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Online Education- MongoDB and Oracle R Enterprise

I really liked the course developed by 10 gen for MongoDB (there are two tracks for Developers and DBAs at https://education.10gen.com/)

The interface is very nice and is a step upwards from Coursera’s ( https://www.coursera.org/) pioneering work (and even http://www.codecademy.com/#!/exercises/0 )- each video has a small question, the videos are not cluttered, and the voice and transcription quality is impeccable. Lastly a certification for people who clear 65% acts as an academic incentive, they get a certificate.

yes it is free.

 

Oracle recently launched a series of nicely made R tutorials at https://apex.oracle.com/pls/apex/f?p=44785:24:0::NO::P24_CONTENT_ID,P24_PREV_PAGE:6528,1but I wish Oracle R had some certifications too!

If only more techie companies like SAS Institute (expensive SAS training), IBM (cluttered website), Revolution Analytics (expensive partners in Certification), Google (unpolished Python lectures)

put an effort with polished e-learning interfaces than be dependent on external partners…..or internal gurus…interfaces matter especially in education.

\Well Anyways!!

Happy Mongo DBing/ Oracle R!

 

Data Frame in Python

Exploring some Python Packages and R packages to move /work with both Python and R without melting your brain or exceeding your project deadline

—————————————

If you liked the data.frame structure in R, you have some way to work with them at a faster processing speed in Python.

Here are three packages that enable you to do so-

(1) pydataframe http://code.google.com/p/pydataframe/

An implemention of an almost R like DataFrame object. (install via Pypi/Pip: “pip install pydataframe”)

Usage:

        u = DataFrame( { "Field1": [1, 2, 3],
                        "Field2": ['abc', 'def', 'hgi']},
                        optional:
                         ['Field1', 'Field2']
                         ["rowOne", "rowTwo", "thirdRow"])

A DataFrame is basically a table with rows and columns.

Columns are named, rows are numbered (but can be named) and can be easily selected and calculated upon. Internally, columns are stored as 1d numpy arrays. If you set row names, they’re converted into a dictionary for fast access. There is a rich subselection/slicing API, see help(DataFrame.get_item) (it also works for setting values). Please note that any slice get’s you another DataFrame, to access individual entries use get_row(), get_column(), get_value().

DataFrames also understand basic arithmetic and you can either add (multiply,…) a constant value, or another DataFrame of the same size / with the same column names, like this:

#multiply every value in ColumnA that is smaller than 5 by 6.
my_df[my_df[:,'ColumnA'] < 5, 'ColumnA'] *= 6

#you always need to specify both row and column selectors, use : to mean everything
my_df[:, 'ColumnB'] = my_df[:,'ColumnA'] + my_df[:, 'ColumnC']

#let's take every row that starts with Shu in ColumnA and replace it with a new list (comprehension)
select = my_df.where(lambda row: row['ColumnA'].startswith('Shu'))
my_df[select, 'ColumnA'] = [row['ColumnA'].replace('Shu', 'Sha') for row in my_df[select,:].iter_rows()]

Dataframes talk directly to R via rpy2 (rpy2 is not a prerequiste for the library!)

 

(2) pandas http://pandas.pydata.org/

Library Highlights

  • A fast and efficient DataFrame object for data manipulation with integrated indexing;
  • Tools for reading and writing data between in-memory data structures and different formats: CSV and text files, Microsoft Excel, SQL databases, and the fast HDF5 format;
  • Intelligent data alignment and integrated handling of missing data: gain automatic label-based alignment in computations and easily manipulate messy data into an orderly form;
  • Flexible reshaping and pivoting of data sets;
  • Intelligent label-based slicing, fancy indexing, and subsetting of large data sets;
  • Columns can be inserted and deleted from data structures for size mutability;
  • Aggregating or transforming data with a powerful group by engine allowing split-apply-combine operations on data sets;
  • High performance merging and joining of data sets;
  • Hierarchical axis indexing provides an intuitive way of working with high-dimensional data in a lower-dimensional data structure;
  • Time series-functionality: date range generation and frequency conversion, moving window statistics, moving window linear regressions, date shifting and lagging. Even create domain-specific time offsets and join time series without losing data;
  • The library has been ruthlessly optimized for performance, with critical code paths compiled to C;
  • Python with pandas is in use in a wide variety of academic and commercial domains, including Finance, Neuroscience, Economics, Statistics, Advertising, Web Analytics, and more.

Why not R?

First of all, we love open source R! It is the most widely-used open source environment for statistical modeling and graphics, and it provided some early inspiration for pandas features. R users will be pleased to find this library adopts some of the best concepts of R, like the foundational DataFrame (one user familiar with R has described pandas as “R data.frame on steroids”). But pandas also seeks to solve some frustrations common to R users:

  • R has barebones data alignment and indexing functionality, leaving much work to the user. pandas makes it easy and intuitive to work with messy, irregularly indexed data, like time series data. pandas also provides rich tools, like hierarchical indexing, not found in R;
  • R is not well-suited to general purpose programming and system development. pandas enables you to do large-scale data processing seamlessly when developing your production applications;
  • Hybrid systems connecting R to a low-productivity systems language like Java, C++, or C# suffer from significantly reduced agility and maintainability, and you’re still stuck developing the system components in a low-productivity language;
  • The “copyleft” GPL license of R can create concerns for commercial software vendors who want to distribute R with their software under another license. Python and pandas use more permissive licenses.

(3) datamatrix http://pypi.python.org/pypi/datamatrix/0.8

datamatrix 0.8

A Pythonic implementation of R’s data.frame structure.

Latest Version: 0.9

This module allows access to comma- or other delimiter separated files as if they were tables, using a dictionary-like syntax. DataMatrix objects can be manipulated, rows and columns added and removed, or even transposed

—————————————————————–

Modeling in Python

(more…)

Interview Rob J Hyndman Forecasting Expert #rstats

Here is an interview with Prof Rob J Hyndman who has created many time series forecasting methods and authored books as well as R packages on the same.

Ajay -Describe your journey from being a student of science to a Professor. What were some key turning points along that journey?
 
Rob- I started a science honours degree at the University of Melbourne in 1985. By the end of 1985 I found myself simultaneously working as a statistical consultant (having completed all of one year of statistics courses!). For the next three years I studied mathematics, statistics and computer science at university, and tried to learn whatever I needed to in order to help my growing group of clients. Often we would cover things in classes that I’d already taught myself through my consulting work. That really set the trend for the rest of my career. I’ve always been an academic on the one hand, and a statistical consultant on the other. The consulting work has led me to learn a lot of things that I would not otherwise have come across, and has also encouraged me to focus on research problems that are of direct relevance to the clients I work with.
I never set out to be an academic. In fact, I thought that I would get a job in the business world as soon as I finished my degree. But once I completed the degree, I was offered a position as a statistical consultant within the University of Melbourne, helping researchers in various disciplines and doing some commercial work. After a year, I was getting bored doing only consulting, and I thought it would be interesting to do a PhD. I was lucky enough to be offered a generous scholarship which meant I was paid more to study than to continue working.
Again, I thought that I would probably go and get a job in the business world after I finished my PhD. But I finished it early and my scholarship was going to be cut off once I submitted my thesis. So instead, I offered to teach classes for free at the university and delayed submitting my thesis until the scholarship period ran out. That turned out to be a smart move because the university saw that I was a good teacher, and offered me a lecturing position starting immediately I submitted my thesis. So I sort of fell into an academic career.
I’ve kept up the consulting work part-time because it is interesting, and it gives me a little extra money. But I’ve also stayed an academic because I love the freedom to be able to work on anything that takes my fancy.
Ajay- Describe your upcoming book on Forecasting.
 
Rob- My first textbook on forecasting (with Makridakis and Wheelwright) was written a few years after I finished my PhD. It has been very popular, but it costs a lot of money (about $140 on Amazon). I estimate that I get about $1 for every book sold. The rest goes to the publisher (Wiley) and all they do is print, market and distribute it. I even typeset the whole thing myself and they print directly from the files I provided. It is now about 15 years since the book was written and it badly needs updating. I had a choice of writing a new edition with Wiley or doing something completely new. I decided to do a new one, largely because I didn’t want a publisher to make a lot of money out of students using my hard work.
It seems to me that students try to avoid buying textbooks and will search around looking for suitable online material instead. Often the online material is of very low quality and contains many errors.
As I wasn’t making much money on my textbook, and the facilities now exist to make online publishing very easy, I decided to try a publishing experiment. So my new textbook will be online and completely free. So far it is about 2/3 completed and is available at http://otexts.com/fpp/. I am hoping that my co-author (George Athanasopoulos) and I will finish it off before the end of 2012.
The book is intended to provide a comprehensive introduction to forecasting methods. We don’t attempt to discuss the theory much, but provide enough information for people to use the methods in practice. It is tied to the forecast package in R, and we provide code to show how to use the various forecasting methods.
The idea of online textbooks makes a lot of sense. They are continuously updated so if we find a mistake we fix it immediately. Also, we can add new sections, or update parts of the book, as required rather than waiting for a new edition to come out. We can also add richer content including video, dynamic graphics, etc.
For readers that want a print edition, we will be aiming to produce a print version of the book every year (available via Amazon).
I like the idea so much I’m trying to set up a new publishing platform (otexts.com) to enable other authors to do the same sort of thing. It is taking longer than I would like to make that happen, but probably next year we should have something ready for other authors to use.
Ajay- How can we make textbooks cheaper for students as well as compensate authors fairly
 
Rob- Well free is definitely cheaper, and there are a few businesses trying to make free online textbooks a reality. Apart from my own efforts, http://www.flatworldknowledge.com/ is producing a lot of free textbooks. And textbookrevolution.org is another great resource.
With otexts.com, we will compensate authors in two ways. First, the print versions of a book will be sold (although at a vastly cheaper rate than other commercial publishers). The royalties on print sales will be split 50/50 with the authors. Second, we plan to have some features of each book available for subscription only (e.g., solutions to exercises, some multimedia content, etc.). Again, the subscription fees will be split 50/50 with the authors.
Ajay- Suppose a person who used to use forecasting software from another company decides to switch to R. How easy and lucid do you think the current documentation on R website for business analytics practitioners such as these – in the corporate world.
 
Rob- The documentation on the R website is not very good for newcomers, but there are a lot of other R resources now available. One of the best introductions is Matloff’s “The Art of R Programming”. Provided someone has done some programming before (e.g., VBA, python or java), learning R is a breeze. The people who have trouble are those who have only ever used menu interfaces such as Excel. Then they are not only learning R, but learning to think about computing in a different way from what they are used to, and that can be tricky. However, it is well worth it. Once you know how to code, you can do so much more.  I wish some basic programming was part of every business and statistics degree.
If you are working in a particular area, then it is often best to find a book that uses R in that discipline. For example, if you want to do forecasting, you can use my book (otexts.com/fpp/). Or if you are using R for data visualization, get hold of Hadley Wickham’s ggplot2 book.
Ajay- In a long and storied career- What is the best forecast you ever made ? and the worst?
 
 Rob- Actually, my best work is not so much in making forecasts as in developing new forecasting methodology. I’m very proud of my forecasting models for electricity demand which are now used for all long-term planning of electricity capacity in Australia (see  http://robjhyndman.com/papers/peak-electricity-demand/  for the details). Also, my methods for population forecasting (http://robjhyndman.com/papers/stochastic-population-forecasts/ ) are pretty good (in my opinion!). These methods are now used by some national governments (but not Australia!) for their official population forecasts.
Of course, I’ve made some bad forecasts, but usually when I’ve tried to do more than is reasonable given the available data. One of my earliest consulting jobs involved forecasting the sales for a large car manufacturer. They wanted forecasts for the next fifteen years using less than ten years of historical data. I should have refused as it is unreasonable to forecast that far ahead using so little data. But I was young and naive and wanted the work. So I did the forecasts, and they were clearly outside the company’s (reasonable) expectations, and they then refused to pay me. Lesson learned. It’s better to refuse work than do it poorly.

Probably the biggest impact I’ve had is in helping the Australian government forecast the national health budget. In 2001 and 2002, they had underestimated health expenditure by nearly $1 billion in each year which is a lot of money to have to find, even for a national government. I was invited to assist them in developing a new forecasting method, which I did. The new method has forecast errors of the order of plus or minus $50 million which is much more manageable. The method I developed for them was the basis of the ETS models discussed in my 2008 book on exponential smoothing (www.exponentialsmoothing.net)

. And now anyone can use the method with the ets() function in the forecast package for R.
About-
Rob J Hyndman is Pro­fessor of Stat­ist­ics in the Depart­ment of Eco­no­met­rics and Busi­ness Stat­ist­ics at Mon­ash Uni­ver­sity and Dir­ector of the Mon­ash Uni­ver­sity Busi­ness & Eco­nomic Fore­cast­ing Unit. He is also Editor-in-Chief of the Inter­na­tional Journal of Fore­cast­ing and a Dir­ector of the Inter­na­tional Insti­tute of Fore­casters. Rob is the author of over 100 research papers in stat­ist­ical sci­ence. In 2007, he received the Moran medal from the Aus­tralian Academy of Sci­ence for his con­tri­bu­tions to stat­ist­ical research, espe­cially in the area of stat­ist­ical fore­cast­ing. For 25 years, Rob has main­tained an act­ive con­sult­ing prac­tice, assist­ing hun­dreds of com­pan­ies and organ­iz­a­tions. His recent con­sult­ing work has involved fore­cast­ing elec­tri­city demand, tour­ism demand, the Aus­tralian gov­ern­ment health budget and case volume at a US call centre.

Python with Friends

Wanted to learn Python? Stuck on a desk with no redemption. You have two very lucid options. One is use Google. I mean not the search engine, but their class on learning Python.

The videos are available on Youtube at http://www.youtube.com/user/GoogleDevelopers (starting at http://www.youtube.com/watch?v=tKTZoB2Vjuk&feature=plcp)


http://code.google.com/edu/languages/google-python-class/

The other is new module of Python at code academy. It is truly awesome even if you dont know any programming!

So learn some awesome python today and be an excellent hacker tommorow!

http://www.codecademy.com/tracks/python

JSS launches special edition for GUI for #Rstats

I love GUIs (graphical user interfaces)- they might be TCL/TK based or GTK based or even QT based. As a researcher they help me with faster coding, as a consultant they help with faster transition of projects from startup to handover stage  and as an R  instructor helps me get people to learn R faster.

I wish Python had some GUIs though ;)

 

from the open access journal of statistical software-

JSS Special Volume 49: Graphical User Interfaces for R

Graphical User Interfaces for R
Pedro M. Valero-Mora, Ruben Ledesma
Vol. 49, Issue 1, Jun 2012
Submitted 2012-06-03, Accepted 2012-06-03
Integrated Degradation Models in R Using iDEMO
Ya-Shan Cheng, Chien-Yu Peng
Vol. 49, Issue 2, Jun 2012
Submitted 2010-12-31, Accepted 2011-06-29
Glotaran: A Java-Based Graphical User Interface for the R Package TIMP
Joris J. Snellenburg, Sergey Laptenok, Ralf Seger, Katharine M. Mullen, Ivo H. M. van Stokkum
Vol. 49, Issue 3, Jun 2012
Submitted 2011-01-20, Accepted 2011-09-16
A Graphical User Interface for R in a Rich Client Platform for Ecological Modeling
Marcel Austenfeld, Wolfram Beyschlag
Vol. 49, Issue 4, Jun 2012
Submitted 2011-01-05, Accepted 2012-02-20
Closing the Gap between Methodologists and End-Users: R as a Computational Back-End
Byron C. Wallace, Issa J. Dahabreh, Thomas A. Trikalinos, Joseph Lau, Paul Trow, Christopher H. Schmid
Vol. 49, Issue 5, Jun 2012
Submitted 2010-11-01, Accepted 2012-12-20
tourrGui: A gWidgets GUI for the Tour to Explore High-Dimensional Data Using Low-Dimensional Projections
Bei Huang, Dianne Cook, Hadley Wickham
Vol. 49, Issue 6, Jun 2012
Submitted 2011-01-20, Accepted 2012-04-16
The RcmdrPlugin.survival Package: Extending the R Commander Interface to Survival Analysis
John Fox, Marilia S. Carvalho
Vol. 49, Issue 7, Jun 2012
Submitted 2010-12-26, Accepted 2011-12-28
Deducer: A Data Analysis GUI for R
Ian Fellows
Vol. 49, Issue 8, Jun 2012
Submitted 2011-02-28, Accepted 2011-09-08
RKWard: A Comprehensive Graphical User Interface and Integrated Development Environment for Statistical Analysis with R
Stefan Rödiger, Thomas Friedrichsmeier, Prasenjit Kapat, Meik Michalke
Vol. 49, Issue 9, Jun 2012
Submitted 2010-12-28, Accepted 2011-05-06
gWidgetsWWW: Creating Interactive Web Pages within R
John Verzani
Vol. 49, Issue 10, Jun 2012
Submitted 2010-12-17, Accepted 2011-05-11
Oscars and Interfaces
Antony Unwin
Vol. 49, Issue 11, Jun 2012
Submitted 2010-12-08, Accepted 2011-07-15

Interview Alvaro Tejada Galindo, SAP Labs Montreal, Using SAP Hana with #Rstats

Here is a brief interview with Alvaro Tejada Galindo aka Blag who is a developer working with SAP Hana and R at SAP Labs, Montreal. SAP Hana is SAP’s latest offering in BI , it’s also a database and a computing environment , and using R and HANA together on the cloud can give major productivity gains in terms of both speed and analytical ability, as per preliminary use cases.

Ajay- Describe how you got involved with databases and R language.
Blag-  I used to work as an ABAP Consultant for 11 years, but also been involved with programming since the last 13 years, so I was in touch with SQLServer, Oracle, MySQL and SQLite. When I joined SAP, I heard that SAP HANA was going to use an statistical programming language called “R”. The next day I started my “R” learning.

Ajay- What made the R language a fit for SAP HANA. Did you consider other languages? What is your view on Julia/Python/SPSS/SAS/Matlab languages

Blag- I think “R” is a must for SAP HANA. As the fastest database in the market, we needed a language that could help us shape the data in the best possible way. “R” filled that purpose very well. Right now, “R” is not the only language as “L” can be used as well (http://wiki.tcl.tk/17068) …not forgetting “SQLScript” which is our own version of SQL (http://goo.gl/x3bwh) . I have to admit that I tried Julia, but couldn’t manage to make it work. Regarding Python, it’s an interesting question as I’m going to blog about Python and SAP HANA soon. About Matlab, SPSS and SAS I haven’t used them, so I got nothing to say there.

Ajay- What is your view on some of the limitations of R that can be overcome with using it with SAP HANA.

Blag-  I think mostly the ability of SAP HANA to work with big data. Again, SAP HANA and “R” can work very nicely together and achieve things that weren’t possible before.

Ajay-  Have you considered other vendors of R including working with RStudio, Revolution Analytics, and even Oracle R Enterprise.

Blag-  I’m not really part of the SAP HANA or the R groups inside SAP, so I can’t really comment on that. I can only say that I use RStudio every time I need to do something with R. Regarding Oracle…I don’t think so…but they can use any of our products whenever they want.

Ajay- Do you have a case study on an actual usage of R with SAP HANA that led to great results.

Blag-   Right now the use of “R” and SAP HANA is very preliminary, I don’t think many people has start working on it…but as an example that it works, you can check this awesome blog entry from my friend Jitender Aswani “Big Data, R and HANA: Analyze 200 Million Data Points and Later Visualize Using Google Maps “ (http://allthingsr.blogspot.com/#!/2012/04/big-data-r-and-hana-analyze-200-million.html)

Ajay- Does your group in SAP plan to give to the R ecosystem by attending conferences like UseR 2012, sponsoring meets, or package development etc

Blag- My group is in charge of everything developers, so sure, we’re planning to get more in touch with R developers and their ecosystem. Not sure how we’re going to deal with it, but at least I’m going to get myself involved in the Montreal R Group.

 

About-

http://scn.sap.com/people/alvaro.tejadagalindo3

Name: Alvaro Tejada Galindo
Email: a.tejada.galindo@sap.com
Profession: Development
Company: SAP Canada Labs-Montreal
Town/City: Montreal
Country: Canada
Instant Messaging Type: Twitter
Instant Messaging ID: Blag
Personal URL: http://blagrants.blogspot.com
Professional Blog URL: http://www.sdn.sap.com/irj/scn/weblogs?blog=/pub/u/252210910
My Relation to SAP: employee
Short Bio: Development Expert for the Technology Innovation and Developer Experience team.Used to be an ABAP Consultant for the last 11 years. Addicted to programming since 1997.

http://www.sap.com/solutions/technology/in-memory-computing-platform/hana/overview/index.epx

and from

http://en.wikipedia.org/wiki/SAP_HANA

SAP HANA is SAP AG’s implementation of in-memory database technology. There are four components within the software group:[1]

  • SAP HANA DB (or HANA DB) refers to the database technology itself,
  • SAP HANA Studio refers to the suite of tools provided by SAP for modeling,
  • SAP HANA Appliance refers to HANA DB as delivered on partner certified hardware (see below) as anappliance. It also includes the modeling tools from HANA Studio as well replication and data transformation tools to move data into HANA DB,[2]
  • SAP HANA Application Cloud refers to the cloud based infrastructure for delivery of applications (typically existing SAP applications rewritten to run on HANA).

R is integrated in HANA DB via TCP/IP. HANA uses SQL-SHM, a shared memory-based data exchange to incorporate R’s vertical data structure. HANA also introduces R scripts equivalent to native database operations like join or aggregation.[20] HANA developers can write R scripts in SQL and the types are automatically converted in HANA. R scripts can be invoked with HANA tables as both input and output in the SQLScript. R environments need to be deployed to use R within SQLScript

More blog posts on using SAP and R together

Dealing with R and HANA

http://scn.sap.com/community/in-memory-business-data-management/blog/2011/11/28/dealing-with-r-and-hana
R meets HANA

http://scn.sap.com/community/in-memory-business-data-management/blog/2012/01/29/r-meets-hana

HANA meets R

http://scn.sap.com/community/in-memory-business-data-management/blog/2012/01/26/hana-meets-r
When SAP HANA met R – First kiss

http://scn.sap.com/community/developer-center/hana/blog/2012/05/21/when-sap-hana-met-r–first-kiss

 

Using RODBC with SAP HANA DB-

SAP HANA: My experiences on using SAP HANA with R

http://scn.sap.com/community/in-memory-business-data-management/blog/2012/02/21/sap-hana-my-experiences-on-using-sap-hana-with-r

and of course the blog that started it all-

Jitender Aswani’s http://allthingsr.blogspot.in/

 

 

BigML meets R #rstats

I am just checking the nice new R package created by BigML.com co-founder Justin Donaldson. The name of the new package is bigml, which can confuse a bit since there do exist many big suffix named packages in R (including biglm)

The bigml package is available at CRAN http://cran.r-project.org/web/packages/bigml/index.html

I just tweaked the code given at http://blog.bigml.com/2012/05/10/r-you-ready-for-bigml/ to include the ssl authentication code at http://www.brocktibert.com/blog/2012/01/19/358/

so it goes

> library(bigml)
Loading required package: RJSONIO
Loading required package: RCurl
Loading required package: bitops
Loading required package: plyr
> setCredentials(“bigml_username”,”API_key”)

# download the file needed for authentication
download.file(url="http://curl.haxx.se/ca/cacert.pem", destfile="cacert.pem")

# set the curl options
curl <- getCurlHandle()
options(RCurlOptions = list(capath = system.file("CurlSSL", "cacert.pem",
package = "RCurl"),
ssl.verifypeer = FALSE))
curlSetOpt(.opts = list(proxy = 'proxyserver:port'), curl = curl)

> iris.model = quickModel(iris, objective_field = ‘Species’)

Of course there are lots of goodies added here , so read the post yourself at http://blog.bigml.com/2012/05/10/r-you-ready-for-bigml/

Incidentally , the author of this R package (bigml) Justin Donalsdon who goes by name sudojudo at http://twitter.com/#!/sudojudo has also recently authored two other R packages including tsne at  http://cran.r-project.org/web/packages/tsne/index.html (tsne: T-distributed Stochastic Neighbor Embedding for R (t-SNE) -A “pure R” implementation of the t-SNE algorithm) and a GUI toolbar http://cran.r-project.org/web/packages/sculpt3d/index.html (sculpt3d is a GTK+ toolbar that allows for more interactive control of a dataset inside the RGL plot window. Controls for simple brushing, highlighting, labeling, and mouseMode changes are provided by point-and-click rather than through the R terminal interface)

This along with the fact the their recently released python bindings for bigml.com was one of the top news at Hacker News- shows bigML.com is going for some traction in bringing cloud computing, better software interfaces and data mining together!

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