mjw

22 ms·

151.
by mjw 15y ago
To be an utter pedant, that's quadratic not exponential growth :)
152.
by mjw 15y ago
Ask a silly question, get a silly answer: for i = 0 to ackerman(list.length, list.length) pass return quicksort(list);
153.
by mjw 15y ago
Would someone be willing to do a quick "for engineers" précis of the core ideas of his theory of constraints? I ask as I've seen The Goal and some other books of his on a colleague's desk. Have to admit that on the surface it does look like
154.
by mjw 15y ago
You can have the 'customer pays' model in Britain too if you want it - just roll up to a BUPA (or some other private) hospital and whip out your wallet.
155.
by mjw 15y ago
Good points. To add to this: if you want an intermediate path that'll give a bit more insight than just basic linear algebra, reading a bit about Hilbert spaces might be worthwhile too. Depending which space(s) you choose to work in, it doe
156.
by mjw 15y ago
Assuming it's consistent, that is! Perhaps they shouldn't be so ready to belittle their competitors -- you never know, ZFC might yet turn out to share all the advantages of Falso :)
157.
by mjw 15y ago
Interestingly I was reading a paper about this the other day: http://faculty.cs.tamu.edu/ioerger/ICAI04-linli1.pdf It uses textbooks as its example too :) There seems to be a reasonable amount of literature on algorithms for this kind of
158.
by mjw 15y ago
Nevertheless there is this useful notion of addition for ordinal numbers, as well as multiplication, exponentiation and so on. And so the 'omega + 1' notation is common. It is an ambiguous notation though -- you need to know whether it's or
159.
by mjw 16y ago
Not that this helps, but: always worth asking whether an 'average' is a mean (likely to be skewed higher by a heavy tail of high salaries in certain industries, certain areas etc), or a median.
160.
by mjw 16y ago
One advantage it has over Scala is that it doesn't do erasure of type parameters. I wonder how this works when it comes to interop with existing Java code though. The other broad advantage seems to be that it's designed with a bit more rest
161.
by mjw 16y ago
Is anyone here applying abstract algebra to technology projects which might interest us HN readers? I studied it as an undergraduate; when I think about applications I've found in technology work and computer science, the following spring t
162.
by mjw 16y ago
Ouch. This affects JRuby, and potentially anyone with a JSON-based API running on the JVM with a JSON parser using the java stdlib to parse JSON floats: jruby-1.5.2 > JSON.parse('{"float": 2.2250738585072012e-308}') ^C^C^C^C
163.
by mjw 16y ago
My lessons from painful rewrites: Even if you have little time to invest in refactorings along the way, at least do this: try and plan from the start to componentize wherever practical as you go along -- as soon as you start to get a decent
164.
by mjw 16y ago
I wondered this too as an amateur. Although how about this: Normally the emergence of a contradiction in the course of a proof serves as a red flag that something's wrong. When proving by contradiction, you're operating without the safety o
165.
by mjw 16y ago
(Incidentally, does anyone know if one needs to do anything special to post these threads to the 'ask' section?)
166.
Ask HN: Good masters programmes for 'smart-ups' / late-20s career advice
6 points by mjw 16y ago|2 comments
167.
by mjw 16y ago
In general it'd be reducible to the halting problem, if you allowed a Turing-complete language for the number-generating programs. I imagine you could tackle a good subset of the problem though with a symbolic algebra package (mathematica?)
168.
by mjw 16y ago
Good point in that the aesthetics of a model are in the eye of the beholder - although: > that does not make a simple model better than a complex model that matches observation better Perhaps this is less of an issue in physics than som
169.
by mjw 16y ago
I'm not convinced by Cyc either, but this argument is a bit off. A system like this would need to define axioms and inference rules. But it wouldn't need to collect upfront a database of every possible inference which might be made from the
170.
by mjw 16y ago
[only tangentially related to the sentiment here but:] There is this tendency (which I can sympathise with but only to an extent) in mathematics and to an extent computer science. "Let me solve the problem once, in as general and as abstrac
171.
by mjw 16y ago
Well, I think you'd want to think carefully before pulling things out of HTTP and forcing HTTP to sit on top of a stateful, session-based protocol in order to achieve them. The statelessness of HTTP is one of its major strong points, making
172.
by mjw 16y ago
Gotcha. Is there not any scope for improvement on this front using alternative HTTP auth schemes though? (As far as I'm aware the standard has room for schemes other than Basic and Digest, although I suppose limited to the challenge-respon
173.
by mjw 16y ago
What about for SSL-based APIs? it seems a pretty optimal choice for those.
174.
by mjw 16y ago
It's certainly not dead when it comes to RESTful web services APIs. It's often the best choice for authenticating these. In a browser context, most of the UI criticisms have little to do with the protocol itself and could be easily addresse
175.
by mjw 16y ago
To the downvoter - curious what exactly you disagreed with?
176.
by mjw 16y ago
I see it as a high-level vs low-level thing. The relational model is a high-level language for describing the structure of data. And a pretty elegant one if you can look past the awkwardness of dealing with current SQL databases (not a faul
177.
by mjw 16y ago
I too have noticed that some testing practises seem to be particularly optimal for (and preferred by) consultants and agencies working on short-to-mid-term web development projects. When they go on to over-generalise TDD as the one true 'pr
178.
by mjw 16y ago
Nor does the emergence of a new design methodology preferred by some programmers in some situations, in itself serve as a reason to dismiss older processes out-of-hand as "flawed" and the new process as "better". There's a big difference be
179.
by mjw 16y ago
For sure. Hence the need for browser vendors to provide hooks - via new HTML5 form attributes, a Javascript API, or ideally both, to enable us to develop our own, usable HTML-based session login and logout forms with HTTP auth.
180.
by mjw 16y ago
I'd be interested to hear thoughts on HTTP digest auth as an alternative to full end-to-end encryption for avoiding these attacks. Personally I'm hopeful that Firesheep will be what it takes to persuade browser vendors (and the HTML5 crowd)

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