, etc., but not simply tests of underlying libraries such as BLAS or LAPACK). This benchmark could be run periodically to make sure that changes during development do not introduce regressions in performance. | |||
=Packaging= | =Packaging= | ||