Getting Started with
Computing in Economics

- last updated August 15, 2013 -


Access to MTSU's computing facilities and what is available

What programs should I consider?

General purpose programs

Programs to work on or connect to a MTSU server

Math programs

Programs to produce good-looking equations and text

Statistics/Econometrics programs

Mapping and Visualization

How do I run programs that are located on a server?

Accessing programs on a server via PUTTY

Accessing programs on a server via PUTTY and Xming

How do I set up the X-Windows program Xming on my PC?

 


Access to MTSU's computing facilities and what is available

1. Much of your work will be done on one of three computers: Beast, Beast2, and Nitti. The first 2 are department servers, the third is a server managed by ITD for the university at large. Addres questions on the first two to Dr. Zietz. All of these computers  require that you establish a VPN connection to MTSU first. How to accomplish that is communicated by ITD.

2. Regardless of the machine you are using, you will need to become familiar with a number of programs that will allow you to do your work on these servers. The programs that you will need will be discussed in some detail below.

3. As an MA or Ph.D. student, your can request an access card  to the graduate PC lab in room BAS N304. You will get the key from the department secretary. All of these PCs have an Internet connection, allow access to the three servers without VPN access, and have a number of core programs installed. In particular, each one of the 8 PCs is likely to have at least the following programs installed:

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What programs should I consider?

The description below goes by the assumption that you want to conduct much of your work from your desktop computer at home or from your labtop. Since the Business School computer lab lab tends to be busy, noisy, and not conducive to thinking, the only viable option for work on a campus machine is to work at one of the computers in the Ph.D. lab on the third floor of BAS (N304) or on one of the computers in the library.

Note that the discussion that follows is specific to computers running Microsoft Windows. If you have a different operating system, such as a MAC OS, or LINUX, you will be on your own in finding the equivalent programs that fit your machine configuration. However, this should not discourage you from choosing a non-Windows environment for your computing, especially if you are short on money. In fact, you can download ready-to-run free-of-charge Linux distributions with lots of programs that allow you to do everything that is described below and more. Getting familiar with Linux also has the advantage that the command and file structure is the same one that you will find on the three servers mentioned earlier. If you are new to Linux, please consider one of the many LIVE-CD or LIVE-DVD distributions that boot up from a CD or DVD drive in almost any PC and do not touch the harddisk. Hence, you cannot mess up the operating system that is installed on the computer. All that you need for your work is a USB flash drive to save your work and configuration. In order to run these LIVE-Linux distributions you will need to change the boot order of your PC. It needs to first boot from the CD or DVD drive, not from a floppy, and not from the hard drive. Many of the Live-CD or DVD distributions can be loaded on a harddrive to replace Windows as your standard operating system. Ubuntu is the distribution that is by far the easiest to deal with.

Additional information on programs that are useful for economists and are available for Linux as well as Windows is provided here.

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General purpose programs

a. Consider an Internet browser that is relatively safe and eliminates pop-ups. Mozilla Firefox appears to work well in this respect, is available free of charge, and nicely transfers bookmarks and other settings from your present browser. So you do not have to redo everything. However, you can, of course, continue with the browser that you are currently using.

b. An Office Suite, with word processor, spreadsheet, and presentation software. Most people use the Microsoft Office Suite. If you would rather not spend that much money on an office suite, you can download LibreOffice free of charge. This office suite is quite good and pretty compatible with Microsoft Office.

c. Adobe Acrobat is essential to read files on the Internet and to communicate with people that use different word processors and other programs. Acrobat Reader is available free of charge from Adobe. However, for all practical purposes, the free reader will not get you through your graduate program. You will also want to produce Acrobat files. You can do that if you download and install the free software pdfcreator.

d. Use your MTSU email account for all your school work and completely separate school email from private email.

e. Internet security programs are important. You do not want to become known for spreading viruses to instructors or fellow students by carelessly neglecting basic security precautions. You also want to make sure that all your work on your computer is not wiped out by some undetected virus or other avoidable problem. You should consider the following precautionary measures: (i) Log onto www.microsoft.com and check for security updates for your Windows program. This is an indispensable security measure. Do this every week and download and install all critical updates. You will need to use Internet Explorer for this operation. Mozilla Firefox will not work for Windows updates. (ii) Install an antivirus program. There are some free programs out there. A good choice is AVAST. (iii) Back up all your work on a flash drive. Hard disk crashes do happen, typically when you least expect them. Leave a copy of your work some place other than your home, just in case. (iv) Install on your computer a program to remove ad-ware. These are markers left on your computer by web pages you visit. By running an ad-aware program once a week or so, you can eliminate this nuisance and also keep your computer from slowing down over time. Try either Spybot or Ad-aware. Both are free of charge for personal use.

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Programs to work on or connect to a MTSU server

a. An FTP (File Transfer Protocol) program allows you to move files from your computer to a server and vice versa. Consider the WinSCP program that is free of charge for academic use. This program is helpful, for example, when you spend much time on preparing input files for a program that you may not have on your home computer, such as the statistical package STATA. Instead of working on your files online and editing them with a file editor on Frank that you are not familiar with or do not like, you can make use of the familiar programs that you have on your home computer to edit your input files. As a note: MS Word is not a useful program editor because it inserts all sorts of codes into the file that cause errors in other programs! Crimson Editor is a better and free alternative. If you use Crimson Editor as your file editing program, you can ftp your file directly to a server or retrieve a file from the server, all without ever leaving the editor.

b. To work on a server, that is, to run programs, or to create, edit, or delete program files, you will need a PC program that converts your home computer into a remote terminal. Use the program putty for that purpose. Putty allows some limited cut and paste operations similar to those on your Windows PC. The big disadvantage of Putty: you cannot see any useful graphical output on your screen from any of the programs running on Frank. To get a graphical interface, you will need to supplement it with an X-Windows program as in the next section below. Putty by itself is typically used to run server programs in batch mode. Batch mode means that you submit a program input file that contains all commands for the program you are using (possibly hundreds of commands). After the program has run, you can look at the results and/or the error messages in the output file that was created by the server program. When you are running large programs, batch mode is often preferred over interactive mode in a GUI environment because you can easily correct a mistake and resubmit your complete program in very little time. To get graphical output from batch files, you will typically have to write some program code to make the server program dump a graphical output file onto your server account. The code differs from program to program. If you would rather see a graph on the screen as you are running a server program, you will again need to use a GUI interface to interact with the server. These GUI interfaces are known as X-Windows programs. More on that in the next section.

c. X-Windows programs simulate a Windows like graphical user interface on your PC while you are connected to Linux server. Use the free X-Windows program XMing. It is highly recommended that you install it on your personal computer. Instructions on that are provided further below.

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Math programs

As you are going through ECON 6100 and other courses in the graduate program, you will find it helpful to have at your disposal a computer program that can deal with numeric or symbolic math problems. Click here for an overview of these types of packages and additional links.

There are many online sources that get you started in the use of two popular commercial packages. The Maple and the Mathematica web sites are also very good starting points to look for applications. Both packages have special pricing for students.

If you would rather not spend any money on computer algebra software, Maxima is a good choice. Maxima is a powerful and reliable program that is available for free. It is based on the discontinued Macsyma program originally developed at MIT and it is very similar in its command structure to Maple. As of late, it has become even more userfriendly because of the GUI frontend called wxmaxima. Wxmaxima turns Maxima almost into a point and click math program. Download the complete Maxima/Wxmaxima package from here.

Think of Maxima and its commerical cousins as symbolic calculators that allow you to differentiate, integrate, solve equations etc. Another set of math packages are designed more with numerical calculations rather than symbolic manipulations in mind. Matlab is the foremost commerical package in this category. It is available on 5 computers of the Ph.D./graduate student lab, but also on Nitti. It is very popular in quantitative macroeconomics. If you are interested in that area, you may also want to take a look at the program Dynare, which allows you to solve stochastic dynamic general equilibrium models without too much fuss.

Since Matlab is expensive, few students end up buying it. Most load a Matlab clone on their computer. Its name is Octave. Most Matlab programs run in Octave, except those that require special Matlab add-on packages called toolboxes.

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Programs to produce good-looking equations and text

Sooner or later you will run into the problem that you have to produce papers that contain a fair amount of equations. Ordinary word processors are not very good at equations. They need extra help. This also applies to Microsoft Word, although the lastest versions have improved in that respect. When you installed Microsoft Office, you are likely to have chosen the "standard install" option. This automated installation mode leaves off the equation editor. Hence, you will have to reinsert the installation CD and add the installation of the equation editor. Once the equation editor is installed, you should use it for all your math!

As you go through the graduate program, you may notice at some point that some of your instructors and fellow students at MTSU or at other universities produce printed output of technical papers that look perceptively better than anything that you have been able to produce with Word and the equation editor. Most likely you have seen output from a TeX or LaTeX program. These are mark-up writing programs that have text attribute codes embedded in the text to identify the formatting that is to be done by a separate compiler. These programs take a little getting used to since they are typically not of the what-you-see-is-what-you-get type, such as Microsoft Word. They are more like the early wordprocessors on mainframe computers in the late 1970s and early 1980s, such as IBM-Script, that also required two steps: first write an ascii file with typesetting commands, then submit it to a compiler to get the typeset output. Your best bet is to install the program Lyx with MIKTEX in the background as your LATEX compiler..

Scientific Workplace from MacKichan Software is a commercial program that works similar to Lyx for Latex typesetting, but adds a powerful computer algebra system similar to Maple. This allows you to type an equation into your document, leave the cursor on it, hit a solve button, and then get the solution to the equation right in your document. This convenience will cost you $245 if you are a student, far more later. It will give you a word processor that can handle difficult math with ease and looks very professional.

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Statistics/Econometrics programs

As you will discover early on in your graduate study, economics does not only require a heavy dose of mathematics but an equal if not larger dose of statistical methods. In fact, much of economics is inconceivable without recourse to the analysis of data using statistical methods. If you would like to have access to an online easy-to-read overview of statistical techniques, bookmark this site.

There is a fair number of programs available on Frank that allow you to do your statistical work. MTSU's Office of Information Technology provides a brief overview of what is available. However, this list is somewhat outdated and therefore not complete. It also does not mention the programs that you find in the Ph.D. lab in BAS - third floor. Additionaly, there is a large number of statistical programs available on the Internet (see also here). This is not the place to go through all of the available programs. Let me just mention a few points that one needs to understand to avoid getting overwhelmed.

(i) SAS is a general purpose statistical program that has been extended over the years in all sorts of directions. You will need to become familiar with it if you plan to join a company, such as FED EX. It is heavily used in industry, but rarely anymore in academics. You can invoke SAS on Nitti simply by typing "sas". This will work both in Putty and in X-Windows mode. The full documentation for SAS is available on the SAS web site.

(ii) STATA is the most popular general purpose package in academics these days. It available on all MTSU servers. Use "stata" in Putty and "xstata" if XMing is up and running to get a graphical interface; xstata-mp invokes a large memory version that can handle millions of observations. If you plan to do work of this nature, you will need an account on the server Beast2. The xstata version is point and click and, therefore, provides a good overview of what is available. Make use of its help facility to learn more. The following introduction may be helpful. It is part of the UCLA Stata Portal.

(iii) As mentioned above, there are numerous very useful statistical packages available free of charge. For a general stastistical package, consider R. This is a free clone of the commercial package S-Plus. R is a favorite with statisticians all over the world. Hence, new estimators are likely to be available relatively fast in R. The program runs well on a PC and produces nice graphs, once you get used to its somewhat idiosyncratic syntax. By far the most user-friendly econometrics program that you can download for free is called GRETL. It is "point and click" but also allows you to run commands in batch mode, with commands that are very simple and intuitive. 

 

Mapping and Visualization

If you are doing some spatial analysis later in your graduate program, consider the following alternatives to the commercial package Arcview: GeoDa and Quantum GIS. Both can do most of what Arcview can do and then some, but they are free of charge. The program R also offers an increasingly large array of packages that allows you to do spatial analysis.

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How do I run programs that are located on a server?

Accessing programs on a server via Putty

The first step in using PUTTY is to configure the program PUTTY after you have installed it. I will describe the installation so you can also easily combine PUTTY with the X-Windows program XMing later. You will get the following interface


In the space entitled Host Name, type the address of your server, such as beast.mtsu.edu. In the line below, click on SSH. In the left frame of the PUTTY configuration screen, you will need to click on SSH-Tunnels. Depending on your version of PUTTY, you will get something similar to the following

Click in the space for Enable X11 forwarding. Next, click again in the left frame on Session to get back to the earlier screen.

Type the name of your server, e.g.  beast.mtsu.edu into the space below Saved Sessions. Then click the Save button. Now you have installed PUTTY to run your server sessions either in batch mode or in X-Windows mode via the program XMing, which is discussed in the next section.

 

Accessing programs on a server via PUTTY and XMing

Let us assume that you have the program XMing set up on your PC (See the next section on how to do that). First, click on the Xming icon on the desktop or on the equivalent START>ALL PROGRAMS>XMING>XMING sequence. Use the Xming icon not the XLaunch icon! Once Xming is started, its icon will appear in the system tray in the lower right-hand corner of the Windows desktop.

Second, start the program PUTTY by clicking on the server address in the Saved Sessions area; then click Load, followed by Open.

You will get a server prompt that let's you log in

Log in to get a server prompt. Now you can call up any graphical program version that runs on the server. Notice below what happens when I give the command xstata in PUTTY. It somehow miraculously brings up the graphical version of STATA on your Windows desktop. This is accomplished by Xming, which is running the background.

The STATA you are seeing is running on the server. As a consequence, you can access all files on the server, but of course none of your Windows PC files. However, you can copy and paste from your XSTATA screen into a program on your Windows PC, such as Word. For example, by right-clicking your mouse when it is in the REVIEW area of STATA, you can copy all previously given commands to the clipboard and then paste the clipboard into a PC Windows program of your choice.

You communicate with the program just as you would if you had a Windows program in front of you. To exit STATA, simply click File and Exit. Once you exit STATA, you will get a server prompt back on your PUTTY screen.

Now you can launch another X-Windows program of your choice. For example, to launch the graphical PC-Windows like version of SAS, simply type sas. To launch the graphical version of Matlab, type matlab.

A note on printing:

Do not try to print what you see in Maple or in other X-Windows software on your screen when you are running Xming. You need to save your work to a file on the server (use FILE>SAVE AS or FILE>EXPORT), then FTP the file to your PC. 

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How do I set up the X-Windows program Xming on my PC?

First, download the software from the following site. Download both the Xming program and the Xming-fonts.

 

The download generates the two files below.

Double-click the first one. Follow the defaults during the installation process except as noted.

 

 

Create an icon on the desktop for Xming and XLaunch.

Unmark the Launch button because the fonts need to be installed first!!

 

Now, the Fonts need to be set up. Double-click the installation file.

 

 

YES, install in the same directory as the program!

 

 

Install mark the 100dpi fonts and the DejaVu TTFs. This is the end of the installation. Xming is now ready to run.

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Author: Joachim Zietz, jzietz@mtsu.edu
Original file location: http://www.mtsu.edu/~jzietz/module1/page-1.html