Articles

Data Analysis with Stata

Enayetur Raheem — Wed, 22 Jun 2011 01:30:07 +0000

Deck:

With Practical Examples, Codes and Comments

Author(s):

Enayetur Raheem

Clifford Ekwempe

Stata is a popular statistical package for data analysis. This is one of the popular statistical packages that is being used by researchers and practitioners alike. Most notable users are from Epidemiology, Econometrics, Sociology.

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Stata is a popular statistical package for data analysis. This is one of the popular statistical packages that is being used by researchers and practitioners alike. In this article, we outline some of the essential components of data analysis with Stata. The article will be updated from time to time with more data analysis tools.

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Adapted from stata.com

Export a Table Created by R to a TeX File

Tanvir Khan — Mon, 18 Apr 2011 00:53:45 +0000

Author(s):

Tanvir Khan

Producing tables in LaTeX might be a difficult task as we can not just copy and paste a table in the editor; we have to write all the numbers and other codes. But with the help of xtable package of R it is possible to produce all the necessary codes for producing table in LaTeX and also possible to export the codes in a tex file. Suppose we have produced summary statistics for Air Pollution Data and now want to export it to a tex file as a tabular format. Here are the codes-

library(xtable)
data<-read.table("data_air.txt", header=T)
data<-data[,1:4]
s<-summary(data)

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I am using xtable package of R to produce all the necessary codes for producing table suitable for LaTeX, and also discussing how to export the codes to a tex file.

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Tanvir Khan

Add an animated R plot to your LaTeX document

Tanvir Khan — Sun, 10 Oct 2010 06:35:31 +0000

Author(s):

Tanvir Khan

My first introduction with LaTeX was not very pleasant. I got tired and frustrated by writing so many codes for producing a simple document; but a few days ago I could write a function for producing an animated plot in R and also could export it to my LaTeX document with all its animations intact (using animation package of R).

That really made me interested in learning LaTeX; just think a PDF book has animated plots and the readers can rewind and reverse and also can control the motion of the plots just by clicking mouse! It will be very helpful for both the writer and the readers.

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It is possible to animate a R plot and this plot can also be exported to a LaTeX document with all its animations intact. Adding this animated plot to a PowerPoint slide or save it as a flash movie file (that you can upload to YouTube) is also possible. In this article I will try to show how these can be done by some simple functions.

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Tanvir Khan

Installing softwares in Ubuntu without an Internet connection

Tanvir Khan — Sun, 26 Sep 2010 06:54:22 +0000

Deck:

Shows how to install R

Author(s):

Tanvir Khan

I am a new Linux user, for only about 3/4 months I am using Ubuntu. I think the biggest problem a new Ubuntu user faces is the problem of installing softwares (especially if s/he has no or a very slow internet connection). Ubuntu comes with a very good suite of necessary softwares, but it is obvious that we will need to install some others according to our personal needs.

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In this article I discuss about installing softwares for Ubuntu even if you have slow or no Internet connection. Keryx software is useful in offline software installation in Ubuntu. In particular, I will show step by step how to install R in Ubuntu using Keryx.

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Three dimensional plots using rgl package

Tanvir Khan — Wed, 15 Sep 2010 18:06:26 +0000

Deck:

Shows how to make a three dimensional scatter plot in R

Author(s):

Tanvir Khan

We all know that R can do amazing things including 3 dimensional plots. scatterplot3d is probably the most popular package for doing this. But a few days ago I got introduced with rgl package which can do 3 dimensional graphs with some added advantages like we can rotate the plot using mouse, zoom in or out using the mouse scroll wheel and even can play beautiful animations.
The data I have used for all the examples here is-

    X    Y       Z
 2276 1902   156.6
 2925 2138  -274.4
 2209 1777    57.7
 2712 1603   269.4
 3128 1545   391.4
 .... ....   .....

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In this article I will discuss about how to create three dimensional scatter plots using rgl package of R. We can rotate these three dimensional plots using mouse, zoom in or out by mouse scroll wheel and even can play some beautiful animations.

Main Image:

mei2.png

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Tanvir Khan

Some useful bar plots using R

Tanvir Khan — Tue, 14 Sep 2010 15:07:45 +0000

Author(s):

Tanvir Khan

In this article I am trying to show how to produce bar plots using R. Many of my friends think SPSS is the most useful software for producing plots and they keep using it (some of them even use Excel!).
My goal is to show that R can do every type of graphs that other commercial softwares can do. In fact it does much better than the simple point and click packages, as R gives us much better control over our analysis.

The data of my concern is -

   sex income   district
female     21      dhaka
  male     11      dhaka
  male     43 chittagong

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hmmm.jpeg

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Tanvir Khan

How to do this graph using R

Enayetur Raheem — Tue, 27 Apr 2010 03:44:29 +0000

Deck:

R statistics, R package, With example for expressions, text, lines, density plots, shading

Author(s):

Enayetur Raheem

I am showing three examples that will help an average R user to create beautiful graphs. The interesting (may be useful) parts of these examples are the use of some very smart but tricky functions to, for example, add a Greek symbol on a plot, add a title to a plot with some mathematical symbols. In these examples I used expression and paste functions repeatedly. For more examples please see this site.

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poisson-lam2.png

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Poisson distribution with rate=2

GRE (Graduate Record Examinations)

Ehsan — Fri, 22 Jan 2010 15:28:06 +0000

Deck:

Some suggestions and guidelines

Author(s):

Ehsan Karim

GRE is NOT an English proficiency test like ielts / toefl: its a graduate admission measurement test (measures verbal reasoning, quantitative reasoning, critical thinking, and analytical writing skills), based on which scholarship is determined, especially in U.S. universities.

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From the Internet

Emacs, LaTeX and ESS: Shortcuts for Beginners

Enayetur Raheem — Wed, 30 Dec 2009 00:20:06 +0000

Deck:

Emacs, ESS and latex tips

Author(s):

Enayetur Raheem

A list of most frequently used Emacs keyboard shortcuts are given. Shortcuts for Emacs and also for ESS are listed. This file will be updated as I learn more about Emacs and ESS. I was inspired from this site to create this page. I plan to provide more useful shortcuts suitable for those who have just started using Emacs.

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A list of most frequently used Emacs keyboard shortcuts are given. Shortcuts for Emacs and also for ESS are listed. This file will be updated as I learn more about Emacs and ESS.

Main Image:

emacs.png

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By Enayetur Raheem

Using gedit or Rgedit with R

Enayetur Raheem — Sat, 26 Dec 2009 17:17:41 +0000

Deck:

Editor for R statistical package

Author(s):

Enayetur Raheem

Recently I've made the switch from Windows Vista to Ubuntu Linux. After switching, the first thing I needed was an editor for R package. R is my favourite and most-used environment for statistical computing. It is free and simple yet a very powerful tool for simple to high profile statistical computing.

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Main Image:

r_and_gedit.png

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Image created by Enayetur Raheem

A Ready-made Beamer Presentation Template

Rifat Jahan — Thu, 17 Dec 2009 15:02:04 +0000

Deck:

A latex presentation template using Beamer, Version 1.1, May 2, 2010

Author(s):

Rifat Jahan

In this article, a beamer template is provided which can be used as is or with minimum modification. Beamer is used among the scientific community to produce beautiful and fancy presentations where the content is predominantly mathematical. Powerpoint is perhaps better suited for non-mathematical presentations, whereas beamer shines where there is math!

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A ready made beamer template is provided for instant use with minimal modification. Just put your title, name, and slides and you are good to go.

Main Image:

beamer_slide_photo.gif

Main Image Credit:

Image created by Enayetur Raheem

Installing LaTeX on a windows machine

Enayetur Raheem — Tue, 15 Dec 2009 21:05:37 +0000

Deck:

MikTeX, Ghostscript, GSView and WinEdt(R)

Author(s):

Enayetur Raheem

There are probably millions of pages of instructions available on the Internet about how to install LaTeX on an Windows machine. Still, I am writing another one because I always find people around me who needs help in installing the packages.

LaTeX as defined in Wikipedia, is a document preparation system. LaTeX is most widely used by mathematicians, scientists, engineers, philosophers, economists and other scholars in academia and the commercial world, and other professionals.

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There are probably millions of pages of instructions available to install LaTeX on an Windows machine. Still, I am writing another one because I always find people around me who needs help in installing the packages.

Main Image:

miktex.gif

Main Image Credit:

Enayetur Raheem

Applying for Admission in Canadian Universities

Ehsan — Fri, 11 Dec 2009 14:07:42 +0000

Author(s):

Ehsan Karim

Obviously whether you want to get into 'grad studies' is a big decision to take since it involves a lot of money (for applying fees, for english tests, for sending admission packages, eventually airfare etc.). Then there are social and cultural costs: since going abroad for higher studies will probably mean long years apart from home, family and frinds, living in an almost alien environment, not speaking bangla for days. So, be careful what you wish for: your wish might just come true!

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The Canadian education system encompasses both publicly-funded and private universities. Education institutions are not officially ranked in Canada, as all Canadian educational institutions offer high quality

Main Image:

study_in_canada_100_2825.jpg

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Enayet Raheem

For Today’s Graduate, Just One Word: Statistics

Stattler — Fri, 11 Dec 2009 01:18:46 +0000

Author(s):

Enayetur Raheem

Here is an encouraging post in New York Times newspaper about the prospect of statistics as a subject matter that will dominate the world in the coming years. Please spend some time to read it. It is a must -read for those studying statistics, particularly Applied Statistics in Bangladesh. The main report is written by Steve Lohr for the NY Times, published on August 5, 2009. Please read below.

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Here is an encouraging post in New York Times newspaper about the prospect of statistics as a subject matter that will dominate the world in the coming years.

On probability distribution

Enayetur Raheem — Thu, 10 Dec 2009 16:23:02 +0000

Author(s):

Enayetur Raheem

Probability distribution is central to anything that you might think about statistics. There are many terms in statistics which are not readily understandable when you hear them for the first time. As the time passes, you would probably pretend to have understood those mysterious words, yet, they might not resonate very well to you. I can reasonably assume that there are people who would not visualize many things on the first attempt. Probability distribution is one of those terms in statistics that you will hear almost all the time, but would probably find somewhat inconvenient to grasp.

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Probability distribution is central to anything that you might think about statistics. There are many terms in statistics which are not readily understandable when you hear them for the first time.

What do statisticians do?

Stattler — Fri, 11 Dec 2009 01:20:37 +0000

Author(s):

Stattler.com Staff

Statisticians help determine the sampling and data collection methods, monitor the execution of the study and the processing of data, and advise on the strengths and limitations of the results. They must understand the nature of uncertainties and be able to draw conclusions in the context of particular statistical applications.

Surveys: Survey statisticians collect information from a carefully specified sample and extend the results to an entire population. Sample surveys might be used to:

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Statisticians help determine the sampling and data collection methods, monitor the execution of the study and the processing of data, and advise on the strengths and limitations of the results.

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Planche_de_Galton.jpg