How can I place my bed on glass blocks?

Question: I'm a little confused by why I can't place a bed on a floor of glass in 1.7.2.  I can place other objects, such as furnaces and crafting tables, without difficulty.  However, my bed refuses to be placed.  How can I get around this and why is it happening?
Answer: From the Minecraft Wiki:

Like certain other blocks, beds can not be placed on snow, ice, glowstone, glass, carpet or leaves. If you remove the blocks underneath the bed, the bed will not be removed, but will remain floating. To put a bed on glass you must use this trick to make the bed float, and after that place the glass underneath.

(Emphasis mine)
For an alternative explanation, see this video.
Comment: Whilst this works for sleeping on, later visitors might want to know that it will not function as a spawn point (giving the obstruction error) if placed in the above way.

How can I place my bed on glass blocks?


What caster level is used for PC supernatural abilities?

Question: As per this answer, D&D 3.0 lets you  use dispel magic to remove supernatural abilities from targets.  Typically, this is something PCs do to monsters, so, the applicable caster level is defined in the MM in terms of the creature's HD, as stated here.  However, PCs can get supernatural abilities as well, typically from their class (such as a druid's Wild Shape), and of course, some monsters do cast dispel magic.  What caster level is used for PC supernatural abilities, and does it depend on what mix of class levels the character has for a given amount of Hit Dice?
Answer:
Unless otherwise noted, a supernatural ability has an effectivecaster level equal to the creature's Hit Dice. The saving throw (if any) against a supernatural ability is 10 + 1/2 the creature's HD + the creature's ability modifier (usually Charisma)."

Source
It really just functions off of your hit die. What classes you have is largely irrelevant except for the hit die and maybe the ability mod that goes with it. I would just use the same formula for pc's as for monsters to keep things simple.
Comment: Welcome to the site, Ilyando :)
Comment: You should make sure to format this properly using blockquotes so it's clear which part is quoted; you should also add a link or some other attribution.
Comment: Oh ok. I'm new to the site so I'll look into the formatting and such. Thanks for the feedback.


Attacks against RC4 when index $i$ is unknown

Question: RC4 uses two 8-bit indices. One, $j$, is key-dependent and secret, and the other, $i$, increments by one for each byte output. The $i$ index is typically considered to be public, but what if the RC4 keystream starts at an unknown position, putting $i$ anywhere in the range of $0$ to $255$ with equal probability? I can think of a few inefficient and naïve techniques, but what would be the most efficient technique to discover $i$?
Answer: The most efficient way I can think of (not that it's all that practical) is to take a very long section of the keystream (think a Gigabyte+), and check it against the known RC4 digraph statistics; some of these biases (actually, most of them) depend on the value of i, and so the value of i that is correct will show up as more strongly biased than incorrect values.
The practical downside is that it requires a lot of keystream; on the other hand, it is computationally efficient (and works even if the RC4 key is large)
Comment: That is the naïve technique I was thinking about. Is that really the most efficient way?


How to install a PostgreSQL client

Question: I have a PostgreSQL server setup on Box A. I want to connect to the server from Box B using psql. What do I need to install on Box B? I can't find a client installation binary for PostgreSQL. Or do I have to install the entire PostgreSQL distribution?
Comment: What is the OS? Most Linux systems will offer client-only packages.
Comment: What is your OS: Linux, Windows, others?
Comment: It's Ubuntu. I will look for a package then.
Answer: On Debian the package you are looking for is called postgresql-client and I guess it will be the same on Ubuntu.
Comment: Where do I put pg_hba.conf though? It's supposed to be under the data directory, but there is none in a client only setup.
Comment: You need pg_hba.conf only on the server side, not the client side. It defines which client might connect from where and how.

How to install a PostgreSQL client


Why is global.asax missing from a Website Project

Question: A couple of questions regarding the role of global.asax:

Why is it not included in the Website Project in Visual Studio? Are there other ways of achieving the same functionality without this file?
If I would create a Web Application project, as far as I remember, a global.asax file would be created. If I were to delete it, would the project run?

I tried to look for some explanation regarding the global.asax compilation but didn't find any info about this.. would appreciate help/links. :)
Thanks!
Answer: An ASP.NET site can run without the global.asax file.  Here is a question which talks about alternatives of global.asax file.
Even if you delete a global.asax file your site will work.
Answer: Globax.asax is not required by ASP.NET for a website to run.  It is, however, very useful for application-level functionality (like unhandled exception logging).
Answer:
You can add Global.asax to the website project and it will work fine.
Global.asax is not added by default for web applications. If you have it, you can delete it without problems.

Be careful to include the .compiled files when deploying the website or else the events in Global.asax will not fire.
Answer: It sounds like you are familiar with Web Application Projects, now see a Web Site "project" and wonder what's going on. In any case, I'll answer as though that were true. ;-)
In Visual Studio 2005, Microsoft introduced Web Site "projects", which are not projects - they're just directory structures on a local disk, FTP site, etc. They do many things differently from Web Application Projects, and can therefore be confusing (especially if you're like me, trying to answer people's questions, not knowing which they are using).
With Visual Studio 2005 SP1, they restored Web Application Projects. If that's what you're more familiar with, then I suggest you use them. They're real projects, just like they always were.
And, BTW, there will be a global.asax, just like there used to be...


What's the purpose of a "Pause Animation" button on a loading animation?

Question: Many of the loading spinners on Chase bank's rewards portal have a "Pause Animation" button below them. Is there a reason to include this below animations?
Comment: Looks like overengineering to me
Comment: $10 says someone complained about the animation being distracting in QA and this was the smallest solution to make everyone happy. Also, combining both opinions into the final product doesn't really solve the root problem, which is an flashy icon that draws attention to the wait animation (the button draws *even more* attention) and a long loading time which might be harder to solve, but nonetheless would be a far preferable UX
Comment: The page didn't have enough useless stuff on it so...
Comment: What's next? Change animation fps?
Comment: @KyleMit: "I clicked 'PAUSE ANIMATION', but only the circle stopped rotating, while loading continued! Can you make it so that loading is paused, too?' ;)
Answer: It's a WCAG accessibility requirement (2.2.2):

For any moving, blinking or scrolling information that (1) starts
automatically, (2) lasts more than five seconds, and (3) is presented
in parallel with other content, there is a mechanism for the user to
pause, stop, or hide it unless the movement, blinking, or scrolling is
part of an activity where it is essential

Animations distract from other content on the page, and this can cause issues in individuals with attention-related disabilities.
Answer: The one reason I can think of (which only applies to mobile devices) is that it can save processing power, and thus, battery power.
When I turn my phone onto Battery Saving mode all animations stop being processed. This in turn saves my battery juice for a little longer by not running those processes.
Since your example is on a desktop/laptop or otherwise, I would guess it might be due to incompatibility in some browsers... maybe it looks weird in IE?
Otherwise, as @LisaTweedie said, it's over-engineering.
Answer: Root problem is the loading indicator is way too overbearing (IMHO you could get dizzy if you stare at it too long)
So rather than fix the loading indicator and change it to something more elegant and fitting, a pause button was added.
Answer: While it's hard for us to know exactly why they implemented this, I agree with Izquierdo that this is probably for accessibility. (Though the implementation itself is not great imo)
Anyone who wants to take this accessibility option into account.
CSS now has a prefers-reduced-motion media feature which you can use to check if the user wants to disable motion, like this animation.
If true you could hide the animation and instead show some text, e.g.:

Data is loading...

.loading-animation {
  display: block;
}
.loading-text {
  display: none;
}

@media (prefers-reduced-motion) {
  .loading-animation {
    display: none;
  }
  .loading-text {
    display: block;
  }
}


Given a matrix $A$, show that bases exist in two vector spaces such that a transformation has $A$ as transformation matrix

Question: Let $T: V \to W$ be a linear transformation of two finite dimensional vector spaces $V,W$ (both over a field $F$).
I'm also given a transformation matrix $A$.
My assignment is to show that there exists a basis $B$ in $V$ and a basis $C$ in $W$ such that the transformation $F$ with respect to the bases $B$ and $C$ actually does have $A$ as a transformation matrix.
I'm asking this question in a kind of general sense (i.e not giving you $A$) so that I can solve it myself and learn as much as possible. But need some help kind of parsing the question and finding a strategy for finding a solution.
Since $V,W$ are vector spaces of course they have bases and I can do a transformation with respect to the bases from $V$ to $W$. But how do I show that (some specific?) bases exist such that the transformation with respect to these bases have a given a $A$ as a transformation matrix?
One naive idea:
Assume $A$ is transformation matrix of $T$. Then we take one vector in $V$ expressed in (some basis) $B$ and when we transform it to some vector in $W$, expressed in (some basis) $C$. So $A$ does at least change the basis of a vector, but I since $V$ and $W$ might be of different dimension I don't really know where to go from here. Am I one the wrong track?
What can I say about the existence of bases if I assume that A is in fact the transformation matrix?
Or should I rather "bruteforce" it by trying out pairs general bases and hope that I stumble upon $A$?
Edit:
I have to admit I'm stuck. I can't solve it. My given transformation matrix is: $\begin{bmatrix}
I &0 \\
 0& 0
\end{bmatrix}$, where I is the identity matrix "of a certain size". Can anyone perhaps help me out?
Answer: Hint: assume $\dim V = n$ and $\dim W = n$, then, by Steinitz's Theorem, $V$ and $W$ have bases with $n$ and $m$ elements respectively. Elements which you can write as the columns of two matrices, say $B$ and $C$. Now, think about how $B$ and $C$ are and how do they interact with $A$.
Comment: I have to admit I'm stuck. I can't solve it. My given transformation matrix is: $\begin{bmatrix}
I &0 \\
 0& 0
\end{bmatrix}$, where I is the identity matrix "of a certain size". Can anyone perhaps help me out?


Fira to Santorini Airport transportation early in the morning

Question: Due to COVID-19 our leaving flight from Santorini, Greece to Athens (middle of September) got moved early in the morning. We are scheduled to leave from Santorini Airport at 06:20 (in the morning).
Therefore we have to be at the airport at 05:00 in the morning.
What (safe) means of transportation are there in order to get from Fira to the airport in time? We're thinking of leaving our accommodation at around 04:00.
What options do we have? Taxi, bus? Any shuttle service?
Answer: Take a taxi.  There are plenty of taxis on Santorini.  Just make sure you arrange the trip ahead of time, given the early hour.  I would expect that your accommodation can help you order a taxi for the right time.
Answer: Similar case here some years ago. We arranged a Taxi with the hotel the day before (around 20€ from Imerovigli)


Will the rms current be affected by inserting dielectric in the capacitor in an LCR circuit?

Question: MY thoughts: I think it will not be as the expression for RMS value is dependent only on the peak value of current. Is my thinking correct?
Answer: The capacitance will increase when the dielectric is inserted because the relative permittivity of the material compared to air is likely to be higher. However, the current could reduce (or increase) depending how you have the LCR circuit configured.
If you are applying a frequency that corresponds to the resonant frequency of the LCR then maximum current will be circulating in the capacitor and inductor (parallel tuning). If you increased the capacitance this would mean a decrease in current because the LCR is now non-ideally "tuned" to the input frequency.
The reverse could happen if F corresponds to the new resonant frequency after dielectric material is inserted into the capacitor.
Answer: You missed something, When you insert a dielectric into capacitor it is capacitance increases. When the capacitance increases, what happens to the peak value of the current? Think about that
Comment: Then, the current would decrease.
Comment: So the current when you put a dielectric is different from the case when you don't. Thus the RMS value when you put a dielectric will be different than when you don't put it. Does that answer your question?
Answer:
Will the rms current be affected by inserting dielectric in the
  capacitor in an LCR circuit?

The answer is:  maybe.  You haven't given enough context to give a more definitive answer than that.
What one can say for sure is that inserting a dielectric between the plates of an air capacitor will increase the capacitance (assuming no other changes).
This means that the AC current through, for a given AC voltage across, the capacitor will increase.
But, consider a series LCR circuit driven by an AC current source.  Clearly, the current through the capacitor is independent of the capacitance (the current source fixes the current through the capacitor).  In this case, the AC voltage across the capacitor will decrease.
So, without more context or a circuit diagram, it's not possible to give a yes or no answer to your question.
Comment: So, in the case of a series LCR circuit if the current doesn't change in inserting a dielectric slab in the capacitor what changes due to increase in capacitance will take place?
Comment: @RajathKrishnaR, I answered that in my penultimate paragraph:  *In this case, the AC voltage across the capacitor will decrease.*


TortoiseHg - how refresh list of files from api?

Question: I have in repo some files with specific binary format. I want see its contents.
For such binary file I put in repo specific txt file, containing md5 and nice content from binary.
To minimize manual movements I wrote precommit hook in python that see changes in binary and check is txt-formatted file match new binary one.
If matching fails, hook automatically refresh txt-content and does not allow commit.
Here I need to manually push F5 to refresh list of changes, becouse TortoiseHG does not include in commit files that Modified, but not present in list...
Answer: without any others decisions I emulate pressing F5 by ctypes.windll.user32.SendInput :)


emails were send from my own email address

Question: A friend of mine has just received an email from my exactly own email adrress. What could this be and how do I stop it?
Comment: 1) It is trivial to spoof an email sender. 2) someone might have hacked your account
Answer: Your email provider either has a relay open on an SMTP server or they don't use SPF or DKIM records to prevent mail from being sent as domains that use their domain name.
Another possibility is that the e-mail is not from your address but the display name of the sender has been set to your e-mail address. (FROM: "firstname.lastname@example.com"<email@example.com>) This is more often the case and can create confusion for email recipients.
My advice would be to first determine if the email actually came from your email address or if it came from a fake email address using your real email address as a display name.
If the e-mail actually came from your address, look through the headers of the email your friend received to determine where it came from. You can also use the headers to check for DKIM and use online tools like DMARC Analyzer to check to see if your email provider's domain has an SPF record. If your provider does use DKIM and/or SPF and the e-mail did come from your address, then you may want to contact your provider to see if there are any issues with third-party mass-mailing vendors who have permission to send as your email address's domain.
Comment: I'm not sure the advice to inspect the headers and contact the email provider is useful. I certainly wouldn't do any of that. As an employee within the email provider, that's what you would do. But as a customer, that's not very useful. I'd simply report the fake email to support instead of diagnosing the problem for them and suggesting a course of action.
Comment: My assumption was that the person asking might be looking for a more technical answer and advice. I can't comment on their question to ask what type of user they are because I don't yet have 50 reputation points.


How to call useRouter inside useFetch's onFetchError by VueUse?

Question: I need to create a custom fetch composable from VueUse using createFetch() and I want to check if a request returns 401 status, I'd like the route to be redirected to the login route.
export const useApiFetch = createFetch({
  baseUrl: import.meta.env.VITE_API_BASE_URL,
  options: {
    beforeFetch({ options }) {
      const { user } = useSessionStore()
      if (user)
        options.headers.Authorization = `Basic ${user.user_id}:${user.password}`
      return { options }
    },
    onFetchError(response) {
      const route = useRoute()
      const router = useRouter()
      if (route.name !== 'login' && response.status === 401)
        return router.push('/login')
    }
  }
})

But everytime it hits the error, useRoute and useRouter are undefined, and yes.. I have checked that it runs in setup

Did I miss something or is there a better way to do this? thanks
Answer: Vue composables are primarily expected to be called in setup block. Other usages depend on their implementation and needs to be confirmed. The main restriction is that a composable is linked to specific component instance, in this case useRouter uses provide/inject to get router instance through component hierarchy; this often can be be deduced without checking the actual implementation.
It's possible to directly import router instance instead of using useRouter but this may result in module circular dependencies and this may not be work for other composables.
createFetch wasn't designed for this usage and needs to be wrapped with custom composable that guarantees that other composables will be called in time:
let useApiFetchFn;

const useApiFetch = (...args) => {
  if (!useApiFetchFn) {
    const sessionStore = useSessionStore()
    const route = useRoute()
    const router = useRouter()

    useApiFetchFn = createFetch(...)
  }

  return useApiFetchFn(...args);
}

Whether it's correct to cache the result to useApiFetchFn depends on the implementation, in this case it's acceptable. At this point it may be more straightforward to use useFetch directly and compose the options similarly to how createFetch does that, most of its code is dedicated to TS support and variadic arguments that may not be needed in this case.


What is the legality of atheist marriage among consanguineous couples in India?

Question: I am preparing an academic report on laws regarding incest in India. Hinduism law and both major schools under Islamic law consider sibling marriage void. A Special Marriage Act was introduced to govern the marriage among atheists. However I could not find any information regarding consanguineous couples.
Answer: See footnote 9 from your Wikipedia link to the Special Marriage Act:

Necessary Conditions For A Marriage
The following conditions are necessary :
...

That the parties are not within the degrees of prohibited relationship. However where a custom governing at least one of the
parties permits a marriage between them, such marriage may be
solemnized nonwithstanding that they are within the degrees of
prohibited relationship as follows:

degrees of prohibited relationship
A man and any of the person mentioned in part I of the first schedule
and a woman and any of the person mentioned in Part II of the said
schedule are with in the degrees of prohibited relationship.
Relationship includes
(a) relationship by half or uterine blood as well as by fool [sic] blood;
(b) illegitimate blood relationship as well as legitimate;
(c) relationship by adoption as well as by blood; and all terms of
relationship in this Act shell be construed accordingly.
''Full blood'' and ''half blood''- Two person are said to be related
to each other by full blood when they are descended from the common
ancestor but by different wives.
''Uterine blood''- Two persons are said to be related to each other by
uterine blood when they are descended from a common ancestress but by
different husbands.
''Ancester'' includes the father and ''ancestress'' the mother.

Parts 1 and 2 of the First Schedule provide a comprehensive list of the prohibited relationships but are too voluminous to quote here.
Comment: Or perhaps it refers to one who marries unwisely, lol. Seriously if it seems to be an error in the source, it can be indicated by including "[sic]" to call attention to it, and indicate that it is not your error.
Comment: I'm ahead of you. Already done.
Comment: Is "fool blood" a typo for "full blood", perhaps an error in the source?
Comment: @DavidSiegel It must be a typo. lol


Improper integral with periodic function

Question: Let $f(x)$ be a continuous function on all real numbers such that $|f(t)| \le Ke^{at}$ for all $t \ge 0$ and for some constants $K>0$ and $a$ a real number. And let $f(x)$ be a periodic function for a period T, $f(x)=f(x+T)$
Prove that $\int_0^{\infty}f(t)e^{-st}dt =  \frac{1}{1-e^{-sT}} \int_0^{T} f(t)e^{-st}dt$. I tried everything, using properties of periodic functions, but I'm stuck. Only thing I proved is that function function converges when $s>a$ (which was a first part to the problem). Any ideas?
Answer: Hint: Split the integral up into a sum over intervals of the form $[nT,(n+1)T]$. On each interval use periodicity of $f$ and properties of exp to translate it into an integral over $[0,T]$.
Comment: Thank you for your answer, it's a little bit more clear to me, but I'm still kind of stuck. If I understood correctly should I split that integral over infinite sum like from 0 to T, then T to 2T, then 2T to 3T.. and so on. What should I do next with it when I look at that interval? I changed f(t) to f(t+T). Should I use an substitution for z=t+T? Elaborate please if you can. Thank you!
Comment: Yes an infinite sum as you say. On each interval make a substitution $t=nT+x$ with $0\leq x\leq T$ and use $e^{a+b}=e^a e^b$. You will see a geometric series popping out.
Comment: I finally solved it. I was actually thinking that somewhere should appear geometric series because of that constant on right side of equation. Thank you so much for your help!


Left Invariant vector field on SO(3)

Question: I have a Lie group, namely on SO(3), i.e. $SO(3,\mathbb{\mathbb{R}})=\left\{ A\in GL\left(3,\mathbb{R}\right)\mid A^{T}A=\mathbb{1},\,\det\left(A\right)=1\right\}$.
I have a Left action $L_g$ and I know that by definition a left invariant vector field is a vector field such that
$$(L_g)_{\ast}(X_e)=X_g$$
I worked out few thing with the tangent space at the identity and I arrived at formulating the idea that this should be a left invariant vector field on $SO(3)$:
$$L_{\mathbf{1}}=y\frac{\partial}{\partial z}-z\frac{\partial}{\partial x}$$
But now how to I effectively demonstrate that is left invariant. Can anybody show me the computation that once in a lifetime must be seen? Or at least give a refernce that actually shows the computation technique?
Comment: The field you've written down is given in coordinates $x, y, z$ (presuambly it is supposed to be defined on $\Bbb R^3$), but a left-invariant vector field is defined *on the group itself*, and you've given $SO(3, \Bbb R)$ as a subset of $GL(3, R) \subset \Bbb R^{3 \times 3}$.
Answer: This kind of formula only works when you have the action of the lie group $G = SO(3)$ on some manifold $M$, in this case, the euclidean space $\mathbb{R}^3$. Let then $G$ act on $M$ by $(g,x) \mapsto gx$.
A left-invariant vector field $V$ in $G$ induces a vector field on $M$ such that the flow in $M$ is: $${\gamma(t,x) = \exp(tV)x,}$$ where $\exp: \mathfrak{g} \rightarrow G$ is the exponential map. Define the induced vector field $\tilde{V}$ on $M$ by: $${\tilde{V} = \frac{d}{dt}\exp(tV)x|_{t=0}.}$$Then we have defined a map $\mathfrak{g} \rightarrow \mathfrak{X}(M)$ by $V \mapsto \tilde{V}$.
In your case, take an element of $\mathfrak{so}(3)$ (the lie algebra of $SO(3)$, e.g.: the tangent space at the identity), namely:
$$X = \begin{bmatrix}
0 & 0 & 0\\
0 & 0 & -1\\
0 & 1 & 0
\end{bmatrix}$$
(You can see that this is an element of $\mathfrak{so}(3)$ because it is an antissymetric matrix).
Then your induced vector field is $\tilde{X} = -z\frac{\partial}{\partial y} + y \frac{\partial}{\partial x}$.
Comment: Here, the exponential map is only the matrix exponential $e^X = I + X + \frac{1}{2} X^2 +...$ that can be done by hand for the matrix in question.
Comment: Thank you for your explanations, I upvoted the answer, but could you also show that X gives rise to a left invariant vector field? I'm not sure if I have understood... thank you
Comment: As a group of matrices, $SO(3)$ has a Lie Algebra of matrices. The vector field you want is only an induced vector field by the action of this group (as a group of symmetry, for example) in a manifold. If you want to understand that in physical terms, the left-invariant vector field $X$ has an associated operator $\tilde{X}$ that acts on your space as a differential operator on functions, and therefore, as a geometrical vector field.

Left Invariant vector field on SO(3)


Is food containing spirit vinegar halal?

Question: I am not sure if spirit vinegar is halal. I have asked at different mosque and called on Islamic TV shows but each of them have a different view. There is a hadith which mentions that the Prophets favorite was vinegar. However there is also another hadith which say that a person asked the Prophet if it is permissible to make vinegar from alcohol and he said no. He had said that no amount of alcohol should be used to make something else by purpose but otherwise it is permissible to consume. Nowadays spirit vinegar is made from alcohol by purpose. And I was wondering maybe the vinegar that the Prophet liked was different to the vinegar today.
Comment: "However there is also another hadith which say that a person asked the Prophet if it is permissible to make vinegar from alcohol and he said no.": Out of curiosity, do you know which hadith this is? Some fatwas say that vinegar from alcohol is halal. If this was a sahih hadith, then those fatwas are clearly wrong.
Comment: I cant remember but I saw it online and when I called some Islamic Q&A shows they quoted the Hadith
Answer: Spirit vinegar is not made from alcohol/wine it's

made from sugar cane or from chemically produced acetic acid.

Vinegar of all forms are halal, provided that have not come in contact with anything haram and najis, even if it's made from wine. This is by the rule of istihalah (transformation) i.e. anything that has chemically transformed.
Sources from the website of Ayatullah Sayyid Ali Husaini Sistani:

Any liquor which becomes vinegar by itself, or by mixing it with vinegar or salt, becomes Pak.

[...] if alcohol turns into vinegar it becomes tahir. As a resultthe bottle or glass that contains it becomes tahir too.

Question: There is this vinegar that is made from wine, in the sense that it was wine and then, through a manufacturing process, changed into vinegar. Therefore, the label on the bottle reads: "wine vinegar" as opposed to the vinegar made from barley or other items. One of the signs [of differentiating between "wine vinegar" and the wine itself is that] the bottles of this vinegar are displayed in the area of vinegar, and it has never happened that these bottles are placed on the shelves of wines. Moreover, there is no difference between such vinegar and the vinegar made from dates for example. So, can this wine which has turned into vinegar be considered vinegar under the rule of change (istihalah)?
Answer: If the name "vinegar" can be applied in the view of common people upon that product, as has been assumed in the question, the same rule governing vinegar would apply to it. [That is, it is pure as well as permissible.]
From here.
Answer: Depends on how the vinegar is made.  Here is a quote from a fatwa which explains the difference:

When wine turns to vinegar by itself, without any deliberate treatment
  needed for it to be changed, it is permissible to eat, drink and
  handle it, according to the consensus of the scholars, because of the
  hadeeth quoted above.
But if the wine has become vinegar because of deliberate treatment, by
  adding vinegar, onions, salt etc., or by any other process, in this
  case the scholars (may Allaah have mercy on them) differ as to whether
  it is permissible.

You can read the full fatwa here: http://islamqa.info/en/2283
Comment: Thats what I mean. Spirit vinegar is used in alot of ready made food as an ingredient but how will I know how the spirit vinegar used was made?
Comment: Certain islamic schools of thought suggest that when you're unsure of something, avoid it.  I think this may be an example of such a situation?
Comment: Yeah thats what I have been doing for the past three years :(
Comment: wa yaakum.  Why not search for spirit vinegar alternatives for the food you want to use it in or on?
Comment: If you think that Haram can be converted into halal then you should leave Islam as it is better for you!

Haram always produces haram!


what is the difference between LTE and LTE Band 4?

Question: I see some mobile operators mentioned LTE and some are mentioning LTE with band 4. What is the difference between those two ?
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: LTE is a standard for building a mobile network. It lists the available bands on which to operate on and Band 4 is one of those bands. See https://en.wikipedia.org/wiki/E-UTRA#Frequency_bands_and_channel_bandwidths for a full list.
If someone mentions only "LTE" than the band is not specified but you can look up which bands are in used by a specific operator in a given country on https://en.wikipedia.org/wiki/List_of_LTE_networks. For example, where I live (Sweden), that would be band 3, 7, 8 and 20 for my operator but no-one ever refers to it as "LTE with band 3,7,8 and 20", it's just called "4G" or "LTE".
There could be a few different reasons for specifically mentioning the support of a band. If it is from a representative of the mobile operator it is likely they perceive it as a selling point. Lower frequencies have lower attenuation and therefore propagate further enabling better coverage. Higher frequencies are usually handed out in larger blocks so to enable higher throughput. Note how 20MHz of 900MHz spectra will enable the same speed as a 20MHz block in the 2600MHz band.
Another reason, however a bit unlikely to be pitched by a operator representative, is that certain bands are less commonly supported on handsets, so you might want to check that the device you intend to use support the bands that the operator is using.
Comment: As I understand it some bands are more commonly used than others. If your carrier is using an uncommon band you have to be careful to buy phones that support the right bands or you won't get 4G.
Comment: @PeterGreen I added something to that effect in my answer, thanks :)


Internet browsing confidentiality

Question: I wonder how easy or difficult it is to find out who I am, using information security's most advanced techniques. And what can I do that will not affect my browsing experience too much, as a lambda internet user, against that?
Comment: Thanks for the link, which points out some interesting keywords for me to search further.
Comment: I personally emphasise the anonymity part
Comment: As well as the fact about not being a power user but still being in demand for ways to not give up too easily personal information to people that will use it for god-only-knows objectives.
Answer: Yes, there are many ways that your ISP, your DNS provider, the web sites you visit, third-party content providers, advertisers, government agencies, etc. can track your web browsing and identify you.  The methods that they use are based on your IP address, cookies, super-cookies, browser fingerprinting methods, and the like.
To make it more difficult to be tracked, you may want to consider using the TOR network, or TAILS.
Comment: I used the term 'more difficult' because some people suspect that government agencies may have the ability to monitor traffic on the TOR network.  See http://security.stackexchange.com/questions/115361/why-hasnt-anyone-taken-over-tor-yet
Comment: What do you mean by "more difficult" ? Do you imply that is still possible to be deanonymized even if I use such tools ?
Comment: As far as supposed anonymity goes, there's also issues like http://motherboard.vice.com/read/how-the-nsa-or-anyone-else-can-crack-tors-anonymity.
Answer: If you do not like the experience of TOR or other routing networks, you can enable some browser plugins which give you an idea of who is tracking you and prevent them from doing so. The Electronic Frontier Foundation has a handy plugin Privacy Badger which you can use to visualize and manage various trackers on a site-by-site basis.
Comment: It may be worth adding that these plugins do not protect you from being tracked by your ISP. I'm not sure if the OP cares about that, but the question is so unspecific, it's hard to tell.
Comment: True. The OP's question does mention "will not affect my browsing experience too much", so I believe he is looking for a solution which is not drastically different from the normal. Such plugins do provide you with some basic idea that you are being tracked, but of course do not use onion routing or other techniques to take it to the next level.

Internet browsing confidentiality


What is the definition of "geometric pitch angle" for a propeller?

Question: My question is regarding the geometric pitch angle of a propeller. Is it the angle between the rotational/propeller plane and the zero lift line of the particular airfoil at a propeller section? Or is it between the propeller plane and the chord line of the airfoil?
Answer: From a variety of online sources (e.g. 1 and 2), the geometric pitch angle is simply the incidence angle between blade reference chord and the plane of rotation.
This makes sense from the definition of blade pitch, which is the distance that a point on the prop would move forward in one rotation, if it's gripping in a solid medium. The conversion from pitch to pitch angle, therefore, has nothing to do with aerodynamics (i.e. lift) and is geometric only.


When implementing dropout in neural networks with SGD, how does one calculate the gradient?

Question: Specifically, I know that in SGD one sums all the gradients for weights/biases for each minibatch and divides by the mini batch size, would one do the same thing for dropout networks?  Or would they divide by the number of networks in the mini-batch for which the weight/bias is not dropped out?
Answer: Typically, given a 50% dropout (standard), the weights are multiplied by 0.5 when predicting new instances. The gradient is always computed as the average over minibatches, without scaling. That said, dropout networks use a far higher learning rate (10 to 100 times the usual values), so you can think of that as a form of scaling.
You can read all about it in the paper that introduced dropout.


Google CSE has indexed robots.txt itself

Question: Google CSE has indexed robots.txt and now if someone searches for 'txt' it returns the robots.txt file which is really not ideal (as this is a bog-standard Drupal site, the string robots.txt actually appears in the text). How can I avoid this? Is there a setting somewhere in Google or should I add /robots.txt to erm, robots.txt or...?
Answer: You could add this to robots.txt:
Disallow: /robots.txt

In What if robots.txt disallows itself? Google's John Mueller says:

The only thing this would affect is if a link were pointing to the robots.txt and Google would otherwise index the content of the robots.txt file. That wouldn't be possible when it's disallowed by robots.txt.

So it seems that adding a disallow rule in robots.txt for robots.txt itself can help prevent robots.txt from getting indexed without preventing Googlobot from fetching the file to see what else is disallowed.
Another way to handle it would be to add a HTTP header to robots.txt that prevents indexing.  This would be a similar solution to the problem Prevent XML sitemaps from showing up in Google search results.  You would want the following HTTP header served for robots.txt:
X-Robots-Tag: noindex

Under Apache you would implement it with this .htaccess code:
<Files ~ "robots\.txt$">
  Header append X-Robots-Tag "noindex"
</Files>

Comment: This is great information, it's very hard to google for this. One important note: `Header` is not always available, it's from `mod_headers` which for example Ubuntu doesn't load by default.
Comment: Yes, you might have to enable the module with `sudo a2enmod mod_headers`
Comment: Another hack that would work, I'm reluctant to even suggest this since it's so hacky, is to serve a HTML page, with a robots noindex meta tag, around the robots.txt directives. Search engines generally ignore invalid robots.txt directives, so you could add a simple HTML boilerplate on top, and still have the robots.txt directives in the file. This might throw other tools off, and I wouldn't recommend it for general use, but if you can't serve an x-robots-tag header and really, really need the URL gone ...
Comment: We know that Disallow: /robots.txt will not stop Google from fetching the file.  But what about other search engines?  Lots of search engines out there, big and small, and we don't know how they will react to that line.


What are the newest innovations in generative theories of music?

Question: I was just reading "A generative theory of tonal music" by Fred Lerdahl and Ray Jackendoff, and my impression was that it is a monumental work.  However, I haven't found much that has been done by other authors to contribute to the subject since it came out in 1983. Are there any more recent works that build on their approaches?
Comment: The book's Wikipedia page states that "The theory has been influential, spurring further work by its authors and other researchers in the fields of music theory, music cognition and cognitive musicology" and the footnotes and bibliography list a dozen later publications in the field. https://en.wikipedia.org/wiki/Generative_theory_of_tonal_music
Comment: i don't have an answer but based on the description of the book (i have not read the book) it reminds me of this.... https://www.youtube.com/watch?v=ne6tB2KiZuk
Answer: From what I've seen, there are academics that are big advocates, but also many that aren't at all enthused. I think some of the pros and cons being discussed tend to mirror the way in which Chomsky's generative grammar has also kind of gone up and down in status.
There is a lot to be said for new work being done via brain scanning, also from the direction of cognitive psychology building on foundational studies on sensory perception and on how we encode experience, and these new insights are not so dependent on complicated grammar-tree rules.
At issue, in part, what does a complete analysis get you that you didn't have before doing the "generative grammar" analysis of a piece? If it isn't giving particularly meaningful new insights about the music, is it worth the trouble? And believe me, figuring out their approach means embracing a considerable learning curve.


According to political scientists and historians, what is the most effective and bloodless way to topple an authoritarian regime?

Question: A great volume of knowledge about authoritarian regimes and revolutions has been amassed. Using that scientific knowledge, what is the best algorithm to bring down such a regime without much (any, if possible) bloodshed? Is there a recipe, to begin with? Or is the best strategy just to sit and do nothing hoping it will go away by itself (for example, Karimov died and the power in Uzbekistan was transferred to the relatively reformist successor Shavkat Mirziyoyev, no bloody revolutions; Egypt underwent a violent revolution, nothing changed)?
Comment: Scientific knowledge in political science tends to be more aspirational than actual.
Comment: It wouldn't surprise me if it turns out to be the least bloodiest "revolutions" are palace coups by a future dictator. But there are exceptions both ways.
Comment: Please clarify if you mean "topple an authoritarian regime and replace it with another one" or "change the entire society such that authoritarian regimes can no longer be an emergent property of them". Further, if the authoritarian regime is a good one, where society is happy and the monarch or whoever is highly regarded , do you accept "do not topple" as a possible "most bloodless" answer?
Comment: The answers will be correlational, and the correlations probably vary with time too.
Comment: @Frank "Emergent property"?
Comment: There is the amazing book by Luttwack, "coup d'etat, a practical handbook" which addressed this question.
Comment: @SergeyZolotarev Yes, I was trying to convey succinctly that, for example the failed attempts at social remodelling by the US in the Middle East, where by toppling the dictator you do not create a new type of society that is not oligarchical, dictatorial, or otherwise not authoritarian. Elitist societies, in my experience, are elitist not because of the elite, but because of everyone involved. People who prefer nepotism and family, as opposed to the system itself, tend to produce their own elite. And all elites are authoritarian.
Comment: @SergeyZolotarev https://en.m.wikipedia.org/wiki/Emergence
Answer: Growth of the middle class. If the autocracy is successful and the country develops and grows richer, eventually a strong middle class is formed and calls for more opportunities to participate in the decision-making process. Steadily the state would grant more and more powers to elected bodies.
This is basically what happened in the West and some of the East Asian countries. Democracy cannot function without the middle class - the people who pay more in taxes than receive from the government. The middle class is also the economic class that creates the most new jobs and businesses, leading to greater economic stability and better opportunity for others.This gives people better access to education and resources, which helps others get involved in decision-making processes and reduces the power of potential autocrats.
Comment: Didn't Libya have a middle class before descending into chaos and war? Same for Syria. It may be necessary but not sufficient.
Comment: Re _"**the** people who generate wealth"_: is *"the"* necessary?  Not every person who "generates wealth" is middle-class.
Comment: I'd knock out the "wealth generation" bit and instead give some more historical examples, starting with the way that middle class traders originally displaced the feudal power structure. The Industrial Revolution in the UK was largely driven by a disenfranchised middle class who then demanded electoral reform (to oversimplify a complicated story). The history of Spain and Taiwan in the 1970s also provides examples of middle-class growth leading to liberal democracy.
Comment: @Ivana I think the point is that it needs a strong middle class that is free to make good economic and job decisions. Libya had a strong middle class, but the leadership was overthrown and the nation was partially torn apart by Islamic extremist and other groups (https://en.wikipedia.org/wiki/Libyan_Civil_War_(2014%E2%80%93present)). In Syria, the middle class was dwindling as far back as 2015 according to some sources (https://www.ft.com/content/4aea5cc4-f96a-11e4-ae65-00144feab7de) due to rebels and loyalists alike antagonizing the middle class, leading to further instability.
Answer: It should be obvious, that there will be no conclusive answers here, only some options, because if there was an effective way to do that, the last century would have looked quite different.
The main problem is the word "bloodless", which kind of narrows it down to two options:
1.
You convince the dictator's power base that democratic transition would be better for all (or them...).
Although it might appear different on a superficial level, there are no "true autocrats", or to put it differently: Nobody rules alone.
Dictators have a power base that usually consists of a number of key figures which they have to keep happy for the exact purpose of not being toppled by them. A great number of these key figures will for obvious reasons be military.
If you want to topple the dictator without bloodshed or at least no blood spilled other than his, there is no other way than doing what Philipp suggested in his answer: Talk to the generals. As long as the military is loyal, there will for sure be no bloodless transition of power.
There are countless modern examples, but I prefer the old ones: The Praetorian Guard was maybe the most infamous "organisation" that can be held as an example for the necessity to involve those key figures in your plans.
The amount of meddling in political affairs done by them is quite ridiculous and includes the toppling and assassination of several roman emperors. If you wanted to restore the Roman Republic without starting another civil war, you'd better get them on your side.
The big problem with this approach is: Why would those people want a transition to democracy instead of taking the dictators place (which tends to be what happens most of the time in reality...)?
2.
You convince the dictator or his successor.
Not all autocrats are crazy maniacs who want to establish a dynasty of successors. Not all of their successors are crazy maniacs who want to continue their predecessors legacy.
Before Franco, the dictator of Spain, died he had designated Prince Juan Carlos as his successor to rule as a monarch. After Franco's death, Juan Carlos facilitated a transition to a constitutional monarchy.
Depending on whom you ask, you will hear Atatürk, the father of the modern Turkish Republic, being described either as a great hero or a vile dictator. This depends on whether the person you ask likes the vast reforms he managed to enact by maintaining a rather firm grip on power.
In the end however he did not leave behind a dictatorship but a sometimes more and sometimes less stable republic.
Therefore  you could try to convince the dictator or his successor that HE could be the one remembered for leading his nation into a modern golden age of democracy and freedom...and good luck with that. As said in the beginning: If it were so easy, the 20th century would have been quite different.
Answer: The Arab Spring in the early 2010s allowed us to see how democratic revolutions turn out in present times.
While Tunisia and Egypt experienced a relatively bloodless transfers of power (Egypt didn't get much democracy in the end, but that's a different story), others like Libya and Syria experienced devastating civil wars which go on to this day.
Looking at what these different outcomes have in common, an important factor seems to be whether or not the military is loyal to the regime. If the military is willing to back the regime and use violence against protesters, then the revolution either dies down (like it happened in Bahrain) or escalates into a civil war. If the military sides with the protesters and refuses to suppress them through violence, then democratic reforms are possible.
Conclusion: If you want to change an authoritarian regime, talk to the generals.
Answer: There isn't really an answer to this question, because the question presumes that the term 'authoritarian regime' points at a uniform, singular thing, which it decidedly doesn't. It's much like asking the question: "How can I win against a professional athlete?" That seems like a sensible question at first glance, until we realize that winning against a professional basketball player is different from winning against a professional gymnast or a professional fencer, and that no one has actually specified whether we are trying to beat them at their own sport, or at some alternate sport (like curling), or at (say) a game of chess. How do I beat Simone Biles at curling or LeBron James at chess? Damned if I know, but I sincerely doubt there is one unique strategy that accomplishes both.
Authoritarian regimes run the gamut. There are Leftist authoritarian regimes like the corporatist USSR or the North Korean Juche system; there are Rightist authoritarian regimes like the Fascist regimes of the 1930s and the modern Russian regime under Putin. Authoritarian regimes might be based in military power, religious dogmatism, economic control, domination through surveillance and information, or any combination of those. The only thing authoritarian regimes have in common is a top-down hierarchical ordering that concentrates power in the hands of an individual or small group, and clearly the goal of regime change is to displace that individual or small group and replace them with something else. But a religious ruler like the King of Saudi Arabia rules by different mechanisms than a militaristic ruler like Bashar al-Assad of Syria. And what source does this regime change attempt have? A popular uprising? A small rebellious faction under a charismatic leader? An external nation trying to uproot a regime for their own purposes? This too changes things.
The only thing close to a 'bloodless' revolution we've seen historically was the Indian independence movement under Mahatma Gandhi, and that was only bloodless in the sense that Gandhi's followers (mostly) refrained from attacking the British. There was plenty of bloodshed throughout the rest of the Indian push for independence. One might credit Martin Luther King with a similar (if smaller scale) regime change in the US to pass civil rights laws that ended the authoritarian tendencies of Southern 'Jim Crow' states. We could also look at the "People Power Movement" in the Philippines, which avoided bloodshed mainly because the US convinced then-ruler Marcos to abandon power rather than use military force against non-violent protesters. But that only worked, arguably, because of the Philippines' close connections to the US: an ex-territory with a prominent US military presence. In other authoritarian regimes, non-violent protests have simply been crushed, or their leaders 'disappeared' (whisked away in secret to be imprisoned, tortured, and/or killed).
Non-violent protest is an effective tool under certain conditions, but it is hardly a cure-all, and entails some significant risks.
The thing to keep in mind here — and this is perhaps the other uniform feature of authoritarian regimes — is that authoritarians identify themselves as and with the nation as a whole. An authoritarian leader does not distinguish between patriotism and self-interest: what's bad for him is bad for the country. Trying to unseat an authoritarian leader (even for the best and most reasonable of reasons) will be viewed indistinguishably as an attack on the leader and an attack on the nation, and such an authoritarian leader will attack personally with the full power of his position: power which he sees as a natural and inviolate extension of himself. It's the 'royal we' taken to extremes — I am the country and the country is me — and such a person will only willingly give up his position in the same dire straights that he might willingly give up an arm or a leg. Convincing such a leader to release power without excess bloodshed is a difficult and context dependent task.
Comment: What about South Afrika?
Comment: @Ivana: maybe, but there was so much state violence in that process I have a hard time thinking of it as 'bloodless'.
Answer: The flaw with this question is that it assumes there's a proven "universal recipe".
I strongly doubt that.  The world has 190 odd countries, some of which are true dictatorship.  Overthrowing dictators has really come into play in the 20th century.  Or at least, overthrowing dictators in a 20th century context (TV, radio, mass transport, large populations, large armies, now the internet and cellphones) is largely a post 1950 phenomenon.
There can't have been more than 20-30 or so popular overthrows of real honest-to-goodness dictators (I am discounting palace coups by wannabe dictators).  Africa, a good storage spot for them, has trended towards gradually less flawed elections, rather than overthrows.  Eastern Europe doesn't really count as its circumstances were driven by the collapse of the USSR, rather than local events, except in Rumania, where Ceaușescu wasn't quite willing to let go.  And that one certainly wasn't bloodless.  Places like South Korea and Taiwan evolved, from military dictatorships to fully open elections.  Adpol's answer is spot on, but doesn't concern an overthrow and is predicated on a measure of actual economic success, something that isn't a given in many dictatorships.
Of the actual bunch of candidate overthrows to examine, there is a wide range of circumstances and outcomes that makes it very hard to conclusively say "well, this worked in country X, it will work in country Y".

Marcos in Phillipines
the Arab Spring countries
Post-Franco opening up in Spain
Duvalier overthrow in Haiti
Shah overthrow in Iran
Ceaușescu in Rumania
Bashir in Sudan

Not all of these are bloodless, no, but that would limit them even more.
Now contrast some of what worked with was tried, and emphatically, hasn't worked, in Venezuela.  Or Syria.  Is it different?  Not necessarily, but the outcome ended up different because the combination of the dear leader, military and population, spiced up with country's history with free or not free governments, culture and religion ended up making a difference.  And a lot of it still depends how a few individuals, starting with the despot, top military and top opposition react in the final days and hours.  Not to mention the support or opposition from influential foreign countries.
While Assad could have taken the coward's way out and let his people free, he courageously set about murdering them in their thousands, with nerve gas, no less, with the kind help of Brother Putin and encouraged by his glorious father's example.
That's just a very different script from Tunisia or Egypt (not that Egypt isn't back to dictatorship now) and its outcome was driven by a very small number of people, none of which were in the opposition.
Beyond a trite "the people need to be fed up and ready to do something about it" there is very little hard commonality in what worked. *
The process is completely non-deterministic and has way too many variables and too few datapoints to draw firm conclusions. What works in some circumstances may very well end up a total bloodbath and a failure in others.
I challenge for example any "methods" to be applicable to North Korea.
* the world can offer some assistance, among other things by:

sanctions against the regime, undercutting its power base.  Despots love luxury and general love their toys.   Take them away and alternative modes of government seem more attractive.
offer of sanctuary.  A cornered rat will fight much harder than one who can slink away.  France offered Duvalier a way out, AFAIK without any self-interest in doing so.  The world should probably balance the interest of justice in something like the ICC vs. offering amnesty for expedience and to facilitate peaceful transitions.
moral condemnation of the despot by religious leaders, when applicable.
dangling economic sweeteners like EU membership for Serbia
Answer: Straight off the top of my head, it seems that the most effective and bloodless way is to either, assuming you are in a democracy, vote in different people. In a pure and absolute democracy (where everyone votes on everything) you can just convince people to vote for something different or even commit voter fraud. (By just throwing in a couple million additional "people" that don't exist) However, since you are talking about an authoritarian regime, the best way would probably be the route you described, by just waiting for the old dictator to die and a better replacement to step in the top job.
Another possibility is to commit a small coup, in which you simply kill the old leader, and instill a new one. However, history suggests that this is not the case. A good video to watch on something like this would be The Rules for Rulers it provides a good overview of that sort of thing. It is extremely difficult to keep that kind of thing quiet if you don't have the military behind you, hence replacing one authoritarian regime with another. The main problem is that there is no scientific way to do this sort of thing, as people are not machines, and will often do something that you do not want them to do. Another good way to look at this is to study Game Theory, which deals with what people do in situations.
I would just give a comment and not an answer, but I don't have the reputation.


How to include Inline JavaScript?

Question: Is there any way to add javascript in craft
Answer: You can use {% js %} Twig tag.
It is essential to using JS in Twig. It takes JS code passed to it and appends it at end of the template, right before ending body tag. Multiple js tags can be used - content from each of them will be concated with the rest. You don't need to wrap code passed to {% js %} into

How to include Inline JavaScript?


How much time to fully sync Watcher Node

Question: How much time does it take for a watcher node to sync?
Answer: If you don't need the full history, you can easily have it up and running within an hour. In this case you will have details on all accounts and account balances but no details about the whole transaction history prior to the first ledger (block) that was processed by that node.
If you want a COMPLETE_CATCHUP=true containing the whole history from ledger #1 it will take a couple of days or even weeks (iirc it took me about one or two weeks a year ago). Using a fast storage (SSD over HDD) will significantly speed up the initial process.
Comment: Thanks for your answer. I've `COMPLETE_CATCHUP=true`


What are the advantages of HDF compared to alternative formats?

Question: What are the advantages of HDF compared to alternative formats? What are the main data science tasks where HDF is really suitable and useful?
Answer: Perhaps a good way to paraphrase the question is, what are the advantages compared to alternative formats?
The main alternatives are, I think: a database, text files, or another packed/binary format.
The database options to consider are probably a columnar store or NoSQL, or for small self-contained datasets SQLite.  The main advantage of the database is the ability to work with data much larger than memory, to have random or indexed access, and to add/append/modify data quickly.  The main *dis*advantage is that it is much slower than HDF, for problems in which the entire dataset needs to be read in and processed.  Another disadvantage is that, with the exception of embedded-style databases like SQLite, a database is a system (requiring admnistration, setup, maintenance, etc) rather than a simple self-contained data store.
The text file format options are XML/JSON/CSV.  They are cross-platform/language/toolkit, and are a good archival format due to the ability to be self-describing (or obvious :).  If uncompressed, they are huge (10x-100x HDF), but if compressed, they can be fairly space-efficient (compressed XML is about the same as HDF).  The main disadvantage here is again speed: parsing text is much, much slower than HDF.
The other binary formats (npy/npz numpy files, blz blaze files, protocol buffers, Avro, ...) have very similar properties to HDF, except they are less widely supported (may be limited to just one platform: numpy) and may have specific other limitations.  They typically do not offer a compelling advantage.
HDF is a good complement to databases, it may make sense to run a query to produce a roughly memory-sized dataset and then cache it in HDF if the same data would be used more than once.  If you have a dataset which is fixed, and usually processed as a whole, storing it as a collection of appropriately sized HDF files is not a bad option.  If you have a dataset which is updated often, staging some of it as HDF files periodically might still be helpful.
To summarize, HDF is a good format for data which is read (or written) typically as a whole; it is the lingua franca or common/preferred interchange format for many applications due to wide support and compatibility, decent as an archival format, and very fast.
P.S. To give this some practical context, my most recent experience comparing HDF to alternatives, a certain small (much less than memory-sized) dataset took 2 seconds to read as HDF (and most of this is probably overhead from Pandas); ~1 minute to read from JSON; and 1 hour to write to database.  Certainly the database write could be sped up, but you'd better have a good DBA!  This is how it works out of the box.
Comment: Both databases and HDF provide "the ability to work with data much larger than memory", so I don't think it is accurate to say that this is an advantage of databases over HDF since (what they call 'partial i/o' is a core feature http://davis.lbl.gov/Manuals/HDF5-1.8.7/UG/12_Dataspaces.html
Comment: Can we say that HDF *is* a columnar storage format? I'm not overly proficient with either of these, but the HDF samples I've worked with do seem to present external features of column based data aggregation.
Comment: "a database is a system (requiring admnistration, setup, maintenance, etc) rather than a simple self-contained data store"  - HDF is a binary file format - it requires tools to read and write too.  If it was a human readable format, then maybe this argument in favor of HDF over RDMS would be stronger.   You can use tools to dump a database to a single binary file too...
Comment: As of 2022, I would argue that the argument in favour of HDF5 vs other binaries is a lot weaker. Parquet is better supported outside of the python ecosystem
Answer: One benefit is wide support - C, Java, Perl, Python, and R all have HDF5 bindings.
Another benefit is speed.  I haven't ever seen it benchmarked, but HDF is supposed to be faster than SQL databases.
I understand that it is very good when used with both large sets of scientific data and time series data - network monitoring, usage tracking, etc.
I don't believe there is a size limitation for HDF files (although OS limits would still apply.
Comment: From personal experience I'd add that built-in documentation/label is huge. Now all my datasets can can be stored with explicit records of where they came from, sampling frequency, anomalies, etc. etc.
Answer: To add, check out ASDF in particular their paper ASDF: A new data format for Astronomy; ASDF tries to improve upon HDF5 and the paper describes some downsides of HDF5 format.
Answer: HDF5 pros

supported by pandas out of the box
therefore, supported by jupyter-notebook out of the box
good support by other software
includes good amount of metadata
single file can store multiple data frames
each dataframe includes good amount of metadata (I think)
thus:
it's great for making sense of data, it's self-describing
it's great for experimentation

HDF5 cons

with naive tools: file must fit in RAM
with a bit more care: the dataframe you access must fit in RAM, and
the file must be in local storage
each dataframe has a schema, it's homogenous
some cloud systems don't support it out of the box ( aws)
thus:
not for humongous data
not for network storage (e.g. s3)
not for cases where schema changes over time


What is the difference between 'drawback' and 'side effect'?

Question: In terms of Computer Programming, people around me mostly say 'side effect', when they talk about something that will happen behind the scenes, and it sounds pretty negative. However, when I read some documents, I've seen 'drawbacks' as the almost same meaning(I guess). So.. what's different and which one's more casual term and more formal term?
Comment: *side effects* are unintended consequences, which could be positive, neutral or negative. *drawbacks* are usually negative.
Answer: As the Cambridge Dictionary entry that you quoted says, a side-effect refers to any effect that happens in addition to the intended effect of an action. Side-effects may be negative, but they are not necessarily so.
In the world of pharmaceuticals, for example, side-effects are generally regarded as negative, but on occasion the side-effect can be beneficial. The drug finasteride is intended to calm down an enlarged prostate, and it has a side-effect of slowing the progress of male pattern baldness. For many men, this side effect is desirable, and so finasteride can be prescribed to men with healthy prostates, just to get the side-effect of slowing down male pattern baldness.
One could argue that in this case reducing baldness is the main, or intended, effect and any stabilising effect on the prostate (which would be beneficial) is a side-effect.
When writing software, side-effects can in principle be beneficial, but most experienced programmers try to avoid even beneficial side-effects, because these effects are not obvious to anybody who might later need to make changes to the code. The side-effect may be beneficial at the time the code was originally written, but be inappropriate if the code is modified without an understanding of the side-effect.
A drawback is different in two ways. First, it is a feature of a situation or course of action: it is not necessarily an effect of an action. Here are some examples where a drawback is not an effect:

I like living in a city, but the noise and pollution are major drawbacks.
  One of the drawbacks of this solution is that it only works in 70% of cases.

Second, a drawback is always, unequivocally, negative.
Answer: I am not a native speaker. I have been working on the Computer Programming for a long time.
IMO, a side-effect is something generated unintentionally while you are trying to add some features or fix some defects. It could be bad, good or it doesn't matter at all. Most of time, side-effects are annoying. Rarely, they are nice.
Well, a drawback is an aspect of something or someone that makes them less acceptable than they would otherwise be. It's a negative thing, I think.
Answer: side effect refers to mathematics e.g.
A or (B or C)
if it eveluates different going left-to-right side than the other way around, you have a side effect. You should not, by the way.
Drawback does not refer to math. So side effect is more formal.
Comment: Why is this -4 votes?
Comment: Thank you for your answer, however, where can I see **side effect** refers to mathematics? I'm using Cambridge Dictionary https://dictionary.cambridge.org/us/dictionary/english/side-effect
Comment: the whole site is a joke, dude


internal routing and bottom bracket sleeve

Question: I was wondering regarding the sleeve that comes with the bottom bracket I got from chris king.
My frame has internal routing, that I believe entails that cables should go through the bottom bracket. However, to me it seems that the sleeve takes up all the space there, I don't see how any cables should go in there? Is the only way to do it is by removing the sleeve? is it okay to remove to sleeve? I add here some photos. With/without the sleeve. And also, what seems to be an opening just below the bottom bracket, perhaps for water? Added a photo without its cover as well.
Thank you very the assistance and have a great week
Comment: from the picture, it looks like the internal diameter of the bearing is larger than the typical 24mm that you find on most Shimano/SRAM cranks. It you are trying to fit a 30mm axle into a standard BSA BB, it's possible that there's just not enough space for the cables and the crankset.
Comment: Apparently there is another route (thankfully), I just realised that now. It is not clear in the photos, but basically, below the bottom bracket, where there is an opening that is sealed with a cover and a screw- if you open it, it gives you access to the area below(!) the bottom bracket, but still internal. and there is access to move cables in there below the bracket. seems like it solves my problem thanks.
Comment: Hey thanks @Renaud. I see. you mean that even if I were to remove the sleeve, it might not help in my case since the axle is 30mm? (which it is).
Comment: If there's enough space, not sure there's much you can do, except changing the crank or choose another route (which doesn't seem feasible). I would not remove the sleeve, because in this case there will be a direct contact between the axle and the cable, which become a wear point.
Comment: I will still be curious to understand for the future, whether a sleeve can be removed, if that was the only option (assuming the axle was not 30mm). I can see your point of view - recommending not to do it, since there will be a direct contact between the axle and cables.
Answer: The sleeve prevents the cables and hoses from rubbing against the crank spindle. You're spinning at 70-90 rpm for hours on end. Eventually, you would wear through the spindle, and this would be bad. It might not cause an immediate accident, but you now need to replace the whole crankset unless it's a modular system that lets you change spindles.
In at least some frames, the hose goes out of the frame, routes around the bottom or the top of the BB, then it goes back in at the chainstay. I can't see any evidence for this, but the photos might not be at the right angle.
First step would be check with the manufacturer. They might not have intended for the bike to have a 30mm spindle. Now, this isn't a problem on a lot of bikes, but that looks like a BSA shell, and they can take 30mm spindles but they were not really designed with that diameter in mind. Alternatively, the manufacturer may say there's room for one hose but no shift cable - I assumed that in the question you meant hoses, but I guess I don't know for sure. If that frame was not designed for internal routing at all - and there would be various stops on the outside where you ziptie the rear brake hose plus the shift cable and housing - then you would need to use an electronic groupset.
Comment: The first paragraph in @Weinwen Ng's answer is critical. Don't event think about riding with internally routed cables and BB sleeve removed. You will damage both cable and crank axle much faster than you think.
Comment: Thank you very much, appreciate your answers.


oracle export and import datapump

Question: I have a quick question on oracle datapump. I have a small oracle database 11gR2 which contains different schemas (more than 8).I want to move this database to a new server and i am trying to use impdp/expdp method. I did a full export of the database under system user. THe new server also runs 11gR2.
Now if create a new database with same tablespaces on the new server, can i use a full import. Is this the recommended way to do it?
I know i can do it schema wise, but however it would require me creating the roles, and other supporting objects first and also identifying which schemas actually have objects on them.
Answer: I don't think there's such a thing as a "recommended" way to do it.  You might as well ask what's the "recommended" data to put in an Oracle database.  It kind of depends what your needs are.
The only problem that I've had with using a "full" import/export in the past, is that the export then also includes SYSTEM (and other default Oracle schemas) which you don't really want overwriting your new database.  (Actually, this used to cause me some problems with the old imp/exp command -- but theoretically it would be the same problem with Data Pump).
Fortunately, Data Pump allows you to exclude certain objects from your export.  When I do full exports, I tend to exclude all the schemas that are already created in the new database, at db-creation time.  Include the following in your parameter file:
EXCLUDE=SCHEMA:" IN ('SYS','SYSTEM','WMSYS','OUTLN','MGMT_VIEW','XDB','ANONYMOUS','SYSMAN','ORDSYS','ORDSYS','ORDPLUGINS','SI_INFORMTN_SCHEMA','MDSYS','EXFSYS','DBSNMP','DMSYS','CTXSYS','DIP','TSMSYS','ORACLE_OCM')"

oracle export and import datapump


What difference does it add when you write それで or これで instead of それは/それが and これが/これは?

Question: What difference does it add when you write the で particle after words like それ and これ?
Comment: Please look up particle で in dictionaries.
Answer: これで can generally be translated as "with this". It's used to indicate the result or conclusion following some action or happening. For example:

[今日]{きょう}の[活動]{かつどう}は、これでお[開]{ひら}き。
With this, today's activities come to a close.

You can find more of these examples on Jisho's sentence search.
For これは and これが, you need to look up the differences between は and が, which is a complex topic (but it's been answered many times before). Generally, they mean "this is".


Is there anyway to find the time stamp of a YouTube thumbnail?

Question: A lot of channels are generating views from clickbait thumbnails. Is there a way to scan a video beforehand and determine the timestamp of the thumbnail, if it is even in there?
Comment: I was just thinking that if you are clicking on a video solely out of curiosity from the thumbnail, knowing the timestamp would allow you to immediately watch the desired clip and avoid feeding the algorithm watch time. If the thumbnail isn't in the video, you might also be more disinclined to click on it.
Comment: Why/how would knowing the timestamp of the thumbnails in the video help you detect/stop clickbait?
Answer: Partial answer from Bellingcats's Advanced Guide on Verifying Video Content:

There is no easy way to determine which frame a video will automatically select as a thumbnail, as Google developed a complex algorithm for YouTube to select the best thumbnail for an uploaded video (for more on this, see the Google Research Blog entry on the topic here). Perhaps the best tool to find these thumbnails is Amnesty International's YouTube DataViewer, which generates the thumbnails used by a video on YouTube and allows you to conduct a reverse image search on them in one click.

This gives you the thumbnails, but not their timestamp in the video. You would still have to go through the video to locate that frame.
Answer: No, this would be not possible to achieve by any easy means. Also, verified YouTube accounts are able to upload custom thumbnail which may not even be from video footage.

Create a custom video thumbnail
To upload custom thumbnails, you must have a verified account.

https://support.google.com/youtube/

Best you can do is to fast-preview the video on mouse-hover (eg. before clicking on the video and adding unwanted +1 view) to determine if the content of it is matching the thumbnail context.


How can I expand already built rooms?

Question: If I build foundations connecting to the existing room and remove the partitioning wall, the space where the division-wall was is "outside".
Comment: Dear SE user: Note that since this game is an Alpha, the developent cycle should have made this question obsolete by the time you read it. It is already one year old.
Answer: This is a bug (link leads to internal bugtracker), due to a missing check for the space where the wall used to be.
Quoting from the bug report, there is a workaround:

Make building foundation.
Make another building foundation adjacent to it
This will, correctly, remove one of the otherwise double walls.
Use foundation demolish to remove the interior wall.
Leaves unusable outside area inside.

The work-around is to replace step 4 with:
  4. Build concrete floor material along length of inside wall, which correctly labels the area as interior.
Answer: One part of the issue is now solved, which is done by what is noted above. Even though it would be neat to create a building outside of the other building, without having to do these tricks: Make the building end atleast one row inside the wall of the building you're trying to connect it with. Note that this will cost you additional money, since it will be like you're building the new building PLUS the space inside the old building => try to calculate the space you need the first time around you build it, in order to save money.
This is of course hard to work around when you're expanding, but quite crucial initially trying to make the economy work when you start off with a new prison.

How can I expand already built rooms?


streaming radio on windows phone

Question: i would like to know if is it possible to read a radio stream from a RSS feed on a WP device and while using C# language.
ty
Answer: It is possible but it depends on the format of the stream you will be obtaining. The RSS feed by itself contains no streaming data whatsoever, other than the location of the actual media. You might need to use HttpWebRequest to get the data and implement MediaStreamSource to actually process the streamed content.

streaming radio on windows phone


Find the point of intersection with only one endpoint and a slope.

Question: So, I'm in the process of making a game, and I need coordinates to snap to a line. I have a point, and a segment, so I have a segment that is perpendicular to the other segment, and goes though my point. I can get it's slope with the negative reciprocal, but how can I get the point at which that perpendicular segment intersects my original segment? In simpler terms, I have a slope and an endpoint, and another segment of which I have two endpoints, how can I tell what the point of intersection is?
Answer: Don't use slope like in math class.  Instead you should use a parameterized equation for your line segment.  You can create the following for a line segment going through the points $(x_0, y_0)$ and $(x_1, y_1)$:
$$
x = x_0 + t\Delta x \\
y = y_0 + t\Delta y
$$
Where $\Delta x = x_1 - x_0$ and $\Delta y = y_1 - y_0$.  Now the perpendicular line segment will be:
$$
x_\perp = \begin{cases} x_0 - t\Delta y & \left|\Delta y\right| > \left|\Delta x\right| \\
x_0 + t\Delta y & \left|\Delta y\right| < \left|\Delta x\right| \end{cases} \\
y_\perp = \begin{cases} y_0 + t\Delta x & \left|\Delta y\right| > \left|\Delta x\right| \\
y_0 - t\Delta x & \left|\Delta y\right| < \left|\Delta x\right| \end{cases}
$$
You should do the test because you don't want to negate something very close to zero (in fact it may actually be zero).
And the reason you should do it this way, is what if you have a vertical segment (or a horizontal segment)?
edit  If you have a point $(x, y)$ which you want to then drop a perpendicular to your line segment, you just need to solve the equations:
$$
x_\perp = x - t\Delta y = x_0 + s\Delta x \\
y_\perp = y + t\Delta x = y_0  + s\Delta y
$$
Everything here is known except $t$ and $s$.  Multiply both equations by $\Delta y$ and $\Delta x$, respectively:
$$
x\Delta y - t\left(\Delta y\right)^2 = x_0\Delta y + s\Delta x \Delta y\\
y\Delta x + t\left(\Delta x\right)^2 = y_0 \Delta x + s\Delta y\Delta x
$$
Subtract them to cancel the $s$'s:
$$
y\Delta x - x\Delta y  + t\left(\left(\Delta x\right)^2 + \left(\Delta y\right)^2\right)= y_0\Delta x - x_0\Delta y\\
t = \frac{\left(y_0 - y\right)\Delta x + \left(x - x_0\right)\Delta y}{\left(\Delta x\right)^2 + \left(\Delta y\right)^2}
$$
Then just plug into your equation for the perpendicular line:
$$
x_\perp = x - t\Delta y \\
y_\perp = y + t\Delta x
$$
Here $x_\perp$ and $y_\perp$ are the points which should connect to $(x, y)$ to create a perpendicular to the original line segment of $(x_0, y_0)$ and $(x_1, y_1)$.
Comment: But actually, what you need is the $s$ of the second part of the answer, which is the parameter of the line through $(x_0,y_0)$ and $(x_1,y_1)$. $t$ is the parameter of the perpendicular line. Then you can replace $s$ with $0$ if $s<0$ and with $1$ if $s>1$ to get the closest point of the segment.
Comment: What does the t mean? Other than that, I think I understand.
Comment: It's just a variable that gives your line, so for instance if you plug in $t = 0$ to the original you get $(x_0, y_0)$ or if you plug in $t= 1$, you get $(x_1, y_1)$.
Comment: And you actually don't need those case--negating a $0$.  That's the beauty of doing it this way (which I didn't even fully believe at first).
Comment: @LutzL It really depends on what the OP is trying to do.  I'm not totally certain.  It's pretty straightforward to solve for $s$ instead of $t$ in the above.  Instead of multiplying the first by $\Delta y$ and the second by $\Delta x$, switch it so that now the $t$'s can cancel instead of the $s$'s.
Comment: The original question is http://stackoverflow.com/questions/22889023/how-can-i-find-the-point. I interpreted the "snap point or component to segment" as "find the closest point on the segment". But you are right, the end of the question seems only to ask for the closest point on the line, which can be computed with either one of s and t.


Sharding and indexes

Question: I want to shard my database but I'm not professional in this topic. So here are my considerations. Though sharding key is excellent index for directing requests to the right nodes, what about the rest of indexes that will be defined upon my tables? I want requests referencing those indexes to be delivered to the right nodes as well so that only one node process the request. As far as I understand for this purpose some centralized index nodes must exist. So my question is whether this functionality is already present in RDBMS like MYSQL or should I use other special products.
Answer: Disclaimer: I work for ScaleBase, I live and breath sharding every day...
I would advise here that if you shard according to column A for example, a WHERE with columnA=xx will go to a single shrad. WHERE columnB=xx will have to go all shards because there might be columnB=xx in all of them. Unless columnA and columnB are related. And then you really need to save the relation in a mapping table.
I can say that running on all DBs can be super-fast, you need to run in parallel and merge results. At ScaleBase we support merging ORDER BY, GROUP BY etc. It's not easy...
Hey see more info in my blog: http://database-scalability.blogspot.com
Comment: Yes, this is what I don't understand. If you had separate nodes dedicated to db indexes (record physical position + machine id) you could make each query referencing B column go to only those machines where the data actually are! This is faster!
Answer: Andrey, what you are describing is exactly how the Clustrix database works, where data and indexes are automatically distributed, then queries are distributed across nodes. Clustrix "brings the query to the data" and has a shared-nothing architecture (so no centralized index is needed). MySQL does not have any built-in functionality for distributed computing, and while there are various bolt-on options, they will ultimately encounter scaling limits when the centralized resources limits are hit.

Sharding and indexes


MTP device acess denied

Question: I'm using linux kde, I was able to use mtp device on it but recently I'm facing problem error is mtp device access denied but it working with kde connect. How I can get rid it of ? I had also checked with live media if driver is corrupted but problem is still same.
Comment: What linux distro and version are you using? What kernel version?
Answer: Assuming you have rebooted the device and are not forgetting to activate MTP on each connection from the notification drop-down which is required on Marshmallow and newer Android OSes, it is likely that your Media Storage and External Storage databases are out of sync and not updating properly.
Note that none of the following actions deletes or modifies your files, pictures, or other data, just the databases that index those files are forced to be rebuilt.
Disconnect the USB cable, although the exact menu entries could vary by OEM, here are some general instructions on how to rebuilt those databases... Go to Settings - Apps and tap the 3-dot menu and select Show System. Then scroll through and find External Storage and tap into it, then select Storage, and inside that select Clear Data and Clear Cache, then press back twice to the main Apps menu and scroll down to Media Storage and perform the same action. Go home and reboot. DO NOT CONNECT THE USB cable at this time, once the phone is rebooted and the startup appears complete, wait at least 5-10 minutes (the databases are rebuilding in the background, without watching the logcat there is no way to see if they are complete, sometimes it is a quick process and sometimes it can take 30+ minutes depending on your device and number of files), then connect the USB cable and the folders and files should appear.
If this doesn't work, your issue is likely not Android related but a permissions or setup issue in your Linux distro with your user, and that question would be more suited to the Super User, Ask Ubuntu, or Unix & Linux sites.
Comment: I'm using ics phone, I don't think there any issue with pc because I've already checked with live bootable and there problem still remained.

MTP device acess denied


How to capture the address an application contacts?

Question: An application contacts an Internet host on each start of it. It seems to take just an instant. I don't know if it is HTTP, plain TCP or UDP or what is used but tend to suppose HTTP. What tool can I use to track this connection?
Answer: Have a look at  wireshark.
Answer: Watch all network traffic
In a terminal, as root, run
tcpdump

and watch the packets fly. If you have other network activity, filter that out. For example, to show everything except incoming and outgoing SSH traffic:
tcpdump not port 22

Watch what the application is doing
Run strace -o myapp.strace myapp. This writes a log of every system call that the application performs to myapp.strace. Look for lines that begin with connect(; these are the application opening a TCP or UDP connection. The target IP address and port are on that line. The protocol is determined by the previous socket call which comes before and is usually very close. Traffic to port 53 is DNS traffic.


Super Resolution in GIMP

Question: Does anyone have any tips on how to apply Super Resolution techniques in GIMP? I have done a lot of reading but I could not find any examples for GIMP...
Answer: Sorry to say, resynthesizer will not manage to obtain real detail, since it's adding fake points through interpolation, rather than obtaining more real detail. What the original question suggests is about stacking multiple real shots and obtain higer resolution, like this:
http://mentat.za.net/supreme/
https://aperture64.wordpress.com/2014/03/19/improving-image-quality-with-stacking-and-super-resolution/
Comment: Although your answer is 100% correct, it might also become 100% useless if that link is moved, changed, or the main site just disappears... :-( Therefore, please [edit] your answer, and copy the relevant steps from the link into your answer, thereby guaranteeing your answer for 100% of the lifetime of this site! ;-) You can always leave the link in at the bottom of your answer as a source for your material...
Answer: You could try the resynthesizer plugin available here. It can do a resize of the image, intelligently interpolating missing pixels using the resynthesizer algorithm. I haven't had much luck with it; but, I'm sure results will vary, depending on the type of image.

Super Resolution in GIMP


Wither [autosave]?

Question: Just an hour ago autosave had half a dozen questions listed under it, but now the tag has been emptied. It's still there for the moment, but empty. I'm just wondering what's up with this, is it being deleted or merged? If so, why empty it first?
Comment: We can't "outright delete" tags. Or even mark tags.
Comment: http://meta.gaming.stackexchange.com/questions/3800/have-we-not-been-clear-enough-that-meta-tags-are-a-bad-thing
Comment: @yx. Well, if that is the case then a mod should just outright delete it and mark it as a bad tag.
Comment: Oh, I thought tags were outright deleted.
Answer: autosave, and some other ones in the same class like save-points, aren't entirely useful tags to have.
When it comes to a dependent tag, one has to figure the importance of the categorization and the utility of it. Which is to say... "Is autosave a meaningful enough categorization that it deserves to mark itself apart from other questions?". The answer is, in my opinion, no.
We are divorced from subscription on dependent tags - it is unlikely that anyone will ever subscribe and follow a tag like autosave. So their utility relies on how much use they provide for our audience in terms of categorization, in terms of meaningfulness and necessity. Autosave functions, while present in many games, are not something that is an exceptionally meaningful subdivision of an individual game's questions. Meaningful subdivisions help identify entire classes of questions that may be difficult to otherwise group together. You might phrase it as, "What is the likelihood that people will reference the collection of all questions of this class for a given game?". Autosave is the kind of functionality that people are more likely to search for individual problems, not for a set of concepts. To that end, it doesn't really make for a strong and meaningful subdivision.
The same would go for save-points. I might say save-games as well, but it's got a large number and it would be better to investigate the tag fully before delving into that question.
Answer: I removed it because it's a meta tag and meta tags are bad.
It's not just this tag that is bad. It's all meta tags. We're actually kind of on a mini-crusade to flush them out of the system completely. The mods don't have a tool to delete a tag, but some admins can push a button and erase a tag's existence. They tend not to hang around too often or notice all the questions, however, so we do what we can for tags that don't have too many questions on them yet.
We don't want to clutter up the front page by re-tagging hundreds of questions at once, because some of the meta tags are pretty wide-spread, but we do want to get rid of the simple ones and put some spotlights on the less-than-trivial ones.
Comment: Meta tags describe the question itself -- e.g., `subjective`.  A question tagged that is not likely to be "about subjective".  A question tagged `autosave` is likely to be about autosaves, though.  It's a real tag -- dependent on the game tag it's used with and probably not useful, as Grace says, but not a meta tag.
Comment: Next time just put in an entry in the tag wiki saying it is slated for removal. Documentation along the way helps keep things clear.
Comment: @CyberSkull I don't see how that's necessary. The act of me manually removing that tag from all questions it was on should speak for itself. No need to edit the tag wiki for something that's going to be deleted in short order.
Comment: No, it's not. Just a sentence saying "This tag is going away." helps someone walking into the situation.
Comment: @CyberSkull I maintain that it is unnecessary. An empty tag is empty for one reason and one reason only: it was specifically removed from all the questions that it once existed on. There isn't even any way to access that tag at that point without specifically searching for it. It's a small enough audience of people who might get confused that I'm willing to take that risk.

Wither [autosave]?


Can I put a bounty on a question where I have answered and award the bounty to my answer?

Question: Can I put a bounty on a question where I have answered and award the bounty to my answer as an exemplary answer? Moreover does the author of the question have anything to say on whom I decide to award the bounty?
Comment: Glad you asked before trying this. If this were possible it would allow free advertising. Bounties are meant to be used for altruistic reasons only.  This aspect (increased exposure) explains why the minimum amount is raised to 100 points, if you have answered the question yourself.
Comment: To elaborate on @Jyrki's point, some users used to answer a question and then put a bounty of 50 points on it. Then due to the increased exposure they got lots of upvote on their answer (more than 5), resulting in a net gain of reputation. This was seen as gaming the system, and this is why 1/ the min amount is now 100 for questions you have answered 2/ the min amount increases for each new bounty (because you used to be able to do that an unlimited amount of times, basically).
Answer:
Can I put a bounty on a question where I have answered

Yes, you can, but for questions you have answered, the minimum bounty value is 100, rather than the general 50.

and award the bounty to my answer as an exemplary answer?

No, you can't do that. Awarding a bounty to oneself would be kind of pointless, wouldn't it?

Moreover does the author of the question have anything to say on whom I decide to award the bounty?

No, within the restrictions of the system, you alone decide which answer the bounty is awarded to - unless you let the bounty period and grace period pass without awarding the bounty, then the system may award half of the bounty automatically (if there is an answer eligible for automatic awards).
Comment: A little known clause gives the author some say in cases when the bounty setter fails to award it. If they accept an eligible answer during the bounty period, that answer gets the full amount of bounty. http://meta.stackexchange.com/questions/16065/how-does-the-bounty-system-work
Comment: It says "If _the bounty starter_ accepted an answer during the bounty period", I interpret it so that only if the question author started the bounty an accept causes the full bounty to be awarded.
Comment: Ah, I overlooked that clause. It somehow made more sense for me the other way.