Geometric realization of Hochschild complex

Question: Let $A$ be a commutative $\mathbb{C}$-algebra, and consider $C_{\bullet}(A,A)$ the simplicial Hochschild homology module of $A$ with respect to itself (i.e. $C_{n}(A,A)=A^{\otimes (n+1)}$). This is a simplicial commutative $\mathbb{C}$-algebra and we can take its $Spec$ levelwise, to get a cosimplicial $\mathbb{C}$-scheme $X_A :=Spec(C_{\bullet}(A,A))$. If $A$ is of finite type over $\mathbb{C}$, then we may take levelwise the associated topological space for the analytic topology, and get a cosimplicial topological space, denoted $X_{A}^{top}$. My question is whether somebody knows what the geometric realization of $X_{A}^{top}$ looks like (e.g. any relation to the topological free loop space of $(Spec(A))^{top}$?).
Comment: what happens if you take the geometric realization of the simplicial set underlying $C_\bullet(A,A)$?
Comment: I thought it was a cyclic thing, not a simplicial one. Maybe I am mistaken though.
Comment: A cyclic is simplicial by forgetful.
Answer: Let $Y$ denote the associated topological space for $Spec(A)$. It looks like the cosimplicial space $X_A ^{top}$ is just
$ Y \to Y \times Y \to Y\times Y \times Y \to \ldots$,
where there should be two arrows at the first step which are both the diagonal, then the other arrows are given by various diagonal maps. This is the cosimplicial diagram which computes the homotopy fibre product
$ Y \times _{Y\times Y} Y$
i.e. the free loop space of $Y$.
I am writing this in a bit of a hurry, so I hope this makes sense!
Comment: The standard cosimplicial space modeling the homotopy fiber product $X\times_Z Y$ in degree $n$ is $X\times Z^{n}\times Y$; you appear to be missing some terms.
Answer: Nice question. I did this computation a while ago, but I guess what you get, by taking the levelwise  analytification of $X_A$, is the canonical cosimplicial model for the (topological) free loop  space of $(SpecA)^{top}$ (i.e. its totalization is homeomorphic to the free loop space $L((SpecA)^{top})$).
Comment: Thanks! where can I find this canonical model written down?
Answer: Sam Gunningham had the right idea, but I would like to fix it up for the construction of the homotopy pullback that I am aware of.
Alternatively one can compute $HH(A;A)$ as $\mathrm{Tor}^{A^e}(A,A)$ where $A^e$ is the enveloping algebra of $A$, $A\otimes A^{op}$, since your $A$ is commutative $A^{e}\cong A\otimes A$. These Tor groups can be calculated via the simplicial complex which in degree $n$ is $A\otimes (A^{e})^{\otimes n}\otimes A\cong A^{\otimes {2n+2}}$. As a side note the geometric realization of this complex gives a topological commutative ring (Because $A$ is commutative) which models $THH^{HZ}(HA;HA)$ via the Eilenberg-Maclane functor. Applying your contravariant functor to spaces to the simplicial algebra we obtain a cosimplicial space modeling the homotopy pullback $Spec(A)^{top}\times_{Spec(A)^{top}\times Spec(A)^{top}}\times Spec(A)^{top}$ (see 3.3 of http://www.math.uiuc.edu/~reldred2/tot-primer.pdf ) which as Sam pointed out, models the free loop space.
Comment: Ah, thanks! I still believe that the cosimplicial space that I wrote down calculates the free loopspace though (just as both complexes calculate the Hochshild homology). I think the idea is that my diagram sits inside yours as a retract.


How Does A Special Memorandum Account Work

Question: I've noticed that a lot of brokerage firms mention Special Memorandum Accounts (SMA) within the context of calculating margin requirements for margin accounts.  Can anybody explain or perhaps direct me to resources for understanding how Special Memorandum Accounts work?  Do they vary from brokerage to brokerage?  I really do not know anything about them...
Comment: If one can make any sense of the Investopedia article http://www.investopedia.com/terms/s/specialmemorandumaccount.asp I'd be curious to understand what they meant here.
Comment: it sounds like a margin stop loss?
Comment: wait no, it's unrealized gains you can use to count towards your margin but nothing else
Comment: Another link to Investopedia suggests that it's used to keep track of what looks like margin excess (http://www.investopedia.com/exam-guide/series-7/customer-accounts/special-memorandum-account.asp).  Are margin excess and the amount specified in a special memorandum account always the same?  The link in this comment does not keep track of the SMA from the time the margin account was created...
Answer: Here is another explanation of an SMA.

SMA refers to the Special Memorandum Account which represents neither equity nor cash but rather a line of credit created when the market value of securities in a Reg. T margin account increase in value.  For example, assume the market value of securities purchased at a cost of $10,000 on margin (at 50%) increase in value to $12,000.  This $2,000 increase in market value would create SMA of $1,000, which provides the account holder the ability to either: 1) buy additional securities valued at $2,000 (assuming a 50% margin rate) without depositing up additional funds; or 2) withdraw $2,000 in cash, which may be financed by increasing the debit balance if the account holds no cash.
It should be noted that while an increase in market value over original cost creates SMA, a subsequent decline in market value has no effect on SMA.  SMA will only decline if used to purchase securities or withdraw cash and the only restriction with respect to its use is that the additional purchases or withdrawals do not bring the account below the maintenance margin requirement. SMA will also increase on a dollar for dollar basis in the event of cash deposits or dividends.

More details at
http://ibkb.interactivebrokers.com/article/66
Comment: It is generally advisable to put some details in the answer and then link it up. Link only answers are generally discouraged. I have edited this post. Feel free to edit if you feel to put it differently
Answer: The Margin Account holds the funds that are MUST for any margin trades. Any funds excess of the MUST for margin trades are kept in the SMA account. These funds can be used for further Margin trades in new securities [funds get transfered into the Margin Account]. They cannot be used to met the Shortfall due to margin calls on existing trades. New funds need to be arranged.
More at
http://en.wikipedia.org/wiki/Special_memorandum_account


How do you force wiringPI library to use local time instead of UTC time?

Question: I am running Pi 3 along with Real-Time Clock chip ds1302 and using wiringPI library to read and set date and time to and from ds1302 chip. After I set my Pi's system date and time to local date and time in 12 hour format, I set the Real Time Clock ds1302 chip its date and time by sudo ./ds1302 -sdsc Then, I read what was written into clock chip and it reads back UTC time in 24 hour format. So, then I continued with the test by issuing sudo ./ds1302 -slc to set the Pi's date and time from clock chip date and time. Now, my pi's time is one hour ahead in 12 hour format. I am confused. Is there way to force wiringpi library to use only local time in 12 hour format?
Comment: You could always try reading the data sheet. I would just throw this obsolete chip, which is not supported by Device
Tree and is not a particularly good RTC, and use a more modern chip, such as DS3231
Answer: The use of UTC time seems to be hardcoded in ds1302 utility. Note the following line:
gmtime_r (&now, &t) ;

This converts your system time to UTC, before writing it to the DS1302 chip. When the chip is read back, your system time is set to whatever is received from the chip, without any conversion (which frankly looks like a bug).
There are two things you can do:

replace gmtime_r with localtime_r and recompile. Hopefully, you will have your local time in both RPi and DS1302.
configure your RPi to use UTC time with raspi-config. Then the conversion done by gmtime_r will be identical to localtime_r. Whether using UTC time is convenient to you is another story.
Answer: Linux uses UTC. So many subsystems depend on it that you'd be better off doing a localtime conversion for the times you need, and let the system clock run on UTC as it's supposed to.
You should be able to use hwclock to set and retrieve the time from a 1302. It should make the conversion to/from UTC for you.


What may be effect of air friction to the velocity of satellite?

Question: What is the effect of air friction to the velocity of satellite? I have heard satellite's speed increases with air friction. But I'm in confusion how is it possible?
Comment: Comment to the question (v2): Do you have a reference for the claim?
Answer: Air friction does increase the velocity  of the satellite. sort of.
Assume for example, that the satellite is in a circular orbit with the appropriate velocity for the height it is at.  Now it hits small patch of atmosphere, that slows the satellite a little (yes, slows).
The satellite is now at its apogee in an new elliptical orbit.  As it proceeds in pure vacuum, it drops lower towards its perigee, and must, by conservation of both angular motion and energy, speed up.
At the moment of perigee, the satellite just happens to encounters another small patch of atmosphere, which again slows it a little.  It just happens that the slowing is enough to give the satellite a circular orbit, at the new, lower height, and thus at a higher velocity, than it had at the start of this process.
The three steps of frictional slowing, orbital speed-up and frictional slowing combine to give an orbital speed-up
Orbital dynamics are weird...
Answer: I would expect the speed of the satellite to slow down upon reentry; not speed up.  Most terrestrial satellites, even ones in low Earth orbit, do not encounter sufficient atmosphere or air resistance to significantly degrade their orbits so that they reenter the atmosphere.  It is true that the Iridium satellites in LEO often do this.  They have relatively brief service lives (a few years) before reentry occurs owing to their skirting the upper atmosphere, but this is the exception.
In order for atmospheric friction to increase the speed of a satellite, the atmosphere of the planet it is orbiting would need to be one that undergoes super rotation, or in other words, the atmosphere would have a velocity greater than the velocity of the satellite.  This would be an unusual situation, to say the least, as the atmosphere would also tend to escape the planet.
Answer: Air friction (simply a form of friction) as we observe in our everyday life opposes the motion/state of the body (in this case motion of satellite ).
 It's true that air friction is responsible for decreasing the speed of the satellite, thereby decreasing the kinetic energy and ultimately the total energy of satellite.
But as we know that any form of system transits to lower energy state after losing energy (exactly the case of excited electrons coming back to ground state after losing energy in an atom).
As satellite also begins to revolve in a new orbit of smaller radius than earlier, thus by the conservation of angular momentum it must have higher angular velocity around the planet.
And increase in angular velocity means definitely increase in its velocity, v=rw.


Cannot view all inbox items without creating a Meta Stack Exchange account

Question: When I click "View all inbox items," if I hadn't joined the Meta community, it will redirect my to "Confirm new account" for Meta. For some reason, I need to have a profile on Meta in order to view all inbox items. This seems like a bug to me. This is minor because it's not that hard to join the Meta community but it's a bug nevertheless, so I thought I might point it out.
Answer: The system is intentionally designed this way. The global inbox is stored on stackexchange.com and requires logging in to view. It was too costly for us to maintain separate login/signup systems for Area 51 and stackexchange.com and the systems in those places had not been updated in years before we removed them.
Rather than rebuild and maintain another system for those two codebases that would require additional maintenance every time something changed, we made the decision to use Meta as a hub to allow authentication on them in a way that we could build it and not have to do anything else with it. If something regarding authentication changes, we can make changes once on the main sites and the others will utilize it just fine.
The implementation does have the side-effect of requiring a profile on Meta in order to work, but we believe the trade-off is fair. We have zero interest in going back to separate login systems for those sites.
Comment: It's really as simple as that: the only page we provide that does query the full list is in a place that requires a Meta profile to view. We could get the full list and put it somewhere else, we just don't. That would require cramming it into an already cluttered profile page on every site.
Comment: @Sonic It doesn't always and I'm not familiar enough with it to know why it does/doesn't in certain cases. But stackexchange.com is very, very different code from anything else. I'd still prefer getting to a point where logging in there isn't necessary but that project got sidelined long ago for various reasons.
Comment: The same login flow through Meta [is able to log users into Area 51 without creating a Meta account](https://meta.stackexchange.com/a/333393/377214). Why isn't the same thing implemented for stackexchange.com?
Comment: You're also directing users to that page with the inbox reminder emails. This is really a weird experience for a new user that doesn't know what meta is. Especially if you just clicked on a link and suddenly the site wants to create an account, but you already created one (from the user's perspective).
Comment: But if your normal inbox is can be quickly accessed without a Meta profile, I'm not quite sure I understand why this implementation requires a Meta profile to query the remaining items. If that's the case, why _don't_ you need a Meta profile to view any of your items? Does it have to do with your network profile?
Comment: That's simply where the full list is available to view.
Comment: But if _some_ of the list _can_ be queried without needing a MSE profile, then why _can't_ the _full_ list be queried _without_ an MSE profile? I don't quite understand.
Comment: Ok then thanks for clarifying.


Inverting Amplifier Circuit using Single Power Rail

Question: For my homework, we are supposed to simulate an inverting and noninverting amplifier using a single supply and the LM324 opamp. I built the inverting amplifier using a voltage divider, but my output voltage is not a sinusoidal wave rather a square wave that has a cutoff. The output signal should be amplified sinusoidal wave. so, how can I fix this?
Heres the schematic of the circuit:

Here are the screenshots of the results
Answer: Two problems; firstly you need to AC couple the 2.5 Vrms signal to the 470 ohm resistor (R1) or you inevitably are trying to force the op-amp to produce an output voltage that is highly offset from mid-rail: -

If you can't AC couple, you should bias the 2.5 Vrms signal so that it has the same DC level as the node of R3 and R4. Maybe by doing this: -

The 2nd problem is that 2.5 Vrms is 7.071 volts RMS and, with an amplifier gain magnitude of approximately 20 (R2/R1) the op-amp will try and produce an output level of 141.4 volts p-p. That of course is impossible for the LM324 or any op-amp on the limited power supply voltage of 9 volts.
Comment: Other than decreasing the R2 and R1 ratio, Is there a way I can fix the 2nd issue, or is that an issue that exists in the simulation but not in the real world?
Comment: You can't expect an op-amp to produce an output signal in peak-to-peak values that is close to or bigger than the voltage difference between its power rails @MohitSingh
Comment: [What you should consider doing next](https://i.stack.imgur.com/mKrn6.png) if you are done with this question and answer. If you need clarification, add a comment.


Did space and time exist before the Big Bang?

Question: I accept the Big Bang theory. What I can't understand is how there can be a where or when to the Big Bang if space time did not exist prior to it.  Did space and time exist prior to the Big Bang?
Comment: Review your question considering this: does it make sense to talk about things 'before' the existence of time? Of course that doesn't mean the Big Bang theory is complete and there isn't anything wrong with it/strange about it, but I'm really far too tired to be writing up any sort of useful answer...
Comment: Actually, I think your answer was very good. It was  very well put. Thank you.
Comment: Search this site for "flrw metric" for lots of related answers
Answer: All of our known physical laws including GR (which have so far assumed spacetime to be smooth and quite flat) breakdown at singularities due to the infinite curvature of spacetime. Hence, we say, "One second after the big bang..., An hour after the big bang..., etc." Because, we simply don't know what happened at the instant of big bang. If there were events before the big bang, we cannot use those events to determine what happened in its future, because our laws don't work at singularities.
As far as we know, there haven't been a single consequence of the events before the big bang. So, it doesn't make any sense to talk about those events. Since they're of no use, we should probably throw them out of our model of universe and declare that time should've been created since the big bang.
Comment: Nice.  Just to add another phrasing of the same idea, **we have no way of knowing**.
Comment: I'm just glad you guys didn't laugh at me. LOL I admit I sometimes don't really know where the line is between a philosophical question and a scientific one. :-)
Comment: Understanding that really I'm not interested in a philosophical answer... Which is why responses like "does it make sense to talk about things before time" are really very helpful; they help me learn where and how to draw that distinction between physics and metaphysics.


Default layout colour

Question: I'm wondering why, every time I create a new Android project, Eclipse opens a main activity with a white background, when in previous versions, it was black.
Is there any way for me to change that back to black as a default color for future activities?.
Answer: They changed the default theme that eclipse uses in your resources to the light theme.  Change your resource files (delete the stuff eclipse added that you don't use) and it will go back to black.
Answer: So if you want to reskin your whole application to black, you can use following line in your manifest file.
Write to Application tag attribute theme.
<Application
    android:theme="@android:style/Theme.Black" //old targeted application
    OR
    android:theme="@android:style/Theme.Holo" //for new devices
    ... >

Now all activities in this application have black theme.
You can "override" this by using theme attribute in Activity tag.
<Activity
      android:theme="some theme"
      ...>

Default layout colour


Customising a custom ROM

Question: I want to know is it possible to edit a custom ROM from zip and then zipping it again (flashable) to a device.  Will it brick the device?
Thanx
Comment: Depends on what type of customization you make to the ROM.
Answer: Depends on how the ROM is packaged and what you change in it before repacking. You should be able to unpack and make edits using suitable tools for unpacking the ROM.
A better option is to first flash it, then root and make your changes in the files as needed :-)
And yeah it can brick the device if you flash bad code
Comment: What possible ways are there to pack / compile a rom...  I mean there must be a universal way to extract the rom file the contents may vary within it...  Care to explain a bit please
Answer: Well, the best would be to first flash the rom, test all of its functions and bugs and then, after testing, you can unzip the rom zip, make your own changes and then just rezip the files.But be careful for all the changes you make, a few changes can be like changing and removing if you want any system apps, change the default wallpapers and ringtones, but you shouldn't never touch any other files.
Comment: @ghost_83 theming hacks need the core framework to be modified which requires rebuilding ROM
Comment: No. You need source code obviously.
Comment: Is it possible to make a significant change like removing / adding preinstalled apps to rom or like changing the default launcher,  status bar and other theming hacks...  I know how to do all these with magisk modules nd xposed but I'm curious to make these changes to the rom so that j don't need to waste hours on flashing and then molding stuff
Comment: Can the rebuilding be done without syncing the aosp manifest or any other rom manifest?
Answer: Yes it is certainly possible. You need a Linux system however
First determine the format that has been used
If the zip has a system directory it's the old KitKat format
Otherwise check system.transfer.list for the version
Anyway if it's just a system directory you can just extract the zip, add files, modify the updater-script and pack it back
The more complicated stuff:
Case 1: assume system.new.dat
This is actually a sparse (iirc, not really sure) system image that you can extract with sdat2img
You'll get a system.img
Mount this as an ext4 loop device
Perform your modifications
Unmount the system image
Use img2simg to convert system.img to a sparse image then flash it with fastboot like this
fastboot flash system system.img
Case 2: system.new.dat.br
This is just a system.new.dat compressed with brotli. Do not directly run sdat2img on this
First install brotli and decompress it to system.new.dat
Follow everything as said in case 1
There is no easy way to convert it back to system.new.dat. You could use the AOSP build system to do so but if you want to make a flashable zip use the edify command "package_extract_file()" to extract the system.img from a flashable zip onto the system partition.
Also be careful. Remember that any files you add this way will have incorrect selinux contexts. You will have to use chcon to set the correct selinux contexts. Use ls -Z to check what contexts other files have and apply a suitable context

Customising a custom ROM


Which picture has better quality?

Question: I have two exact same pictures and they are both the same x:y size. But one of them is 105 KB and the other one is 109 KB. Which of them is of better quality?
Answer: Greater KB — bigger files — means more data, but doesn't necessarily mean more information. A file with a lot of sharp detail will be bigger than a blurry one, but also a file with lots of noise will be bigger than a clean one.
There's no way to tell anything about image quality from small differences in file size — and that's even if you have a solid, workable definition of "quality". There isn't a standard one; quality can mean different things to different people, and a given photo can be high in certain technical aspects and flawed in others. And a completely technically-flawed photo can be a complete success in other ways.
In your particular case, especially if the images are visually identical, it's likely that the difference isn't in the image at all, but in the metadata. Metadata is encoded information about the image, like the time it was taken, technical camera settings, color information, and so on. And in fact, as @flolilolilo points out, such a small difference could simply be a difference in encoding with no real change in included information at all.
Comment: Also, it could come down to compression efficiency: E.g. a better suited Huffman-table could be used.
Comment: True — there might not even be more data!

Which picture has better quality?


What would someone look like with golden blood?

Question: Not actual gold, only golden in color. This is entirely for appearance wise only, how would gold-coloured blood look on someone who is very, VERY pale. Not only skin tone, but how would it affect things like their lips, inside of their mouth, waterline of their eyes, etc.. Also, would those same characteristics of the skin carry over to someone with darker skin or would the melanin cover it up?
Comment: So basically take a miner who hasn't gotten out of their cave for two decades, and give them golden blood, I see ^^. This brings up a minor question : Does the golden blood change color when its nutriments are absorbed by the system, like it does with red arteries vs blue veins? A transition from clean gold to a slightly copperish color, for instance?
Comment: Note that the lips (and areolas) are reddish because they are colored by [phaeomelanin](https://en.wikipedia.org/wiki/Melanin#Pheomelanin), not because blood shows through, which it doesn't.
Comment: @Tortliena Miner who spend two decades underground eating gold ore in the dark.
Comment: Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
Answer: Less Rosy

Here is a pale person with red blood. You can see the skin is light in color and rosy where there is more blood near the surface. If the blood is orange instead of red, the rosy parts are less pronounced and more orange.
AlexP says lips (and areolas) are red because of red pigment and not blood. You can of course have the lips be orange by having orange pigment instead.

Feel free to make your own image for the areolas.
Hair color is not based on blood color.
Sometimes these pale people become redder when they blush.

This is because blood rushes to the surface of the skin. If the blood is gold instead of red then your blushers might look like this:
Answer: There are actually two real life compounds that can perform the same functions as blood and have an appearance that can be close to blood.  The first is called Coboglobin and uses Cobalt as the base to bind oxygen to it (the function of Iron in every red blooded human).  When oxygenated, Cobogloben is colorless, so your special effects team can render bleeding by show trickles of water like liquid from the alien's wounds.  An otherwise human looking alien with Cobogloben based blood would look very pale, but still human.  Like Hemogloben, Cobogloben does age and needs to be replaced by the body, but Hemogloben ages in terms of weeks while Cobogloben takes days which means blushing can be explained, but it's not as strong.  Cobogloben is not naturally occurring in Earth Life and was created in a lab synthetically.
The second type that can meet this definition and is easier to state what the skin would look like is chloro-carbonyl-bis(tri phenylphosphine)-iridium (try saying that five times fast).  Instead of Iron, this compound uses Iridium to bind Oxygen it (We'll refer to it as I-blood because I am not going to refer to it as chloro-carbonyl-bis(tri phenylphosphine)-iridium every time I have to say it).  In a deoxygenated state it's bright yellow and will become a sullen orange when Oxygenated.  Some concerns for your alien doctors are that any species with this blood would have a very complex system of lungs, as I-blood is less effecient than Hemoglobe (4 times less) and there could be some intersting biochemistry because it can also carry hydrogen in a similar manner to Oxygen, which our blood cannot do... ask a bio-chemist for more details.  In terms of what their skin looks like, that's actually easy.  If they are outwardly human in all other respects, you will want them to be exclusively played by actors of African Descent with very dark skin...  I-Blood, when oxygenated is extremely photosensitive and will decompose if exposed to strong light over a period of days or weeks (and turn form orange, to green and then bluish-black during this process.).  So anyone actor who has little natural melanin in their skin is going to get your biochemist fans to complain loudly.  You also need doctors who can perform surgeries in almost zero light environments.


Where can I retreive the end of day fx prices?

Question: I'm developing a reporting tool and I need a data source for end of day price data. For example, it should give me the XAUUSD price at a specific date, say 2019-12-05.
Do you know such a data source?
Thanks
Answer: Some brokerage does provide such info. For instance FXCM or DukasCopy (I believe some others too) provide access to it's historical quotes. See for example here https://www.dukascopy.com/swiss/english/marketwatch/historical/.
Answer: You may want to check out W. Antweiler's Pacifix Exchange Rate Service. It's free, but you should check whether your application is in line with its terms of use.  Some time ago I wrote a small R package for downloading data from the site, but I have not used the package for years.
Answer: From experience, the most reliable data sources are from central banks. The problem is that they often only report the exchange rate to their own currency. For example, the European Central Bank reports every currency against the EUR (ECB), the US Fed against the USD (Fed) and the Swiss national Bank all currencies against the CHF (SNB).
But it's easy to compute the rates from any pair given you have official rates against a major currency (EUR, USD, CHF etc.)
$$ \frac{C_1}{C_2} = \frac{1}{\frac{C_3}{C_1}} * \frac{C_3}{C_2} $$
$C_1$ being your first currency (e.g. AUD), $C_2$ the second (USD) and $C_3$ a major currency you got common exchange rate information for (e.g. EUR).
Data from the ECB (end of day exchange rates against EUR) is also available for free on Quandl. There's also a API for which you need to register to get a free API key.
In R this is how I calculate:
<code>library(tidyverse)
library(Quandl)

Quandl.api_key(KEY) # get your personal API key on Quandl.com

get_exchange <- function(currency1, currency2) {
  if (currency1 == "EUR") {
    out <- Quandl(paste0("ECB/", currency1, currency2))
    return(out %>% rename(!!paste0(currency1, currency2) := 2))
  }
  if (currency2 == "EUR") {
    out <- Quandl(paste0("ECB/", currency1, currency2))

    out <- out %>%
      mutate(Value = 1/Value)

    return(out %>% rename(!!paste0(currency2, currency1) := 2))
  }

  EURcur1 <- Quandl(paste0("ECB/EUR", currency1))
  EURcur2 <- Quandl(paste0("ECB/EUR", currency2))

  currencies <- left_join(EURcur1 %>% rename(EURcur1 = 2),
                          EURcur2 %>% rename(EURcur2 = 2),
                          by = "Date")

  currencies %>%
    mutate(!!paste0(currency1, currency2) := 1/EURcur1 * EURcur2) %>%
    select(-EURcur1, -EURcur2)
}

AUDUSD <- get_exchange("AUD", "USD")

AUDUSD %>% as_tibble()
</code>
Answer: End of day is tricky in Foreign Exchange, which trades around the world in multiple centers (multiple time zones). By 'end of day price data' I assume you mean the 5pm New York price. (Could also be London, where XAU is heavily traded, etc.).
My favorite is https://barchart.com/forex/quotes/%5EXAUUSD/price-history/historical
I signed up to receive the data every day in an Email that is sent to me from Barchart.Com at 5:45pm NY Time every day. It is convenient and it is free.
(For 2019-12-05, the date that you mentioned, they give a price of 1,475.64).


What is the bar on a CBP automated passport control (APC) slip?

Question: What does the black bar, measured in a percentage, mean on the CBP APC slip? Some measured at 100%, others 85%, etc, so is this a risk factor assessment for the passport or customs inspectors? Example image:
Comment: That paper has nothing to do with the TSA.  TSA runs security inspection checkpoints to prevent people from bringing weapons and other instruments of violence onto airplanes.  You generally pass through these before departure; only in some circumstances would you encounter one after arrival.  The paper you're asking about is related to immigration and customs inspection of travelers arriving in the US.  That's why it says "U. S. Customs and Border Protection" on it; CBP is a different agency.  That said, I do not know what that bar indicates.
Comment: @CHJ that image was posted by an actor on Twitter, no need for redactions.
Comment: Example of such a bar available here: https://twitter.com/hstefson/status/812504371040755713
Comment: @CHJ "Since you already have a big 'X' on your receipt, means you are not allowed to go through the fast lanes but have to go through regular passport control lanes!!" Not necessarily - at many Airports there's a dedicated lane for APC users who got the X. At times, it may in fact be quicker, if there are few "X people"
Comment: I think he means APC, not ACP, and CBP, not TSA. He's asking about the vertical bar just to the right of the picture on an APC machine receipt.
Comment: I don't know for sure as a google search did not yield any information. But the "L, M, H" probably means Low, Medium, High (Risk?) percentage. Since you already have a big 'X' on your receipt, means you are not allowed to go through the fast lanes but have to go through regular passport control lanes!! Also, some people get receipts that do not have the bar on the left but just a 'X'. This probably means you are high risk traveler...? just guessing. Seems counter intuitive since you already have APC benefits so you shud be a low risk traveler.
Comment: Also, in the future, I would recommend redacting sensitive information such as your full name and DOB from whatever you post on internet, especially on open forums.
Comment: Maybe some suspected terrorist has the same name as yours...
Comment: Question is what "FM" means, as it's clearly that parametre that's displayed on the bar. The reason why you got the X, by the way, is some sort of "enforcement issues". Did you have trouble with the law in the US or Canada in the past?
Comment: @JonathanReez He clearly had issues with US authorities, given the code on the receipt
Answer: Warning: This answer is based off of strong speculation and contains no real sources.
Border crossing technology is either really dumb, or at the forefront of data mining and AI. It either processes your declarations form and verifies your documents, or it's using facial recognition, behavioral pattern matching, and data mining to assess. Basically, it's working to replace the officer with both the mundane paperwork and validation, and the "gut feeling" officers use to determine if the person warrants further interrogation.
So, while the cynical might say it's a threat risk assessment, it is probably a confidence assessment, which is a bit more benign. Instead of it being a measure of your risk to the U.S. it is probably a measure of the computer's ability to determine if you are legitimate. So a high number is not so much of a "he's a threat," as much as it is "I don't have enough information and I need a human's help with this person."
Comment: As user71659 said in their answer, the number is most likely the inverse of my answer, where a higher number is a higher confidence, and a *lower* number would say "I need a human's help."
Answer: Logical guess is the bar and FM = Face Match. It's how well the picture matches the photograph stored on the RFID chip of the passport.
It has been reported that the APC kiosks match this:

This requires that APC kiosks authenticate identity by matching people's faces to the biometric record in their e-passport...
"Now, there is added security as the CBP requires facial biometrics to be matched to the e-passport being presented. Almost 500 million e-passports have been issued globally; these hold facial biometrics while some also contain fingerprints. Our SITA APC kiosks comply with all the latest requirements and help bolster more efficient security checks at the airports."
Answer: I had the same question, and have a new possible answer to posit: I think it's in reference to your height.  Mine was 29, my husband's was 48, and we're about 18 cm apart in height.  Since the kiosk automatically adjusts its height to take your picture, it's a possible explanation. Also, my height in cm is about 158, and his is about 178, so possibly the measurement begins at 130cm at the bottom of the bar.
If my assumptions are correct, then that would make the gentleman in the picture 200cm, or 6.5 feet.  Perhaps he could confirm his height for us? And if anyone else has an example, we could easily validate or invalidate this answer.
Comment: This doesn't feel right. Why would your height matter to the CBP? It's probably not even recorded in the biometric data in most passports. Also, the H/M/L labels don't make much sense, an English speaker wouldn't use "high" or "low" to refer to someone's body height. Also the upper end of the scale would then be around 230 cm (7'6") which sounds pretty unlikely and would unnecessarily squeeze the range of common values.


How to flag series of votes

Question: Few minutes before Four answers(1,2,3,4)(unfortunately these ware the top voted answers for me) ware down-voted by someone. Is there any possibility to flag/report such series votes(up - down) to get attention of the moderators.
Comment: See updated answer, If the perpetrator has shown such behavior before and continues to do so, Mods will investigate themselves. They have tools to find out evidence.
Comment: @NSNoob : thanks for the response, Will it give any punishment or notice for the down-voter?
Answer: SE does not need this feature because there is already a way for system to detect malicious voting patterns and correct the reputation accordingly.
If someone serial up-votes and down-votes your answers/questions, you have to wait for at least 24 hours. When the script is run, your reputation will be corrected to pre-malicious-voting level.
Read this page for help.
Quoting from the same page:

When a single user continually votes (up or down) on many of your
  posts within a short period of time, the system considers these votes
  to be invalid and removes them.

What to do when you think you are victim of serial voting?

If you see very unusual votes being targeted at your account, don't
  worry about it. You should wait at least 24 hours after noticing
  before becoming concerned, as the automated system should detect it
  and reverse it for you. If, after 24 hours, you do not see any fix to
  your reputation, please contact the team using the "contact us" form
  located at the bottom of any page.

What happens to the perpetrator(s):

If such a voting pattern continues to happen between two users
  mutually or from one user towards another, or otherwise falls outside
  of normal voting patterns, moderators and/or developers may
  investigate the matter; intentionally voting merely to reduce or
  inflate another user's reputation is considered abuse.

The exact nature and rules of the reversal script are kept in secret to avoid potential abusers from finding work-arounds. Relax, your reputation will be back by tomorrow.
Comment: @un-lucky it is not, that was just an example. Don't worry about it, we all have been victims of serial downvoting and we all get our rep back. The exact details of script are kept in secret to avoid potential abusers to circumvent around it
Comment: Glad to inform you that, i got those reputations back
Comment: Fine, Is there any limit for such votes? How many votes i can cast to a single user? Will the script detects daily votes
Comment: @un-lucky as evident from the help page, system only concerns itself with votes cast in a short span of time. For example, you can't go around upvoting someone's five posts within one minute, system will detect it as malicious
Comment: is that limit is `5`. `you can't go around upvoting someone's five posts within one minute`. Oh god he may be aware of this he castes only `4`
Comment: Thanks for spending your valuable time with me for explaining this.
Comment: It doesn't work. I got serial downvoted last week and it was never reversed and I just got serial downvoted again.
Comment: @Hack-R Then follow the due process which says `If, after 24 hours, you do not see any fix to your reputation, please contact the team using the "contact us" form located at the bottom of any page.` Explain your situation and Stack Exchange employees will get it fixed for you if it is indeed serial voting.

How to flag series of votes


how to fasten wood joist to cinder block notch

Question: I want to lay three 2x4 in the cinder block notch(as shown in the pic) as joist for synthetic deck, I need to fasten the wood to the cinder block in order to align the three 2x4 and to make sure it doesn't move, I thought about filling the notch with new concrete and bonding agent but not sure if such a small notch of concrete will provide enough strength and durability. I might be able to put in an angled screw or nail into the wood and block, but not sure if that is the best option. Any advice is appreciated
Comment: How big are those notches in relation to a 2x4? They look like a 2x4 would fit reasonably snugly in there. Once the wood's in the slot, if the fit is snug, it won't go anywhere...
Comment: Building floor joists are held in notched in masonry walls by nothing more than gravity, quite well. Do you have a reason to expect substantial uplift forces here?
Comment: I think this is a deck.  So worst case up-lift forces (wind storm, hurricane, etc) may be more than can be resisted just by weight/gravity.  Joists in a typical deck construction are fastened to the beam and ledger.
Comment: Looks at Simpson or UPS for hurricane tie down straps, or something similar.
Comment: What is the 'cement pond' beneath this 'bridge' design? I question even the use of PT lumber in an always wet environment.
Answer: Wedge them in.
I think @Freeman is right in the comments - it looks like you could tap the 2x4s down into the slots with a rubber mallet and they would wedge tight.
If the slots are little too wide and the 2x4s rattle back and forth you could tap in some wood shims to wedge them tight.
Answer: Suggest detail to fasten the 2 X 4.
Comment: It looks like the CMUs are already filled, so it might be necessary to drill and epoxy the rods.


Installing perl module

Question: How to install perl module Util.pm .I am missing this module .What is the procedure to install a perl module
Comment: Any particular platform?
Comment: Linux,Cent Os....
Comment: You can usually just do "yum provides */" to find out what package, if any, provides the module.
But in this specific case "Util.pm" is a very common name and tens of packages provide it.
You need to identify  which module requires its "Util.pm" by looking at the source or at the path in the error message.
Answer: Regardless of which platform you may be on, you may be able to install the module using the CPAN shell. You can drop down to the CPAN shell by running the command:
perl -MCPAN -e shell

and from there use the install command to fetch and install the module you need installed.
The perldoc for CPAN is helpful in understanding how to use CPAN and what it does and how it works.
You may use the i /Util/ command to search modules and packages that match the given pattern. Or, you could go to search.cpan.org and look for the module you are looking for.
Comment: Do u mean to say install util.pm??
Comment: And how to list and remove modules..
Comment: @Rajeev: I have updated my answer with more information. I am afraid you will have to find the exact name of the module you are looking to install.
Answer: I really like cpanm, it makes it very easy to install perl mods.  Have never had a problem with it and saves me a lot of time.
cd /tmp
wget http://search.cpan.org/CPAN/authors/id/M/MI/MIYAGAWA/App-cpanminus-1.4008.tar.gz
gunzip App* && tar -xvvf App*
cd App*
perl Makefile.PL
make && make install

( make sure you have gcc installed)
Now all you have to do if you want a mod just
cpanm <_MOD_NAME_>
( cpanm POSIX::RT::MQ )  POSIX::RT::MQ is the mod you want / etc
Answer: Quite a lot of Perl module are available as rpm packages for CentOS, some in the base repos and quite a few more in rpmforge and epel repos. Easier and faster than using cpan and the module will be updated when you update your CentOS install if an update is available.
See this page for a list of extra CentOS repos.
Comment: I upvoted this answer, because using precompiled binaries is faster and cleaner than using CPAN. Specially on a production server
Answer: You might want to install Utils, not Util.
The easiest way is to use CPAN. Just type:
cpan install Utils

Installing perl module


Kaplan Meier for Annual Survival with Staggered Entry

Question: I am carrying out survival analysis for two populations of mammals. The data available is GPS collar data: date collared, date of death or date of end of study.
I am using the non-parametric Kaplan Meier estimator in R to create survival curves.  And I am using a log-rank test to compare between the survival curves of my two study sites. The data I used was number of days that each individual was collared (or alive) and whether or not they were alive at the end of the study.
I have two concerns with what I have done so far.
I haven't managed to find code to analaysis specifically for annual survival. To display annual survival I shortened the x-axis to 365 days. I worry that 1) this is not correct and 2) that my log-rank test only tests for differences between the 2 complete curves, and not between just one year.
Additionally, I found a paper (Pollock et al, 1989) which modified the Kaplan Meier estimator (originally for medical trials) to allow for a staggered entry design, useful for collaring studies. I have two study sites. At one study site all jackals were collared on the same day. For the other study site the jackals were collared over a range of dates. I followed a tutorial online and their data did share the same study start date. I am looking for annual survival, and not survival at a set point in time ie end of a specific season or at a specific event, and so I am unsure if the Pollock version would be more approporiate to use or not?
I did not use the Cox-proportional hazard because we have no covariates
Answer: I'm not sure if you are still looking, but generally you might try to use survival package and:
output<-summary(survfit(Surv(as.numeric(enter, exit), event)~(as.factor(year)), conf.type = "log-log", data=data)).

From your output you can extract year (output$strata) and survival values (output$surv) and SE and CI components (output$std.err, output$lower, output$upper)


close the application when session is idle for more than 10mins

Question: I want to close the application when my application is idle for more than 10 min.Any one have idea.Give me some solutions.Thanks in adavance
Answer: see this link.Its working fine  Close the application when it is idle for 10 min
Answer: Well, that's difficult: how do you define idle? No user interaction? No button presses? No scrolling by the user?
If you go with button presses as the metric for activity, I would suggest creating a Handler object, scheduling a message to be delivered in 600000 milliseconds and then any time the user presses a button cancel the message and reschedule it. If the message ever goes off you can just call finish().
Answer: you dealt with this by using the AlarmManager to schedule and cancel timeout action.
Then in the onPause() event of all of your activites, I schedule the alarm. In the onResume() event of all of your activities, You have to check to see if the alarm goes off. If the alarm went off, you will finish your app. If the alarm hasn't gone off yet you cancel it.
You have to create Timeout.java to manage my alarms. When the alarm goes off a intent is fired:
Have a look on the following URL
Lock android app after a certain amount of idle time
Thnaks
Deepak
Comment: Thanks Deepak.I am tried with http://stackoverflow.com/questions/4075180/application-idle-time Do u have any idea on this


How do I replace a dimmer switch with a single switch?

Question: I'm trying to replace a dimmer switch with a regular light switch. The same box also has another dimmer and fan control switch next to the one I want to replace. The dimmer has 2 wires, a pink and black. I want to know which wires to use for this light switch. Everywhere I look dimmers have 3 wires. Should I unwrap one of the bare wires and use it with the new switch? The switch controls a light with 3 bulbs and this is the only switch.
Answer: To make the switch work, you'll simply attach the two wires you removed from the dimmer to the new switch. If there wasn't a grounding conductor attached to the dimmer, you have a couple options for grounding the new switch.
Add a grounding conductor
You can use a length of bare copper or green insulated wire, and connect it in an approved manner to the other grounding conductors in the box. Then you'll attach the other end of your grounding pigtail to the switch.  You could use a twist-on connector, crimp connector, terminal block, push-in connector, or any other UL listed product designed for this.
Adding a grounding conductor is the preferred method.
Self grounding device
If it's a metal box, you could use a self grounding device.  The switch will then be grounded to the box through the attachment screw, assuming of course that the box itself is grounded (which it should be if it's metal, but don't make assumptions when working with electricity). Self grounding devices will be labeled as such, and will have a little copper doohickey around the attachment screw hole.

NOTE:
If you're attaching a grounding pigtail to the other grounding conductors in the box, make sure all the existing grounding conductors stay connected. DO NOT permanently remove grounding conductors from the bundle, they must all be connected together.


Marlin (on RUMBA board) switch extruder fan automatically

Question: I have wired in a new extruder with its own cooling fan and I tried to change the Marlin firmware to switch it on automatically above a specific temperature (50 °C).
I did noting in the Configuration.h
I changed a line in the Configuration_adv.h
from
#define EXTRUDER_0_AUTO_FAN_PIN   -1

to
#define EXTRUDER_0_AUTO_FAN_PIN   8

as described in this article.
But the fan is not starting when I bring the temperature above 50 °C (manually). However it starts if I switch the fan on manually from Repetier.
Am I missing something? How do I control the fan automatically on FAN0 output when the temperature  reached the set limit?
Comment: Maybe 8 is not the correct pin to turn on the fan for your board? Which board do you have, and what output is the fan connected to?
Comment: I have a Rumba board. The fan is connected to Fan0 and the extruder to Extruder0. If I leave that line with -1 instead of 8 the fan does not even start manually therefore I assume that pin 8 is correct for such output. The issue is that does not start automatically as I said above. Something I have not said is that I am testing heating up the extruder manually (not printing, just heating it).
Comment: The auto fan functionality is separate from the manual control, so I don't understand why your setting here should affect the manual control. The primary fan on the Rumba board is on pin 7, and a secondary fan output is on pin 8. Perhaps setting it to 7 will work? You might need to remove the regular FAN_PIN define to make this work.
Comment: @TomvanderZanden, sorry you are correct. Even if I set #define EXTRUDER_0_AUTO_FAN_PIN -1, the manual on/off from Repetier works. I tried then to set #define EXTRUDER_0_AUTO_FAN_PIN 7 but I get this error:  #error "You cannot set EXTRUDER_0_AUTO_FAN_PIN equal to FAN_PIN. How do I solve this?
Answer: The RUMBA board has two fan outputs. The primary fan output is switched by pin 7, the secondary one by pin 8. The reason your fan is not working when you set #define EXTRUDER_0_AUTO_FAN_PIN 8 is because it's switching the secondary fan. If you switch the wires over to the secondary fan output it will work correctly.
If you do want to use the primary fan output then you can achieve this by setting #define EXTRUDER_0_AUTO_FAN_PIN 7 but you will need to search for the #define FAN 8 in the appropriate pins.h file and change 8 to something else (-1 or 7, for example).
I would recommend the first solution, because you should have a controllable print cooling fan, and an automatic extruder cooling fan.


foder an file, thumnails, for all types of files. Ubuntu 20.04.2

Question: 20.04.2. I just uninstalled my windows 10 and I'm feeling much better already. I would like to have thumbnail preview icons for all types of picture formats and video formats. I would also like to see a briev folder icon preview of whats in that folder. Currently .jpg and some other formats have a picture preview icon but not .webp formats, and I'll probably find other formats also not having a preview icon.
Comment: See also --> https://askubuntu.com/questions/992947/how-to-preview-images-in-folders-icons and https://askubuntu.com/questions/900785/how-to-set-folder-icons-of-multiple-folders-automatically
Answer: First try installing restricted codecs for your operating system. Simply search online for directions for your OS. This way the OS can read the files on its own. Then update in app store. Reboot. Test by copying, pasting a video file to desktop. If you see video thumbnail it worked. You just need to refresh thumbnail cache at that point.
I reset thumbnail cache by going to ~/.cache/thumbnails and deleting the images in the folders forcing system to refresh them.
I did this in PopOS and it worked, which is Ubuntu based so should work on Ubuntu also.


What is the difference in usage between "Möhre" and "Karotte"?

Question: I've been doing a bit of German practice and encountered the words Möhre and Karotte. Supposedly, they both mean carrot, but I can't see where these would differ in usage. Any ideas?
Comment: I tend to use "Karotten", as I still can't always remember whether "Möhren" is the correct word, or if it's "Mohren", which has a **very** different meaning.
Comment: In colloquial usage, _alte Möhre_ also refers to an old run-down car. I've never heard anyone use _alte Karotte_ or _alte Mohrrübe_ in that sense. I'm a native speaker from the Mohrrüben region.
Answer: The use differs from region to region.
The linguistic atlas Atlas zur deutschen Alltagssprache shows the areas of distribution of "Möhre", "Karotte", and other variants:
Comment: @geuetzel: apart from those two blue guys. Maybe they're just visiting ;-)
Comment: It's interesting how you can still see the kingdoms of old in this map.
Comment: In Austria everyone says 'Karotte'. 'Möhre' is considered German German here :)
Comment: We are from Hamburg (now living in Bavaria) and we use *Wurzel*
Comment: Although in Germany according to that map _Möhre_ should be more popular than _Karotte_, there are both of them in product names. See [Möhrensaft](https://shop.rewe.de/getraenke/moehrensaft/schneekoppe-moehrensaft-330ml/PD5804205) and [Karottensaft](https://shop.rewe.de/getraenke/moehrensaft/rewe-bio-karottensaft-mit-apfelsaft-honig-0-5l/PD999977) in the Rewe super market chain online shop. The former is a brand product and the second one is the chain's own biological products line. Both of them share the SEO keyword _moehrensaft_ in the URL though. So maybe that one is more popular after all.
Comment: obligatory upvote for citing "Atlas zur Deutschen Alltagssprache" :-)
Comment: @Raphael Not necessarily kingdom though. Regional differences exist regardless of whether there was a separate regime or not. In China and the US things have always been under one central regime theoretically but still regional dialects vary greatly. Though I get your point.
Answer: In theory they  have  different meanings: Möhre is the species (Daucus carota), and Karotte is one subspecies (sativus) of Möhre, but as the Karotte is the only commonly cultivated form subspecies of Möhre, they are synonyms as long as you are not talking to a biologist.
Answer: I'm from the southwest where "gelbe Rübe" is a commonly used term (see Loongs post), but in my experience it's not really in use elsewhere and people might have difficulties understanding it.
"Möhre" and "Karotte" are both pretty well understood everywhere in my experience, so you should be able to use whichever.
If I know nothing about the audience (i.e. regional preference), I'd personally use "Karotte" for more formal settings (e.g. scientific work) and "Möhre" for more informal settings (e.g. childrens books or restaurant menus), simply because "Möhre" sounds softer than "Karotte". This is entirely subjective though and might be caused by the order in which I was exposed to the different terms.
Answer: There is no difference in meaning, but these two as well as the missing third term gelbe Rübe have (in my opinion: strongly) different regional distribution. So in conversation, simply switch to the other term if receiving strange glimpses.
Answer: As others already said there is no difference in the meaning of Möhre vs. Karotte apart from a regional different preference in usage.
When looking at the etymology of these words we may find a clue as to why there are so many apparently different words for the same thing in contemporary German.
The oldest words are Möhre and Rübe that were already known in Old High German (mor(a)ha and ruoba), used for almost every edible plant root (Wurzel) in those days. Regionally Wurzel is also used for a carrot until today.
To sub-classify these edible roots we used their color with Rübe, hence the terms weiße Rübe, gelbe Rübe (the color orange was not yet defined those days), or rote Rübe (used for beetroot).
This color code is present untit today but at the time the color scheme was applied in some regions, other regions started to exclusively use Möhre for carrots. This also is why we have the mixed-up term Mohrrübe.
Karotte on the other hand is a relatively new word introduced as a loanword from French carotte (from Latin carota) by the end of the 16. Century. It is used until today, sometimes in parallel with the older terms, including the botanical term daucus carota sativus.

What is the difference in usage between “Möhre” and “Karotte”?


What is the difference between kosher dill pickles and Polish dill pickles?

Question: What is the difference in taste between kosher dill pickles and polish dill pickles? Do they have any visual distinctions that would make it possible to differentiate between them on sight?
Answer: Those are two different processes. Unfortunately English language don't have two words for the outcome and they are both called "pickles".
Usually Polish pickles "kiszony" should be made with:
cucumbers, dill, fresh horseradish, garlic and salt. No vinegar.
Kosher pickles, called in polish "korniszony", are made with brine that contain vinegar.
I assume that those two recipes have been mixed outside Poland and both things are "korniszony" with the difference that "polish ones" call for ingredients used in "kiszony". The difference in taste is that polish one is much more spicy while kosher one is sweet.
Comment: In the United States, kosher dill pickles, or kosher dills are usually lacto-fermented, i.e. cured in a salt brine, not in vinegar.  They are not sweet, although some of them - the so-called "half sours" are not very sour.
Comment: Lacto-fermented is exactly "kiszony". From what I've seen in such case "kosher" is usually in quotes or the full name is "lacto-fermented kosher dill pickles". In the substance lacto-fermented are softer and the brine is cloudy while kosher pickles are crunchy with clear brine.
Answer: After a quick google, it would seem that Polish pickles might/would contain more spices.
From ehow:

Due to their similar origin, Polish and kosher dill pickles resemble one another in preparation, making it difficult to distinguish between the two -- that is, until you taste them. While kosher dills are made with garlic, Polish dills are often made with more pickling spices, giving you a zesty, peppery pickle.

From Our Everyday Life:

Polish dills contain more spices and garlic than either traditional dill pickles or kosher dill pickles. These pickles tend to be peppery and may be flavored with mustard seeds. Their flavor is similar to the kosher dill and they are served in the same way.
Answer: Kosher pickles are naturally fermented by the weight of the fruit x 0.02% of salt as similar to Amish style I believe.
Malted vinegar is added to Polish pickles with some sugar. I have seen polish pickles that are naturally fermented too and called sour dill. Generally, Kosher Pickles do not have any added sugar, but in this modern world, the commercial stuff tends to be modified and only the name is used.  If you want the real deal make them yourself it isn't hard.
Oh, and kosher pickles exclusively use Kosher salt too.  I doubt that commercial makers use kosher salt. They would use cheap non-iodized cooking salt.
Answer: In my experience, the Polish dill pickles are sweeter. That's why I like them. No company in the US makes a sweet Polish Dill pickle. I haunt Polish delis looking for the good stuff.
Answer: Polish dill pickle spears are sweeter than kosher pickles. They are not spicier than kosher pickles. Kosher pickles are spicier.
Comment: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).


ImportError: import tensorflow_model_analysis as tfma [ PYTHON on datalab]

Question: I would like to add model analysis to my model but was unable to import the libraries:
I am using datalab environment.
import tensorflow as tf
!pip install tensorflow_model_analysis
import tensorflow_model_analysis as tfma

The error is:
ImportErrorTraceback (most recent call last)
<ipython-input-6-f85e4d8fbd99> in <module>()
----> 1 import tensorflow_model_analysis as tfma

/usr/local/envs/py2env/lib/python2.7/site-packages/tensorflow_model_analysis/__init__.py in <module>()
     15
     16
---> 17 from tensorflow_model_analysis import view
     18 from tensorflow_model_analysis.api import tfma_unit as test
     19 from tensorflow_model_analysis.api.model_eval_lib import *  # pylint: disable=wildcard-import

ImportError: cannot import name view

Please advice what will be the right way to import the library.
Thanks,
eilalan
Answer: Working for me now with the following installation:
python 2.7 - to support apache beam
pip install pip==9.0.3  # I am not sure what is the reason, but essential for apache beam pipelines execution
pip install --upgrade tensorflow
pip install tensorflow-model-analysis
import tensorflow_model_analysis as tfma


Repository Pattern with NPoco, Worth it?

Question: I am considering NPoco for a large business application. I am a bit concerned that is it worth to develop a repository pattern?
I will need to handle complex SQL statements and extensive database operations on several entities in a same use case.
NPoco provides a variety of db operations functions, which I think will not be (directly) exposed to the consumer layer(s) by my repository layer.
Edit-1
Which approach is better to get most out of NPoco?
Answer: If you want to invest time in unit tests, then the Repository Pattern is worth it. However if most of your application logic is in stored procs and functions, then you will be limited with unit tests and just spend your time in integration testing.
Comment: in my case, business logic is not in db stored procedures/functions and will be the responsibility of the services layer.


Hard system in integers related to natural number representations

Question: Update: Observing a necessary condition, and "unbalanced" variation
A necessary (but not sufficient) condition for a number to be a solution to this Diophantine system (Representing "balanced" triple palindromes) presented in the "The problem-system" section of this question, is for it to be a solution of the following linked Diophantine System (Representing "balanced" double palindromes).
Number is a triple (double) palindrome if it is palindromic in three (two) consecutive number bases.
Double and triple palindromes are "balanced", if they have the same number of digits in all of their consecutive palindromic bases. Otherwise, they are unbalanced.
Unbalanced variation of this problem is not known if it has solutions or not, at all; Does there exits an "unbalanced" triple palindrome?

I suspect that there are finitely many "unbalanced" double palindromes for every fixed case of digits? - where it is also not known if an unbalanced triple palindrome exists. This conjecture was motivated by the fact that the opposite is true for "balanced" double palindromes: It is known that there exists infinitely many "balanced" double palindromes for every fixed case of digits.

Update on $d\ge 5$ cases
The case $d=5$ is now proven computationally. But the case is still referenced as conjectured in the text below. - A human solution would still be very useful if possible. (Can we bypass the 2-palindrome step and solve directly for 3-palindromes?)
The solutions for 2-palindromes from this answer's $d=5$ case are extendable computationally to base $b-2$ and yield the conjectured $d=5$ solutions presented here.
I'm not sure if it is possible to do the similar thing with $d\ge 7$. - The obstacle being the limitations of using a CAS to solve the given system of equations.

Table of contents
This post will be a bit longer than usual, so here is a table of contents:

Problem and progress: Stating the problem and presenting known solutions so far.
Questions on possible ways to continue making progress?
Context of the problem and some basic stated theory used to prove $d=3$ solutions.
Going over the proof of $d=3$, can we extend it to conjectured $d=5,7,\dots$ solutions?
Related problems and the generalized system-problem, motivation

In short, progress in this helps solve problems related to special numbers  that depend on representations in multiple number bases, especially ones that deal with the digits of the number.
Such as the two linked questions on existence of a $4$-palindrome and finding $3$-palindromes.

Problem and progress
The problem-system

Let $a_i,A_i,B_i,o_i,h_i,b,d\in\mathbb N_0,i\in\{1,\dots,d\}$ be non-negative integers. Can we solve:
$$
0 \le a_i\lt b,a_1\ne0 \\
0 \le A_i=A_{d-i+1}\lt b-1,A_1\ne 0\\
0 \le B_i=B_{d-i+1}\lt b-2,B_1\ne 0
$$
If it is given $d\gt 1$, and:
$$
a_{j}=a_{d-j+1},j\in\{1\dots d\} \\
A_i=\sum_{k=1}^{i}\binom{d-k}{i-k}a_k + o_{i} - o_{i-1} (b-1) \\
B_i=\sum_{k=1}^{i}\binom{d-k}{i-k}2^{i-k}a_k + h_{i} - h_{i-1} (b-2)
$$
For all $(a_1,\dots,a_d;b),o_i,h_i$ that satisfy these conditions?
Where also note that $o_i,h_i=0$ for $i=0,d$.

These equations in short, arise from:
$$
\sum_{k=1}^d a_kb^{d-k}=\sum_{k=1}^d A_k(b-1)^{d-k}=\sum_{k=1}^d B_k(b-2)^{d-k}
$$
By writing $A_k,B_k$ in terms of $a_k$, and using $o_i,h_i$ to regularize the equations - which is explained in the context of the problem part of this post.
When the equations are regularized by $o_i,h_i$, the $a_k,A_k,B_k$ can be viewed as digits of a number in bases $b,b-1,b-2$ that are required to be palindromic by the problem-system.

Progress so far
$(0)\space$ If solution exists: $(a_1,\dots,a_d;b)$ for some $d$, then $o_i,h_i$ that allow it are unique.
$(1)\space$ If $d$ is even, the system has no solutions.
$(2)\space$ If $d=3$, I have all the solutions.
$(3^*)\space$ For $d=5,7$, I conjecture I have all the solutions.
$(4^*)\space$ For $d\ge 9$, I suspect there are no solutions, or at most finitely many solutions. I do not have yet any examples (counterexamples) for this.
$(\infty)\space$ Mathematica can solve any $d$ case for $(a_1,\dots,a_d)$, but for one fixed $b$ at a time.

Observation: If there are families of infinitely many solutions, they will appear periodically among consecutive values of $b$. Otherwise, only a finite number of solutions could exist, for small enough values of $b$.
This observation can be used to computationally solve individual $d$ cases - but I have no ways of proving there aren't any more solutions, because I do not know how to set up any upper bounds, even thought they should clearly exist in the context of periods and the smallest base after which all periods should be visible.

Known infinite families of solutions
For $d=3,5,7$, I strongly conjecture I have all such solutions. For $d=3$ only, I managed to actually prove it by exhausting all $o_i,h_i$ cases (by going over all regularized expressions) systematically (which is explained by the end of this post).
For convenience, lets write the the solutions in terms of the smallest one $+$ increment for $a_i$ terms, and $b$ in terms of a constant $+$ period of the solutions in the family. Also, since $a_i=a_{d-i+1}$, we can write solutions by writing only the first $\frac{d+1}{2}$ values of $a_i$. Then:
We have for $k\in\mathbb N_0$ the families with infinitely many solutions:
$$
(a_1+c_1k,\dots,a_{(d+1)/2}+c_{(d+1)/2}k)=(a_i)+(c_i)k
$$
$$
\begin{array}{l,l,l,l}
d & (a_i)&(c_i)k & b\\
d=3 & (2,6)&(1,1)k & 2k+8\\
d=5 & (31,32,0)&(3,2,1)k & 4k+47 \\
d=7 & (34,50,10,74)&(1,1,1,1)k & 2k+76 \\
d=7 & (8,33,0,41)&(1,3,1,3)k & 6k+58 \\
d=7 & (112,15,0,36)&(4,0,1,0)k & 6k+175 \\
d=7 & (227,160,187,200)&(5,3,5,3)k & 6k+280 \\
d=7 & (5,23,6,14)&(2,6,5,0)k & 12k+39 \\
d=7 & (93,78,30,50)&(10,6,7,0)k & 12k+119 \\
d=7 & (47,150,249,26)&(2,6,11,0)k & 12k+291 \\
\end{array}
$$
Notice solutions for $d=3,5,7$ have (largest) periods $p=2,4,12$.
For $d=9,11$, if infinite solution families exist, period is greater than $500,300$ respectively. (Checked bases $b$ from $10^9$ to $10^9+p$), which seems unlikely - That is, it seems unlikely that these cases have solutions at all- And this would be an unexpected result for me.

Known finite sets of solutions
We have for $d=3$ the $(3,6;9)$ solution, for $d=5$ none, for $d=7$ we have $12$ solutions among $b$ from $11$ to $51$. For $d=9,11$ there also seem to be none so far.

Question - Possible ways to make progress?
Fully solve the system?

$Q_1:$ Is it possible to solve this problem-system for general
  expressions in terms of $b$?

I can do it for one fixed $b$ at a time like mentioned in $(\infty)$ claim, then find general expressions in terms of $b$ by observing consecutive $b$ values. For example, like I did for $d=3,5,7$.
But I have no ways of proving there aren't any more solutions I have missed.
If it is not possible to directly find (prove all) solutions in terms of $b$ for given $d$, an alternate way that could attack this problem, partially instead:
Start partially solving cases of $d$?

$Q_2:$ Can we give an upper bound on the period $p$ for solutions of
  the infinite families, and an upper bound for the value $b$ after
  which no new families can exist?

For example, for $d=3,5,7$, these periods are exactly $p=2,4,12$, and such $b$ are exactly $b_p=8,47,291$. (True for $d=3$, conjectured for $d=5,7$).
If we can find such upper bounds, the lower bounds can be increased computationally using $(\infty)$ claim, until reacing or surprassing the upper bounds, and thus we can start proving all solutions for one case of $d$ at a time.
Computationally solve (prove) cases of $d$?

$Q_3:$ Is it possible to generalize the approach used to prove $d=3$,
  and make a CAS use it to prove individual cases of $d$ systematically?

But I'm having trouble figuring out how to systematically go over all regularized expressions for given $d$ in an effective and usable way. - Which $o_i,h_i$ combinations make sense to verify for solutions and which ones can we disprove (prove yield no solutions)?

Context of the problem and theory for proving $d=3$ case

The context of the system
The context in which this problem-system arises is, the problem of finding all $3$-palindromes. - Numbers palindromic in three consecutive number bases. We are also requiring them to have $d$ digits in those number bases.
Lets define a number representation in base $b$, but also allow the irregular representations - that the digit are $\in\mathbb Z$ or $\ge b$.
Every number $n\in\mathbb N$ has infinitely many irregular expressions in base $b$, and one unique expression  - the standard regular representation in a number base.
$$n=\overline{a'_1a'_2\dots a'_{d'}}=(a_1,\dots,a_d)_{b}=\sum_{k=1}^{d}a_kb^{d-k}$$
For example: $100=(1,0,0)_{10}=(1,2,1)_{9}=(2,-7,1)_{9}=(11,1)_{9}=\dots$ Where the first two expressions are regular, and the other two are irregular.
From here, we can get the inequalities by definition for some $n\in\mathbb N$:
$$n=(a_i)_b=\sum_{k=1}^{d}a_kb^{d-k}=\sum_{k=1}^{d}a_k((b-1)+1)^{d-k}=\sum_{k=1}^{d}A_k(b-1)^{d-k}=(A_i)_{b-1}$$
Where you expand $a_k((b-1)+1)^{d-k}$ by binomial theorem to get the expressions for $A_i$, which are given at the beginning if you ignore the $o_i$ parameters.
In this case, the representation given by $A_i$ is irregular, unless $A_i<b-1$ for all $i$, but in that case, we cannot have a palindrome in $b-1$ (observe the formula for $A_i$ without $o_i$ parameters).
This means we are working with irregular expression for $A_i$ if we want to find solutions.

Regularizing the representations
This is where $o_i$ parameters come into place. To actually check for the digits $A_i$ to make a palindrome in base $b-1$, they need to be a part of the regular expression.
This means we need to regularize these $A_i$ expressions so they make up a regular representation in number base $b-1$. Only then we can actually verify whether $n$ can be palindromic in $b-1$.
By definition, you can borrow "from" or "to" neighbouring digits, without changing the value of $n$, like so:
$$
n=(\dots,a_t,a_{t+1},\dots)_b=(\dots,a_t+o_{t},a_{t+1}-o_{t}b,\dots)_b
$$
For $o_i\in\mathbb Z$. But since we have observed that $A_i\lt b-1$ does not work assuming $(A_i)_b$ is regular for all $o_i=0$, and since $A_i\gt 0$, we need to reduce the $A_i$ digits to get to a regular representation. Thus, we can work with $o_i\in\mathbb N_0$.
Similar story with $B_i$ and base $b-2$, and "borrowings" to regularize the expression with $h_i$.
If we were working with $b,b+1,b+2$ instead of $b,b-1,b-2$, then $o_i,h_i$ could also be negative, which gives a harder system to analyse.

Claims $(0)$ and $(1)$
From the uniqueness of the regular expression and definition of $o_i,h_i$, the $(0)$ follows easily.
The $(1)$ is true (for the presented system at the beginning), since it can be shown that if a number is palindromic in number base $b$ and has an even number of digits, then it is divisible by $b+1$. This means if we have a palindrome with $d=2l$ digits in base $b-1$, then it cannot be palindromic in base $b$, because of divisibility it should end with $0$, and we have that $a_1,A_1\ne0$.

Solving the system for $d=3$ - proving $(2)$ claim.
Here, the system presented at the beginning is based on bases $b,b-1,b-2$ and works in terms of $o_i,h_i$. By using the definition of irregular expressions, we can avoid writing down $o_i,h_i$ and the system explicitly.
We will first find all $2$-palindromes then extend to $3$-palidnromes. We will do this, by finding all possible regularized expressions for base $b-1$ by going over $o_i$ parameters. Then we will go over $h_i$ just for the now found $2$-palindromes, to again find and check all regular expressions for being a palindrome.
We have that:
$$n=(a_1,a_2,a_1)_b=(A_1,A_2,A_3)_{b-1}=(a_1,2a_1 + a_2,2a_1+ a_2)_{b-1}$$
We will observe two cases:
$1.)\space a_1 \le a_2$, That is, we can parameterize: $a_2 = a_1 + r_1,r_1\in\mathbb N_0$.
Now we can also parameterize the number base:
$$b=\max\{a_1,a_2\}+t=a_2+t=a_1+r_1+t,t\in\mathbb N$$
Like this, since $a_1,a_2$ need to be $<b$, since $(a_1,a_2,a_1)_b$ is a regular expression.
Now we have:
$$
(A_i)_{b-1}=(a_1,3a_1 + r_1,3a_1+ r_1)_{a_1+r_1+t-1}
$$
If we assume $b-1\gt 3a_1+r_1$, then we have a regular expression, but it can't be a palindrome since $A_1=a_1\lt A_3=3a_1+r_1 \implies A_1\ne A_3$.
Thus, $b-1\le 3a_1+r_1$. Now we have an irregular expression. Lets regularize it:
$$
(a_1,3a_1 + r_1,3a_1+ r_1)_{b-1} \\
=(a_1+1,3a_1 + r_1-(b-1)+1,3a_1+ r_1-(b-1))_{b-1} \\
=(1+a_1,2-t+2 a_1,1-t+2 a_1)_{a_1+r_1+t-1} \\
$$
By applying the first case of $o_i$ parameters - By using the "borrowings" to satisfy regularization under $b-1\le 3a_1+r_1$ condition.
Now this is either regularized or not. If you assume not, and continue going for other cases of $o_i$ and regularizing in all other possible ways, you'll every time reach a case with no solutions for $A_1=A_3$.
Thus lets assume this is now regularized.
Thus we need to solve:
$$
A_1=A_3\iff 1+a_1=1-t+2 a_1\iff t=a_1
$$
If you also look at the conditions under which this is regularized, you'll get:
$$
(c_1):\space (1 \le a_1 \le 3 \land r_1 \ge 4 - a_1) \lor (a_1 \ge 4 \land r_1 \ge 0)
$$
We have now solved case $1.)$ for $2$-palindromes. That is, we have solutions:
$$
(a_1,a_2;b)=(a_1,a_1+r_1;2a_1+r_1),a_1,r_1\in\mathbb N\land(c_1)
$$
Or in the context of $2$-palindromes:
$$
(a_1,a_1+r_1,a_1)_{2a_1+r_1}=(1+a_1,2+a_1,1+a_1)_{2a_1+r_1-1}
$$
Now we need to check the expression in base $b-2$ and go over all regular expressions by going over $h_i$ combinations. After now checking these for $B_i$ conditions for base $b-2$, you can show that the final solution to the $d=3$ for case $1.)$ is:
$$ (a_1,a_2;b)=(a-2,a+2;2a),a\ge 4 \lor  (a_1,a_2;b)=(3,6;9) $$
Or in $3$-palindrome context (the first part, the second part is just number $n=300$ in bases $9,8,7$):
$$
(a-2,a+2,a-2)_{2a}=(a-1,a,a-1)_{2a-1}=(a,a+1,a)_{2a-2},a\ge 4
$$
Now, in a similar way, you can handle the $2.)\space a_1\gt a_2$ case, and find all $2$-palindromes in bases $b,b-1$. But when checking for $B_i$ as well, for base $b-2$, there will be no final solutions for $3$-palindromes.
That is, for  $2.)\space a_1\gt a_2$, we can show there aren't any solutions after doing a similar process for $A_i$ and then finally considering $B_i$ conditions as well.
Thus, we can show the final solution for $d=3$ is:

$$ (a_1,a_2;b)=(a-2,a+2;2a),a\ge 4 \lor  (a_1,a_2;b)=(3,6;9) $$

Which agrees with solutions given in $(2)$ claim.

Generalizing the proof for $(2)$ claim?

Is it possible to implement this process in a CAS? To solve for any given $d$ in general?
I've tried in Mathematica, but I'm not sure how to properly go over
  all regular expression.

My idea was to go over all $\frac{d+1}{2}!$ cases of permuting $a_i$ in $a_1\le a_2\le \dots\le a_{(d+1)/2}$.
Now we can parameterize the base $b=\max\{a_i\}+t,t\in\mathbb N$, and every digit in terms of $r_i\in\mathbb N_0$ and $\min\{a_i\}$. Then, what is left, is to go over all regular expressions in each of these cases, and then solve just the system of equalities $A_i=A_{d-i+1}$ now. This will give all $2$-palindromes.
What is left then, is to apply the same process but now only for these $2$-palindromes, and in base $b-2$. We will be again solving just a system of equalities $B_i=B_{d-i+1}$ in every case, for every regular expression in that case.
But I had trouble going over all regular expressions and of keeping track of $o_i,h_i$ that make sense to consider (Not all need to be considered, depending on the sizes and conditions so far on $b,A_i,B_i$), and also getting duplicate solutions for $2$-palindromes in supposedly different regularized expressions. And on top of that, it was running extremely slowly to find the next set of $2$-palindrome solutions for $d\gt 3$.
So I'm not sure how to implement this process properly, or if it can actually work for a general case of $d$ in current CAS that are avaliable?

Generalized system and related problems
This system of inequalities and palindromic equalities, is related to the a bit more general similar system - where there can be more $A_i,B_i$ expressions instead of exactly $d$ such expressions.

The general problem
The generalized inequalities also allows $A_i,B_i$ for $i\le 0$, where then they are just given as:
$$
A_i=o_{i} - o_{i-1} (b-1) \\
B_i=h_{i} - h_{i-1} (b-2)
$$
And if $i_A$ is the smallest such $i$ for which $A_i$ is not zero, and if $i_B$ is the smallest such $i$ for which $B_i$ is not zero, then the system we are solving changes to:
$$
A_{i_A}=A_d,A_{i_A+1}=A_{d-1},\dots \le b-1,A_{i_A}\ne 0 \\
B_{i_B}=B_d,A_{i_B+1}=B_{d-1},\dots \le b-2,B_{i_B}\ne 0 \\
$$
Such that the equalities stay palindromic.
And now these along with given $a_i=a_{d-i+1}$, actually represent equations for digits of a number $n\in\mathbb N$ in number bases $b,b-1,b-2$, which are required to be palindromic in all of those three number  bases, which is the context this system was found in.

Find all numbers palindromic in three consecutive number bases?
That have $d$ digits in number base $b$. In the general problem, number of digits does not need to be equal in all number bases as implied by $i_A,i_B$ - just in the base $b$, where $b-1,b-2$ could have more digits. If $i_A,i_B=1$, that is, the problem-system in this post is given, then number of digits, is required to be equal in all bases $b,b-1,b-2$ and is exactly $d$.

Related problems
Even thought related problems imply the generalized system, all infinite families of solutions that are known so far, are given by the problem-system, $i_A=i_B=1$.
Also note that in the related problems (of mine), it is considered $b,b+1,b+2$ instead of $b,b-1,b-2$, and it is talked in context of palindromes themselves, as those posts predate this system and the $b,b-1,b-2$ approach. - Which is equivalent to $b,b+1,b+2$ in terms of solutions, but easier to work with in the terms of the problem-system.
The related problems and motivation:

The motivation behind searching for these so called $3$-palindromes, is to answer the question, whether there exists a $4$-palindrome?
The solutions from $(2),(3^*)$ were already mentioned in a question that is asking about $3$-palindromes in that context, without setting up a system.

Note that as those questions predate this system and the ability to solve for any fixed $b$ using it in Mathematica - I used to have to run an optimized brute force search in c++ instead, which was exponentially slower and was impossible to be used on bases like $10^9$ which now take similar time as bases $10^2$. - Now the computations are still exponentially related to $d$, but near constant time related to $b$, where they used to be exponentially related to both in a brute force search.

Motivation
Similar systems could be set up for problems that depend on digits of numbers in number bases - or for diophantine equations that can be related to such problems.
Answer: These questions have been addressed here and there. To summarize:
Answer to $Q_1$ and $Q_3$ is Yes as explained in my answer at MO. (3*) is also confirmed there.
As of (4*), I've confirmed that there are no parametric 3-palindromes for $d=9$ and $d=11$. UPDATE: and $d=13$.
Comment: @Vepir: I prefer to keep detailed answers and discussions in a single place rather than making forks and then worrying about making updates (if something new pops up) everywhere.


How to tag content from external databases?

Question: I have an external database with a couple of hundred rows and columns. Is there a way in which I can tag content while or after I import the database to my drupal 7 website? Is there any module already contributed which could be used for this purpose?
Answer: by tagging you mean reference taxonomy terms ?
you could import those rows with the migrate module as nodes, with taxonomy reference (a normal taxonomy field), into your drupal DB.
Comment: the database has a couple of tables but they are not tagged right now. they are just normal database tables. i want to tag them along with migrating them to my drupal DB or just using them externally. But I am not sure how to tag the database if I don't migrate it.
Comment: what do you mean by tag ? / what does the external data represent ?
Comment: thanks for your prompt reply. the purpose for using tag is that I want to implement search functionality that would use these tags to look/search for relevant data and display the fields/rows/columns accordingly. i do not have taxonomy reference right now. the basic way in which I would want to go about the process is (I am not sure if that can be done or not): import the external database into my Drupal 7 website as either custom content types or as a database alone, use content tagging to facilitate search and perform search functionality and have different views for every search criteria.
Comment: drupal search will include everything of the nodes. so i suggest (again) to import your data as nodes (with a special content type), using the migrate module. additionally you can setup a taxonomy vocabulary handling your tags, and add this vocabulary to the new content type. while importing; you can add 'tags' to the newly created nodes.


How to unban a certain player without the use of an admin

Question: So I have a problem. I'm making a datapack in minecraft 1.19 and I want a way to unban players from the server using it. It's supposed to be done by throwing or using a nether star (unban the player whose the item is named after) the datapack basically bans a player  with a certain number of deaths. Also if there's a different, or a better way to do it, please send it here, it will help! Also remember, a different player will unban the banned player, and I need a way to do it without the use of more commands.
Answer: /pardon requires permission level (archive) 3. Functions normally only have permission level 2, but you can define it differently in server.properties:
function-permission-level=3

Once you set that and restart the server, using /pardon in functions will just work like you would expect.
If you don't run a dedicated server, you cannot do what you want, at least not without mods (and I don't know a mod that does this). Another way would be using a "server wrapper" that sends commands to the server console, which has permission level 4, but that would likely require you to write custom software for your usecase (and still only works on a dedicated server).
Comment: No, I know which command unbans the player, I want to make it so a player can unban someone, I dont know how to make it, it can be made by naming the item the name of the player or somehow otherwise. I want the players to get a nether star, so they can use it to unban a player.
Comment: I'm pretty sure that, if the player isn't on the server (and they can't in this case), then you need to use the exact name in the command, you can't use selectors (because they would never match). So if you want it more general, without hardcoding the names, a server wrapper would be the only way, a datapack couldn't do it. Alternatively, you could just not ban players automatically and instead teleport them to some far place.


Is there any way to connect the Database server from Selenium RC?

Question: Does anyone know how to connect DB from Selenium RC? I need to run a lot of user IDs and passwords with different role access. Currently I am using this as data suite with an HTML file.
Answer: Well, I know that Selenium tests can be outputted and run as as JUnit tests. From JUnit you can easily write test infrastructure that connects to your DB and does whatever else you need it to do.
Edit: You're of course not limited to JUnit and Java. You can run Selenium via Ruby, .Net, Python or pretty much whatever you'd like.
Answer: You cannot connect to the database with Selenium RC. Selenium RC is just a small program that listens on a port and does things to the browser. It does not know about where the data you are testing comes from.
As Mike said above, you can export or write your tests either in your favorite programming language or some testing framework. This allows you to create a DB connection, preload your database with data (like your users/roles) and do your tests in a more dynamic and maintainable fashion.


Adobe Premiere is slow. Please recommend

Question: My Adobe premiere is slow running on my pc. Playing video slow, edit text slow.
Below is my computer spec. What else can I upgrade so my Premiere can running fast.
Answer: You seem to have a low-end $50 GPU on a low-to-mid range Windows PC (Core i5) with the bare minimum of RAM (24 GB). I'm betting you're using a "spinning rust" drive instead of an SSD as well.
If you're serious about video editing, you should START with the recommended requirements described at this link: https://helpx.adobe.com/premiere-pro/system-requirements.html
A "decent" system for Premiere will typically have an nVidia Quadro GPU, possibly 2 of them.
Premiere will take all the hardware you can give it and still come back for more. Adobe gives short shrift to non-CUDA GPU. Plan on buying at least an $800 GPU for serious editing work.
Please describe the type of video work you want to do. Premiere requires a serious investment to get real work done, but you may be able to use a lesser tool for what you need to do. Nowadays I tell a lot of beginners to get an iPad Pro and use iMovie or LumaFusion, or on Windows - Camtasia/Vegas.
Comment: I can't agree that you need a Quadro.  GeForce cards will give more bang for the buck if you don't need high precision floating point for 3D rendering work.  You also definately don't need dual GPUs for a "decent" system.  I use Resolve rather than Premiere, but a single GTX1080 is enough to edit 4K raw video in real time.  You can get by with a $450 or so graphics card to be "decent".
Answer: Depending on what you are working on, your RAM is probably fine.  More would help with RAM preview in AE and would help if you have buffering issues, but mostly you have a GPU and CPU problem.
GPU is underpowered by a lot.  Getting at least a $450-$500 GTX card would significantly boost your mercury playback engine support.  CUDA capable GPUs will give you the most bang for your buck in general.
Hard drive, if you don't have SSDs is also a huge limiting factor depending on what your working with for video.  If video can't transfer to/from the drive fast enough to supply Premiere, then it is going to stutter while it waits for the data to load.  Magnetic drives can't read from random locations well and if they have to read multiple video files and renders at the same time, it will have to do a lot of seeking that absolutely destroys the data retrieval speed.  SSDs, even a fairly slow one, remove this limitation and greatly improve performance.  Probably not quite as much as improving the graphics card, but if you have to choose between a $450 graphics card and an SSD or an $800 graphics card and no SSD, I'd take the $450 graphics card with an SSD (or preferably a few SSDs.)
The i5 is also a bit limiting.  There's a lot of media related instructions supported on the i7 and i9 CPUs that are not supported by the i5, resulting in more work having to be done when things are offloaded to the CPU rather than CUDA cores.  Overall this is probably a much smaller limitation than GPU and file I/O though.


why are my plants all dying? cucumbers, spaghetti squash and flowers?

Question:
I just planted them last week, I watered them everyday until I saw that they were starting to die. some of the leaves are crispy, some of them are limp and soft. So I am not sure if I need to water them more or to water them less? I thought maybe they didn't get good oxygen from the soil. I bought the soil from the same nursey that I got the cukes from. did I need to mix the soil with mulch or something? I'm just trying to not kill everything. my flowers are also dying. the second I planted them they all started dying.
Comment: Do the containers have drainage holes in them?
Answer: In your first two pictures, it looks like you planted the seedlings too deep. The top of the compost that the seedling was growing in should be level with the soil surface when you transplant it. The pictures seem to show individual leaves poking out of the soil rather than a single stem of the plant, which looks like you "buried" the original plug of compost in the soil.
If that is what you did, the base of the plant stem will rot where it is buried in damp compost, which will kill the plant.
It's hard to see what went wrong with your flowers, from your photo looking straight down.