On 6. Februar 2016 06:08:42 GMT+00:00, Panicz Maciej Godek <godek.mac...@gmail.com> wrote: >Hi > >2016-02-06 1:47 GMT+01:00 Cao Jin <l...@null.net>: > >> It's interesting. I have used Matlab for many years, but never tried >R. As >> for as I know, there are tons of state-of-the-art library in R and >Matlab. >> >> After skimming your paper, I wander that >> 1) Are these library used in your code example implemented by >yourself? Or >> other libraries are called, such as LAPACK for linear algebra? >> > >Everything is either written from scratch, or uses one of the helper >libraries (two such libraries are included in the repo; the other is >SRFI-1). >The point of the book is that it is not a tutorial on using libraries, >but >it explains some methods and translates these explanations to Scheme, >so >that they can be modified and extended easily. > >If you are looking for some serious numerical libraries for Scheme, >there's a very powerful scmutils package available > >http://www.cs.rochester.edu/~gildea/guile-scmutils/ > >I've actually used its code for Singular Value Decomposition to perform >Principal Component Analysis. > >2) Is it easy to use scheme and your library, or maybe some others, to >do >> computational job? In practice, those who use R or Matlab want their >idea >> to be proved quickly, not to spend time on coding style, right? >> >> I think it depends on a point of view. I initially tried using R, but >it >was causing many unexpected problems, but I already knew Scheme quite >well, >and for me even implementing the libraries from scratch wasn't that >much >of a job. >But the book is mostly about fun, and about understanding. >Also, interfacing Guile with Emacs through Geiser is an incredible >productivity boost. > >Interestingly, when I benchmarked the genetic algorithm that I wrote >with >genalg package from R, the Scheme version run in Guile actually >outperformed the R version, although it was written in completely >performance-naive style. > >On the other hand, if you wanted to use the decision trees classifier, >you'd probably want to apply memoization. > >If scheme can do most computational job as python numpy does, I will >switch >> to it. >> > >I think that in practice Scheme can be even more convinient, as it >provides >native support for complex numbers > >I also think it would be helpful to interface Guile with plot >generation. I >see that Nala has a guile-plot package, but I haven't tried it. I >personally wrote some code for generating LaTeX pgfplots for the >project, >and can add it to the repo if you llike.
Interesting. Will have a look at how they expose operators. Myself I have implemented http://github.com/wedesoft/aism for array operations. -- Jan Wedekind http://www.wedesoft.de/
