Dear all,
some students want to develop stuff for PolyMath. There is already some ideas in the PolyMath issue tracker here: https://github.com/PolyMathOrg/PolyMath/issues If you are need something you can add more here. Thank you. -- Serge Stinckwich UCBN & UMI UMMISCO 209 (IRD/UPMC) Every DSL ends up being Smalltalk http://www.doesnotunderstand.org/ -- You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
Hi serge
here is a list I created around matrix. I do not know if it helps. Here is a list Johann DICHTL gave me and I think that he would be good to have him as client What I'm missing in polymath is mostly related to the DhbMatrix and DhbVector classes: - support for working in homogeneous coordinates (2d and 3d) - - setting the translation without two "at: ... at: ... put: ..." messages - - support to convert between 2d vectors and point objects - - setting the rotation sub-matrix via angle (and accessing the angle of a rotation matrix) - - accessor methods for the rotation sub matrix - - for 3d rotation matrix: - - - get/set euler angles - - - support for quaternions - matrix constructors: - - zero(s): creates a matrix with all values set to zero - - identity: creates an identity matrix - matrix solver: solving the linear equation system - support for 32bit floats: it's simply faster, and the precision of a double is usually not needed for my work. I only found the "DhbLargestEigenValueFinder" class (undocumented), and it does not seem to compute all eigenvalues, as I would need. The DhbMatrix class does not provide any methods to compute eigenvalues/-vectors. On a side note, I'm using Pharo 4, things might look a bit different with Pharo 5. There are two more things that I forgot last time about "missing in PolyMath": - SVD (Singular Value Decomposition) - Eigenvalues / -vectors Le 5/11/16 à 17:52, Serge Stinckwich a écrit : > Dear all, > > some students want to develop stuff for PolyMath. There is already > some ideas in the PolyMath issue tracker here: > https://github.com/PolyMathOrg/PolyMath/issues > If you are need something you can add more here. > > Thank you. > -- You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
About eigenvalues, I discussed with one student in the #polymath
channel on Slack. He was interested to add stuff to be able to compute eigenvalues/vectors. Apparently there is an existing DhbLargestEigenValueFinder that does not compute all the values and the class is not documented. Anyone know more about this class ? If I remember correctly, eigenvalues/vectors are also implemented in the Lapack package ? On Sat, Nov 5, 2016 at 6:04 PM, stepharo <[hidden email]> wrote: > Hi serge > > here is a list I created around matrix. I do not know if it helps. > > > > Here is a list Johann DICHTL gave me and I think that he would be good to > have him as client > What I'm missing in polymath is mostly related to the DhbMatrix and > DhbVector classes: > > - support for working in homogeneous coordinates (2d and 3d) > - - setting the translation without two "at: ... at: ... put: ..." > messages > - - support to convert between 2d vectors and point objects > - - setting the rotation sub-matrix via angle (and accessing the angle > of a rotation matrix) > - - accessor methods for the rotation sub matrix > - - for 3d rotation matrix: > - - - get/set euler angles > - - - support for quaternions > - matrix constructors: > - - zero(s): creates a matrix with all values set to zero > - - identity: creates an identity matrix > - matrix solver: solving the linear equation system > - support for 32bit floats: it's simply faster, and the precision of a > double is usually not needed for my work. > > > I only found the "DhbLargestEigenValueFinder" class (undocumented), and > it does not seem to compute all eigenvalues, as I would need. The DhbMatrix > class does not provide any methods to compute eigenvalues/-vectors. On a > side note, I'm using Pharo 4, things might look a bit different with Pharo > 5. > > There are two more things that I forgot last time about "missing in > PolyMath": > - SVD (Singular Value Decomposition) > - Eigenvalues / -vectors > > > Le 5/11/16 à 17:52, Serge Stinckwich a écrit : >> >> Dear all, >> >> some students want to develop stuff for PolyMath. There is already >> some ideas in the PolyMath issue tracker here: >> https://github.com/PolyMathOrg/PolyMath/issues >> If you are need something you can add more here. >> >> Thank you. >> > > -- > You received this message because you are subscribed to the Google Groups > "SciSmalltalk" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [hidden email]. > For more options, visit https://groups.google.com/d/optout. -- Serge Stinckwich UCBN & UMI UMMISCO 209 (IRD/UPMC) Every DSL ends up being Smalltalk http://www.doesnotunderstand.org/ -- You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
The class DhbJacobiTransformation computes all eigenvalues and vectors for a symmetrical matrix. To my knowledge, there is no general algorithm for a non-symmetrical matrix other that attempting to find the largest eigenvalue. Let M be the matrix, I be the identity matrix and m be the largest eignevalue, one can recurse on the matrix M-mI to find the next largest eignevalue and so on. The eigenvectors corresponding to each eignevalue can be solved with a linear system obtained from the definition of the eignevalue: M v = m v. Your student could try to build such an algorithm. Cheers, Didier On Fri, Dec 2, 2016 at 2:21 PM Serge Stinckwich <[hidden email]> wrote: About eigenvalues, I discussed with one student in the #polymath You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
In reply to this post by SergeStinckwich
serge
could you check the mail I sent to you a while ago about matrixes and other enhancements? Stef > Dear all, > > some students want to develop stuff for PolyMath. There is already > some ideas in the PolyMath issue tracker here: > https://github.com/PolyMathOrg/PolyMath/issues > If you are need something you can add more here. > > Thank you. > -- Using Opera's mail client: http://www.opera.com/mail/ -- You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
Yes I already have a look to your email but this is sometimes
difficult to know if the functionalities asked, are already implemented or not. About eigenvalues/eigenvectors, if I understand correctly Didier, most of the functionalities are already here. What is maybe missing this is documentation of the DhbJacobiTransformation/DhbLargestEigenValueFinder classes and actual examples how to use it. I open an issue about this here : https://github.com/PolyMathOrg/PolyMath/issues/15 Didier can you provide more examples that we could commit on the repository ? You can put them in the issue. In fact there is one example that is available in class comment of DhbJacobiTransformation: | m jacobi eigenvalues eigenvectors | m := DhbSymmetricMatrix rows: #((84 -79 58 55) (-79 84 -55 -58) (58 -55 84 79) (55 -58 79 84)). jacobi := DhbJacobiTransformation matrix: m. eigenvalues := jacobi evaluate. eigenvectors := jacobi transform columnsCollect: [ :each | each]. Regards, On Sat, Dec 3, 2016 at 12:24 PM, stepharo <[hidden email]> wrote: > serge > > could you check the mail I sent to you a while ago about matrixes and other > enhancements? > > Stef > >> Dear all, >> >> some students want to develop stuff for PolyMath. There is already >> some ideas in the PolyMath issue tracker here: >> https://github.com/PolyMathOrg/PolyMath/issues >> If you are need something you can add more here. >> >> Thank you. >> > > > -- > Using Opera's mail client: http://www.opera.com/mail/ -- Serge Stinckwich UCBN & UMI UMMISCO 209 (IRD/UPMC) Every DSL ends up being Smalltalk http://www.doesnotunderstand.org/ -- You received this message because you are subscribed to the Google Groups "SciSmalltalk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [hidden email]. For more options, visit https://groups.google.com/d/optout. |
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