How to Run Batch Operation on Cluster Computer

If you are pursuing your higher studies in the field of machine learning, its very likely that you have to “deal” with big data. By “deal”, I mean you might have to extract features, or say for example, find the eigenvectors and eigenvalues of large matrices. Carrying out these types of simulations on real or synthetic data on typical desktop/laptops may take days to run. Its suggested that you run these simulations on your University’s super computer or cluster computer. I am assuming that you have access to such a cluster.

These clusters are typically multi-core computers with huge amount of RAMs and tremendous processing powers. But you cannot just run any code on these clusters. You need a batch script (SLURM) to utilize the resources. You have access to a front end node and through that node you have to submit your batch job. I will show how to run a MATLAB code on the cluster using the sbatch command. I am assuming that you are on MacOSX/Linux and can use the terminal. If you are on Windows, install PuTTY to emulate the terminal.

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How to Get Working Internet on Linux Mint/Ubuntu from Behind A Squid Proxy

Almost all of us have to encounter proxies in our work environments. Sometimes those are useful (providing security and firewall), and sometimes those are just a pain. For example, at my work place, I have to go through a Squid proxy. In this tutorial, I will show how to set a Linux Mint/Ubuntu (and possibly other distros) computer to get “internet connection” from behind a proxy. By “internet connection”, what I mean is to get the Synaptic package manager (or APT) and other applications (like the browsers) send http requests through the proxy. Let’s get to it.

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Home Networking: File Transfer

Many of us have two or more computers at our home and like to share files between these PCs. If you don’t have a huge PenDrive or portable HDD or a DVD writer, then you might have problem to transfer large files from one PC to another. You can easily create a Local Area Network (LAN) among the computers for sharing files among the PCs.

This article shows how to connect two PCs using a cross-over LAN cable for file sharing purposes.

Here are the descriptions of the PCs

PC1: Ubuntu 8.04 with a Tenda 10/100Mbps LAN card
PC2: Windows XP Profesional with Built-in 10/100Mbps LAN card

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Changing the default ‘generic’ kernel to ‘server’ kernel in Ubuntu

If you install Ubuntu from the live cd or alternate install cd, the ‘generic’ kernel would be installed by default. The ‘generic’ kernel focuses on i586 and i686 CPU architectures. But if you have a newer CPU, like Pentium 4 HT, Dual Core or Core2Duo, you might want to install the ‘server’ kernel to improve your PC performance. The ‘server’ kernel focuses on i686 architectures and posses some unique advantages over ‘generic’ kernel in case of task management.

Note that you should not change the default kernel if you don’t have a CPU that belong in the families stated above. And also be aware of the fact that kernel changing might cause big problems in your computer [such as making the system unstable!].

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Installing LaTeX on Ubuntu

LaTeX is a very handy and commonly used for editing professional style documents. It is mainly used for writing scientific papers, reports, articles and any official documents.

In Windows, usually we use WinEdt as front end LaTeX editor and Texlive or Miktex as compiler. Texlive is available through Ubuntu repository. But Miktex is not so easily installable in Ubuntu. You have to compile it from scratch after downloading the source from

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Connecting to the Internet with Sony Ericsson K550i in Ubuntu

When I first installed linux, my nightmare was to connect to the internet. I had an internal modem, but as it was very old, my linux distros [Fedora Core 4, Ubuntu 6.06 LTS] didn’t have driver for it. I googles for my modem’s driver and found one. But I couldn’t make it work.

Anyway, now I have a Sony Ericsson K550i phone which I use as an EDGE modem. Sony Ericsson does not provide any driver or PC suit software for linux. The phone driver is not required because linux detects it easily. The trick is to get connected to the internet using it.

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Instaling MATLAB R2007a on Ubuntu

One of the most prominent reason’s for which I had to stay in Windows was MATLAB. As an engineering student, I need MATLAB very often. But I didn’t find MATLAB CD/DVD for linux in the computer markets of Dhaka. I have installed VMWare Server on my Ubuntu and installed Win XP inside the virtual machine and thereby tried to use MATLAB in linux. But the performance was too poor to be useful. At last I got MATLAB R2007a Unix DVD and thought “wow, now i don’t have to stay in windows!!”. I am giving here the complete procedure of installing MATLAB R2007a Unix on Ubuntu 8.04.

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