This is a fairly long post and is a basic collection of material for a book/paper. It is on interfaces to use R. If you feel I need to add more on a particular R interface, or if there is an error in this- please feel to contact me on twitter @decisionstats or mail ohri2007 on google mail.
● R Interfaces There are multiple ways to use the R statistical language. Command Line- The default method is using the command prompt by the installed software on download fromhttp://r-project.org For windows users there is a simple GUI which has an option for Packages (loading package, installing package, setting CRAN mirror for downloading packages) , Misc (useful for listing all objects loaded in workspace as well as clearing objects to free up memory), and Help Menu. Using Click and Point- Besides the command prompt, there are many Graphical User Interfaces which enable the analyst to use click and point methods to analyze data without getting into the details of learning complex and at times overwhelming R syntax. R GUIs are very popular both as mode of instruction in academia as well as in actual usage as it cuts down considerably on time taken to adapt to the language. As with all command line and GUI software, for advanced tweaks and techniques, command prompt will come in handy as well. Advantages and Limitations of using Visual Programming Interfaces to R as compared to Command Line.
Advantages
Limitations
Faster learning for new programmers
Can create junk analysis by clicking menus in GUI
Easier creation of advanced models or graphics
Cannot create custom functions unless you use command line
Repeatability of analysis is better
Advanced techniques and custom flexibility of data handling R can be done in command line
Syntax is auto-generated
Can limit scope and exposure in learning R syntax
A brief list of the notable Graphical User Interfaces is below- 1) R Commander- Basic statistics 2) Rattle- Data Mining 3) Deducer- Graphics (including GGPlot Integration) and also uses JGR (a Jave based GUI) 4) RKward- Comprehensive R GUI for customizable graphs 5) Red-R – Dataflow programming interface using widgets 1) R Commander- R Commander was primarily created by Professor John Fox of McMaster University to cover the content of a basic statistics course. However it is extensible and many other packages can be added in menu form to it- in the form R Commander Plugins. Quite noticeably it is one of the most widely used R GUI and it also has a script window so you can write R code in combination with the menus. As you point and click a particular menu item, the corresponding R code is automatically generated in the log window and executed. It can be found on CRAN athttp://cran.r-project.org/web/packages/Rcmdr/index.html
Advantages of Using R Commander- 1) Useful for beginner in R language to do basic graphs and analysis and building models. 2) Has script window, output window and log window (called messages) in same screen which helps user as code is auto-generated on clicking on menus, and can be customized easily. For example in changing labels and options in Graphs. Graphical output is shown in seperate window from output window. 3) Extensible for other R packages like qcc (for quality control), Teaching Demos (for training), survival analysis and Design of Experiments (DoE) 4) Easy to understand interface even for first time user. 5) Menu items which are not relevant are automatically greyed out- if there are only two variables, and you try to build a 3D scatterplot graph, that menu would simply not be available and is greyed out. Comparative Disadvantages of using R Commander- 1) It is basically aimed at a statistical audience( originally students in statistics) and thus the terms as well as menus are accordingly labeled. Hence it is more of a statistical GUI rather than an analytics GUI. 2) Has limited ability to evaluate models from a business analysts perspective (ROC curve is not given as an option) even though it has extensive statistical tests for model evaluation in model sub menu. Indeed creating a Model is treated as a subsection of statistics rather than a separate menu item. 3) It is not suited for projects that do not involve advanced statistical testing and for users not proficient in statistics (particularly hypothesis testing), and for data miners. Menu items in the R Commander window: File Menu – For loading script files and saving Script files, Output and Workspace It is also needed for changing the present working directory and for exiting R. Edit Menu – For editing scripts and code in the script window. Data Menu – For creating new dataset, inputting or importing data and manipulating data through variables.Data Import can be from text,comma separated values,clipboard, datasets from SPSS, Stata,Minitab, Excel ,dbase, Access files or from url. Data manipulation included deleting rows of data as well as manipulating variables. Also this menu has the option for merging two datasets by row or columns. Statistics Menu-This menu has options for descriptive statistics, hypothesis tests, factor analysis and clustering and also for creating models. Note there is a separate menu for evaluating the model so created. Graphs Menu-It has options for creating various kinds of graphs including box-plot, histogram, line, pie charts and x-y plots. The first option is color palette- it can be used for customizing the colors. It is recommended you adjust colors based on your need for publication or presentation. A notable option is 3 D graphs for evaluating 3 variables at a time- this is really good and impressive feature and exposes the user to advanced graphs in R all at few clicks. You may want to dazzle a presentation using this graph. Also consider scatterplot matrix graphs for graphical display of variables. Graphical display of R surpasses any other statistical software in appeal as well as ease of creation- using GUI to create graphs can further help the user to get the most of data insights using R at a very minimum effort. Models Menu-This is somewhat of a labeling peculiarity of R Commander as this menu is only for evaluating models which have been created using the statistics menu-model sub menu. It includes options for graphical interpretation of model results,residuals,leverage and confidence intervals and adding back residuals to the data set. Distributions Menu- is for cumulative probabilities, probability density, graphs of distributions, quantiles and features for standard distributions and can be used in lieu of standard statistical tables for the distributions. It has 13 standard statistical continuous distributions and 5 discrete distributions. Tools Menu- allows you to load other packages and also load R Commander plugins (which are then added to the Interface Menu after the R Commander GUI is restarted). It also contains options sub menu for fine tuning (like opting to send output to R Menu) Help Menu- Standard documentation and help menu. Essential reading is the short 25 page manual in it called Getting “Started With the R Commander”.
R Commander Plugins- There are twenty extensions to R Commander that greatly enhance it’s appeal -these include basic time series forecasting, survival analysis, qcc and more.
Note the naming convention for above e plugins is always with a Prefix of “RCmdrPlugin.” followed by the names above
Also on loading a Plugin, it must be already installed locally to be visible in R Commander’s list of load-plugin, and R Commander loads the e-plugin after restarting.Hence it is advisable to load all R Commander plugins in the beginning of the analysis session.
However the notable E Plugins are
1) DoE for Design of Experiments-
Full factorial designs, orthogonal main effects designs, regular and non-regular 2-level fractional
factorial designs, central composite and Box-Behnken designs, latin hypercube samples, and simple D-optimal designs can currently be generated from the GUI. Extensions to cover further latin hypercube designs as well as more advanced D-optimal designs (with blocking) are planned for the future.
2) Survival- This package provides an R Commander plug-in for the survival package, with dialogs for Cox models, parametric survival regression models, estimation of survival curves, and testing for differences in survival curves, along with data-management facilities and a variety of tests, diagnostics and graphs.
3) qcc -GUI for Shewhart quality control charts for continuous, attribute and count data. Cusum and EWMA charts. Operating characteristic curves. Process capability analysis. Pareto chart and cause-and-effect chart. Multivariate control charts
4) epack- an Rcmdr “plug-in” based on the time series functions. Depends also on packages like , tseries, abind,MASS,xts,forecast. It covers Log-Exceptions garch
and following Models -Arima, garch, HoltWinters
5)Export- The package helps users to graphically export Rcmdr output to LaTeX or HTML code,
via xtable() or Hmisc::latex(). The plug-in was originally intended to facilitate exporting Rcmdr
output to formats other than ASCII text and to provide R novices with an easy-to-use,
easy-to-access reference on exporting R objects to formats suited for printed output. The
package documentation contains several pointers on creating reports, either by using
conventional word processors or LaTeX/LyX.
6) MAc- This is an R-Commander plug-in for the MAc package (Meta-Analysis with
Correlations). This package enables the user to conduct a meta-analysis in a menu-driven,
graphical user interface environment (e.g., SPSS), while having the full statistical capabilities of
R and the MAc package. The MAc package itself contains a variety of useful functions for
conducting a research synthesis with correlational data. One of the unique features of the MAc
package is in its integration of user-friendly functions to complete the majority of statistical steps
involved in a meta-analysis with correlations. You can read more on R Commander Plugins at http://wp.me/p9q8Y-1Is —————————————————————————————————————————- Rattle- R Analytical Tool To Learn Easily (download from http://rattle.togaware.com/) Rattle is more advanced user Interface than R Commander though not as popular in academia. It has been designed explicitly for data mining and it also has a commercial version for sale by Togaware. Rattle has a Tab and radio button/check box rather than Menu- drop down approach towards the graphical design. Also the Execute button needs to be clicked after checking certain options, just the same as submit button is clicked after writing code. This is different from clicking on a drop down menu. Advantages of Using Rattle 1) Useful for beginner in R language to do building models,cluster and data mining. 2) Has separate tabs for data entry,summary, visualization,model building,clustering, association and evaluation. The design is intuitive and easy to understand even for non statistical background as the help is conveniently explained as each tab, button is clicked. Also the tabs are placed in a very sequential and logical order. 3) Uses a lot of other R packages to build a complete analytical platform. Very good for correlation graph,clustering as well decision trees. 4) Easy to understand interface even for first time user. 5) Log for R code is auto generated and time stamp is placed. 6) Complete solution for model building from partitioning datasets randomly for testing,validation to building model, evaluating lift and ROC curve, and exporting PMML output of model for scoring. 7) Has a well documented online help as well as in-software documentation. The help helps explain terms even to non statistical users and is highly useful for business users. Example Documentation for Hypothesis Testing in Test Tab in Rattle is ” Distribution of the Data * Kolomogorov-Smirnov Non-parametricAre the distributions the same? * Wilcoxon Signed Rank Non-parametricDo paired samples have the same distribution? Location of the Average * T-test Parametric Are the means the same? * Wilcoxon Rank-Sum Non-parametricAre the medians the same? Variation in the Data * F-testParametricAre the variances the same? Correlation * Correlation PearsonsAre the values from the paired samples correlated?” Comparative Disadvantages of using Rattle- 1) It is basically aimed at a data miner. Hence it is more of a data mining GUI rather than an analytics GUI. 2) Has limited ability to create different types of graphs from a business analysts perspective Numeric variables can be made into Box-Plot, Histogram, Cumulative as well Benford Graphs. While interactivity using GGobi and Lattiticist is involved- the number of graphical options is still lesser than other GUI. 3) It is not suited for projects that involve multiple graphical analysis and which do not have model building or data mining.For example Data Plot is given in clustering tab but not in general Explore tab. 4) Despite the fact that it is meant for data miners, no support to biglm packages, as well as parallel programming is enabled in GUI for bigger datasets, though these can be done by R command line in conjunction with the Rattle GUI. Data m7ining is typically done on bigger datsets. 5) May have some problems installing it as it is dependent on GTK and has a lot of packages as dependencies. Top Row- This has the Execute Button (shown as two gears) and which has keyboard shortcut F2. It is used to execute the options in Tabs-and is equivalent of submit code button. Other buttons include new Projects,Save and Load projects which are files with extension to .rattle an which store all related information from Rattle. It also has a button for exporting information in the current Tab as an open office document, and buttons for interrupting current process as well as exiting Rattle. Data Tab- It has the following options. ● Data Type- These are radio buttons between Spreadsheet (and Comma Separated Values), ARFF files (Weka), ODBC (for Database Connections),Library (for Datasets from Packages),R Dataset or R datafile, Corpus (for Text Mining) and Script for generating the data by code. ● The second row-in Data Tab in Rattle is Detail on Data Type- and its apperance shifts as per the radio button selection of data type in previous step. For Spreadsheet, it will show Path of File, Delimiters, Header Row while for ODBC it will show DSN, Tables, Rows and for Library it will show you a dropdown of all datasets in all R packages installed locally. ● The third row is a Partition field for splitting dataset in training,testing,validation and it shows ratio. It also specifies a Random seed which can be customized for random partitions which can be replicated. This is very useful as model building requires model to be built and tested on random sub sets of full dataset. ● The fourth row is used to specify the variable type of inputted data. The variable types are ○ Input: Used for modeling as independent variables ○ Target: Output for modeling or the dependent variable. Target is a categoric variable for classification, numeric for regression and for survival analysis both Time and Status need to be defined ○ Risk: A variable used in the Risk Chart ○ Ident: An identifier for unique observations in the data set like AccountId or Customer Id ○ Ignore: Variables that are to be ignored. ● In addition the weight calculator can be used to perform mathematical operations on certain variables and identify certain variables as more important than others. Explore Tab- Summary Sub-Tab has Summary for brief summary of variables, Describe for detailed summary and Kurtosis and Skewness for comparing them across numeric variables. Distributions Sub-Tab allows plotting of histograms, box plots, and cumulative plots for numeric variables and for categorical variables Bar Plot and Dot Plot. It also has Benford Plot for Benford’s Law on probability of distribution of digits. Correlation Sub-Tab– This displays corelation between variables as a table and also as a very nice plot. Principal Components Sub-Tab– This is for use with Principal Components Analysis including the SVD (singular value decomposition) and Eigen methods. Interactive Sub-Tab- Allows interactive data exploration using GGobi and Lattice software. It is a powerful visual tool. Test Tab-This has options for hypothesis testing of data for two sample tests. Transform Tab-This has options for rescaling data, missing values treatment, and deleting invalid or missing values. Cluster Tab-It gives an option to KMeans, Hierarchical and Bi-Cluster clustering methods with automated graphs,plots (including dendogram, discriminant plot and data plot) and cluster results available. It is highly recommended for clustering projects especially for people who are proficient in clustering but not in R. Associate Tab-It helps in building association rules between categorical variables, which are in the form of “if then”statements. Example. If day is Thursday, and someone buys Milk, there is 80% chance they will buy Diapers. These probabilities are generated from observed frequencies. Model Tab-The Model tab makes Rattle one of the most advanced data mining tools, as it incorporates decision trees(including boosted models and forest method), linear and logistic regression, SVM,neural net,survival models. Evaluate Tab-It as functionality for evaluating models including lift,ROC,confusion matrix,cost curve,risk chart,precision, specificity, sensitivity as well as scoring datasets with built model or models. Example – A ROC curve generated by Rattle for Survived Passengers in Titanic (as function of age,class,sex) This shows comparison of various models built. Log Tab- R Code is automatically generated by Rattle as the respective operation is executed. Also timestamp is done so it helps in reviewing error as well as evaluating speed for code optimization. —————————————————————————————————————————- JGR- Deducer- (see http://www.deducer.org/pmwiki/pmwiki.php?n=Main.DeducerManual JGR is a Java Based GUI. Deducer is recommended for use with JGR. Deducer has basically been made to implement GGPLOT in a GUI- an advanced graphics package based on Grammer of Graphics and was part of Google Summer of Code project. It first asks you to either open existing dataset or load a new dataset with just two icons. It has two initial views in Data Viewer- a Data view and Variable view which is quite similar to Base SPSS. The other Deducer options are loaded within the JGR console. Advantages of Using Deducer 1. It has an option for factor as well as reliability analysis which is missing in other graphical user interfaces like R Commander and Rattle. 2. The plot builder option gives very good graphics -perhaps the best in other GUIs. This includes a color by option which allows you to shade the colors based on variable value. An addition innovation is the form of templates which enables even a user not familiar with data visualization to choose among various graphs and click and drag them to plot builder area. 3. You can set the Java Gui for R (JGR) menu to automatically load some packages by default using an easy checkbox list. 4. Even though Deducer is a very young package, it offers a way for building other R GUIs using Java Widgets. 5. Overall feel is of SPSS (Base GUI) to it’s drop down menu, and selecting variables in the sub menu dialogue by clicking to transfer to other side.SPSS users should be more comfortable at using this. 6. A surprising thing is it rearranges the help documentation of all R in a very presentable and organized manner 7. Very convenient to move between two or more datasets using dropdown. 8. The most convenient GUI for merging two datasets using common variable. Dis Advantages of Using Deducer 1. Not able to save plots as images (only options are .pdf and .eps), you can however copy as image. 2. Basically a data viualization GUI – it does offer support for regression, descriptive statistics in the menu item Extras- however the menu suggests it is a work in progress. 3. Website for help is outdated, and help documentation specific to Deducer lacks detail. Components of Deducer- Data Menu-Gives options for data manipulation including recoding variables,transform variables (binning, mathematical operation), sort dataset, transpose dataset ,merge two datasets. Analysis Menu-Gives options for frequency tables, descriptive statistics,cross tabs, one sample tests (with plots) ,two sample tests (with plots),k sample tests, correlation,linear and logistic models,generalized linear models. Plot Builder Menu- This allows plots of various kinds to be made in an interactive manner. Correlation using Deducer. ————————————————————————————————————————– Red-R – A dataflow user interface for R (see http://red-r.org/ Red R uses dataflow concepts as a user interface rather than menus and tabs. Thus it is more similar to Enterprise Miner or Rapid Miner in design. For repeatable analysis dataflow programming is preferred by some analysts. Red-R is written in Python. Advantages of using Red-R 1) Dataflow style makes it very convenient to use. It is the only dataflow GUI for R. 2) You can save the data as well as analysis in the same file. 3) User Interface makes it easy to read R code generated, and commit code. 4) For repeatable analysis-like reports or creating models it is very useful as you can replace just one widget and other widget/operations remain the same. 5) Very easy to zoom into data points by double clicking on graphs. Also to change colors and other options in graphs. 6) One minor feature- It asks you to set CRAN location just once and stores it even for next session. 7) Automated bug report submission. Disadvantages of using Red-R 1) Current version is 1.8 and it needs a lot of improvement for building more modeling types as well as debugging errors. 2) Limited features presently. ———————————————————————————————————————- RKWard (see http://rkward.sourceforge.net/) It is primarily a KDE GUI for R, so it can be used on Ubuntu Linux. The windows version is available but has some bugs. Advantages of using RKWard 1) It is the only R GUI for time series at present. In addition it seems like the only R GUI explicitly for Item Response Theory (which includes credit response models,logistic models) and plots contains Pareto Charts. 2) It offers a lot of detail in analysis especially in plots(13 types of plots), analysis and distribution analysis ( 8 Tests of normality,14 continuous and 6 discrete distributions). This detail makes it more suitable for advanced statisticians rather than business analytics users. 3) Output can be easily copied to Office documents. Disadvantages of using RKWard 1) It does not have stable Windows GUI. Since a graphical user interface is aimed at making interaction easier for users- this is major disadvantage. 2) It has a lot of dependencies so may have some issues in installing. 3) The design categorization of analysis,plots and distributions seems a bit unbalanced considering other tabs are File, Edit, View, Workspace,Run,Settings, Windows,Help. Some of the other tabs can be collapsed, while the three main tabs of analysis,plots,distributions can be better categorized (especially into modeling and non-modeling analysis). 4) Not many options for data manipulation (like subset or transpose) by the GUI. 5) Lack of detail in documentation as it is still on version 0.5.3 only. Components- Analysis, Plots and Distributions are the main components and they are very very extensive, covering perhaps the biggest range of plots,analysis or distribution analysis that can be done. Thus RKWard is best combined with some other GUI, when doing advanced statistical analysis.
Image via Wikipedia
GrapherR
GrapheR is a Graphical User Interface created for simple graphs.
Depends: R (>= 2.10.0), tcltk, mgcv Description: GrapheR is a multiplatform user interface for drawing highly customizable graphs in R. It aims to be a valuable help to quickly draw publishable graphs without any knowledge of R commands. Six kinds of graphs are available: histogram, box-and-whisker plot, bar plot, pie chart, curve and scatter plot. License: GPL-2 LazyLoad: yes Packaged: 2011-01-24 17:47:17 UTC; Maxime Repository: CRAN Date/Publication: 2011-01-24 18:41:47
It is bi-lingual (English and French) and can import in text and csv files
The intention is for even non users of R, to make the simple types of Graphs.
The user interface is quite cleanly designed. It is thus aimed as a data visualization GUI, but for a more basic level than Deducer.
Easy to rename axis ,graph titles as well use sliders for changing line thickness and color
Disadvantages of using GrapheR
Lack of documentation or help. Especially tips on mouseover of some options should be done.
Some of the terms like absicca or ordinate axis may not be easily understood by a business user.
Default values of color are quite plain (black font on white background).
Can flood terminal with lots of repetitive warnings (although use of warnings() function limits it to top 50)
Some of axis names can be auto suggested based on which variable s being chosen for that axis.
Package name GrapheR refers to a graphical calculator in Mac OS – this can hinder search engine results
Using GrapheR
Data Input -Data Input can be customized for CSV and Text files.
GrapheR gives information on loaded variables (numeric versus Factors)
It asks you to choose the type of Graph
It then asks for usual Graph Inputs (see below). Note colors can be customized (partial window). Also number of graphs per Window can be easily customized
Using R from other software- Please note that interfaces to R exist from other software as well. These include software from SAS Institute, IBM SPSS, Rapid Miner,Knime and Oracle. A brief list is shown below- 1) SAS/IML Interface to R- You can read about the SAS Institute’s SAS/ IML Studio interface to R athttp://www.sas.com/technologies/analytics/statistics/iml/index.html 2) Rapid Miner Extension to R-You can view integration with Rapid Miner’s extension to R here athttp://www.youtube.com/watch?v=utKJzXc1Cow 3) IBM SPSS plugin for R-SPSS software has R integration in the form of a plugin. This was one of the earliest third party software offering interaction with R and you can read more athttp://www.spss.com/software/statistics/developer/ 4) Knime- Konstanz Information Miner also has R integration. You can view this on http://www.knime.org/downloads/extensions 5) Oracle Data Miner- Oracle has a data mining offering to it’s very popular database software which is integrated with the R language. The R Interface to Oracle Data Mining ( R-ODM) allows R users to access the power of Oracle Data Mining’s in-database functions using the familiar R syntax.http://www.oracle.com/technetwork/database/options/odm/odm-r-integration-089013.html 6) JMP- JMP version 9 is the latest to offer interface to R. You can read example scripts here athttp://blogs.sas.com/jmp/index.php?/archives/298-JMP-Into-R!.html R Excel- Using R from Microsoft Excel Microsoft Excel is the most widely used spreadsheet program for data manipulation, entry and graphics. Yet as dataset sizes have increased, Excel’s statistical capabilities have lagged though it’s design has moved ahead in various product versions.
R Excel basically works at adding a .xla plugin to Excel just like other Plugins. It does so by connecting to R through R packages.
Basically it offers the functionality of R functions and capabilities to the most widely distributed spreadsheet program. All data summaries, reports and analysis end up in a spreadsheet- R Excel enables R to be very useful for people not knowing R. In addition it adds (by option) the menus of R Commander as menus in Excel spreadsheet. Advantages- Enables R and Excel to communicate thus tieing an advanced statistical tool to the most widely used business analytics tool. Disadvantages- No major disadvatage at all to a business user. For a data statistical user, Microsoft Excel is limited to 100,000 rows, so R data needs to be summarized or reduced. Graphical capabilities of R are very useful, but to a new user, interactive graphics in Excel may be easier than say using Ggplot ot Ggobi. You can read more on this athttp://rcom.univie.ac.at/ or the complete Springer Bookhttp://www.springer.com/statistics/computanional+statistics/book/978-1-4419-0051-7
The combination of cloud computing and internet offers a new kind of interaction possible for scientists as well analysts.
Here is a way to use R on an Amazon EC2 machine, thus renting by hour hardware and computing resources which are scaleable to massive levels , whereas the software is free.
Here is how you can connect to Amazon EC2 and run R. Running R for Cloud Computing. 1) Logging onto Amazon Console http://aws.amazon.com/ec2/ Note you need your Amazon Id (even the same id which you use for buying books).Note we are into AmazonEC2 as shown by the upper tab. Click upper tab to get into the AmazonEC2 2) Choosing the right AMI-On the left margin, you can click AMI -Images. Now you can search for the image-I chose Ubuntu images (linux images are cheaper) and latest Ubuntu Lucid in the search .You can choose whether you want 32 bit or 64 bit image. 64 bit images will lead to faster processing of data.Click on launch instance in the upper tab ( near the search feature). A pop up comes up, which shows the 5 step process to launch your computing. 3) Choose the right compute instance- – there are various compute instances and they all are at different multiples of prices or compute units. They differ in terms of RAM memory and number of processors.After choosing the compute instance of your choice (extra large is highlighted)- click on continue- 4) Instance Details-Do not choose cloudburst monitoring if you are on a budget as it has a extra charge. For critical production it would be advisable to choose cloudburst monitoring once you have become comfortable with handling cloud computing.. 5) Add Tag Details- If you are running a lot of instances you need to create your own tags to help you manage them. It is advisable if you are going to run many instances. 6) Create a key pair- A key pair is an added layer of encryption. Click on create new pair and name it (note the name will be handy in coming steps) 7) After clicking and downloading the key pair- you come into security groups. Security groups is just a set of instructions to help keep your data transfer secure. You want to enable access to your cloud instance to certain IP addresses (if you are going to connect from fixed IP address and to certain ports in your computer. It is necessary in security group to enable SSH using Port 22. Last step- Review Details and Click Launch 8) On the Left margin click on instances ( you were in Images.>AMI earlier) It will take some 3-5 minutes to launch an instance. You can see status as pending till then. 9) Pending instance as shown by yellow light- 10) Once the instance is running -it is shown by a green light. Click on the check box, and on upper tab go to instance actions. Click on connect- You see a popup with instructions like these- · Open the SSH client of your choice (e.g., PuTTY, terminal). · Locate your private key, nameofkeypair.pem · Use chmod to make sure your key file isn’t publicly viewable, ssh won’t work otherwise: chmod 400 decisionstats.pem · Connect to your instance using instance’s public DNS [ec2-75-101-182-203.compute-1.amazonaws.com]. Example Enter the following command line: ssh -i decisionstats2.pem root@ec2-75-101-182-203.compute-1.amazonaws.com
Note- If you are using Ubuntu Linux on your desktop/laptop you will need to change the above line to ubuntu@… from root@..
(Note X11 package should be installed for Linux users- Windows Users will use Remote Desktop) 12) Install R Commander on the remote machine (which is running Ubuntu Linux) using the command
Here are some reasons why cloud computing is very helpful to small business owners like me- and can be very helpful to even bigger people.
1) Infrastructure Overhead becomes zero
– I need NOT invest in secure powerbackups (like a big battery for electricity power-outs-true in India), data disaster management (read raid), software licensing compliance.
All this is done for me by infrastructure providers like Google and Amazon.
For simple office productivity, I type on Google Docs that auto-saves my data,writing on cloud. I need not backup- Google does it for me. Ditto for presentations and spreadsheets. Amazon gets me the latest Window software installed whenever I logon- I need not be bothered by software contracts (read bug fixes and patches) any more.
2) Renting Hardware by the hour- A small business owner cannot invest too much in computing hardware (or software). The pay as you use makes sense for them. I could never afford a 8 cores desktop with 25 gb RAM- but I sure can rent and use it to bid for heavier data projects that I would have had to let go in the past.
3) Renting software by the hour- You may have bought your last PC for all time
An example- A windows micro instance costs you 3 cents per hour on Amazon. If you take a mathematical look at upgrading your PC to latest Windows, buying more and more upgraded desktops just to keep up, those costs would exceed 3 cents per hour. For Unix, it is 2 cents per hour, and those softwares (like Red Hat Linux and Ubuntu have increasingly been design friendly even for non techie users)
Some other software companies especially in enterprise software plan to and already offer paid machine images that basically adds their software layer on top of the OS and you can rent software for the hour.
It does not make sense for customers to effectively subsidize golf tournaments, rock concerts, conference networks by their own money- as they can rent software by the hour and switch to pay per use.
People especially SME consultants, academics and students and cost conscious customers – in Analytics would love to see a world where they could say run SAS Enterprise Miner for 10 dollars a hour for two hours to build a data mining model on 25 gb RAM, rather than hurt their pockets and profitability in Annual license models. Ditto for SPSS, JMP, KXEN, Revolution R, Oracle Data Mining (already available on Amazon) , SAP (??), WPS ( on cloud ???? ) . It’s the economy, stupid.
Corporates have realized that cutting down on Hardware and software expenses is more preferable to cutting down people. Would you rather fire people in your own team to buy that big HP or Dell or IBM Server (effectively subsidizing jobs in those companies). IF you had to choose between an annual license renewal for your analytics software TO renting software by the hour and using those savings for better benefits for your employees, what makes business sense for you to invest in.
Goodbye annual license fees. Welcome brave new world.
Running R on an Amazon EC2 has following benefits-
1) Elastic Memory and Number of Processors for heavy computation 2) Affordable micro instances for smaller datasets (2 cents per hour for Unix to 3 cents per hour). 3) An easy to use interface console for managing datasets as well as processes
Running R on an Amazon EC2 on Windows Instance has following additional benefits-
1) Remote Desktop makes operation of R very easy 2) 64 Bit R can be used 3) You can also use your evaluation of Revolution R Enterprise (which is free to academics) and quite inexpensive for enterprise software for corporates.
You can thus combine R GUIs (like Rattle , R Cmdr or Deducer based upon your need for statistical analysis, data mining or graphical analysis) , with 64 Bit OS, and Revolution’s REvoScaler Package to manage huge huge datasets at a very easy to use analytics solution.
(note if you select SQL Server it will cost you extra)
Then go through the following steps and launch instance
Selecting EC2 compute depending on number of cores, memory needs and budget
Create a key pair (a .pem file which is basically an encrypted password) and download it. For tags, etc just click on and pass (or read and create some tags to help you remember, and organize multiple instances) In configure firewall, remember to Enable Access to RDP (Remote Desktop) and HTTP. You can choose to enable whole internet or your own ip address/es for logging in Review and launch instance
Go to instance (leftmost margin)
and see status (yellow for pending) Click on Instance Actions-Connect on Top Bar to see following Download the .RDP shortcut file and Click on Instance Actions-Request Admin Password
Wait 15 minutes while burning few cents for free as Microsoft creates a password for you Have coffee (or tea is you are health minded) Click Again on Instance Actions-Request Admin Password Open the key pair file (or .pem file created earlier) using
notepad, and copy and paste the Private Key (looks like gibberish)- and click Decrypt.
Retrieve Password for logging on.
Note the new password generated- this is your Remote Desktop Password.
Click on the .rdp file (or Shortcut file created earlier)- It will connect to your Windows instance.
Enter the new generated password in Remote Desktop
Login
This looks like a new clean machine with just Windows OS installed on it. Install Chrome (or any other browser) if you do not use Internet Explorer Install Acrobat Reader (for documentation), Revolution R Enterprise~ 490 mb (it will automatically ask to install the .NET framework-4 files) and /or R
Install packages (I recommend installing R Commander, Rattle and Deducer). Apart from the fact that these GUIs are quite complimentary- they also will install almost all main packages that you need for analysis (as their dependencies) Revolution R installs parallel programming packages by default.
If you want to save your files for working later, you can make a snapshot (go to amazon console-ec2- left margin- ABS -Snapshot- you will see an attached memory (green light)- click on create snapshot to save your files for working later If you want to use my Windows snapshot you can work on it , just when you start your Amazon Ec2 you can click on snapshots and enter details (see snapshot name below) for making a copy or working on it for exploring either 64 bit R, or multi core cloud computing or just trying out Revolution R’s new packages for academic purposes.
4) INSTALL R – Cran R is a standard Ubuntu Package
using
sudo apt-get install r-base
then type R
and install.packages(“Rcmdr”)
Note – you should be able to see the grey colored Tcl/Tpk script showing cran locations
in a seperate window if X11 is working
5) doSNOW package works on the Ubuntu 64- The results are below for
check <-function(n) {check <-function(n) {
+ for(i in 1:1000)
+ {
+ sme <- matrix(rnorm(100), 10,10)
+ solve(sme)
+ }
+ }
>
> times <- 100
> system.time(x <- foreach(j=1:times ) %dopar% check(j))
user system elapsed
0.150 0.080 7.303
> system.time(for(j in 1:times ) x <- check(j))
user system elapsed
27.460 2.300 29.757
The time of 7.3 is almost 5.5 times faster than running it locally on a dual core, and still 3 times faster than running foreach locally. Note I used 4 cores this time in snow.
5) The Tcl/Tk interface of R Cmdr takes a long time to load on EC2 than locally. It may be due to the fact I was running Ubuntu using a VM Player (http://www.vmware.com/go/downloadplayer/ ). However there seems to be a general slowing down when viewing graphics.
His argument of love is not very original though it was first made by these four guys
I am going to argue that “some” R developers should be paid, while the main focus should be volunteers code. These R developers should be paid as per usage of their packages.
Let me expand.
Imagine the following conversation between Ross Ihaka, Norman Nie and Peter Dalgaard.
Norman- Hey Guys, Can you give me some code- I got this new startup.
Ross Ihaka and Peter Dalgaard- Sure dude. Here is 100,000 lines of code, 2000 packages and 2 decades of effort.
Norman- Thanks guys.
Ross Ihaka- Hey, What you gonna do with this code.
Norman- I will better it. Sell it. Finally beat Jim Goodnight and his **** Proc GLM and **** Proc Reg.
Ross- Okay, but what will you give us? Will you give us some code back of what you improve?
Norman – Uh, let me explain this open core …
Peter D- Well how about some royalty?
Norman- Sure, we will throw parties at all conferences, snacks you know at user groups.
Ross – Hmm. That does not sound fair. (walks away in a huff muttering)-He takes our code, sells it and wont share the code
Peter D- Doesnt sound fair. I am back to reading Hamlet, the great Dane, and writing the next edition of my book. I am glad I wrote a book- Ross didnt even write that.
Norman-Uh Oh. (picks his phone)- Hey David Smith, We need to write some blog articles pronto – these open source guys ,man…
———–I think that sums what has been going on in the dynamics of R recently. If Ross Ihaka and R Gentleman had adopted an open core strategy- meaning you can create packages to R but not share the original where would we all be?
At this point if he is reading this, David Smith , long suffering veteran of open source flameouts is rolling his eyes while Tal G is wondering if he will publish this on R Bloggers and if so when or something.
Lets bring in another R veteran- Hadley Wickham who wrote a book on R and also created ggplot. Thats the best quality, most often used graphics package.
In terms of economic utilty to end user- the ggplot package may be as useful if not more as the foreach package developed by Revolution Computing/Analytics.
However lets come to open core licensing ( read it here http://alampitt.typepad.com/lampitt_or_leave_it/2008/08/open-core-licen.html ) which is where the debate is- Revolution takes code- enhances it (in my opinion) substantially with new formats XDF for better efficieny, web services API, and soon coming next year a GUI (thanks in advance , Dr Nie and guys)
and sells this advanced R code to businesses happy to pay ( they are currently paying much more to DR Goodnight and HIS guys)
Why would any sane customer buy it from Revolution- if he could download exactly the same thing from http://r-project.org
Hence the business need for Revolution Analytics to have an enhanced R- as they are using a product based software model not software as a service model.
If Revolution gives away source code of these new enhanced codes to R core team- how will R core team protect the above mentioned intelectual property- given they have 2 decades experience of giving away free code , and back and forth on just code.
Now Revolution also has a marketing budget- and thats how they sponsor some R Core events, conferences, after conference snacks.
How would people decide if they are being too generous or too stingy in their contribution (compared to the formidable generosity of SAS Institute to its employees, stakeholders and even third party analysts).
Would it not be better- IF Revolution can shift that aspect of relationship to its Research and Development budget than it’s marketing budget- come with some sort of incentive for “SOME” developers – even researchers need grants and assistantships, scholarships, make a transparent royalty formula say 17.5 % of the NEW R sales goes to R PACKAGE Developers pool, which in turn examines usage rate of packages and need/merit before allocation- that would require Revolution to evolve from a startup to a more sophisticated corporate and R Core can use this the same way as John M Chambers software award/scholarship
Dont pay all developers- it would be an insult to many of them – say Prof Harrell creator of HMisc to accept – but can Revolution expand its dev base (and prospect for future employees) by even sponsoring some R Scholarships.
And I am sure that if Revolution opens up some more code to the community- they would the rest of the world and it’s help useful. If it cant trust people like R Gentleman with some source code – well he is a board member.
——————————————————————————————–
Now to sum up some technical discussions on NeW R
1) An accepted way of benchmarking efficiencies.
2) Code review and incorporation of efficiencies.
3) Multi threading- Multi core usage are trends to be incorporated.
4) GUIs like R Commander E Plugins for other packages, and Rattle for Data Mining to have focussed (or Deducer). This may involve hiring User Interface Designers (like from Apple 😉 who will work for love AND money ( Even the Beatles charge royalty for that song)
5) More support to cloud computing initiatives like Biocep and Elastic R – or Amazon AMI for using cloud computers- note efficiency arguements dont matter if you just use a Chrome Browser and pay 2 cents a hour for an Amazon Instance. Probably R core needs more direct involvement of Google (Cloud OS makers) and Amazon as well as even Salesforce.com (for creating Force.com Apps). Note even more corporates here need to be involved as cloud computing doesnot have any free and open source infrastructure (YET)
“If something goes wrong with Microsoft, I can phone Microsoft up and have it fixed. With Open Source, I have to rely on the community.”
And the community, as much as we may love it, is unpredictable. It might care about your problem and want to fix it, then again, it may not. Anyone who has ever witnessed something online go “viral”, good or bad, will know what I’m talking about.
Just checked out cool new series from NVidia servers.
Now though SAS Inc/ Jim Goodnight thinks HP Blade Servers are the cool thing- the GPU takes hardware high performance computing to another level. It would be interesting to see GPU based cloud computers as well – say for the on Demand SAS (free for academics and students) but which has had some complaints of being slow.
To give users hands-on experience, the program is underpinned by a virtual computing lab (VCL), a remote access service that allows users to reserve a computer configured with a desired set of applications and operating system and then access that computer over the Internet. The lab is powered by an IBM BladeCenter infrastructure, which includes more than 500 blade servers, distributed between two locations. The assignment of the blade servers can be changed to meet shifts in the balance of demand among the various groups of users. Laura Ladrie, MSA Classroom Coordinator and Technical Support Specialist, says, “The virtual computing lab chose IBM hardware because of its quality, reliability and performance. IBM hardware is also energy efficient and lends itself well to high performance/low overhead computing.
Thats interesting since IBM now competes (as owner of SPSS) and also cooperates with SAS Institute
You’re effectively turbo-charging through deployment of many processors within the blade servers?
Yes. We’ve got machines with 192 blades on them. One of them has 202 or 203 blades. We’re using Hewlett-Packard blades with 12 CP cores on each, so it’s a total 2300 CPU cores doing the computation.
Our idea was to give every one of those cores a little piece of work to do, and we came up with a solution. It involved a very small change to the algorithm we were using, and it’s just incredible how fast we can do things now.
I don’t think of it as a grid, I think of it as essentially one computer. Most people will take a blade and make a grid out of it, where everything’s a separate computer running separate jobs.
We just look at it as one big machine that has memory and processors all over the place, so it’s a totally different concept.
GPU servers can be faster than CPU servers, though , Professor G.
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Usage of accelerated BLAS libraries seems to shrouded in some mystery, judging from somewhat regularly recurring requests for help on lists such as r-sig-hpc(gmane version), the R list dedicated to High-Performance Computing. Yet it doesn’t have to be; installation can be really simple (on appropriate systems).
Another issue that I felt needed addressing was a comparison between the different alternatives available, quite possibly including GPU computing. So a few weeks ago I sat down and wrote a small package to run, collect, analyse and visualize some benchmarks. That package, called gcbd (more about the name below) is now onCRAN as of this morning. The package both facilitates the data collection for the paper it also contains (in the vignette form common among R packages) and provides code to analyse the data—which is also included as a SQLite database. All this is done in the Debian and Ubuntu context by transparently installing and removing suitable packages providing BLAS implementations: that we can fully automate data collection over several competing implementations via a single script (which is also included). Contributions of benchmark results is encouraged—that is the idea of the package.
And from his paper on the same-
Analysts are often eager to reap the maximum performance from their computing platforms.
A popular suggestion in recent years has been to consider optimised basic linear algebra subprograms (BLAS). Optimised BLAS libraries have been included with some (commercial) analysis platforms for a decade (Moler 2000), and have also been available for (at least some) Linux distributions for an equally long time (Maguire 1999). Setting BLAS up can be daunting: the R language and environment devotes a detailed discussion to the topic in its Installation and Administration manual (R Development Core Team 2010b, appendix A.3.1). Among the available BLAS implementations, several popular choices have emerged. Atlas (an acronym for Automatically Tuned Linear Algebra System) is popular as it has shown very good performance due to its automated and CPU-speci c tuning (Whaley and Dongarra 1999; Whaley and Petitet 2005). It is also licensed in such a way that it permits redistribution leading to fairly wide availability of Atlas.1 We deploy Atlas in both a single-threaded and a multi-threaded con guration. Another popular BLAS implementation is Goto BLAS which is named after its main developer, Kazushige Goto (Goto and Van De Geijn 2008). While `free to use’, its license does not permit redistribution putting the onus of con guration, compilation and installation on the end-user. Lastly, the Intel Math Kernel Library (MKL), a commercial product, also includes an optimised BLAS library. A recent addition to the tool chain of high-performance computing are graphical processing units (GPUs). Originally designed for optimised single-precision arithmetic to accelerate computing as performed by graphics cards, these devices are increasingly used in numerical analysis. Earlier criticism of insucient floating-point precision or severe performance penalties for double-precision calculation are being addressed by the newest models. Dependence on particular vendors remains a concern with NVidia’s CUDA toolkit (NVidia 2010) currently still the preferred development choice whereas the newer OpenCL standard (Khronos Group 2008) may become a more generic alternative that is independent of hardware vendors. Brodtkorb et al. (2010) provide an excellent recent survey. But what has been lacking is a comparison of the e ective performance of these alternatives. This paper works towards answering this question. By analysing performance across ve di erent BLAS implementations|as well as a GPU-based solution|we are able to provide a reasonably broad comparison.
Performance is measured as an end-user would experience it: we record computing times from launching commands in the interactive R environment (R Development Core Team 2010a) to their completion.
And
Basic Linear Algebra Subprograms (BLAS) provide an Application Programming Interface
(API) for linear algebra. For a given task such as, say, a multiplication of two conformant
matrices, an interface is described via a function declaration, in this case sgemm for single
precision and dgemm for double precision. The actual implementation becomes interchangeable
thanks to the API de nition and can be supplied by di erent approaches or algorithms. This
is one of the fundamental code design features we are using here to benchmark the di erence
in performance from di erent implementations.
A second key aspect is the di erence between static and shared linking. In static linking,
object code is taken from the underlying library and copied into the resulting executable.
This has several key implications. First, the executable becomes larger due to the copy of
the binary code. Second, it makes it marginally faster as the library code is present and
no additional look-up and subsequent redirection has to be performed. The actual amount
of this performance penalty is the subject of near-endless debate. We should also note that
this usually amounts to only a small load-time penalty combined with a function pointer
redirection|the actual computation e ort is unchanged as the actual object code is identi-
cal. Third, it makes the program more robust as fewer external dependencies are required.
However, this last point also has a downside: no changes in the underlying library will be
reected in the binary unless a new build is executed. Shared library builds, on the other
hand, result in smaller binaries that may run marginally slower|but which can make use of
di erent libraries without a rebuild.
Basic Linear Algebra Subprograms (BLAS) provide an Application Programming Interface(API) for linear algebra. For a given task such as, say, a multiplication of two conformantmatrices, an interface is described via a function declaration, in this case sgemm for singleprecision and dgemm for double precision. The actual implementation becomes interchangeablethanks to the API de nition and can be supplied by di erent approaches or algorithms. Thisis one of the fundamental code design features we are using here to benchmark the di erencein performance from di erent implementations.A second key aspect is the di erence between static and shared linking. In static linking,object code is taken from the underlying library and copied into the resulting executable.This has several key implications. First, the executable becomes larger due to the copy ofthe binary code. Second, it makes it marginally faster as the library code is present andno additional look-up and subsequent redirection has to be performed. The actual amountof this performance penalty is the subject of near-endless debate. We should also note thatthis usually amounts to only a small load-time penalty combined with a function pointerredirection|the actual computation e ort is unchanged as the actual object code is identi-cal. Third, it makes the program more robust as fewer external dependencies are required.However, this last point also has a downside: no changes in the underlying library will bereected in the binary unless a new build is executed. Shared library builds, on the otherhand, result in smaller binaries that may run marginally slower|but which can make use ofdi erent libraries without a rebuild.
And summing up,
reference BLAS to be dominated in all cases. Single-threaded Atlas BLAS improves on the reference BLAS but loses to multi-threaded BLAS. For multi-threaded BLAS we nd the Goto BLAS dominate the Intel MKL, with a single exception of the QR decomposition on the xeon-based system which may reveal an error. The development version of Atlas, when compiled in multi-threaded mode is competitive with both Goto BLAS and the MKL. GPU computing is found to be compelling only for very large matrix sizes. Our benchmarking framework in the gcbd package can be employed by others through the R packaging system which could lead to a wider set of benchmark results. These results could be helpful for next-generation systems which may need to make heuristic choices about when to compute on the CPU and when to compute on the GPU.
Hardware solutions or atleast need to be a part of Revolution Analytic’s thinking as well. SPSS does not have any choice anymore though 😉
It would be interesting to see how the new SAS Cloud Computing/ Server Farm/ Time Sharing facility is benchmarking CPU and GPU for SAS analytics performance – if being done already it would be nice to see a SUGI paper on the same at http://sascommunity.org.
Multi threading needs to be taken care automatically by statistical software to optimize current local computing (including for New R)
Acceptable benchmarks for testing hardware as well as software need to be reinforced and published across vendors, academics and companies.
DECISION STATS 