We may also use Discord and do something "somewhat live" Phil
On Tue, May 16, 2017 at 7:23 PM, <serge.stinckw...@gmail.com> wrote: > I was asking Philippe but hope to see you also at ESUG ! > > Envoyé de mon iPhone > > Le 16 mai 2017 à 19:02, Oleksandr Zaytsev <olk.zayt...@gmail.com> a > écrit : > > I would love to, but to go to Lille from my country I would need a visa. > Which is not that easy to acquire. > So maybe I will come to PharoDays 2018. > And I will definitely try to come to ESUG Conference in September. > > Oleks > > On Tue, May 16, 2017 at 7:26 PM, <serge.stinckw...@gmail.com> wrote: > >> >> >> Envoyé de mon iPhone >> >> Le 11 mai 2017 à 11:43, "p...@highoctane.be" <p...@highoctane.be> a >> écrit : >> >> ---------- Message transféré ---------- >> De : "p...@highoctane.be" <p...@highoctane.be> >> Date : 11 mai 2017 10:54 >> Objet : Re: 11/05/17 - Tabular Data Structures for Data Analysis - >> Oleksandr Zaytsev >> À : "Nick Papoylias" <npapoyl...@gmail.com> >> Cc : >> >> >> >> On Thu, May 11, 2017 at 10:20 AM, Nick Papoylias <npapoyl...@gmail.com> >> wrote: >> >>> >>> >>> On Thu, May 11, 2017 at 5:24 AM, Oleksandr Zaytsev < >>> olk.zayt...@gmail.com> wrote: >>> >>>> >>>> *A. Work done* >>>> >>>> - Downloaded the threaded VM as suggested by Esteban Lorenzano to >>>> make Iceberg work. And it does! I have successfully pushed my >>>> NeuralNetwork >>>> code to GitHub: https://github.com/olekscode/MLNeuralNetwork >>>> - Joined the PolyMath organization on GitHub >>>> - Created a repository for the TabularDataset project >>>> https://github.com/PolyMathOrg/TabularDataset >>>> <https://github.com/PolyMathOrg/TabularDataset> as a part of >>>> PolyMath organization on GitHub >>>> - Fixed a PolyMath issue #25 and made a PR >>>> - Read an article from Wolfram Mathematica documentation regarding >>>> Dataset. It was one of the reading suggestions sent to me by Nick >>>> Papoylias >>>> >>>> >>>> *B. Next steps* >>>> >>>> - Fix more issues of PolyMath, using Iceberg. I have to get used to >>>> it by the time the coding phase starts >>>> - Read the rest of Nick Papoylias's suggestions >>>> >>>> >>>> *C. Help needed* >>>> >>>> - The Dataset in Wolfram, as well as Pandas in Python, has a very >>>> advanced indexing system. Smalltalk has its own special conventions for >>>> indexing, so I think that it would be great if I got familiar with them. >>>> Could you suggest me some reading on this topic (what are the indexing >>>> conventions in Smalltalk?). >>>> For example, in Wolfram, I can write *dataset[[-1]]* to extract the >>>> last row. But in Pharo indexes can not be negative. In Pharo I would >>>> say *dataset >>>> last*. But how about *dataset[[-5]]*? >>>> >>>> This would be a good exercise for you ;) In Pharo you can easily add >>> negative indexing yourself. >>> >>> *Hint:* You know the index of the last element, since this is the size >>> of the collection, so... ;) >>> >>> No need for changes, this exists already. >> >> Use atWrap: index put: value and atWrap: with negative indexes. >> 'hello' atWrap: -2 >> >> There is a specific version for Array using a primitive. >> #[ 10 20 30 40 ] atWrap: -1 >> >> atWrap:0 gives you the last item. >> atWrap: -1 gives 30 >> >> This is different from 0 based index languages. >> >> The interesing thing about atWrap: is that it uses modulo interally so >> you do not need to care about that. >> >> ($/ split: 'abc/def/ghi/jkl') atWrap: -1 >> --> 'ghi' >> >> The Matrix class has a bunch of things API wise but the class is highly >> inefficient, doing copies all the time etc. It would be nice to have some >> kind of futures/copy on write style things in there. >> >> I miss cbind and rbind. These are useful. I have some half baked super >> inefficient implementations of these things for Matrix. >> >> https://stat.ethz.ch/R-manual/R-devel/library/base/html/cbind.html >> >> The ability to name columns is also nice to have. >> >> In R one does: >> >> df <- dataframe() >> cbind(df, c(1,2,3)) >> cbind(df, c(4,5,6)) >> names(df)<-("C1", "C2", "C3") >> names can be found back with: >> >> names(df) >> >> A Smalltalkish style would be welcome. >> >> >> >> >> Interesting ! Are you coming to PharoDays ? We can talk about that if we >> found time. >> >> Maybe looking at the Voyage queries can be helpful. >> >> Phil >> >> >> >>> Try adding an extention method to Ordrered or SequenceableCollection. >>> >>> If the Pharo by example chapter is not enough or the MOOC, read the >>> source >>> itself in the core, to see how basic methods are implemented (it is less >>> scary, >>> than it sounds). >>> >>> You can also try Chapters 9, 10, 11 of the blue book (some API changes >>> may apply): >>> >>> <http://goog_1902892863> >>> http://sdmeta.gforge.inria.fr/FreeBooks/BlueBook/Bluebook.pdf >>> >>> >>>> - Or what is the best way of implementing this index: >>>> *dataset[["name"]]* (extracts a named row), *dataset[[1]*] >>>> (extracts the first row)? Should I create two separate messages: >>>> *dataset >>>> rowNamed: 'name'* and *dataset rowAt: 1*? >>>> >>>> rowNamed: >> rowAt: >> >> yes, look like it. >> >> But if we want to model things like R dataframes for example, this has to >> be seen as a vectorized operation, so you can to use row slices, column >> slices, and logical indexes. >> >> Check this out: >> >> http://www.r-tutor.com/r-introduction/data-frame/data-frame-row-slice >> https://www.r-bloggers.com/working-with-data-frames/ >> >> >> >>> The internal representation of your data-structure can be anything at >>> the moment, *as long as you encapsulate it.* >>> >>> (ie it can be nested OrderedCollections with meta-data for column-names >>> to indexes, or dictionary of collections etc). >>> >>> *If you don't expose it to the user* (ie return it from the public api, >>> or expect knowledge of it in argument passing), >>> we can easily change it later. So *first make it work, and we optimize >>> later ;)* >>> >>> For your case it will be a little bit trickier because *you also have >>> the notions of a) rows and b) columns*, which >>> are exposed to the user. So *you would need to create abstractions* for >>> these too. >>> >>> Cheers, >>> >>> Nick >>> >>>> >>>> - >>>> >>>> >>>> If someone else is having problems with Iceberg on Linux, try >>>> downloading the threaded VM: >>>> >>>> wget -O- get.pharo.org/vmT60 | bash >>>> >>>> And use SSH (not HTTPS) remote URL. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Pharo Google Summer of Code" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to pharo-gsoc+unsubscr...@googlegroups.com. >>>> To post to this group, send email to pharo-g...@googlegroups.com. >>>> To view this discussion on the web visit https://groups.google.com/d/ms >>>> gid/pharo-gsoc/CAEp0Uzu-8fw3dA6ezVoj-QptvLcB8cWPHvZ1tfLg1Ce8 >>>> qkTqfQ%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/pharo-gsoc/CAEp0Uzu-8fw3dA6ezVoj-QptvLcB8cWPHvZ1tfLg1Ce8qkTqfQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Pharo Google Summer of Code" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to pharo-gsoc+unsubscr...@googlegroups.com. >>> To post to this group, send email to pharo-g...@googlegroups.com. >>> To view this discussion on the web visit https://groups.google.com/d/ms >>> gid/pharo-gsoc/CACEStOgLC6HbYJ8HBLHWfs5%2BwqN3ib_kdVGuVizx7G >>> h1c0sM%3DA%40mail.gmail.com >>> <https://groups.google.com/d/msgid/pharo-gsoc/CACEStOgLC6HbYJ8HBLHWfs5%2BwqN3ib_kdVGuVizx7Gh1c0sM%3DA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >
