User:Antonio Pino: Difference between revisions

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<math>\dot{x}=A\cdot x</math>.
<math>\dot{x}=A\cdot x</math>.


Needless to say, they tried to push Matlab to all the students, and I got by with Gnu-Octave, for which I am thankful to the whole developer team.
Needless to say, they tried to push Matlab to all the students, and I got by with Gnu Octave, for which I am thankful to the whole developer team.


== C: Contact ==
== C: Contact ==
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== P: Prerequisites ==
== P: Prerequisites ==
I have access as root to two laptops running Debian Gnu-Linux and Ubuntu, with a reasonably working internet connection during the whole day.
I have access as root to two laptops running Debian Gnu/Linux and Ubuntu, with a reasonably working internet connection during the whole day.


== S: Self-assessment ==
== S: Self-assessment ==
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The project I intend to do is [http://wiki.octave.org/Summer_of_Code_Project_Ideas#Improve_logm.2C_sqrtm.2C_funm Improve logm, sqrtm, funm]; its aim is to improve the existing implementations of [https://en.wikipedia.org/wiki/Matrix_function Matrix Functions] in octave based on the algorithms developed by [http://www.maths.manchester.ac.uk/~higham/NAMF/#People a team lead by Prof. Higham] at the University of Manchester. At this point in time, in Octave there are the following: [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/scripts/linear-algebra/expm.m expm] makes use of Padé approximant, [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/scripts/linear-algebra/logm.m logm] uses a Schur-Parlett algorithm, and [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/libinterp/corefcn/sqrtm.cc sqrtm] using a variant of the algorithm in A New sqrtm for MATLAB[1]. On the other hand, in Octave-Forge there are [http://sourceforge.net/p/octave/linear-algebra/ci/default/tree/inst/funm.m funm] and [http://sourceforge.net/p/octave/linear-algebra/ci/default/tree/inst/thfm.m trigonometric and hyperbolic matrix functions].
The project I intend to do is [http://wiki.octave.org/Summer_of_Code_Project_Ideas#Improve_logm.2C_sqrtm.2C_funm Improve logm, sqrtm, funm]; its aim is to improve the existing implementations of [https://en.wikipedia.org/wiki/Matrix_function Matrix Functions] in octave based on the algorithms developed by [http://www.maths.manchester.ac.uk/~higham/NAMF/#People a team lead by Prof. Higham] at the University of Manchester. At this point in time, in Octave there are the following: [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/scripts/linear-algebra/expm.m expm] makes use of Padé approximant, [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/scripts/linear-algebra/logm.m logm] uses a Schur-Parlett algorithm, and [http://hg.savannah.gnu.org/hgweb/octave/file/9a8be23d2c05/libinterp/corefcn/sqrtm.cc sqrtm] using a variant of the algorithm in A New sqrtm for MATLAB[1]. On the other hand, in Octave-Forge there are [http://sourceforge.net/p/octave/linear-algebra/ci/default/tree/inst/funm.m funm] and [http://sourceforge.net/p/octave/linear-algebra/ci/default/tree/inst/thfm.m trigonometric and hyperbolic matrix functions].


I believe this is of interest to GNU-Octave first, due to the goal of overall MATLAB compatibility and second, because more and more systems are being described by a matrix equation lately.
I believe this is of interest to Gnu Octave first, due to the goal of overall MATLAB compatibility and second, because more and more systems are being described by a matrix equation lately.


Upon completion Octave should have a working funm based on the algorithms by Higham et al., that calls to specific matrix functions if these have an instance of their own: expm, logm, sqrtm etc. Thus, it appears to me that the natural task division for this project is to first improve and test funm (this shoud be ready by the mid-term), and then get to the rest, picking logm first.
Upon completion Gnu Octave should have a working funm based on the Schur-Parlett algorithms by Higham et al., that calls to specific matrix functions if these have an instance of their own: expm, logm, sqrtm etc. Thus, it appears to me that the natural task division for this project is to first improve and test funm (this shoud be ready by the mid-term), and then get to the rest, picking logm first.


'''TENTATIVE TIMELINE'''
'''TENTATIVE TIMELINE'''
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'''weeks 1-2'''
'''weeks 1-2'''


The start should be soft for I am having the finals in this period.
The start should be soft for I am having the finals in this period. At this point the list of algorithms to be used must be completely defined.


'''weeks 3-7'''
'''weeks 3-7'''
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