Functional Analysis by Elias Stein and Rami Shakarchi is a fast-paced book on functional analysis and related topics. By page 60, you’ve had a decent course in functional analysis and you’ve got 360 pages left.
Monthly Archives: February 2012
Facebook meme parody
The current fad on Facebook is 2 x 3 photo arrays. They have a profession name in the tile and the photos have captions like “What society thinks I do,” “What my Mom thinks I do,” “What I think I…
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Using C# like a scripting language
Clift Norris wrote a clever little batch file csrun.bat several years ago. I thought I’d posted it here, but apparently not. If you have a C# program in foo.cs, you can type csrun foo.cs to compile and run the program.…
LISP, CHAP, and FLOP
From the foreword to The Seasoned Schemer: “LISP” originally stood for “LISt Processing.” By the same token, I suppose that the C programming language could have been called CHAP (for “CHAracter Processing”) and Fortran could have been called FLOP (for…
Teach yourself Fourier analysis in two weeks
From William Thompson (Lord Kelvin), 1840: I had become filled with the utmost admiration for the splendor and poetry of Fourier. … I asked [John Pringle] Nichol if he thought I could read Fourier. He replied ‘perhaps.’ He thought the…
Dot, cross, and quaternion products
This post will show that quaternion product = cross product – dot product. First, I’ll explain what quaternions are, then I’ll explain what the equation above means. The complex numbers are formed by adding to the real numbers a special…
Irreproducible research on 60 Minutes
If your research cannot be reproduced, you might end up on 60 Minutes. Two days ago the new show ran a story about irreproducible research at Duke. You can find the video clip here. I believe the 60 Minutes piece…
Hard science, soft science, hardware, software
The hard sciences — physics, chemistry, astronomy, etc. — boasted remarkable achievements in the 20th century. The credibility and prestige of all science went up as a result. Academic disciplines outside the sciences rushed to append “science” to their names…
Globe knots
Here’s a globe knot with 176 facets that a friend of mine, John Venier, tied. See knottool.com for more information on globe knots and other kinds of knots. Update: John sent me another image of his knots. See also his…
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Technology is more than computers
Moira Gunn recently interviewed Michel Stipe and Mike Mills of R.E.M. about how they have incorporated technology into their music. Well there really wasn’t a lot of technology to be thought about when we started. You plugged your amps in…
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Why the symbol for magnetic field is 'B'
I asked on Twitter the other day What is the historical reason for denoting magnetic filed “B”? Eric Eekhoff sent me an answer and with his permission I’m copying his email below: Hi John, I saw your question on your…
Mixing R, Python, and Perl in 14 lines of code
This is a continuation of my previous post, Running Python and R inside Emacs. That post shows how to execute independent code blocks in Emacs org-mode. This post illustrates calling one code block from another, each written in a different…
Running Python and R inside Emacs
Emacs org-mode lets you manage blocks of source code inside a text file. You can execute these blocks and have the output display in your text file. Or you could export the file, say to HTML or PDF, and show…
Programming language popularity
Here are two ways of measuring programming language popularity: Rank by number of questions tagged with that language on Stack Overflow Rank by number of project on GitHub using that language According to this article, these two measures are well…
Example of not inverting a matrix: optimization
People are invariably surprised when they hear it’s hardly ever necessary to invert a matrix. It’s very often necessary solve linear systems of the form Ax = b, but in practice you almost never do this by inverting A. This…
