@JM actually the SSID is considered public information. Even if you disable SSID broadcasting, it's trivial to sniff the packets and obtain it anyway. Similarly for MAC filtering, which is widely recommended: MAC spoofing is so easy it's pointless. In reality it doesn't matter what your SSID is and whether you broadcast it or not; the only important factor is that you use strong encryption (WPA2 and preferably IPSEC as well) with a good password.
@JM personally I use IPSEC with a certificate having a 2048 bit RSA key I generated myself.
@acl Interesting. I suppose I have a soft spot for numerical global optimization for whatever reason, but this does look like some horrible MATLAB code that's been translated literally.
@belisarius Maybe I was born too late, but I always found TAB clear a more interesting type of cola. However, I don't really like cola anyway, so I guess I didn't find it interesting enough to form part of the market it was selling into; maybe a lot of people felt the same way, hence its quick demise...
@OleksandrR I think it's more of "cola that isn't colored traditionally is off-putting". Same thing happened with the clear version of Pepsi, for instance.
@JM You might well be right; people do seem quite wedded to the appearance of foods. I saw an amusing experiment whereby people were offered soup, before and after a toilet brush (straight off the shelf and out of the packet; never been near a toilet or any other unsanitary items) was dipped into it. Most people wouldn't eat it afterwards.
There was also the nice experiment where soup with blue food coloring was mostly rejected by a tasting panel, even if it smelled and tasted the same as an uncolored soup.
@acl I think a "normal" normal cup is meant to have about 100mg. My "normal" cups have way more; probably ~250mg or more. I stopped drinking coffee now, except in the mornings: I drink tea instead now. What put me off mostly was the amount of coffee I drank during exams for my first degree; continuous jittering and heart palpitations are enough to put anyone off for life, I think...
Reminds me: I got my math.SE swag from the post office yesterday. One of the things there is this huge mug. I figure drinking that much coffee will keep me buzzed for the entire day, since I tend to drink black.
@JM Yep, me too (black, that is). I use a drip coffee maker, essentially with the cone completely full, for one cup. In the way of tea, I prefer green tea and Earl Grey.
@JM Yep. I'm not sure how many others have their coffee as strong as that; for me it doesn't taste right otherwise but I never met anyone so far who would happily drink coffee I'd made for myself.
Coffee doesn't work for keeping me awake anymore. That I once had the bad habit of drinking coffee before going to bed may have something to do with it.
@JM Yes, I did that too. I'm not generally good at getting to sleep anyway (it's 2:37 here now) but coffee didn't help. Apart from the heart palpitations, though, what really put me off was the agonizing headache when I'd wake up in the morning and not have coffee right away.
@JM It wasn't that much really; just 5 or 6 cups a day (but full cone each one, so I guess it adds up). But yeah, when I realised I was addicted, that's when I knew it was time to ease up.
@belisarius Oh right, I see. Yes, there are some good tea shops near-ish to here. But generally I get my tea from the supermarket (not too serious about it, really). I should definitely try some more exotic types though.
@belisarius A friend of mine (before he finished his PhD and left our group) was keen on different sorts of tea. Many of them I found too highly spiced... I think I'm quite conservative when it comes to teas (less so with beers!)
@OleksandrR With some of the teas I've tried, my friend put it quite colorfully: "this smells more like something I'd rub on a sore arm than something I'd drink."
Context: I am trying to answer this question about solving the peg solitaire, and I already posted as an answer some code devised for treating the board
as a graph.
The algorithm in Mathematica for solving the problem I implemented there (please don't care to read the code) is a first try bru...
According to Wikipedia: "Some tea bricks were also mixed with binding agents such as flour, blood, or manure to better preserve their form so they could withstand physical use as currency." Eurgh!
@belisarius there we must disagree. It is an infusion created by steeping dried (and fermented, being black tea and all) tea leaves in hot water. How then does it not qualify as being tea?
Here's a conundrum: how to destroy a hard disk in an environmentally responsible manner? I took one apart lately, but the number of pieces that came out was more than I expected, and they aren't recyclable.
How can one convert between the implicit units used by Grid (ems and line height for horizontal and vertical dimensions) and printers points (in GraphicsGrid and Graphics)?
Grid[{{"sample", "text"}}, Frame -> All,
ItemSize -> {{4, 7}, Automatic}]
Row@{Framed["sample", ImageSize -> 60...
@rcollyer Thermite is not so bad I suppose, except that aluminium costs a lot of energy to refine only to turn it to oxide again. But burning PCBs isn't such a great idea, I think.
@belisarius Heike mentioned she liked Twinings green tea a while ago here in the chat. Personally I find it unpleasant, but there is another brand I prefer: Clipper. It's not too bad, though as I say, I'm not exactly a connoisseur of teas.
Fine aluminum dust is a neat thing, tho. Of course, you'll need tinted goggles if you're going to watch it burn up; some of the radiation gets to UV if memory serves...
@OleksandrR It's not the best, but it's not Lipton-level either.
Thermite is a pyrotechnic composition of a metal powder and a metal oxide that produces an exothermic oxidation-reduction reaction known as a thermite reaction. If aluminium is the reducing agent it is called an aluminothermic reaction. Most varieties are not explosive, but can create bursts of extremely high temperatures focused on a very small area for a short period of time. The thermite is simply a mixture of metal, often called the "fuel" and an oxidizer. Its form of action is very similar to other fuel-oxidizer mixtures like black powder.
Thermites can be a diverse class of compos...
@JM I have to admit I never tried burning it. I guess B, Si and C (diamond allotrope) are fairly difficult to combust. Maybe by laser plasma though? That can easily be arranged...
@rcollyer I have worked with some nasty stuff (I will not say what in this public forum), but yes, that looks pretty horrific. The explosive ones are the worst I guess.
@rcollyer I heard a story about a professor who used to do fluorine chemistry years ago. His gas line leaked... and the leak was right in front of his forehead when it occurred, with fluorine at 200 bar. His body was donated to the medicine department and the skeleton is still somewhere around, complete with hole burned straight through the cranium, so I hear.
@JM Only reason I ever had to use ammonium bifluoride is trying to recover sapphire substrates that had been etched using photolithography... it doesn't work, it turns out.
@JM a good God, I would have. Chlorine was nice. The Fe reacting with it was beautiful to watch. My lab partner imprinting the hot glass with his finger prints, priceless.
@JM Sapphire is a great material. We are diamond lovers in my lab, but I think sapphire is highly unappreciated even if it isn't as extreme in its properties as diamond is.
@JM Also, catalysis (AFAI studied at uni) is more effective with small particles (as it is proportional to the exposed surface). Rubies seems to act inversely. Is that a studied phenomena?
@JM General Relativity and Quantum Mechanics are counter intuitive too. One is probabilistic and the other is causal, nonetheless both are right as far as experiments went up to this day. But using rubies as catalysts, being them a few billion years old seems too counter intuitive. Do you have a theory to explain that?
@MrWizard Of COURSE that doesn't mean they will be good moderators. But I prefer high rep people almost always, since they saw many war flames and know they must be stopped before insults arise.
Speaking of rep, I'm only 24 points away from 20K! Unless everyone stops voting for me my answers I should hit it in the next 24 hours. Not bad for less than five months. It's nice that lots of people vote on this site (compared to SO).
@JM I've been using MS-Word since version 2., and each version update is a nightmare. And I use (probably) 10 more text editor environments. I just want to free some neurons for fishing more often.
I'm too lazy to go through the geometric proof at the moment, so I haven't seriously looked into that question. OP could have used a simpler example, though...
@belisarius I haven't looked at that yet. Thanks for pointing it out. By the way, I think it is helpful to point out answers, your own and otherwise, that aren't getting the attention.
@MrWizard agreed with that. If you're like me and don't log in for a few days at a time, it's easy to miss good answers. If they're mentioned here in the chat, it's a lot easier to keep track of activity in chronological order.
@belisarius Word 2000 to XP to 2003 went fairly smoothly for me. So far I've resisted Office 2007 or 2010. (Stupid menu bars require far more clicks to get to any given function.)
@JM I rarely visit SO. The volume of stuff there is just overwhelming, and most of it is crap. I don't have time to browse and pick out the gems (and don't have an SO account anyway).
@JM the ribbon seems to be there for the same reasons as almost all new features since Word XP: to make it easier for people who don't know how to use Word, to blunder through and make a horrible hash of their documents, but sort-of "use" it regardless.
@JM the "auto"-X, Y, and Z functions seem to be particularly targeted to annoy the experienced user. I actually like Word; I consider it the best of the Office applications by far. But I would go mad if I had to use it with default settings.
@JM Which is why I find it particularly irksome that they removed the Save Your Settings tool from Office 2007 when actually (if you install Office 2003 alongside) it works fine! I refuse to use the newer versions out of spite now. :)
Anyway, once again it's getting light, so I probably ought to get to bed if I want to get any work done later today. Bye!
I am looking for pointers on how to pick a set of colours (or a colour gradient) that are clearly distinguishable, for use in scientific figures. Was there any systematic research on this? If yes, I'd appreciate some links.
When creating scientific figures, colour is often used to distinguish ...
@JM I mean this one: mathematica.stackexchange.com/a/6878/57. It was a larger post which has been edited away before being deleted. I got a flag but was still thinking about it when it was gone. Thought you might have been in contact about this or so.
@SjoerdCdeVries I saw the original version; I'm not entirely sure there's something wrong. IIRC it's kosher to show off your own product as long as it's relevant and not done excessively.
(I don't like self-promotion myself, but that's just my opinion.)
@Szabolcs I believe there are various color blindness simulators for iPhone, working on its camera image. You might try that. It's good to know there are three types of color blindness so it might not be the case that one set fits all.
ColorData["TemperatureMap"] is also good. But the consistent recommendation is not to use rainbow-type coloring (jet() for MATLAB users) for serious work.
Sorry to intrude on your conversation. I just discovered a subtle error in my circle spiral program. What is the recommended way to do this? I don't mind deleting the post until I figure a fix, but it seems to suggest I have to go through a voting process.
@Heike I found ways to make it more concise, and then found out there is a subtle error. That is what I get for only checking on RandomInteger. I missed the rare cases where the circle jumps over two underlying circles.
@Heike Out of curiosity, how long did it take you to write your code? It is so elegant, I am jealous :)
Full disclosure: I didn't want to do anything mod-ish because 1) I answered that question, and 2) I haven't seen that dupe thread before. The two aren't exact dupes, but are pretty close. I'd rather we have a canonical question that can have those two questions as dupes.
@SjoerdCdeVries Artes asked to reopen it on the ground that it was specifically about Sine on a unit circle rather than merely a generic complex-value Plot question. Seeing the answers that were already posted I tended to agree. Pardon me if I stepped on your toes in the process; you weren't around at that time or I'd have asked.
@MrWizard This has nothing to do with sensitivities. I.m.o. this question differed from the original one only wrt to the application area, but they are the same in principle. You and I have been closing questions as dupes that differed more than these two, and I just wanted to discuss policy here.
Okay. In light of the answers posted do you think they are different enough? Could we edit the question to better differentiate it from the first while preserving that validity of the answers? Should we?
I am having trouble getting an answer to this question...Am I missing something that anybody can see.
Simplify[Minimize[{(
x (-a + x))/(-a +
H) + (1 - (-a + x)/(-a + H)) ((y (-b + y))/(-b + H) +
H (1 - (-b + y)/(-b + H))), 0 <= a < 100, 0 <= b < 100,
a < x &...
With some diffidence (because there appears to be a Mathematica bug: see below), I would like to offer an answer in the spirit of the OP's original attempt to solve the problem algebraically.
Solution
This problem can be formulated as a binary integer linear program. The reformulation represe...
Preamble
This is a great problem. And here is my first stab at it. This will not be the fastest possible solution (I hope to add some faster ones later), but even it will eat your boards for breakfast, including the full one you started with.
Before we dive into code, I will list the prerequisi...
A symmetry group acts on a set of data structures (the occupancy vectors). The question asks for a procedure to create group-invariant hashes of those data structures. Here is a very general way, requiring only a presentation of the group and explicit definitions of the actions of its generator...
@belisarius Nice. With this and Leonid's answer it should be now easy to check the correctness of my intuition that the number of symmetric situations is relatively low. Have you already tried this?
Went to the beach today and brought back a mauve stinger in a bottle. It glows in the dark if I poke it a bit. I'll let it go tomorrow, hope ti survives til then.
Ohh I see The mauve stinger produces bioluminescent light shows, which are often admired from passing boats, but it also has a reputation as a ferocious stinger.
Thanks to the mention of jellyfish, I now know that the portugese man o'war isn't a jellyfish but a colony of highly specialised organisms, and that blanket octopuses use the tentacles of portugese man o'wars as weapons.
I've got a chance to get a rare Populist badge on English.SE. Will a few of you with accounts there help me get it? I don't even need you to vote for my answer, it's got enough (and that might be vote fraud or something), I just need three votes for the accepted answer. Link