What's the difference between stochastic and random?

Question: What's the difference between stochastic and random?
Comment: There is none. $ $
Comment: I don't like the term "random" because its vague and people misconstrue it as "evenly distributed", but I know of no technical difference.
Comment: @bgins Any example of occurrences of "stochastic variable", WP excepted?
Comment: I agree with @AlexBecker. I would only add that random has many connotations (like entropy), not at all equivalent, and is a more generic term usable outside mathematics. Stochastic means nondeterministic or unpredictable. Random generally means unrecognizable, not adhering to a pattern. A random variable is also called a stochastic variable. Do random numbers exist? We speak of pseudorandom numbers.
Comment: ... but I think that there is no a crucial difference in the meaning, only the difference in terminology used by different groups of scientists. I can say that also in Russia the equivalent of 'random' is used in old-style literature mostly, and 'stochastic' - in the modern one.
Comment: There are random variables, random processes and stochastic processes, random differential equations and stochastic differential equations, random dynamical systems and stochastic dynamical systems etc. I never met the term `stochastic variable` (although you can consider a stochastic process as a random variable on an appropriate space). There may be a slight difference between [random differential equations and stochastic differential equations](http://math.stackexchange.com/questions/72208/whats-the-difference-between-rde-and-sde)...
Answer: A variable is random. A process is stochastic. Apart from this difference, the two words are synonyms.
Comment: The term "stochastic variable" does occur sometimes.  But more often "random" is used.
Comment: I have seen the terminology "random process" used.
Comment: As if random was a subproduct of stochastic?
Comment: I truly love the simple and intuitive way to explain the difference. Thank you.
Comment: The current PyMC3 documentation uses the terms stochastic random variable and deterministic random variable to distinguish between those that have and those that don't have a parent in the dependency graph of random variables in a Bayesian model.
Answer: There is an anecdote about the notion of stochastic processes. They say that when Khinchin wrote his seminal paper "Correlation theory for stationary stochastic processes", this did not go well with Soviet authorities. The reason is that the notion of random process used by Khinchin contradicted dialectical materialism. In diamat, all processes in nature are characterized by deterministic development, transformation etc, so the phrase "random process" itself sounded paradoxically. Therefore, Khinchin had to change the name. After some search, he came up with the term stochastic, from  στοχαστικὴ τέχνη, the Greek title of Ars conjectandi. Being popularized later by Feller and Doob, this became a standard notion in English and German literature.
Funny enough, in Russian literature the term "stochastic processes" did not live for long. The 1956 Russian translation of Doob's monograph by this name was already entitled Вероятностные процессы (probabilistic processes), and now the standard name is случайный процесс (random process).
Comment: So stochastic was a *politically correct* replacement for 'random'?  Fascinating.
Comment: Very interesting! Is there a reference for the story? (it's OK if it's in Russian)
Comment: @Leo, unfortunately, I can't recall the origin of the story. For a long time I had been thinking that it is from Shiryaev's book, *Probability*, but at the moment of writing this post I wasn't able to find it there, so didn't give a source.
Comment: @Leo, by the way, there's a similar story (but with happy ending) about the notion of independence, which contradicted diamat much more seriously. This one is somewhere in Suhov, Kelbert *Probability and Statistics by Example*.
Answer: Neither word by itself has a commonly accepted formal definition in mathematics, so one cannot really ask about "the difference" between them.
They are used in phrases such as "random variable," "random walk," "stochastic process," "stochastically complete," etc, which have accepted definitions of their own.  In all cases both words tend to refer to an element of chance or unpredictability.  But they are generally not interchangeable; if you talk about a "stochastic walk" people will be confused.
Answer: Random process and stochastic process are completely interchangeable (at least in many books on the subject). Although once upon a time "stochastic" (process) generally meant things that are randomly changing over time (and not space).  See relevant citations:
https://en.wikipedia.org/wiki/Stochastic_process#Terminology
In English the word "stochastic" is technical and most English speakers wouldn't know it, whereas, from my experience, many German speakers are more familiar with the word "Stochastik", which they use in school when studying probability.
The word "stochastic" ultimately comes from Greek, but it first gained its current sense, meaning "random", in German starting in 1917, when Sergei Bortkiewicz used it. Bortkiewicz had drawn inspiration from the book on probability by Jakob (or Jacques) Bernoulli, Ars Conjectandi. In the book, published 1713, Bernoulli used the phrase "Ars Conjectandi sive Stochastice", meaning the art of conjecturing.  After being used in German, the word "stochastic" was later adopted into English by Joseph Doob in the 1930s, who cited a paper on stochastic procsses written in German by Aleksandr Khinchin.
https://en.wikipedia.org/wiki/Stochastic_process#Etymology
The use of the term "random process" pre-dates that of "stochastic process" by four or so decades.
Although in English the word "random" does come from French, I strongly doubt it ever meant random in French. In fact, it originally was a noun in English meaning something like "great speed". It's related to the French word "randonée" (meaning hike or trek), which is still used today. To describe a random variable, French uses the word "aléatoire", stemming from the Latin word for dice (which features in a famous quote "Alea iacta est."  by Julius Caesar). The English equivalent "aleatory" is not commonly used (at least in my random circles).
Comment: while the word "randonnée" was derived from the now disused word "randon", the meaning of "randon" was "impetuous, haphazard". (A "randonnée" is a disorganized hike, you could almost say: a "random walk") Quote of the day: "L'hiver survint avec grande furie/ Monceaux de neige et grands randons de pluie" (Jean de la Fontaine).
Answer: Stochastic comes from Ancient Greek whereas random is an old French word. (fun fact: random has totally disappeared in modern French and was replaced by aléatoire which comes from... Latin)
Otherwise there is no difference between them in the realm of Probability Theory.
Answer: The term stochastic in Hydrology science refers to a process which periodically and apparently-independently happens but a kind of dependency exists. For example, if the flow of a river in last (say) 2 weeks has been low, it will probably  be low in the next weeks too. So, the flow of  a river is not a complete random variable but stochastic.
Comment: Likewise, I've noticed that network theory tends to refer to traffic as being stochastic. Such traffic, from the point of view of a router, would be considered random, but of course each packet was deterministically produced.
Answer: In Chinese literature, there is no difference between those two terms at all.
Both of the "stochastic" or "random" are 随机 in Chinese.
Thus, I would argue that the use of "stochastic" and "random" does not differ in mathematics, but only in language conventions.
Answer: The terms "stochastic variable" and "random variable" both occur in the literature and are synonymous.  The latter is seen more often.  Similarly "stochastic process" and "random process", but the former is seen more often.
Some mathematicians seem to use "random" when they mean uniformly distributed, but probabilists and statisticians don't.  I suspect those who do that haven't thought about it much.
Comment: http://scholar.google.com/scholar?hl=en&q=%22stochastic+variable%22&btnG=&as_sdt=1%2C24&as_sdtp=
Comment: Any example of occurrences of "stochastic variable", WP excepted?
Comment: @did : I don't have any at hand, but I've seen it in print.
Comment: @did : https://www.google.com/search?q=%22stochastic+variable%22&btnG=Search+Books&tbm=bks&tbo=1
Comment: Thanks for the links. After skimming very partly through them, what strikes me is that their majority is related to applications of mathematics (electrical engineering, management sciences, econometrics, physics, artificial intelligence, automatics, *water resources research*, others) rather than to mathematics and/or probability theory per se. My guess is that the frequency of "stochastic variable" would vanish, or nearly so, if the corpus was restricted to these fields.
Answer: A random process is unpredictable such as the movement of the tip of a feather In wind. If we assume that the movement of a roller coaster is deterministic, then a stochastic process would be the movement of the tip of a feather attached to a moving roller coaster. That is to say, stochastic processes have components that are both deterministic AND random; e.g. Martingales.
Answer: So. There are Random ODEs and Random PDEs that are not synonymous to SODEs and SPDEs -- although wide classes of RODEs can be converted to SODEs (usually replacing random normal forcings for Ornstein-Uhlenbeck dynamics) through the Imkelller-Schmallflusss correspondence.
I don't know that much about the theory because my work is in simulating/numerically solving these. But they're a natural formulation for systems such as earthquakes, tumor growth, etc.
A nice wide-ranging textbook aimed at scientists (spends a third of the book introducing rigorous probability before entering the subject) is
NECKEL, Tobias; RUPP, Florian. Random Differential Equations in Scientific Computing. Walter de Gruyter, 2013.
A textbook of numerics, a little narrower in scope is
Han, Xiaoying, and Peter E. Kloeden. "Random Ordinary Differential Equations and Their Numerical Solution." (2017).
Kloeden is well known for his textbook on numerical SDEs, of course. If you plug these on Google Scholar you can browse more recent papers that cite them for hours.
EDIT: I found this slideset from a talk by Neckel [PDF link]. It defines RODEs and explains the intuition for the Imkeller-Schmallfluss correspondence.
Answer: An extreme example of a stochastic process is a deterministic signal X(t)=f(t). In this case, E{X(t)}=E{f(t)}=f(t), R(t1,t2)=E{f(t1)f(t2)}=f(t1)f(t2)
AS another example
Using the Poisson points t_i, we form a process x(t) such that x(t)=1 if the number of points in the interval (0, t) is even, and x(t)=-1 if this number is odd. E{x(t)} = exp{-2landa.t}, R(t1,t2) = exp{-2landa.|t1-t2|}
This process is called semi-random telegraph signal because its value x(0)=1 at t=0 is not random. To remove this certainty, we form the product y(t)=ax(t) where a is a random variable taking the values +1 and -1 with equal probability and is independent of x(t). The process y(t) so formed is called random telegraph signal. Since E(a)=0 and E(a^2)=1, the mean of y(t) equals E{a}E{x(t)}=0 and its auto-correlation is given by
E{y(t1)y(t2)} = E{a^2}E{X(t1)X(t2)} = exp{-2landa.|t1-t2|}.
Reference: Papoulis Edition 4.
Comment: @samwolfe In addition to 1- Papoulis Edition 4, there are some other books that will be mentioned in the following, but I am not sure whether they can be helpful or not. : 2-"Probability and Random Processes, Second Edition With Applications to Signal Processing and Communications by Scott Miller, Donald Childers", 3-"Probability Theory and Stochastic Processes by Pierre Brémaud", 4-"Probability, Statistics, and Random Processes for Engineers by Henry Stark, John W. Woods".
Comment: I need a reference regarding telegraph processes. Could I ask you to look into [this question](https://math.stackexchange.com/questions/4503676/telegraph-vs-bernoulli-processes)?
Answer: From a remote sensing point of view, we usually refer to a bounded but unpredictable process as stochastic.  If the process were unbounded and unpredictable I would tend to use random, but this case doesn't occur very much in my world! :)
Answer: I believe there is a difference between random and stochastic. Random has no preciptating or a priori cause i.e acausal. Random action stands alone - not within any system. Stochastic is random, but within a probablistic system. In other words an act of God is random, but a hurricane hitting the east coast of the US is stochastic event. Any individual hurricane may be random but it also exists as a mathmatical probability within a system of many hurricanes that hit or do not hit the east coast every year. The later is therefore stochastic.
A coin flip has an interesting difference than a hurricane since each individual flip of a coin is already stochastically limited to the 50% statistical probability of two possible results.
Answer: I will quote from Robert Gray Gallager's MIT OpenCourseWare notes for "Discrete Stochastic Processes" (1):
"Stochastic and random are synonyms, but random has become more popular for rv's (random variable) and stochastic for stochastic processes. The reason for the author's choice is that the common-sense intuition associated with randomness appears more important than mathematical precision in reasoning about rv's, whereas for stochastic processes, common-sense intuition causes confusion much more frequently than with rv's. The less familiar word stochastic warns the reader to be more careful." (Chapter 1: Introduction and review of probability, page 15, fn 15).
Answer: I would make a distinction: for example in a queueing system the arrival  times (or interval times) might be modelled by a Poisson process which would be time independent and would not be bound my initial conditions. This would be an example of a random process which outputs random variables. Service time in the queue would be dependent on the previous state(s) of the system and possibly initial conditions. This would be an example of a stochastic process which also outputs random variables. I am not sure that the term 'stochastic variable' has any real meaning except possibly to indicate how the variable was produced.
Comment: As this is a four year old Question with an Accepted Answer (and others), Readers would benefit from your supporting any new material in your Answer with some references to the literature, etc.
Answer: There is absolutely a difference between stochastic process and randomness. For example, if I take one step then let's suppose my friend takes two steps. Now my friend's steps are not random, those are dependent on my steps. That means my friend's steps has a process which is the number of steps I take. But it is random because my friend doesn't know how many steps I will take. So the steps I take is a random walk.
Comment: // , Would you please make this example more clear, perhaps by listing its assumptions first, e.g. "Assuming I take a random walk, and let us assume I have a friend, who..."


Unmasking passwords during sign up, is it a good idea?

Question: I just read this article about unmasking passwords at sign up for usability reasons. On the surface it seems reasonable to me, but I'm wondering what additional security concerns that might generate, if any.
Comment: Masking doesn't prevent keylogging... Just shoulder surfing.
Answer: Masking password fields is designed to prevent shoulder-surfing, where an attacker watches you type in a password. Unmasking is a bad idea in public, but it's not so bad in signup scenarios when the user is alone in the room. Whilst I personally disagree with the assertion that users are incapable of typing in a password correctly twice in succession, I'll go along with it for the purpose of this question.
I think the security concerns are covered quite well in some of the comments.
Luca Rosaldi said:

Another good approach (IMHO) would be including the "show password" checkbox, but checked by default. This way, if I'm alone I could check my password without concerns for security, or if I'm not I could uncheck the box and type my password.

To which Ray McCord replied:

It should be exactly the opposite.
It must be masked by default and the user must have to take an explicit action to unmask it — and even then that choice should be honored only very temporarily before reverting to masked.
Why?
Because this password form is acting as your agent and it, therefore, must be made to act in your best interest first — like a bodyguard.

This is a decent compromise - the default is to provide the user with the maximum possible security. If the user decides that it's just too damn hard to put their password in correctly, they can opt to sacrifice security for usability. This has the extra benefit of not patronising users that are perfectly capable of typing properly.
The biggest problem isn't really a security one, but rather a confidence one. Tesmond put it perfectly:

Simply displaying the password field is very uncommon behaviour, it instantly creates cognitive dissonance and perhaps even instant panic as your "secret" password is displayed for all on lookers. You may worry that your password will be visible in all places within the application and may even make you change your password to a less memorable one.

This actually creates a security problem. If you saw your password appear unmasked, you'd be a little confused as to why the site decided to buck the trend. Perhaps they don't care about security? Perhaps they store it in plaintext?! Perhaps your password will be visible on every screen!!? The user will then pick a terrible password that they don't care about having compromised, which puts their account at risk.
Comment: I would agree with you. However, the website designer can either choose to account for it, and work around it, or ignore it and shut off that whole segment. So working around it, securely, is a good requirement in my mind.
Comment: @AviD I'd argue that that's a usability issue with the keypad, not the password box.
Comment: Sometimes it is difficult to type the password correctly - think about smartphones and such.
Comment: I agree. Was just pointing out that, at the end of the day, the root cause is the keypad itself.
Comment: I was just referring to this line: `Whilst I personally disagree with the assertion that users are incapable of typing in a password correctly twice in succession`.
Comment: Where do you see an assertion that users are incapable of typing it correctly twice in succession? If they fail, the worst that happens is they fail to register. The real reasoning is that users _are_ capable of typing it _incorrectly_ twice in succession (for example, by having caps lock or num lock enabled, or having a hand off by one row).
Comment: @AviD I agree with the sentiment in the answer itself: mask by default, and provide an *option* to unmask (temporarily). For smartphone users or users with a disability that may impede their ability to enter the password, it should be relatively trivial to hit the "unmask" button and verify they've entered it correctly.
Answer: To be honest I'd say that the article, in combination with the comments on it cover most of the likely security concerns.
As stated the usual security concern for displaying passwords is a "shoulder-surfing" attack where someone can overlook a user and thereby get unauthorised access to their password.
Obviously this risk is only present in environments where the user can be overlooked (e.g. offices, coffee shops, etc).
I'd largely agree with the opinion expressed by some of the commenters that there's a balance to be had here between security and usuability.  I'd say that an approach which requires the user to actively uncover the password (and which only works temporarily) is a reasonable trade-off.  this could be similar to the windows 8 approach where an icon on the password field can be clicked to reveal the password, but the password is only shown so long as the user holds down the mouse button over that icon.
Answer: The main concern is people snooping over the shoulder, as the article correctly states. In theory, the only difference, when using password masking, is the way the password gets displayed to the user, other than that, on the software level should be is no real difference. However, if the browser doesn't know that a field contains a password or other sensitive data it might behave differently, for example storing the password in a non secure way, as part of the forms auto-fill feature.
Comment: This is already a problem with other sensitive fields.  I've had to go hunting more than once for where autocomplete data was stored after discovering that some site's plaintext entry field had resulted in the browser remembering my SSN.


Do serotonin drugs contain serotonin or a precursor to it, e.g. tryptophan?

Question: With serotonin drugs, is it actually serotonin in the drug, or is it tryptophan which converts into serotonin through the biochemical conversion process after the drug is consumed? Serotonin can be consumed through foods, whereas tryptophan cannot, but the biochemical conversion process is what has brought this question to my mind about the actual drugs which can increase serotonin in the body.
Comment: I think you've got largely (if not exclusively) misconceptions here.  It might be best to do some basic research on something like Wikipedia and then ask a follow-up question to that.
Answer: No, the drugs that interact with serotonin receptors do not contain serotonin nor are they serotonin precursors. There are a lot of serotonin receptor subtypes in the body and the drugs are designed to interact selectively at a single subtype (with greater or lesser success). Many of them bear only a passing resemblance to serotonin as extra functionality is added to enhance selectivity.


How long do I wait to wire my ficus bonsai after re-potting it?

Question: I recently got a ficus bonsai 3 days ago. It's responding well, however, it needs some wiring, pruning and general reshaping before the spring/summer growth. I was wondering how long should I wait before re-wiring it. I was going to wait until spring before pruning it.
Comment: Hello Mack.  Welcome.  If you live in an urban area or near one check to see if they have a Bonsai Club or Society.   These clubs often offer basic classes in taking care of your Bonsai plant.  Also check to see if there is a local Bonsai supply store.
Comment: I was hoping to not have to go back to the store, but since I may have to I will ask them.
Answer: You truly need to take a hands on class with a real expert in Bonsai.  Bonsai is the apex of plants needing our constant help and needing us to know what we are doing.  Not at all akin to a 'house plant'
Do not worry about using a timer for your bonsai for light. Just turn it off when it gets dark outside. What are the specs for the light? Good for you, I can tell you are going to really get into this. If you can care for a bonsai and keep it alive you will be able to grow anything...
Where was this Bonsai purchased?  Indoors, out of doors, green house?  What species is it? Depending on your pot and soil you might need to water every single day which is normal for bonsai. Taking the entire pot and plant and dunking the pot and soil into a bucket of water.
Hopefully, you used sterilized potting medium without water holding gimmicks and without added fertilizer.  You want to be in charge of fertilizer so wait until you know more to add any to your bonsai. Fertilizer has to be carefully added and carefully chosen because a little too much is death.  Also, that Fertilizer needs to be balanced, NPK. I recommend Osmocote extended release all purpose fertilizer.  Use1/4 what the directions recommend.
Fertilizer? Less is Best, More is death and None is dumb, my little ditty about fertilizer.  Fertilizer is NOT in any way some 'food' for plants!! But critical for our garden plants and indoor plants.
I would wait until I signed up for a bonsai class (lucky you!) and use my bonsai as my 'model'.
Get a couple of good books about bonsai, about the basics of raising plants, find a good indoor house plant book but no mistake get books on bonsai to read before the class
starts.  It will make far more sense and you'll be able to get far more out of your class.  Allow your new baby to 'settle' in before trying any pruning.  Take that class first before any wiring or pruning, okay?  Have fun!
Comment: The thing is, I was hoping to get enough information from the lovely people on the internet so I wouldn't have to sign up for a class. I've done a lot of research so far as to how much to water, how to wire, when to prune, how much etc. But a lot of this stuff doesn't go into specifics about timing and are just general guidelines.
Comment: How much time is allowing it to settle in?
Comment: I'm not sure of the exact species of ficus I bought, but I bought it from an indoor greenhouse nursery. I'm using a full spectrum 26 W light bulb, CFL I believe, I can get you the full specs later. I may get some books about bonsai, are there any that you recommend? I'm a beginner but I've done enough research that I feel like I can get into some intermediate and maybe some advanced concepts.
Comment: It is a big change from a greenhouse to your indoors.  Let that bonsai just relax and get used to it's long term spot.  My hubby is an Electrical Engineer so I'd have to ask him about your specifications on the lighting...otherwise, I'll just look it up, grins.  I think tho it should be at the very minimum 300 watts.  Where is your grow light and the area you've placed your bonsai in your home?  You have to send a picture...?  Your pot should be very shallow and wider with a drain hole...some don't use drain holes but make sure yours does...
Comment: Did you use potting medium out of a bag to transplant your bonsai? I don't remember the authors or the titles of books I've read on bonsai.  Shoot!  Taking a class is for those who know a thing or two about biological, botanical, chemistry.  Feel the heft of the pot and plant after watered  (dunk in a bucket of water).  When that heft is obviously lighter that is when it needs to be dunked again.  Not before.  It does turn out that every day dunking is normal but always check the heft first. Some basic books would be Shane Smith and Greenhouse gardening, Jorge Cervantes and Cannabis Encycloped
Comment: The garden center i bought the bonsai at re-potted it for me, I'm not sure what they used but I'm pretty sure they did everything properly. I have another question up about lighting, I think my lighting situation is ok but I'm going to have to start running it for longer. I'll get you a picture and specs when I can
Comment: Is this winter time for you?  Plants get used to a light and dark schedule.  During the summer the ratio is 18/6.  During the winter it becomes 12/12.  Putting on more light isn't necessary during the winter.  Using light 24/0 is just wrong for plants, period.  Your lights should be at least 300 watts. I'll wait for your pic and specs!


Condensing orchestral scores

Question: In the image below is an example of a full orchestral score being "condensed". As far I know this only occurs in hand engraved music, and I was wondering if it could be replicated with software? To my knowledge I don't think it can be done in MuseScore, but is this possible in say Lilypond (which I am exploring now) or Sibelius or Finale?
Comment: [This site](http://brebru.com/musicroom/theory/lesson25/scoreformats.html) and [this site](http://library.queensu.ca/techserv/cat/Sect11/c11m9.html) both indicate that condensed scores involve multiple instrument parts on the same staff/"part", which your picture does not involve. [This](https://musescore.org/en/node/2963) contains a condensed score that fits this definition. I've seen other  Musescore and Sibelius pages that say that condensed scores only involve hidden parts, though, but that does not match any of the condensed scores of concert band/orchestral pieces I've read.
Comment: I don't think that image looks like a condensed score...
Comment: @Dekkadeci I see what you mean. I did not know that there was a standard meaning for 'condensed score'.
Comment: @Dekkadeci It is. All the instrument staves lain out take up the entire page.
Comment: I can't speak for other software types, but it's possible in Finale.
Answer: This is certainly possible in LilyPond.
As I see it, there are two aspects that go into creating a condensed score. The most obvious is the general formatting: staff size, paper size, etc. Such modifications are laid out in the LilyPond Notation Manual.
The second aspect would be to rid of all of the unnecessary empty staves. In LilyPond, this is very easy:

Empty staves can be hidden (for a so-called 'Frenched Score') by applying the \RemoveEmptyStaves command on a context, which can be done globally (in a \layout block) as well as for specific staves only (in a \with block). This command removes all empty staves in a score except for those in the first system. If you want those in the first system to be hidden also, use \RemoveAllEmptyStaves. Supported contexts are Staff, RhythmicStaff and VaticanaStaff. (source)
Comment: In addition to this, information about adding system separators (the '//' break marks) can be found here: http://lilypond.org/doc/v2.18/Documentation/snippets/staff-notation#staff-notation-setting-system-separators
Answer: You actually can have a reduced score with system dividers in MuseScore (at least in Version 3):

Click on Format in the menu, and go down to the Style... submenu item
Open the Score dialog, then
Check the Hide empty staves within systems
Open the System dialog, then
Turn on system dividers by clicking the Left checkbox

NB:
This makes a reduced score (AKA a "Frenched" score) like your picture; removing staves that are just rests in the system.
A condensed score is more sever, referring to a score where each section (i.e. woodwind, brass, percussion, strings) is condensed onto a single staff or grand-staff each.
(According to Samuel Adler The Study of Orchestration (3rd ed.) p. 762-765)
Answer: Yes you can do this in Sibelius. Select a passage then  Layout | Hide Empty Staves
Sibelius also adds the // break mark between condensed passages
Answer: There are two separate issues related to the 'condensed score' layout. First one, which most software tools can easily do, is hiding empty staves. For some, hide empty staves works globally, some let you select a specific passage where you want to hide staves, and some have a few options (hide empty staves in all systems except the first one, etc).
Hiding empty staves doesn't properly condense the score, though. Overwhelming majority of users use software to produce parts for their orchestral works. This is why the default layout for a score will have each instrument on its own staff (1st Flute, 2nd Flute, 1st Oboe, 2nd Oboe, etc). In a proper conductor score, these pairs must be condensed to a single staff (Flutes together, Oboes together, etc).
At this point, the only software that allows you to automatically and dynamically generate a condensed conductor's score (using standard rules) is Steinberg's Dorico. When you select 'Condensing', it will ask a few questions (which instruments should pair), and will offer standard pairings (same instruments together, like flutes, oboes, clarinets, etc), plus some other common pairings (3rd trombone & tuba). Once your condensing settings are chosen, it will dynamically build a conductor's score based on the parts. It will also insert the necessary disambiguation markings (Solo, or 1., 2., a2, as needed, when there's a single line of notes). If the voices cross for too long (which makes it extremely illegible when on the same staff), Dorico will split the two parts into independent staves, for the duration of the passage where voices criss-cross. If the voices criss-cross for just one or two notes, you can keep them together on the same staff (there's a setting specifying how many notes is max.). The condensed score is automatically updated when you make changes to the individual parts/instruments.
Sibelius suggests a work-around for condensing the scores. It doesn't create a dynamic condensed score, though. In your document, you need to add additional staves for each pair of combined instruments. So, you'll have Flute 1, Flute 2, Flutes 1&2; Oboe 1, Oboe 2, Oboes 1&2, etc. You select the entire music for the pair of instruments that you want to combine (Flute 1, Flute 2), hith 'Copy' (Cmd+C), then select the first bar in the target staff (Flutes 1&2), then select 'Reduce' from the 'Note Input' tab. This will cleverly copy the music from the two other staves into a single staff. If the rhythm is common, it will write it in a single voice (two-note harmony on a single stem). It will also add a2, 1., or 2., as needed. It may add some superfluous dynamic markings (when parts don't come in at the same time), but it works rather well. Then, to display the score properly, you can either create a new part, where you pick the staves you want to show, and set the layout the way you want it, or in the Score Layout, you use Focus on Staves to pick the staves you want to show in the condensed score. This work-around doesn't create a dynamic score, though. Any change in the individual stave(s) must be manually done in the combined staff.
This method could be used in other tools (Finale, MuseScore, Lilypond), and it works, with the main constraint that it doesn't automatically update the combined staves when you make change in the individual instruments.
At this point, Dorico is the only music engraving tool that does this automatically, and does it well.
Just to be clear, I'm a Sibelius power user, and have only briefly tried Dorico demo.
Answer: I try to summarize the background of this notation convention:
Orchestral scores typically list all instruments just on the first page, later on only the ones having to play something are listed. (Or phrased differently, the ones not playing are omitted.) If this reduces the required space for a total system so much, that several systems fit on the page, this is done and so called system dividers are inserted for clearly indicating this.
See also these questions:

Please help me identify the bold slashes between staves
Two angled lines in a study score

Condensing orchestral scores


How can I beat defenders 1 on 1?

Question: So I have put countless hours into learning lots of tricks to beat defenders, I am very good on my feet, fast, good touch, but whenever I get 1 on 1 with a defender I freeze up and don't know what to do and usually automatically go to the simple backwards L, even if it's not the right thing to do.
Comment: In what way are you trying to beat defenders?  What position, give us an example?
Answer: From a coach's point of view: remember why you play football.  Your problem appears to be less about skill and more about your stress.
Beyond practice; pick an upcoming game and beforehand decide you're going to go after the defender every chance you get. Explain this to your coach and let him/her know so you have an ally. If you are a forward, this should be expected.  In fact, I will even advise you to lose the ball the first few times. How? Allow yourself to just experiment and hold up the defender - don't over-think it. The only skill advice I will add is be good with both feet.
Get the defender out of your head.  Smile; be creative fluid and fast.  Once you've lost a couple of battles (and likely won a few), keep going after them. Once the stress is gone, you will enhance your team.  You have to want the challenge.
Answer: Here's the perspective from a defender:
What you want to accomplish is to get the defender to commit to a movement. Sign of a quality in a defender is to choose his/her timing to commit to a particular movement; regardless if that's a block, a slide tackle or simply closing a particular angle.
In a 1-on-1 situation with a defender (D), one of three things might happen;

D will rush on you, pressing you to make a move: in which case you make your move (as you said you are skilled, trained and have the flair to just avoid being tackled and proceed.
In a scenario where the D is a bit better/seasoned, he'll likely back up slowly while trying to close of your advancement, waiting for you to "make your move". In that case you need to someone get the defender to act and commit to something. If he commits, then you change direction/do something else.
For instance you might show/feint a shot stance, if he goes for it you just put the ball past the defender and quickly run past him. If he doesn't go for it, then by all means take the shot :)
Another option would be to show/feint dribble to one direction and suddenly change your direction. The linked video shows several different types of such movement, carried out by one of the best players out there. I linked the video to give you an idea on the movements involved, not to tell you to play like Messi, obviously. :)
In the unlikely case where the D stays his ground, just sprint past him (assuming that you have the speed, and space behind the D). You are coming with speed and you are the one choosing the direction of the play, so you have the advantage.

Besides the basic concept above, there is the mental aspect of the game. I have never been a good dribbler so I cannot tell you how you avoid "freezing up". I can only say that the moments where I somehow out-played the defender against me, is when I was too tired or caught-up-in-the-moment to think what I was gonna do, but just did it. It works wonders, not thinking but just doing.
So my best advice is out of a Nike ad: "JUST DO IT" :)
Answer: You weren't specific as to your question. Are you asking what should you actually do in that situation, or how you should improve your reaction to defenders?
If the first, it depends on the situation and the defender you're facing. Good defenders will try to force you to the outside, which means that's the easier way to go, but then you're generally looking to cross the ball, not shoot it yourself. A fake to the outside can sometimes draw a reaction, or rolling your foot across the top of the ball and quickly reversing direction may get you around him. Attackers can sometimes put the ball between the defenders legs, or if you have support a simple give and go can also work. There isn't one solution to this, since it's so situation dependent.
If you're asking how to improve, then you should find a defender who wants to practice his/her defense and go practice with them. In practice, decide what you're going to try beforehand so you don't have to make the instantaneous decision. Practice a move 5-10 times, then another move 5-10 times, then another move 5-10 times, then cycle back around and try the first one again. You can start off with a "dummy" defender - just put out a box or a backpack to mark where the defender is until you get the moves down. Then bring in someone live who will actually respond to you. Once you've practiced it a lot outside of the game, it'll make a big difference in the game.
Once in the game, pay attention to the defender's body language. If they are trying to force you to the outside, their body will be angled upfield so that they can more easily cut in (but not as easily cut out). If they're looking to slow you down, they'll be facing you about 1-2 yards away. If they're challenging you directly, they'll be approaching close. The situation will help you make the decision. Defenders in motion can be more easily cut around with a small move backwards or to the side. Charging defenders most often warrant a give and go, but if you're good with you feet you can get around them yourself. A defender who's trying to force you out may warrant just taking the outside and putting a cross in, but only if you have support in the box.
Answer: Best advice is.. Read the situation. In football being one on one with a defender doesn't mean just go and attack him.
End of the day you don't want to lose the ball and be on the back of that.
For example:
Read the game if you see a player free, play the ball. Drag your defender towards him.
Then take the ball back when in  free situation and take it forward.
Move in to positions where defender forgets to mark you then ask for the ball. The defence will already be out of position allowing you to move forward into attacking position. Making it easier for you to dribble at defenders and stopping you from freezing.
Taking players on is great, but positioning is vital. If your in a better position from the start you already got the upper hand.. Less likely for you to just 'freeze up'
As a player who used run at defenders. Over the years when you play against quicker and strong defenders. You can't simply just skip past them, but you had to position yourself to do it right. Get the defender facing side on.. Dribble one way then change. Making it a lot harder for the defender to get back because of his/her positioning.
Answer: Alright so what I would usually do is take me right foot and motion that I'm going right but actually just draw it over the ball the take it back to my left. Usually works for me. The follow your body movements so when you take it back to your left foot it gives you time to shift your weight quickly depending on your side. Can be reversed depending on the dominant foot.

How can I beat defenders 1 on 1?


Does Lightroom remember or save a 'custom order' after closing?

Question: I've researched and read responses to sort order questions but have not been able to find out if LR will automatically save or remember your custom sort order after closing. Does anyone know if each folder can have one saved custom order in the dropdown? Thanks, Mike.
Comment: I guess my question is will Lightroom save or remember a Custom Order after closing the program. So if I drag files around they'll still be in that order? I know the other sorts are all based on name, date, time etc. and would all work again.
Comment: Yes, your custom order is still maintained as well.
Comment: Honestly, isn't this something that can simply be tested much faster than asking a quesion on SE and wait for answers?
Answer: Each folder has its own sorting order. There is a default but once you change it, the folder keeps being sorted in that order until the sort is changed again. This applies to custom orders and presets such as Capture Time, Added Order, etc.
This unfortunately can get confusing since Lightroom shows the contents of folders recursively and the sort order shown is a property of the selected folder. So if you are on a directory sorted by Time and you then select its parent directory which is sorted by Filename, then the order of the images is going to change in addition to showing any images present in other sub-directories.
Answer: Yes, folders will remember the prior selected sort order.


How can I extract the file names used by IEFrame.dll?

Question: I am working with a program that uses the IEframe.dll to display HTML files which are stored on my disk. I have access to these files, but I need to know in what order they are accessed.
Is there any way to communicate with the rendering engine to extract the files in use at the moment?
I guess another way to skin this cat will be to write a script to extract the list of files in use by a process.
Note: I already tried "handle.exe -p programname > filenames.txt" but I can not see the files there. The program has the option to open these files in a HTML editor and this is how I can know what files are used but this is slow, I need something that I can script it
Edit: I guess the correct name for the rendering engine is "The web browser control" I am not a programmer and I am not sure if I am using the right terminology
Edit2: OK After some googling I found this:
http://www.nirsoft.net/utils/sysexp.html
This program seems to do part of the job in the sense that it able to show me some info but I still don't see a file names there, just handles which I presume are temporary
Edit3: after some reading I realized that the component used by my app is IEFrame.dll and it also uses MSHTML.dll (this seems to be control to display HTML files. The app displays two web paged on the same screen, both files are on my HDD. I am not sure which component is accessing the files on my HDD.
Answer: OK here is how I could find the info that I needed: I used SysInternals' Process Monito with the following filters:
ProcessName=Systmem
Path: Path to the folder where my files were
You will get records for the file access and if you filter what you need (in my case I used Detail contains SyncType) there you go you have your log for your app.
Use Ctrl+C to copy the log and dump it into Excel or whatever to further process it
Another way to do it is via Event Viewer and Windows Audit policies. Audit the access to that folder and export the Event log. The output has a lot more info that you do not really need


How should I design the jaw for rigify pitchipoy?

Question: I decided to try using the Rigify (Pitchipoy) Add-on and watched a tutorial on how to set it up.  When they where working on the face they parented the jaw without weight paints, just normal parent and it looked like the jaw was 2 separate objects from the rest of the mesh, the upper and lower jaws each their own.  I was wondering how I should model the jaws for this.  Should I make separate meshes for the upper and lower jaws and parent them to the mesh and to the armature?  If so, how do I make it so when the character opens his mouth and jaw it doesn't saperate and you see the inside of the back of the head?  Basically, how do you model the inside of the mouth for this rigify (pitchipoy) add-on?
Answer: When rigging you need to be clear about what you want to achieve, because every little function takes time to accommodate for. Which also means that I cannot give you the perfect answer unless you describe your character more clearly. If you want a character with a normal organic jaw, then skip the following paragraph.
The only reason you would parent something without weight paints is if you want a ridged object attached. If this character had an iron jaw for example, it might make sense. I'm not sure if pitchipoy is built for that, but if you were to attach it to just one bone you could probably achieve a ridged effect. However, that would make some mesh items harder to track down. So i'd recommend a ridged bind (flood the influence to one bone) that is IF you want a ridged jaw.
If you want a normal organic jaw, then ignore your tutorial and find a better one because organic meshes generally require weight binding. I'd follow the official video for that: https://www.youtube.com/watch?v=-dwCXMc2V0U
The only thing i'd advise making into separate geometry is the teeth and tongue. That's just so that it's easier and more clean of a job when weight painting. Teeth can have ridged weighting, tongue can have auto weights. For the mouth, it's just a concave section of geometry, and of course attached to the rest of the surround mesh. You will need to ensure that the weights do not collapse the geo into the teeth and tongue when the character open's it's mouth.


Unicode and network communication

Question: I am planning on developing a windows based client app and a platform agnostic server app. The client app basically sends messages to the server app. Client app can send messages in English or in other languages. Should I be using UNICODE for encoding messages in my client app? What is the general practise among applications involved in network communication? My client and server app will be using custom protocol for exchanging messages over TCP/IP. What UNICODE encoding does Windows and UNIX platform support by default? Should I be exchanging the encoding type in my protocol as well for decoding the UNICODE messages? Please advise.
Answer: Look for UTF-8, the encoding of unicode in 8 bit bytes efficient for English and western languages.
It is always a good idea to exchange the encoding type, in case you at a later stage want to support something else.
UTF-8 is supported by all major OS:es and computer languages.
Comment: Indeed. Outside of Windows, UTF-8 is *the* Unicode encoding to use.
Answer: If you control both the server and the client, I'd pick 1 encoding type and stick with it.
I would suggest either UTF-8 (most efficient for english and western languages) or UTF-16 (make sure to chose a byte order).
Answer: You can use whatever encoding you want, you just have to be careful about things like byte order.  Windows internally uses UTF-16 (little-endian), so if you expect most systems to be Windows, then you should probably go with that.  Otherwise, I'd recommend UTF-8, which doesn't have byte-order issues to worry about.
If you do go with UTF-16 (or UTF-32, which I definitely would not recommend), spell out in no uncertain terms what the endianness of the data on the wire is.  Then, for every client which reads or writes a Unicode character to a network socket, convert from the platform's native endianness to the network endianness - this is either a no-op or a byte swap.

Unicode and network communication


Will Java still be relevant in 5 years?

Question: Will Java have the same importance it had in the past, or it will be less relevant than nowadays?
Comment: The language or the platform?
Comment: [Java](http://en.wikipedia.org/wiki/Java_coffee) will always stay relevant in the programming industry. How do you suggest we write *anything* without it?! ;)
Comment: @Chankey - See Meta: http://meta.programmers.stackexchange.com/questions/1/why-would-anyone-accept-an-answer
Comment: We don't do "look into the future and predict what will happen" kind of questions anymore.
Comment: @Jim: great point, decoupling the future of Java language and JVM.
Comment: Not sure what the answer is, but I sure hope so, as I'm building things now that depend on Java on the Desktop.
Comment: Cobol, if I understand correctly still isn't dead.  Java may have a decent lifespan for similar reason's to those for Cobol.
Answer: Yes, Java will certainly continue to be relevant and will probably maintain its position as no.1 overall platform for software development for a long time.
Firstly, reasons why Java is and will continue to be a strong choice:

Java is still the most popular langauge - and this means it has the most developers, most ongoing development, largest installed base etc. There is no sign of any sharp decline - if you look at the TIOBE trend for example it could easily continue to be No.1 for the next 10-15 years
Java, despite its flaws, is still an excellent language for developing enterprise applications. The fact that it is verbose and tends to promote a fairly standardized style of OOP development is a good thing when applications need to be maintained by many different developers over many years in a fairly standardized way. Smart CIOs realize this, which is why you won't see Java disappearing in the enterprise any time soon. BTW, and explicit goal of Java when it was created was that it should be "simple, object oriented, and familiar".
The sucess of languages is not just about the language itself, but around the ecosytem of libraries available for the language. In this respect, Java is second to none, with a massive array of open source and commercial libraries.
Performance - JIT compiled code on modern JVMs runs very close to optimised native code in terms of speed. In practice, this means that Java is typically one of the fastest language/implementation combinations available (see flawed benchmarks if you like). Anyone who thinks that Java is slow (or, for goodness sake, "interpreted") needs to update their facts from the last century.
Major corporate backing - Java is a strategic platform supported by many of the worlds largest and most important technology companies and organisations - we are talking about Google, Oracle, IBM, the Apache Software Federation etc. Java also has substantial support from major users of technology - banks, media companies etc. No other language/platform has such broad industry support (even if the players have the occasional tiffs :-) )
Android - is giving a major boost to Java in the mobile space. Lots of startups are targeting this, and it's not unreasonable to expect that mobile startups will also have good reason to pick Java on the server side as well.
Portability: Java is the closest thing in existence to a genuine cross-platform programming environment. It's on everything from high end servers to smartphones, and compiled pure Java code will run unmodified on all these platforms. Very few languages can say this with the same degree of credibility. Also as a bytecode language, Java has an inherent advantage in the library space because compiled libraries are inherently portable across platforms.
Excellent tools - most of which are free and/or open source. Netbeans and Eclipse are great examples in the IDE space. Developers need good tools to be fully productive, so this is an important factor in language/platform choice.
Java is Open Source - not going to go into why this is a good thing here, but suffice it to say that both a) the core Java implementation in the OpenJDK and b) most of the interesting Java libraries and tool are open source.
Java is not just a language, it's a platform: there are many promising languages on the JVM such as Clojure and Scala that represent the future of the platform on the language front. My prediction would be that the Java language continues to recieve minor enhancements to features (JDK 7, 8 etc.) while these new JVM languages are where the cutting edge innovation will happen. But it is all part of the Java platform.

Secondly, how will Java get replaced? Let's look at the alternative contenders:

C/C++ - will continue to be important in terms of systems programming and for highly optimised native code requirements such as gaming. But that will continue to be a specialised niche and will never take them past Java, which is more suitable for general purpose application development.
Microsoft.NET - C# is a nice language for sure (an improved/polished clone of Java, in essence), but the entire .NET platform represents vendor lock-in to the Microsoft software stack. A large number of people will never adopt a vendor-specific strategy having been burned by this in the past. Mono, despite being a nice open source project, is never going to be fully compatible so most businesses won't bet on this as an option. .NET/C# will continue to be very important in the windows space, but won't be able to displace Java overall.
Objective-C - will no doubt continue to occupy a major niche in Apple-specific development, but probably won't have much traction outside that space. Also, Java has a very compelling counter-story in the mobile space thanks to Android
Python, Ruby - nice languages again, very productive in their niches. But nowhere near the JVM in terms of performance, industry acceptance or range of libraries. Will continue to be successful for sure, but they aren't shaping up to be Java-killers.
JavaScript - will continue to have an important role in client side web development. But no real strength outside that space that is likely to threaten Java anytime soon.
Haskell, OCaml (and various other academic/FP languages) - great languages, but have nowhere near the library support Java has, so not particularly practical for real-world usage. Also, offer no compelling advantages over JVM languages such as Clojure or Scala (which can use Java libraries painlessly)
Clojure or Scala - actually really compelling in the medium/long term. Might actually replace Java in 10-15 years, but both really count as part of the Java platform anyway since they are JVM languages. So Java investments will be safe.
Mysterious unknown new language? - might happen, but history has shown that no matter how compelling a language is, it takes a long time for traction to develop, developers to learn new skills, significant investment by companies to happen etc.

Finally, some conclusions / predictions:

The overall relative positions (in terms of market share) of the major languages will evolve a bit over the next few years but won't change much. Java will stay No.1.
You won't go wrong in choosing the Java platform for the next 10-15 years. Don't worry about Java going away any time soon.
In the near term, Java-the-language is a safe, reliable bet. In the longer term, or if you're feeling the need to be more at the cutting edge of innovation / language design, I'd recommend Clojure or Scala as new JVM languages
People will continue to spread FUD about Java. Just ignore it.
Comment: This is not the earliest response but it is by far the most detailed and convincing as of mid-2011, and thus deserves to be the top answer.  +1
Comment: Great post, people who are using languages like Ruby and Python think that their language is the best thing ever but the reality is that for large-scale intensive applications a dynamic language isn't going to cut it
Comment: Good post. Where do you see Go and maybe Dart in this spectrum?
Comment: @programmx10: Is there more overhead in dynamic languages than there is in Java frameworks like Spring?
Comment: @Kevin: Spring's typically just used for application configuration, so the cost isn't terrible. OTOH, if it was used also for the actual computation and IO servicing, it would be at about the speed of the dynamic languages. The key is that Spring-based apps are really _partially scripted_ — which is actually a great place to be — but we don't tell the bosses that as they like to believe that absolutely everything has to be compiled.
Comment: @Donal: I suppose I was thinking more of the EJB architecture, where one function call expands into 17 layers of Java reflection calls.  If I'm going to pay that cost, I would rather just use a dynamic language.
Comment: +1: Great answer! It summarizes most of the reasons why I consider the Java platform a valuable choice.
Comment: "JavaScript - will continue to have an important role in client side web development. But no real strength outside that space that is likely to threaten Java anytime soon."

Dude. Are you even paying attention?
Comment: @Erik - I'm fully aware of Node.js etc., and I still don't think it is a contender against the JVM languages (Java, Scala, Clojure) or .Net on the server side for serious applications. JavaScript is cool on the client (as I said), but the server currently has much better options. YMMV but I stand by my statements.
Comment: Write anything that works on all popular mobile platforms in Java recently?
Comment: @Erik - mobile applications are generally regarded as "Client Side"
Comment: And FYI - you can write Java apps that work on all popular mobile platforms: http://libgdx.badlogicgames.com/
Comment: And you would use that to write anything that has full access to file I/O and all hardware on any popular mobile device?
Answer: Java is relevant and will continue to be relevant for many years in the Enterprise computing world.
Whether it continues to be relevant in other areas depends a lot on what Oracle does.  If they inject some life (and resources) into ME, desktop applications and other areas, and if they press on with the evolution of the Java language, then Java will do well.
But if Oracle cuts back on R&D and/or tries to stomp other players in the Java space, there's a good chance that someone / some company will develop a better (and more open) Java-like language.  If Oracle win their lawsuit against Google, I predict that the next generation of the Android platform will have a new language, just like happened with C#.  If Google get the openness right ... then, the game is on!
Comment: IBM supports Java on all their major platforms.  This means that even if Java should disappear from the face of the Earth it will still be the running on the mainframes (like COBOL).  The primary advantage for programmers is the ability to develop locally, and the strictness of the JVM meaning it will run in a predictable way.
Comment: Agree. Oracle itself has invested too much of its Enterprise application stack into Java to allow it to decline. Interesting that a lot of the other answers seem to focus on the mobile platform.
Comment: +1 especially for `I predict that the next generation of the Android platform will have a new language, just like happened with C#.` Don't forget that Gosling now works for Google; http://nighthacks.com/roller/jag/entry/next_step_on_the_road
Comment: @Qwerky He now works for Liquid Robotics. http://nighthacks.com/roller/jag/entry/i_ve_moved_again
Comment: Let's not forget what Borland did to Delphi. It was so abandoned that most people today thinks of Delphi as a dying out of business solution. But Embarcadero rescued the product and now it is open for java, mac, html5, android and other programming areas.
Comment: I also agree. Java will be pissing off those of us who know better for a long time to come.
Comment: @Qwerky - but note that Oracle did not win the lawsuit ... so the precondition for my prediction does not hold.
Answer: I would say it's on a decline.  It's not gone, but it's past its peak.
Comment: I don't know if I agree with this terse answer, but the 15 upvotes just demonstrate that I have to stop hanging out in this zoo. This answer has no reasoning and cites nothing. Which is what "source?" probably meant. I don't mind opinions, but "Java dead!" or "Java alive and well!" are both completely unvotable to me. +0.
Comment: Source? (15 chars)
Comment: @Kop - *"this is a stackexchange websites for subjective opinions"*.  That is to misstate the purpose of this site.  Subjective opinions are OK, but objective facts are clearly more valuable.  And it is legitimate to challenge any subjective statement to elicit possible objective supporting evidence.
Comment: @Lorenzo Over the last decade Java has been about as mainstream as it gets and probably the most widely used programming language in industry and education.  I agree with Fishtoaster that it is in decline now, largely due to a lack of direction and progress on Java 7 and the rejection by programmers of heavyweight JavaEE solutions in favour of lighter alternatives in other languages.
Comment: -1: no facts or argument in this answer whatsoever. subjective != random unsupported assertions
Comment: In agreement, past its peak.
Comment: @Yar: Funny how that works.  Iirc, I posted that because no one else was answering- it's not among my best answers.  Of course, the comment thread following it turned out to be interesting and informative; ignore my answer, but vote those guys up!
Comment: @Evan Oracle recently announced quite appealing roadmap for Java 7 (http://www.oracle.com/us/corporate/press/173782). They also announced OpenJDK collaboration with their old enemy IBM (http://www.oracle.com/us/corporate/press/176988). It doesn't look like they're trying to "get rid of Java".
Comment: @Jim - IMO, "source?" and "can you back that up?" are asking essentially the same thing ... unless you are being extremely literal about it.
Comment: @Stephen I said bury it (let the project dissolve) or sell it, because they are the two most viable options to Oracle. Open sourcing it themselves would force Oracle to lose face after suing Google for a quick and dirty profit, selling it to google would be a win-win for both companies. Burying it would still allow the Oracle to profit from Java but save them the long term support responsibility of a project that doesn't really generate much profit.
Comment: @Stephen It's a pretty well known fact that Java was always a losing proposition for Sun because everybody but Sun was doing a better job of making money with Sun's language. The best option for Oracle is to get rid of it. Selling it to Google (to save on the ridiculous legal expenses that Oracle is forcing) would turn a nice profit and save them from being ranked up with MS on the list of diabolical software company PR ratings. If you don't think google would open source it, I'd like to hear a concrete reason why. I can give examples that support why they would.
Comment: I not agree. In the past Java never got really mainstream despite being promised as the solution for almost every programming issue.  It has always been a somehow niche language. Only now, with Android, is gaining an increasing popularity, and its peak (although just as a side effect of Android).
Comment: Oracle will pump it for all it's worth and either bury it or pawn it off to the highest bidder because it's a revenue nightmare. Sun created one of the most used programming platforms known to man and everybody but Sun knew to monetize it. The best possible outcome for Java would be for Google to buy it to settle their patent issues and finally make it a true (unencumbered by patents) open source project.
Comment: @Evan - that assumes that 1) Oracle would want to sell Java, 2) Google would want to buy it, and 3) that Google would at as good stewards of Java.  For a start, I don't think Oracle would want to sell.
Comment: Some languages hang around forever... *cough* COBOL *cough*
Comment: @Steven C - Initially, I was going to fire back at Kop with a similar answer to what you had, but look at the thread: Fishtoaster says "I would say...", Walter says "In agreement"... so the context is already in the "pure opinion" world, not the "subjective, but I've done my research" world. So "Source?" is irrelevant. "Can you back that up" would be fine though. All IMO.
Comment: @Joonas: But that roadmap says not much about the client side. I would say that Java SE, Swing and Java ME is pretty outdated for client side and it doesn't look like Oracle is going to do anything to that situation. Google has done a great job with the Android SDK for client side. However that can change now when Oracle suited Google for that great job.
Comment: @Jonas: The press release roadmap is indeed somewhat quiet on those. Don't know about ME, but JDK7 includes new Swing features (http://openjdk.java.net/projects/jdk7/milestones/) so I don't think that "Swing is dead", and although JavaFX won't replace Swing (http://javafx.com/faq/#5.1), they can be mixed. http://javafx.com/roadmap/ doesn't look too bad at all; especially replacing the goofy JavaFX Script with Java APIs seems a good move. Granted, the big picture is currently somewhat confusing, but there is plenty of work going on at different fronts.
Comment: @Joonas: Yes, there's some minor updates, but as of today Swing is very outdated compared to its competitors like WPF. E.g. all competitors have a declarative layout-system in XML that reduces the code a lot and increases the productivity. All these GUI frameworks has a declarative layout system: WPF+XAML, Adobe Flex+MXML and Android+XML but I don't know about Qt or Mac development but I think that iPhone has something similar. Swing is far from modern even after smaller updates.
Comment: @Jonas: JavaFX has a declarative layout system, if that's so crucial. Of course Swing, a > 10 years old GUI toolkit, is far from *modern* by definition, but so is Unix command line; for some purposes it's quite usable.
Comment: As someone who has been working with Java since 1998 in application and systems development, while paying attention to the evolution of both Java (the programming language) and the JVM, I agree with this answer. If someone disagrees, I'd say either he doesn't work in Java much (which is ok) or he doesn't pay attention to the industry he's working on (which is bad.)
Answer: Two answers:
1)Android
2)Blackberry
Seriously though, on the desktop, it may be in decline, but it powers the two competitors to iPhone.
Also, last year, I helped a bunch of people with Java homework for school. Point being, java is still taught in colleges.
Edit:
As of October 2011, BlackBerry seems to be in decline. Android is still going strong.
Comment: It was never that relevant on the desktop. The meat and bulk of Java development is on the back-end, OLTP market.
Comment: A whatberry? Are they still going? They are to the 2000s what Palm was to the 90s... :)
Comment: @adolf garlic - So what, they are not sold to HP yet ;) That's why there are two answers, anyway. Android is to the 2010s what iPhone is to the 90's. Android's not up to the fading phase yet.
Comment: @Luis.espinal - I was grouping servers, desktop in one group, mobile in the other.
Comment: @luis.espinal , +1
Answer: Even in the worst (best?) case, I can't imagine Java becoming irrelevant within 5 years. Java has been used enough that it's roughly in the same situation as COBOL, Fortran, etc. -- even if everybody with existing code decided to rewrite all the existing systems in another language as quickly as reasonable, it would take more than 5 years to replace it all (and 5 years from now, there would still be enough left in active use that a fair amount of maintenance would still be happening).
Realistically, that's unlikely to happen -- while there are certainly differing opinions of Oracle, I can't imagine them doing anything so obviously awful that all the major players who have huge investments in Java would drop it very quickly. In all honesty, it would probably take close to 5 years of obviously bad decisions before IBM (for example) would even consider working toward using something else in Java's place. They have a large enough investment in Java that they're unlikely to drop it until or unless they believe they have virtually no alternative.
Comment: +1 for the connection to COBOL. Some say that because of Java acting as the modern COBOL, it's fitting for Oracle to have it.
Answer: It was losing importance in the mobile market, but with Android, it has regained it again.
Comment: It will take a long time for sl4a to take off for general development due to performance concerns. I'm still not sold on cross-platform toolkits for high quality applications. For something quick/limited resources, sure
Comment: The Android effect could be short-lived if sl4a gets completed. The eventual goal of sl4a is to allow people to write apps for Android in any programming language. Also, cross-platform toolkits like Appcellerator make it at least partially unnecessary to learn Java for Android development.
Comment: what performance concerns? The Python version is native CPython with all the APIs being called via a Dalvik bridge (IIRC). So it should be nearly as performant as "native" Dalvik code, in the absence of a JIT. Android 2.2 does have a JIT, but at that point, there's no reason not to use Jython anymore, since it would be faster than CPython and not hugely slower than Java.
Comment: +1 for inspiring @Chinmay Kanchi's comment. Didn't know athat sl4a is that interesting.
Answer: Java will be relevant for the foreseeable future, even if you define relevant to only include new code, not legacy maintenance mode.  Yes, the language sucks and treats its programmers like naughty children instead of consenting adults and hasn't had a facelift since the Stone Age.  On the other hand:

Java has some awesome libraries.
The JVM is an awesome platform.
You don't have to program in Java to use these libraries, now that there's been a proliferation of JVM languages.

IMHO the way things will evolve is that Java in the JVM world will become what C is in the natively compiled world.  People will use Scala, Jython, Groovy, etc. in day to day coding, but will keep calling old, crufty Java code from these languages for eternity.  Certain performance-critical code might still be written in Java, because it's probably the lowest-level, most efficient JVM language.  Old libraries will need new features added.  Therefore, Java will remain highly relevant even if it's not used by the average programmer day to day.
Comment: makes me feel old, when you say java will become a native language. sigh
Answer: I think so.  I anticipate that its popularity will increase over the next couple of years, with recent improvements in the plug-in and the syntactic enhancements coming in Java 7.  And it has the advantage of the huge range of good open-source libraries (as compared to .NET) that could easily keep it alive for another 10 years.
Comment: Java 7 rejected many of the best ideas
Comment: @Casebash:  Which were those?
Answer: Currently Qt is killing  Java in Desktop Applications.There are many rewrite from Java to Qt.Currently i'm working on one of them. Since the day i  started  my programming carrer there is always a rumour that Something would kill C++ . For Ex . Visual basic, Java, C#, but in reality C++ is still going. It has many disadvantages but it is still going. All other Competitors had sad death.........
Answer: I don't think it'll lose relevance. Java 7 is just coming out with a lot of neat features that will help developers create great software easier.
Also Java is used to create Blackberry applications; one of the leading corporate mobile phone. It's safe to say it's not going anywhere soon.
Comment: And powers Android, a cell phone gaining momentum and popularity everywhere
Comment: I went to Java One this year. Some of the cool things coming: support of automatic use of multiple cores, automatically offloading to the GPU and automatically offloading to the CPU's vector unit is going to make Java a very efficient platform. And all Java programmers writing the "new" idiomatic java will get it for free. There are some scarily smart guys who have been given some money by Oracle to make Java better. Project Lambda is going to supply closures and do so in a way that works AND is totally backwards compatible without any pain. SAM conversion rocks.  Good things are coming.
Answer: I'm primary a .NET developer, although I do work with other languages (including Java) as needed to get the task at hand. As such, based upon my own experience working with the language, I don't think it's going away anytime soon, here's why:

Current Install Base - There are enough programs out there that are going to need long term support that there is a reason for new developers to learn the language.
Use in the Academic Setting - Most colleges and universities are using as one of their introductory languages to teach OOP and other fundamental concepts, this means that there will continue to be new developers graduating and entering the workforce that will be familiar with the language when they get started.
It's Cross-Platform Nature - An obvious one, but the fact that it is cross-platform is a big deal, even more so as smart phones at support for Java to new devices. The prospect of only having to maintain one code base, but being able to deploy (i.e. sell) apps for multiple platforms is going to be a bit deal. Can you imagine if iOS and Droid both supported apps written in Java?
No Strong Competitor - At this point in time I can't name a language that I consider a strong competitor to Java. Sure C# is starting to show up on more platforms thanks to Mono, but that's not quite the same as having the same cross platform that Java has. Granted there are a number of languages that do what Java does (and it some cases better) they tend to be tailored to what they are doing and for some large projects it doesn't make sense to have a ton of languages to maintain if you can accept any performance hit that Java might have.
Answer: Java the language may be in slow decline, but Java the platform (JVM + JDK) has definitely been booming during the last couple of years (Scala, Clojure and many other languages; Android framework). It's easily the best (only viable?) multi-architecture, multi-OS, multi-language platform out there, scaling from embedded mobile devices to mainframe enterprise, and there are no comparable rivals currently AFAIK. So I would expect Java the platform to be relevant in 5 years, and even in 15 years. That also makes Java the language relevant in the long term, even if its popularity may be past the peak.
Answer: TIOBE rates language uses... http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
Based off their stats Java leads the way and will probably do so for a long time to come - #1 since 2005.  I have used Java over my career and everywhere I have ever worked had Java applications/developers - even in places that considered themselves Microsoft Dev Shops.  Java is just such an easy language to pick up when you have to develop solutions on a Mac or Linux Server.
Also, good ole C/C++ are still holding strong at #2 and #3 - while C# - the language everyone thinks it is the most popular (MS marketing at its best) - isn't even close!  I use C# now, but it will take years to equal the amount of code I've written in Java and Delphi.
So don't be afraid to learn or use Java - there is always jobs posted for them. So, yes Java will will be very relevant for a long time to come.
Comment: Tiobe rates... the amount of people on the internet who talk about a language in the way that tiobe searches for. http://blog.timbunce.org/2008/04/12/tiobe-or-not-tiobe-lies-damned-lies-and-statistics/
Answer: It's one of the biggest names in Enterprise programming (J2EE). I'm pretty sure we won't be seeing it going down for the next couple of years.
Answer: Not sure about JAVA. But surely the JVM will remain relevant supporting many other languages.
Answer: It depends on how the language will evolve.
At present state Java is not very actractive as language. It was born to support one (and just one) paradigm: OOP.
It places itself somewhere midway between languages that permit higher level abstractions (like C++ and its metaprogramming features) and scripting languages with reflection capabilities (like the Python "exec" and "dir" commands) but somehow it fails to find its real place.
It's basically becoming obsolete as "language". Weren't for the fact it's a de-facto standard on mobile devices I think it would be dead by now.
As for the fact it's a good teaching language for OOP I have my doubts from what I can see: all Java-born programmers just spawn Visitor and Observer patterns everywhere but it's not that I have a great experience with Java programmers.
Still there is a lot of legacy code and on mobile devices it's a standard. That said I'd never choose Java for either a desktop or a web application. There is no reason to, apart business ones (most managers nod if you say "Java" and that is, I suppose, the reason it's a standard on mobile devices).
Comment: its widely used for large-scale apps, sure the "coders", "scripters" and "ROR ninjas" don't like it but thats because its a real programming language and is used for building apps that do a lot more than just CRUD applications do, if you have a lot of intensive things going on in the server-side of an app Java is usually the most attractive choice before you would have to go to using C++ or another lower level language
Comment: Does anybody remember when someone from SUN said "Java doesn't need" enums ? C# / VB.NET has enums, and where later added to Java
Answer: IMHO, Java is going to stay very relevant and grow in use, even though it is not really evolving in its constructs or powers.
Here is my reasoning:
 - There is a lot of code out there, and maintenance requires more people than writing new code.

The "VM languages are too slow" camp is slowly losing (especially as Java made it successfully into algo trading).
Major companies still use it across all sectors, including Oracle.
The android platform is growing faster than iOS, with no other competitor in sight, and that does bring in more people to the langauge.
It is more straightforward for folks to use than functional languages. It's easy for language purists and academics to appreciate functional languages and their capabilities, but most newbies without CS degrees do not fully appreciate the power of the Lambda. So I don't think that these languages would take off.
It is fully free (unlike .NET which is still closer to the windows ecosystem despite alternatives).
Answer: Java will not completely lose it's relevance for many more years, but it is certainly on a decline. If recent developments will affect that or if Oracle can change that remains to be seen. But I do think that one day I might be like COBOL, no new projects, but never quite dying either.
Answer: COBOL, Fortran, and C are still relevant.  What's the chance that Java will go away in five years?  Conceivably there won't be much new Java development in five years, but I'd bet against that, too, since there's lots of people who use Java and shops are rather slow to switch their preferred languages.
Answer: I suspect all languages eventually go through a phase where pundits will say "[Language] is the COBOL of the [insert decade here]".
Java has become a standard tool, exclusively or one of the main tools, in a number of areas of software development.  Its VM is popular as a platform upon which to build new languages.   It'll be around way too long just from its massive inertia even as newer better languages become popular.
Comment: But, Java did become the COBOL, mainframe, server speaking
Answer: There have been some trends in the Java world -- particularly the absolutely brilliant adoption of JRuby and Rails or Groovy and Grails -- that indicate that Java still has a lot of life in it. Then there's the Android situation, which is also in Java's favor. As recently as Snow Leopard on Mac, certains changes -- now supporting Midi with no external drivers -- make it so that it's also gaining in possibilities on the desktop. And Swing apps finally look 99% native (or at least there are a lot of nutcases that believe this now: 10 years ago there were none).
Java had an amazing moment in the 90s where it seemed like it was the solution for everything. Now it's clear that nothing is the solution for everything. .Net is kicking ass, and Ruby, and Python, and PHP (with goofy CMS solutions and entire frameworks that people get married to for life!), and Java (with Groovy JRuby JPython whatever), and a whole bunch more. The answer is:
Expect a Pluralistic Universe
Will Java continue to play a major role in this Universe? If you mean "languages that run on the JVM" the answer is most definitely. If the answer is just Java (language, JVM, etc.), then the answer is "maybe not so major." But come on, even Cobol is still hanging in.
Answer: I think academic still need the value of open source in JAVA. There are so many many powerful library (focused on academic purposes) developed on JAVA.
I agree that JAVA will remain relevant, but for smaller segment.
Answer: Google writes a lot in Java and Google is the biggest company in the web. I think the web is the future - web application , cloud computing - and so I think Java is still relevant in the future.
And there is Android, which is the future of smart phones in my opinion. And some people say smart phones are the future of the computer - whats not my opinion :) - but whould also gave Java a big future. So go Java :D
Comment: I'll second that Google is pushing a lot of its internal tools and libraries (e.g., GWT, Guava, etc.) to the community, so it does have external impact beyond just the X number of engineers using it.
Answer: If it's bound to some industry (i.e. banking; mobile platforms; etc.) it's like asking "Will Internet Explorer still be relevant in 5 years.." 5 years ago. Today there are many companies that have IE-specific internal websites that can't be rewritten from scratch. So it's not "relevant" but "unavoidable".
To come to your question-- no, it's not relevant as a driving force for innovation; but yes, it's relevant because many industries will require java applications to be maintained for many years to come.
Answer: Here is an article from ReadWriteEnterprise on Java's decline:
http://www.readwriteweb.com/enterprise/2011/02/javas-not-dying-its-mutating.php

What we're witnessing is not the death of Java, but its transformation. It's moving from being just a general use platform that dominated the enterprise to being the guts of many disparate technologies for various special applications.

It also addresses how specific tools are providing alternatives to Java technology, but not necessarily replacing it:

Although NoSQL databases provide an alternative to relational databases, it doesn't mean that relational databases will go away. Likewise, Node.js provides a specialized alternative to Apache, but won't kill Apache.
Comment: An article from the same site on job trends shows that Java still has more job listings than any other language:  http://www.readwriteweb.com/enterprise/2011/05/it-hiring-and-salaries-up---wh.php

Will Java still be relevant in 5 years?


Can I convert ONE 3 phase connection power supply to become TWO 3 phase connections?

Question: Currently I have a SINGLE 3 phase connection power supply. I intend to convert it from ONE 3 phase connection to TWO 3 phase connections. Is there a way to do that?
Comment: Define connection. Do you mean a receptacle as in outlet? We are going to need a bit more info.
Answer: Assuming you mean receptacle, yes you can split a split a three phase branch circuit into multiple receptacles the same way it is done for regular 120V circuits. It's rare though as most three phase machinery draws a lot of power which warrants dedicated circuits. But, if you have a small shop and you only use one machine at a time, then it's fine.
My grandfather had a mini shop inside my fathers shop and he had a single 20A 208V circuit that ran to three twist lock outlets. He had a mill, lathe and surface grinder. All of which could easily share a single circuit because he never ran more than one at a time.
Answer: Two long for a comment:
A little more information would be helpful. It is possible to have multiple "taps" on the 3 phase supply. Knowing the kind of supply is important is it a delta where 2 legs are the same voltage to ground and the "high leg" is 2x the voltage in the U.S. This is the B phase and is color coded orange. Or is it a wye all 3 legs have the same voltage to ground.  The reason I mentioned this is because the equipment needs to have the proper voltage rating for example the disconnect/ breaker on a 480 wye can be 480/277 but a delta requires 480 because of the high leg. With that said you would want to make sure there is a circuit breaker Sized for the new tap conductors and an equipment ground or earth connection of sufficient size. With some more information I can help you size the breaker and wires that would meet U.S. Codes and others could provide local information and code requirements. What we need to help the size of the supply, the size of the additional load, and what is your location.


Printing: Opacity color or transparency in Adobe Illustrator

Question: I have a client who needs a flyer designed and has a printing restriction of one color, in order to keep cost low. To make the design more interesting and appealing I have used the same color blue in both 100% and opacity 60% in Adobe Illustrator. When this project goes to be printed will this qualify for only one color use with the transparency?
Comment: Scott's answer is an excellent guide. Make sure that your blue really is a single color (not a CMYK color) that will use only a single plate on press. Check your separations preview to be certain. Also, don't use Pantone Reflex Blue -- it's a very popular choice, but it's a nightmare on press because it takes a very long time to dry and has a strong tendency to smear.
Comment: Thank you as well Alan. I will make sure to follow your advice.
Comment: If the below does in fact answer your question please accept it as an answer.  If you still need help please make an [edit] with further detail so we may help you.
Answer: Opacity will lighten colors. Using transparency in itself is not generally a problem.
100% color @ 20% opacity = 20% color @ 100%opacity.
It's 6 of one, half dozen of the other.
The difference is interaction.
A 20% tint over 100% (of the same) color means there's 20% color in that area.
20% opacity over 100% (of the same) color means there's 100% color in that area.
Using tints generally knocks out what's under the object to maintain the tint percentage. Using transparency does not create knockouts and color percentages stack to a maximum of 100%.
In addition, blending modes won't have the same effect on a press as they may have on screen when working with a single color. Blending modes can often create complex values for a single color. Those complex values can't always be pulled off with a single color. In a one color piece, although using things like Multiply will visually alter the objects on screen, when plates are produced and the ink is on press, there's no such thing as "multiply" on the press. So overlapping objects can only ever be 100% solid color at most and never darker. This is often different than what you will see on a digital display.
For one color design it's best to completely avoid altering blending modes and stick to using tints of the single color.
In some cases using overprints can assist. For example, you have a one-color photograph that you want to deepen the overall color by tinting it an additional 20% of the color. You could draw a rectangle over the photo, fill it with a 20% tint of the color and set it to overprint. Then turning on Overprint Preview in the View Menu will show you what it will look like off a press. Actual artwork makes a difference, but this is similar to using the multiply blend mode at times. However, overprinting is more reliable visually when using a single color because overprinting will never show you a color value darker than 100% of the color.
While using transparency can always lighten an object, it will never darken anything above 100% color regardless of what the screen shows. For my money, it's much easier to use a 20% color @ 100% opacity than it is to use 100% color @ 20% opacity. But ultimately, if you aren't adjusting any blend modes it doesn't really matter.


what is a "unique open" in a mailing report?

Question: Included in a mailings report is data on "unique opens" and "total opens". What is the difference between "unique opens" and "total opens"?
Answer: The difference is this, If someone opens an email immediately but then opens it again later on to read it again. CiviCRM will mostly likely track both opens. So in the Total Opens column stat that will = 2. However in terms of unique opens given that its the same person opening twice the unique opens = 1.
Hope that helps


Best Visual Studio 2008 Debugging Tutorial?

Question: Is there a good debugging tutorial for VS 2008 (C#, more precisely)? I have found a good deal of resources on the web, but they are still lacking a comprehensive, step by step, approach. Would you have any suggestions?
Answer: Have a look at these series
Answer: These aren't specific to Visual Studio 2008, but their information is certainly still valid when developing with VS2008.
To get you started immediately, check out Tess Ferrandez, she has great "getting started" set of labs. These will probably tackle your step by step needs and are scenario based.
When your looking for more detail, pick up a copy of John Robbins "Debugging Microsoft .NET 2.0 Applications".  John covers quite a bit of Visual Studio IDE kung fu which may be precisely what your looking for.
If thats not quite enough, and you don't mind your brain melting, you can pick up a copy of "Microsoft Windows Internals (4th Edition): Microsoft Windows Server 2003, Windows XP, and Windows 2000" by Mark Russinovich and David Solomon.  Looks like they have an updated version releasing in June 2009.
Answer: MSDN has a comprehensive resource for application development in Visual Studio - Building, Debugging, and Testing
Answer: There are several books available that cover more advanced uses of Visual Studio and .NET debugging. Some of these include coverage of WinDBG for more advanced scenarios.
One I've learnt a lot from is "Debugging Microsoft® .NET 2.0 Applications" by John Robbins (MS Press).


Given Names - Common Practices

Question: Were the names Rebecca and Elizabeth ever used interchangeably, specifically in Ireland? I am doing some family research, and it seems that these two names may have been used to refer to the same person.
Comment: If useful, I know from my wife's family (English, but forgive that) that it was common to have nicknames - so you'll have "Emily, known as Maud", for example.
Comment: It may well be that some people named "Rebecca" go by the name of "Beth", or some named "Elizabeth" go by the name of "Becca".  This could cause confusion.
Comment: Thank you for the feedback! I am concluding that they could be the same person if they adopted a nickname, or confusion resulted from nicknames. However, as I think about the answers I've received, I am also convinced that I need to do further research before reaching a final decision.
Answer: It is not at all unusual, particularly in the nineteenth-century to find people who were known by names other than the ones they had been given in baptismal records, and, after compulsory registration began (in Britain 1853) on birth certificates. They may have been known by their alternate name only to certain people, or at certain times of their life.
In my own genealogy I have two or three male persons who were always known by the name of their father, which was different to their own.
But I can't think it can possibly be the case that Rebecca and Elizabeth were generally interchangeable. In the Bible those names were held by quite separate people.
Having done considerable amounts of genealogical research in my time, I am not aware of any names (other than recognisable short forms) which were generally interchangeable with others.
Comment: I can recall seeing stuff about a few "interchangeable" names, presumably because the same name translated differently through German and Danish, eg.  But one would not expect this of biblical names.
Comment: @WS2: I don't know whether you should call Peggy a *recognizable* short form of Margaret. Ditto for Sandy and Alexander. I think you might want a different adjective there.
Answer: The names are not alternatives of each other; but it's quite possible for both to be used of the same person. The playwright Shaw was "George" (or "Sonny") to his family but "Bernard" to the literary and theatrical world and on his title pages; only ignorant journalists called him "George Bernard Shaw". My own wife is known by her first name to her family, to government agencies, to billing and Human Resources offices, and to direct-mail and telephone advertisers; but in high school she elected to adopt her middle name among her friends, and she has used that in all professional and social contexts ever since.

Given Names - Common Practices


BGP VPLS - How the destination ip address is mapped?

Question: From RFC and tutorials in the internet I understand that the MPLS cloud acts as a switch and switches traffic between end points in a VPLS. And that VPLS ID along with RD is used to reach the VPLs site across mpls cloud. But I 'm trying to understand how the destination ip address is mapped. Any reference? Any one has sample vpls packet captures ?
In show vpls table cli commands of vendors like cisco and Juniper the VPLS ID is mapped with a destination ip addresses. How is this mapping formed ?
Comment: Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
Answer: A VPLS does not map IP addresses - it is a Layer 2 service.
What you may be seeing in command output is MAC addresses mapped to the IPs of the specific remote PEs they were learnt from.
Answer: Yeah. I am just adding to the Benjamin Dale.
Basically a VPLS has even no visibility of IP address. Its a point to multi point L2 service which only uses Ethernet. VPLS learns MAC address in Flood and learn manner , which means when CE sends th ARP broadcast to learn the MAC address of other hosts in same VLAN , then just like normal LAN switch the PE attached to that CE will learn that MAC address.
However since it sees that Destination MAC Address is all FFs , so it sends the same ARP message to all those PEs that are part of same VPLS instance (it knows which PEs are a part by using VPLS Auto Discovery in case BGP signalling is used). When remote PEs get the ARP packet they knew already from which PE they are getting this source MAC Address (basically they read the source MAC Address after popping the VPLS Label). They do this by already establishing PWs when VPLS is configured.
In this way they know which PE is sourcing the traffic for that MAC. Once MAC tables are populated with SRC/DST MAC Addresses , then traffic from one PE to PE is unicast.


How does an airliner adjust and move exactly over the coloured lines before stopping in front of the jetways?

Question: How does an airliner adjust and move exactly over the coloured lines before stopping in front of the jetways?
Comment: Closely related https://aviation.stackexchange.com/questions/25493/are-aircraft-still-guided-by-ground-marshals
Comment: I'm pretty sure there is another question which has details of several of the automatic gate systems, but I just can't find it...
Answer: There are a few different ways. Probably the most low-tech and widespread is by marshaller guidance, which is a person outside the aircraft guiding the pilots by means of visual signals:

The exact hand signals to use are defined by the ICAO, meaning that they are identical no matter where in the world you are flying.
Most larger airport have some sort of "docking system" at some or all of their stands. There are different types, but they are all external systems that provide visual guidance for the pilots, just like a marshaller. The simplest form is a big mirror next to the parking position:

More common are electronic docking systems, which use various sensors to detect the exact position of the aircraft and calculate any corrections needed by the pilots. They are placed directly in front of the position where the aircraft must stop, typically mounted on the terminal building or a high mast:
Comment: Also, most jetways have some degree of movement, so the plane doesn't have to be super precise, because the end of the jetway can then be moved up to the plane by ground crew before they open the doors.  (This is critical for situations where different types of aircraft may dock at the same gate.)
Comment: And when the pilots (or the marshaller) get it wrong, you then have to wait for a tug to pull the plane in. In some places like the cramped terminals in LAX, the aircraft actually stops quite a distance from its gate position and is pulled into its final position (using the same vehicles which are used for pushback).