DonGateley

Indeed it does! Thank you.

What are central lines?

If you really want to master Regular Expressions in a way you are not likely to forget do what I did in the '80s. Write a regex interpreter and then a compiler. I was doing a contract for an embedded controller and found a great use for compiled regular expressions within it (I remember every nuance of regular expressions but can't for the life of me remember what my use case was.)

Debugging it was the really fun part but my earlier career with IBM had taught me how to test software effectively and some embedded work with PAL's (an early form of programmable logic) taught me how to really use state machines. I was surprised how little time it took to write and debug. I don't think you can really appreciate the elegant logic of the regular expression language without implementing it.

If they'll give me oldest to newest comment browsing I'll forgive them anything. Well, almost anything.

I'm a big fan of causality and the flow of time.

Yes, constant. For the most important feature it would require two 1k point FFT's and two 1k point IFFT's (possibly reducible to 512 pt) every 22 useconds and for an extended feature, 4k. I don't think Javascript is up to that which is why I mentioned somehow making calls to the native coded FFTW routines. If that can be done from Javscript there should be no problem.

It's actually filtering of the browser's output audio samples that remains a total mystery to me. I'm not sure that even can be done which is why I brought it up.

I've done the DSP work at a high level using Matlab. What I want is to be able to deploy it in the browser, using the FFTW library on the host system, such that whatever audio is emanating from the browser due to an open page, like a music or movie player, is is passed through my DSP filter (which also has an interactive control panel) before being sent to the underlying system's audio sink.

I'm a DSP guy and completely naive relative to web programming. Does this sound like something for which the web audio api is appropriate?

The most obvious deployment to me would be a plugin, assuming one can access the outgoing audio stream, but that would not, of course, be browser agnostic.

I should have looked that up, huh? :-)

"Just as the pigment chlorophyll converts sunlight into chemical energy that allows green plants to live and grow, our research suggests that melanin can use a different portion of the electromagnetic spectrum - ionizing radiation - to benefit the fungi containing it,"

One problem with that. Ionizing radiation is not on the electromagnetic spectrum. It's particles with rest mass.

The article is a little short on attributions. John Cocke and Fran Allen are responsible for the optimizing Fortran compiler and their technical report at IBM detailing and justifying the transformations is still excellent reading.

John subsequently invented Risc architecture and supervised the construction of the first machine because his work with the compiler had led him to the conclusion that, for compilers, existing instruction sets were all wrong. It ultimately became the Power PC architecture.

John also won the Turing award for his many contributions to computer science which didn't exist as a field until long after he began. Or when I began for that matter. :-)

Cooley and Tukey invented the fast Fourier transform although I've read that Gauss had preceded them with little notice. When I was in school it was still called the Cooley-Tukey algorithm and considered a bit of a miracle. FFT rolled off the tongue a bit easier and supplanted the name. At that time the term Digital Signal Processing also remained in the future.

How does this affect physicians?

Cool if you like writing with a log.

"The lyrics to this song are like the anthem of Holden Caufield... a wry, disillusioned, antisocial, anticonsumption, post-war love song. Anyone who ever thought otherwise, is a turd who only loved this song because it was Top 40 and reminiscent of some lost High School dance, despite the fact that the song itself is completely anti-pop."

I sorta hate to break it to you but we knew all that back then. I don't think any other point of view was even considered.

The 30 day delay in effect at the time I bought at $125 to test my first use of the system is the only reason I have three Bitcoin instead of 20. By the time I was approved for quicker purchase the booster rocket had kicked in and I simply couldn't believe the price increase to $200 could last. Ah, well. Story of my life.

If with JavaScript you can apply a user controlled process (DSP) to all audio emanating from the browser then I've got an important project/webapp for someone who knows how.

Gotta wonder, however, why on earth I would share more than that publicly if I wanted to earn anything from it.

I seem to have accidentally inverted my real point. Anonymity will always be possible for a dedicated stalker no matter what these jokers do to eliminate it. My concern is removing it as a straight forward option for the stalkee (which I was.) We're on the same side.

I'm curious why you think it won't re-appear within the Dropbox infrastructure. Do you think they bought it for internal use only?

Do you expect the open source pickup by Multyvac to be a bust?

Has your life ever been repeatedly threatened by a very serious internet stalker behind his own well crafted anonymity?

There are reasons for wanting a mask that are legal, ethical and mandatory. My life is of more than middlin' importance to me.

I totally fail to understand the crass blindness of those who limit their reasoning to their own bland case.

Can an author choose to opt in to Google selling suitably protected full copies with royalties?

This could be great for authors since Google will have already have done all the hard work of creating the electronic object and providing availability.

When I reply to a comment, please leave my browser at the point where I replied (like everything else does) rather than moving me to the top of the comments.

Huh? Does a ChromeOS client exist for Workspaces or is it just "good for" it whatever that means?

I would so like to have all comment threads and sub-threads be collapsible with controls on each entry to control the collapse and expansion of what derives from it.

Darn! The irony would be incomparable!

Me too. Superfluous knowledge to me, however. Could I have traded that learning time for something that was generally useful to me I'd have done so in a heartbeat. Dumbing this process down is an excellent direction.

Would a contribution be tax deductible?

Sorry, but that's just plain wrong. Everything was being implemented in C from embedded control to PC apps with C++ just around the corner.

He sure presages his fate in Infinite Jest. A tragic figure for sure and without peer as a writer/philosopher. I'm 70 and widely read and over those years no author has impacted me like he has (despite his propensity toward shaggy dogs.)

He clearly told us in advance that depression such as his was not to be suffered and when all was said and done he left me sympathetic with that point of view.

Brilliant! But where's the algebra of complex numbers. :-)

I agree about his genius. He went completely outside the box in numerous ways to arrive at his unbelievably simple solution.

His attitude is just as unique as his thought process.

Sorry, but the real and imaginary designation is imaginary. The Fourier transform is just a functional decomposition using the sine and cosine as basis functions (the Fourier basis.) They have some special and useful properties such as being the eigenfunctions of a linear system which make them the preferred basis for most work.

Many other functions could be used in those tables which have the properties of orthogonality and completeness and the decomposition would still be one to one and self invertible. The wavelet transform, for example, which doesn't even pretend to be complex.

It was the understanding of wavelet theory that made me realize that sin and cosine decomposition (the Fourier basis) is just one of many.

There is a whole lot easier a way to understand what the DFT does which doesn't involve complex things. First generate two tables of signals. Each table is a set of signals having the same length and the same number of samples as the signal to be transformed; all signals are sampled at N equi-spaced points in the time interval T.

The 0th entry in the first table is just the number one repeated N times. The 1st entry in the table is a sampled sinusoid with a period exactly equal to T. The 2nd is a sampled sinusoid with a period of one half T (twice the frequency of the 1st.) The third is a sampled sinusoid with a period one 3rd of T (three times the frequency of the 1st.) The fourth has a period one 4th of 1st (four times the frequency of the first.) You get the point. The last entry in the table is a sampled sinusoid with a period of just two samples, i.e. the signal alternates between +1 and -1 throughout its duration. Scratch your head a bit and you'll see that this yields exactly N/2+1 entries.

The second table is the same as the first except that sampled cosinusiods (the quaduratures) are used instead of sinusoids.

Now it's time to do the transform. Multiply the signal to be transformed sample by sample with the 0th entry of the first table and sum the result (the signal processing name for this vector inner product is correlation.) Record that number as the 0th result. Do the same with the 1st signal in the table and record that as the 1st result. Do this until all N/2+1 results are recorded. For mathimagical reasons we call this vector of numbers the "real" part.

Repeat this for the second table (the sampled cosinusoids) and call this vector of numbers the "imaginary" part.

That's it. Those two vectors, which we combine into a N/2+1 by 2 column matrix, are the discrete fourier transform of the signal.

It gets all weird when this is mathimaticalized with complex algebra and the convenient identities and concise notation it puts on the table but that's just artifice and in the end the above is all there is to it. Nature never ever evidenced a truly complex or imaginary signal until Bohr, et. al. found things deep down that couldn't do without them.

Formalizing at it that way, though led Cooley and Tukey to visualize the matrix decomposition that led them to the fast logarithmic time transform that revolutionized signal processing. I think I read that Gauss actually beat them to it but when I was getting educated that part of Gauss's work remained in obscurity and those guys were the gods that had just brought it into the computational realm.