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Submission + - Book Review: Beginning Python Visualization (

aceydacey writes: "Sometimes a picture is worth a thousand words. "Beginning Python Visualization: Creating Visual Transformation Scripts", published in February 2009 by Apress, shows how Python and its related tools can be used to easily and effectively turn raw data into visual representations that communicate effectively. The author is Shai Vaingast, a professional engineer and engineering manager who needed to train scientists and engineers to do this kind of programming work. He was looking for a tutorial and reference work, and unable to find a suitable text, wound up writing his first book. He wrote in the easy and clear style of someone comfortable and engaged with the subject matter.

The book uses several very specific examples that illustrate general principles.

The first example is using GPS data. By using Python one can extract data from GPS receivers and enter it into the computer and manipulate it to do what one wants including creating graphs and charts. In this section he shows how to use CSV, comma separated values, as a most useful file format. He shows show to extract data from real world GPS devices and import it via serial ports and the PySerial module. It would be easy for the reader to duplicate and extend this project.

The heart of the book is coverage of useful examples utilizing MatPlotLib, NumPy and SciPy. These related tools are easy to use and fully integrated with Python. MatPlotLib is for plotting data and graphs, including interactive graphs and image files. NumPy is a powerful math library comparable to commercial tools like MatLab, and SciPy extends NumPy to for the sciences. Examples are numerous and include signal analysis using Fourier transforms.

There is also a section on Image Processing using PIL, the Python Imaging Library. This is used for relatively simple image cropping and sizing and also for bit by bit image processing. Interpolation and curve fitting are also well covered. For anyone wanting an introduction to graphical analysis of statistical data, this would be an excellent resource.

The author is obviously a professional in this field. He has a knack for good organizational style and a pragmatic approach to the work. In the book he says "Most of the time, research is organized chaos. The emphasis, however, should be on organized, not chaos." A real value I got from the book is a better understanding of data files, format, and organization as well as methods and guidelines for selecting file formats and storing and organizing data to enable fast and efficient data processing. It is obvious that this book was written by a practicing engineer.

The theme of the book is that Python can be an all purpose environment for data manipulation and visualization, using nothing but free and open source tools that are easily integrated and scriptable without using multiple programming languages. The book should be an invaluable tool for scientists and engineers but it is also easily accessible to anyone interested in math and data analysis. There is no need for an advanced math background. While, as a matter of full disclosure, I have undergraduate degrees in Math and Physics, I feel the book should be easily accessible to anyone with a solid high school math background who is seriously interested in the subject. The book contains a short introductory tutorial on the basics of Python so anyone familiar with programming in any language should be fine.

The book is an easy read from front to back, and I am sure it will also be a good reference resource for the future. The writing style is very clear and unforced and I found surprisingly few errors. While the Python world has a surplus of introductory and general books, books covering this kind of specific domain are especially welcome, and we could use more on other topics by competent authors.

At 363 pages the book is a surprisingly fast read. Its methodology is to use specific, short code examples to make all the key points. Most of the code samples are well selected, short and written in clear, concise Python. This is not the kind of book that overwhelms you with massive amounts of code. Either the book was well edited or else it was written by an exceptionally lucid thinker, or both.

So, if you want to learn how to process, organize, and visualize data from various sources using the Python language, I recommend this book to you. I have also posted a podcast of an interview with the author at Python411"


Submission + - Best practice for AT UI design

tagishsimon writes: "It is a truth universally acknowledged that where an application is designed well for disabled users it will invariably benefit all other users", according to our in-house Assistive Technology staff. But screen reading software such as JAWS is notoriously incapable — in IE, at least — of reacting to rich web applications using the onreadystatechange event of the XMLHttpRequest object. When considering applications that must serve users of assistive technology, do Slashdotters think a single user interface design for the lowest common denominator — JAWS — is the best way to go, or should designers contemplate different user interfaces appropriate to different classes of users?

Comment Re:Tell it to the people who cannot get broadband (Score 2, Interesting) 279

I've had a number of BT engineers visit the house to try to get DSL working. And they've done some work on the line to improve the signal strength. They conclude that it ain't going to happen; anecdotally, because the line is mainly buried, old, and waterlogged.

As they have reached this conclusion, they've marked my phone line on their database as "cannot get broadband" ... and that's it. They'll make no further attempt / take no further interest / decline any further order from me for broadband.

I cannot give a precise distance to the exchange; the straight line distance looks about 4km, by the roads probably 6 or 7. I know the house a half mile before mine in the direction of the exchange can get a slow broadband. And communities all around mine can get broadband, albeit in a number of cases, from different exchanges.

I'm in discussions with my MP, who's talking, as they do, to the useless secretary of state for business (his advice dated 12 months ago: wait for the market to provide, or maybe knit your own in your spare time - I kid you not), and also to BT regional management and the local development agency.

Comment Tell it to the people who cannot get broadband (Score 4, Insightful) 279

Concerned as I am with slow speeds, I'm more concerned that I cannot at home get broadband at all because there's insufficient regulation of the monopoly landline supplier. BT is not interested in fixing the twisted pair arriving at my house such that ADSL will work. The UK government is not interested in extending the Universal Service Obligation - the thing that forces the monopoly to connect you to the phone system for voice calls - to broadband.

HMG's insistence that broadband is of economic and social importance is just so much humbug and cant if they will not bother themselves to lift a regulatory finger to ensure that the whole population can access at least a basic service.

Perish the thought that the vast additional profit arising out of millions of DSL connections should be put towards improving the basic infrastructure.

But I can get 2kbps downstream (yup, that's right) through my 2.5 or 3G connection. Yay. I think I was getting better than that on dialup in about 1995.

Comment Re:Don't pay for CD from these guys (Score 1) 521

And spread the word. It's all very well a few thousand geeks boycotting them but for it to really hurt we need to explain it (in suitably gentle terms) to the normals.

I'm liking these shirts as a conversation starter - although I give it about two days before Sony have them taken down.

We need to find a way to communicate just how outrageous this is to the people who form the bulk of Sony's market - i.e. NOT US.

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"There is nothing new under the sun, but there are lots of old things we don't know yet." -Ambrose Bierce