Prevent folder selection button from displaying in ArcGIS model tool?

Question: I've created an ArcGIS tool using ModelBuilder, 10.3.1.  One of the inputs must be a numeric value typed in by the user.  Thus there is no need for the model to display the default folder selection button for that input (see the red X in the attached screen shot).  How do I remove the button so that the user is not tempted to click it?
Comment: Call it a string or number instead of a folder. How is this value used in the model? Is it a variable? if so you can change the type from 'folder' to 'integer' or 'double'.
Comment: @MichaelMiles-Stimson, with a little more information, you could post this as an answer.
Comment: @Fetzer, I had used the default data type - "Any Value".  Based on the comments from you and MichaelMiles-Stimson, I figured out how to change the data type, and I now have it set to "Double".  That solved it, thanks!  The dreaded button is now gone. I was not aware of this data type setting, so it's nice to learn something.  Feel free to post it as an answer and I'll give you credit.
Comment: @Fezter, I have enough information now to answer the question.
Answer: Model builder parameters have a Type and depending on that type the display and behavior on the tool interface is set.. for example if you set the parameter as 'Feature Class' the browser will only browse for feature classes, either shapefile or geodatabase and not allow numbers, files, folders or drives as input.
You're getting the folder browser because your parameter is set to a type that can be browsed for. Depending on how you create the parameter it is possible to specify the type for variables (right click on blank space, select create variable) but not so much for tool parameters (right click on an oval, select Model Parameter) as the tools themselves have determined the type they expect.
There are limits on how much you can change a variables' type, once created, for a radical change like folder to integer it might be better to remove the parameter and recreate it with the correct type... of course you can change the type to 'any value' but this could cause problems later if you're expecting a number and get a string instead.
For more information read A quick tutorial on creating a model with parameters.


decision making process

Question: I have applied in Munich, Germany to have a tourist visa to visit UK.
Usually, from experience, how long does it take to have the decision made?
I have tracked my visa through TLS.
Thanks in advance!
Answer: According to the statistics published by the UKVI service (which you can find here) 99% of tourist visas handled through Munich in August 2018 were decided in 15 days, with 100% being decided within 30 days.
Note that these are actual figures for actual visa applications. Some visas take longer than others so this is not a guarantee that your application will necessarily be decided as quickly.

decision making process


Jobs profile settings not maintained from initial setup

Question: When I set up my Jobs profile, I indicated that I was "Not looking" but when I went back just now and took a look at my CV it lists me as "Open, but not actively looking".
Comment: This is the second report we've received about this. We're looking at it this morning. Sorry for the inconvenience.
Answer: Thanks for your report. This has now been fixed.
Back in the day, whenever you submitted your CV for review using the form below,
you were also opting in to our candidate database and we automatically changed your job search settings from "not looking" to "passively looking for a job".

The signup/opt in workflow has changed a lot since, and this automatic change of job search state no longer makes sense. I deleted the code and we will not change the job search state settings on your behalf anymore.
Feel free to update your settings back to Not Looking <3


What is the process of making a black lightsaber/Darksaber?

Question: In Star Wars: The Clone Wars and Star Wars: Rebels, we see a Black lightsaber much like a real sword or katana and it was supposedly stolen from the Jedi hundreds of years prior to the Clone Wars by the Mandalorians. But what I don't know is how did it turn black because we all know a red lightsaber turns red by the process of making a kyber crystal bleed known only unto the Sith. So what makes a lightsaber black? And how did it get its Katana like shape, unlike the cylindrical round shape of normal lightsabers?
Comment: This is called the Darksaber.
Comment: http://starwars.wikia.com/wiki/Darksaber
Comment: https://www.youtube.com/watch?v=K7HGafpav4U - Warning *Rebels* spoilers.
Comment: Since it was a rebel lightsaber, wouldn't it just have been made and had that color, although being very rare, because rebels do not choose their color of lightsaber.
Comment: Step 1, call marketing budget. Step 2, profit
Answer: I think that the darksaber isn't made from a kyber crystal. It is reasonable to assume since it is a Mandalorian weapon, that it doesn't require a force wielder to use it effectively. This is pointed out when Darth Maul fought Tor Visla (leader of the Death Watch who had the darksaber) for the leadership of the Death Watch and the blade. This was after the days of the Old Republic, when the darksaber was used to combat the Jedi. Maul with the blade also makes appearances in the Star Wars Rebels TV series. As far as for how it's made, only the Jedi Archives could tell us...


How to improve t2i video crop mode 640x480 with a zoom?

Question: This mode is an 8x multiplier. So a 500mm lens looks like 4000mm. The only problem is the wind. How do you keep the camera completely still on a heavy tripod and light winds?
Comment: Mod note: while [video questions are off-topic here](https://photo.meta.stackexchange.com/questions/28/can-i-ask-videography-related-questions), I'm going to leave this one because the vast majority of the recommendations apply equally to shooting photos.
Comment: Does this answer your question? [How do I keep my tripod mounted camera steady in strong winds?](https://photo.stackexchange.com/questions/48020/how-do-i-keep-my-tripod-mounted-camera-steady-in-strong-winds)
Comment: Curious are Timelapse questions allowed? It is a series of images a second apart in some cases, in a video file format.

Has anyone else tried the mode in the title with a long lens? A t2i is required. Are there any other camera brands with this feature? Which models?
Comment: There's never been a "bright line" as to what is a "photography question" and what is a "video question"; timelapse questions have always been somewhere on that boundary and will be treated on a case-by-case basis. Questions _only_ about a video crop mode are certainly off-topic though.
Comment: Some new ideas there thank you. The difference is I'm in video mode. The vibrations appear different they are not just blur. Harder to remove in post than stopping up front. Even the lightest breeze has an effect at 8000mm. It seems that stopping the light breeze completely with an obstacle is the best idea so far, in my testing.
Answer:
Keep the tripod legs as short as possible.
Use a heavy tripod (you already mentioned you are using a beefy tripod). If it costs under USD 150, it isn't beefy. The tripod head also needs to be beefy. Plastic tripod heads aren't stiff enough.
Balance your camera/lens. Many long lenses have a tripod collar which balances the weight. With a catadioptric lens, you don't have that option.
Block the wind. Trees, walls, cars, ... all make good wind blocks.
Tie a weight to the tripod. Many tripods have a hook or ring on the bottom of the center column for this purpose. The weight must touch the ground so the wind doesn't move the weight. Lots of tutorials on the Internet on using weights (sand bags) on tripods for stabilization.
You can perform stabilization in post processing. For free and not easy to use, FFMPEG. There are many video editors with stabilization features.
With a long lens, heat waves can look like a stability issue. Be sure you aren't experiencing this.
Comment: Some cat lenses do have a tripod collar.  At least one (soviet design) also has changeable aperture. // Gimbal heads help with balancing the camera and lens.
Comment: My cat lens does Tamron SP 500
Comment: I have tried all of these suggestions which do work in normal circumstances. But not beyond 4000mm. Post processing image stabilization does not fix this kind of movement because sometimes it is extreme even in light wind.
Answer: A few more tips/ideas:

Use tent stakes and bungee cords to pull each leg straight down at
the knee.
Jam a monopod taught under the lens of the
already-tripoded camera. A square of mousepad foam or a bean bag can
help.
Don't use a tripod, but a tree and bungee straps and beanbags.
If you don't have beanbags, fill a sock halfway with rice and tie the
ankle.
Put the tripod inside a tent, which blocks the wind. Ice
fishing shelters and duck blinds work too and don't have floors, if
you want to tent stake the legs.
Comment: I have used a sturdy cement wall! Love your tent idea!


Find the matrix of linear transformation.

Question: Find the matrix (in standard base) of the linear transformation $T$:
$R^{4}\rightarrow R^{4}$, given:
$$Ker(T)=lin \{ |2,1,1,2|^{T}, |1,2,1,1|^{T}\}  \\
Im(T)=lin \{ |1,0,1,0|^{T}, |0,1,1,1|^{T}\}  $$
I'm not exactly sure how to approach this problem. Could anyone explain how to solve this?
Answer: First solve the simpler version of this:
$\ker T = \operatorname{span} \{e_1, e_2\}$ and
$\operatorname{im} T = \operatorname{span} \{e_1, e_2\}$. Call the matrix that you get from solving this problem $A$.
Then once you find $A$, find change of basis matrices $P$ and $Q$ with the property that $P$ takes the basis for the kernel to $e_1$ and $e_2$ and $Q$ takes the basis for the image to $e_3$ and $e_4$.
Express the matrix that you want in terms of $A$, $P$, and $Q$.
Answer: First, the cannonical base of $\mathbb{R}^4$ is $\{(1,0,0,0),(0,1,0,0),(0,0,1,0),(0,0,0,1)\}$. You can define a linear transformation by defining what it do to the base. But it will be hard using directly the standard base, so that we will complete $\{(2,1,1,2),(1,2,1,1)\}$ (this set is l.i. so we can do the completion)(note that this will be useful because we will define $T$ to be zero in $\{(2,1,1,2),(1,2,1,1)\}$ and to take $T$ into the wanted image), we take the $\mathbb{R}^4$ base $\{(1,0,0,0),(2,1,1,2),(1,2,1,1), (0,0,0,1)\}$ (if you have trouble finding this you can ask me). So we define:
$$T(1,0,0,0)=(1,0,1,0),$$
$$T(2,1,1,2)=(0,0,0,0),$$
$$T(1,2,1,1)=(0,0,0,0),$$
$$T(0,0,0,1)=(0,1,1,1).$$
Now, we have to compute the value of $T$ at the vectors $(0,1,0,0),(0,0,1,0)$. In fact, we have that: $(0,1,0,0)=(1,2,1,1)-(2,1,1,2)+(1,0,0,0)+(0,0,0,1)$, since $T$ is lineal, we have that:
\begin{align}
T(0,1,0,0) & = T(1,2,1,1)-T(2,1,1,2)+T(1,0,0,0)+T(0,0,0,1) \\
           & = T(1,0,0,0)+T(0,0,0,1) \\
           & = (1,0,1,0)+(0,1,1,1) \\
           & = (1,1,2,1).
\end{align}
And $(0,0,1,0)=(1,2,1,1)-(1,0,0,0)-(0,0,0,1)-(0,1,0,0)$, so that:
\begin{align}
T(0,0,1,0) & = T(1,2,1,1)-T(1,0,0,0)-T(0,0,0,1)-T(0,1,0,0) \\
           & =  -T(1,0,0,0)-T(0,0,0,1)-T(0,1,0,0)\\
           & = -(1,0,1,0)-(0,1,1,1)-(1,1,2,1) \\
           & = (-2,-2,-4,-2).
\end{align}
Summarizing the above, we have obtained:
\begin{align}
T(1,0,0,0) & = (1,0,1,0) \\
T(0,1,0,0) & = (1,1,2,1) \\
T(0,0,1,0) & = (-2,-2,-4,-2) \\
T(0,0,0,1) & = (0,1,1,1).
\end{align}
Therefore, we have that $im(T)=\mbox{span}\{T(1,0,0,0),T(0,0,0,1)\}=\mbox{span}\{(1,0,1,0),(0,1,1,1)\}$. And the kernel is $\mbox{span}\{(2,1,1,2),(1,2,1,1)\}$ as required. And,
$$\left[T\right]_\beta^\beta=\begin{pmatrix}
1 & 1 & -2 & 0 \\
0 &  1 & -2 &  1 \\
1 & 2 & -4 & 1 \\
0 & 1 & 2 & 1
\end{pmatrix},$$
where $\beta$ is the cannonical (i.e. standard) base of $\mathbb{R}^4$ over the field $\mathbb{R}$.
Note: For that matrix we have to fix an orden in the basis that's being used.
Comment: I have trouble understanding two steps. First of all why are we taking {(1,0,0,0),(2,1,1,2),(1,2,1,1),(0,0,0,1)} as a base and not for example {{0,1,0,0),(2,1,1,2),(1,2,1,1),(0,0,0,1)} (it's l.i. and has 4 elements so it's a base too). Secondly, why T transposes necesarilly (1,0,0,0) into (1,0,1,0) and (0,0,0,1) into (0,1,1,1) and not for example the other way around?
Comment: If I understand this correctly there exist infinite number of such transformations (that have `ker(T)=...` and `Im(T)=...`). You have defined `T` in that particular way for the sake of convenience. Choosing  {{0,1,0,0),(2,1,1,2),(1,2,1,1),(0,0,0,1)} as the base would also lead us to some solution (altough the final matrix would be different). Am I correct?
Comment: Hm, there is not reason to taking mine or yours, it don't care :). The main idea is completing $\{(2,1,1,2),(1,2,1,1)\}$ and then sent those vectors to zero (for having the required kernel), and the others 2 (in the order you want) respective to the generators of he image required. There are different ways of do this, in fact if you take a different order of the basis you'll get a different matrix


Quickest way to obtain astral diamonds

Question: Is there a quicker way to get astral diamonds other than to do daily quests?
I am currently lvl 30.
Answer: The Auction House is potentially the best way to gain Astra Diamonds.  However, like anything that requires human interaction, there isn't assured success in selling the items.  That said, the dailies you get are your best bet.
It should also be noted that there is a limit of 24k AD that you can refine each day.  So no matter how many dailies you do, you can still only gain 24k AD from said dailies (as all of the rewarded diamonds for dailies are "rough" and require refining").
There are a lot of ways to get AD, but most of them offer small amounts (for instance, Foundry tips).
Answer: Crafting and selling on the AH.
Shirts and Pants don't drop, they need to be crafted.  Most people don't know this. I've been monopolizing high level shirts/pants for TR and CW for the past week.
My AD is over 4 mil, and I haven't done dailies since level 20ish.
Also, using Gateway, you don't even need to be online to do this.  I expect 10% of your sales, now. ;)

Quickest way to obtain astral diamonds


Leveling-up while Sanctuary is inaccessible in TVHM

Question: I have finished Normal mode, and went through True Vault Hunter Mode until Sanctuary lifts off. I now have a problem leveling up an reaching Sanctuary again. My sub missions are all done, except for those I can not complete yet. I can't level up in True Vault Hunter Mode because the missions must be turned into sanctuary. I struggle to get the Fast Travel Beacon without dying, so I don't have sanctuary on my map.
How can I level up quickly in this situation?
Comment: Are you saying you've went through True Vault Hunter Mode until when Sanctuary disappears?
Comment: Or you have just started TVHM?
Comment: After where you defeat willhelm the sanctuary moves to the sky.. All the loaders and stuff are between level 40 and 42 so I want to level up I did the missions but it must be turned in sanctuary.. And sanctuary isn't on my fast travel map becaus I need to activate the beacom but struggle to get the beacom and all the enimies in normal mode is too weak.. I want to level up quickly
Answer: It seems to me that your key problem is getting Sanctuary back.
I'm not clear on where you're getting stuck, but it's probably one of two big fights:
1. The Gluttonous Thresher
This is the fight to obtain the lunar beacon from the Hyperion dam area in The Highlands - Outwash. The Gluttonous Thresher ate the beacon, and you have to beat it out of his carcass.
There is very much a right way to beating this monster thresher:

Run out into the area where it spawns.

As soon as you see or hear the thresher, perform a rapid strategic withdrawal. (i.e. Run away.) You want to get back through the door and out onto the big industrial "dock" area.
If you're playing an Assassin or a Commando, use your action skill to distract the thresher to ease your getaway.

Once through the big door, find some cover. I use the big containers sitting on the left side of the dock as you exit the big door. (You could also cross the river on the retractable bridge and use the cover over there.)
The thresher will chase after you, but will stop just past the big door, not going past those K rail barricades to one side of the big door. This is the key to this strategy: the cover you're using is outside the range of the thresher's tentacle attacks, and it is the tentacles that make the Gluttonous Thresher fight so difficult if you fight it where it initially spawned.

You will want a shock weapon in this fight, because the Gluttonous Thresher has a crazy-fast shield regeneration. You need to zap the shield away before you can start knocking its health back down again.
2. The Robot Fight In Overlook
After you get the beacon, you're asked to take it back to Overlook where it's used to summon a fast-travel station.
This is also a tough fight. There's not as much of a single right way to fight this one, but again, cover is the key. I typically hide behind the grinder while reloading and waiting for my shield to regenerate. It's good solid cover that you don't have to duck behind to get full benefit from, and you need to be nearby anyway to repair the beacon several times during the fight.
This strategy doesn't work as well against the loaders as it did against the Gluttonous Thresher. Primarily, this is because the robots drop into Overlook at two points, 90° from the grinder. This means that while you're fighting one cohort, the other — which you're protected from — is marching closer to the grinder. You thus have to keep running around behind the grinder to pound on each cohort separately, lest one of them overrun the grinder, denying you benefit of its cover.
I've gotten a lot of use out of my Rolling Thunder grenade mod in situations like this. Any homing grenade can help, too, since you can just throw a bunch of them as you run behind cover, which keeps the robots busy while you recover.
Comment: OP says he has problems with Fast Travel Beacon, so he must be past that Thresher already. Is he retryable, and any good experience-wise?
Comment: @OrcJMR: I think my original read is correct, because what you're talking about is a Fast Travel *Station*, while the Beacon is the step before you get the Station. Still, I've addressed that second fight now, too.
Comment: Oh, right, you've got to *retrieve* the beacon first... Indeed, I was probably less accurate a guess than you!
Comment: But I want to level up to level 40 or 41 before fight the thresher because than I can go back to normal mode in sanctuary to get beter guns to fight of the thresher and those loaders I got a lot of golden keys.. But won't get stronger guns till I level up.. My strongest is a 63000 rpg.. And to go back and kill bandits or loaders takes too long I want to level up faster
Comment: You're backing yourself into a corner here. You want to level up fast but the fastest way to level up is to complete missions, not kill individual enemies. The only other way out of that trap you've made for yourself is to play through one of the DLCs. Hammerlock's Big Game Hunt is appropriate for your level, and since you're in the DLC, you won't need Sanctuary to finish missions. Tiny Tina's DLC is also good for a lot of XP.
Comment: @WarrenYoung That's only assuming he has the DLC's though.
Comment: @DomenikVanBuskirk: Your point? OP says he wants to level up quickly without the ability to complete mainline missions. Solution: Add more missions outside the story line. If he's not willing to do that, he's stuck. Period.
Comment: @WarrenYoung My point is that the only solution you offered may not be available to the OP.
Comment: Thanks you but I connected a other pc with lan and kept him there so the threshers health doesn't regenerate and defeated him if got the beacom went to overlook but quit and saved


Light trough the object on render

Question: I have lamp model and point light inside of it. You can see lights on preview, but i can't see the lights on render. How to make them glow correctly?
Answer: There are numerous possibilities as to what causes this. I tried to list them in order of likelihood

your material for the lamp's glass material does not look transparent (you can set it to translucent, but be ready for some serious noise)
your lamp is too weak for cycles
your lamp's cycles visibility options don't make it show up where it's supposed to illuminate.

There's more, but please make sure the ones above don't apply and if not send another screenshot with the lamp selected, meaning showing its settings as well as its place in the outliner.
Answer: I do not have your blend file so i can not tell you exactly what can be the reason but still
I think you have not added correct Material for lamp glass
you should add translucency in it so that light can be visible out of the lamp with glow.
and also try reducing the size of point light

Light trough the object on render


This case falls into usage, not grammar?

Question: punch1 /pʌntʃ/ ●●● S3 verb [transitive]
1 HIT to hit someone or something hard with your fist
If I don't hit someone on my fist but I hit someone far from my fist with the other means (for example, with a gun), isn't it against grammar but is it just against usage?
I quoted the definition to restrict the meaning of 'punch.'
Answer: Neither. There are a lot more meanings of punch than you quote so your question starts from a false premise.
I can put a mark onto a sword with a metal punch.
I can drink a fruit punch.
I can use a gun to punch a hole in the bad man.
I think you might have a meaningful question to ask but what you did ask doesn't mean anything.
Comment: Note that the middle example is not a different sense of "punch" but an etymologically unrelated word, that happens to have the same spelling and sound.  A fruit punch comes from Hindi, meaning "5" (as they originally were a mix of five ingredients)
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/116756/discussion-on-answer-by-jwpfox-this-case-falls-into-usage-not-grammar).
Answer: A sentence can be grammatical but nonsensical or meaningless; perhaps the most famous example is "Colorless green ideas sleep furiously", made up by Noam Chomsky. It is grammatically well-formed: it obeys all the rules of English grammar (for instance the verb "sleep" agrees with the subject "ideas"), but what does it mean? Nothing as far as either I or Chomsky can tell.
Similarly a sentence like "He punched me with his hair" or "He punched me over the telephone" might be considered nonsensical, or interpreted in a metaphorical way. Punch typically refers to hitting with a fist, although it can be used for other similar motions, but it would require something hard that makes a firm impact (e.g. a hole punch, a leather punch, etc). It would be correct to say that the word "punch" is misused.


Where did the question concerning YHWH/Elohim being part of the Egyptian/Canaanite pantheon go?

Question: I'm sure that one of these questions was decent among all the guff that was appearing on here yesterday? Did it get deleted? Was it off-topic and if so why?
Answer: I deleted them. Each had been closed already, and each were far enough off-topic that there was little hope if editing them into shape. That's evidenced by the closure by the community and,the amount of down-votes.
Cleaning up low quality content by deleting it is standard operating procedure on all StackExchange sites.
In each case, I left a comment for the OP and they are more fully aware of the reason for deletion. I see no need to go further in explaining the action with the community at large. The OP has a more full explanation already. If the OP disagrees or has an issue with it, they can take it up with the moderators by flagging or posting here themselves.
Because the goal of moderation is to keep the site healthy and to help new members fit in, I've also provided links to the help page and various Meta post to help explain what's on topic and how to participate constructively if they choose to do so in the future.
If the OP has any interest in participating constructively, they're more than welcome to edit the questions to be re-opened, or to post new ones that are on-topic and serious.
Comment: Fair enough. I was preparing an answer - never mind.
Comment: There was one left from your cleanup that I deleted after you left. It was the best of the bunch but it still had all the properties you cite and I deleted it for much the same reasons. It wasn't going to go anywhere.
Comment: I think the OP is back, and is creating lots of accounts. Can you check IPs?


Are fairy lights safe if you cut or break the wire?

Question: My string of fairy lights I have got old and somehow the wire at the end broke and fell off. The lights still work, but is it safe to use with that broken wire?
Comment: How are these powered? 120V, 240V, low voltage AC or DC converter? Can you post a picture of the problem wire?
Answer: Your lights may be fine but the end needs to be taped for several reasons. First if 120v or higher an exposed wire could lead to a electrical shock or worse. Second the exposed ends could short together tripping the breaker and causing further damage to the conductors and or insulation. Third if the hot conductor contacts another electrical device that may damage that device and trip the breaker, so putting insulation in the form of tape or wire nuts on the ends will probably make it safe but without a picture it would be difficult to say more.


Did Leto I know about the Gom Jabbar test given to Paul?

Question: In the beginning of Dune, Paul is threatened with being killed if he fails the test of the Gom Jabbar.  Jessica knew about it, but did Leto? If so, why did he allow it?
Answer: It seems unlikely that the Bene Gesserit breeding program would have remained a secret for so many generations if they had been in the habit of letting the nobility know about their tests and movements. As with any long term experiment involving humans the loss of secrecy would likely have been fatal to the breeding program or at the very least would have allowed recalcitrant Houses to use their gene lines for political leverage over the Sisterhood.
Granted it is a slightly abnormal situation as we are told that Jessica genuinely loves Leto and was willing to interfere with the breeding program for him. Nevertheless it seems unlikely that she would jeopardise her relationship with the Duke by admitting that she was allowing potentially fatal experimentation to be carried out on their only son by the Bene Gesserit.
Answer: It is never mentioned in the book itself  so on the surface, no Leto I did not know about the Gom Jabbar test on Paul. It would be safe to say that given everything else going on, the move to Arrakis, the plots against him or even that the Reverend Mother was on Caladan, that Paul and Jessica kept this information from him. It is not even known how much information the 'public' knew about the Bene Gesserit and their quest for the Kwistz Haderach so the fact they were there to test Paul remains a mystery.
We are in a universe of Dukes and Barons and Emperors it is, much like Star Wars, a very brutal world (such is Paul's constant arms training and poison snooping) it would be surprising if no one of the Dukes staff knew about this visit let alone what it was for.
Answer: I doubt it. Jessica was still loyal to the BG, even if she was torn a bit due to her love for Leto. I doubt Leto was even aware that Paul was receiving Prana Bindu or any BG training of any kind, as the details of such are closely guarded secrets of the BG. Jessica never could completely let go of her loyalties to the Bene Gesserit. But before the events of Dune she was much more loyal than after.
It's said in Children of Dune that the ability of the Bene Gesserit to control their bodies on a molecular level is kept secret out of fear for what would happen if the population heard about their ability to stop their aging. They were so afraid of this jealousy that they wouldn't use the ability, and would assassinate any member of the BG who did use it. All non-BG trained people seem to know is that the BG are "witches" and have a "weirding way", but no details as to what those actually are. The only specifics people outside of the BG seem to know about their abilities is Voice, and their abilities as truthsayers, and the former only seems to be known to nobility such as the Baron.


Photos storage on iPhone

Question: How do I know what photos have been downloaded to Photos on my iPhone? Does Apple continuously remove the copies from my local device after a period of time so that I don't run out of space? E.g., I have 80Gb iCloud storage taken up by Photos. I browse my photos through the iPhone Photos app and it downloads images that I linger on. I only have 12Gb space in total available on my iPhone, will I run out of space in the near future or are these downloads removed and reverted to thumbnails at some point?
Answer: Yes, your iPhone will remove originals that you have not browsed recently, and then re-download them when you next look at them. If you want to learn more about it, lookup a cache. With the new Photos app, the originals are stored in the cloud, and the images on your phone are just a cache. (Except that when you edit a photo in the cache, Apple preserves both the original and the edits in the cloud.)

Photos storage on iPhone


Oracle Floats vs Number

Question: I'm seeing conflicting references in Oracles documentation. Is there any difference between how decimals are stored in a FLOAT and a NUMBER types in the database?
As I recall from C, et al, a float has accuracy limitations that an int doesn't have. R.g., For 'float's, 0.1(Base 10) is approximated as 0.110011001100110011001101(Base 2) which equals roughtly something like 0.100000001490116119384765625 (Base 10). However, for 'int's,  5(Base 10) is exactly 101(Base 2).
Which is why the following won't terminate as expected in C:
float i;
i = 0;
for (i=0; i != 10; )
{
    i += 0.1
}

However I see elsewhere in Oracle's documentation that FLOAT has been defined as a NUMBER. And as I understand it, Oracle's implementation of the NUMBER type does not run into the same problem as C's float.
So, what's the real story here? Has Oracle deviated from the norm of what I expect to happen with floats/FLOATs?
(I'm sure it's a bee-fart-in-a-hurricane of difference for what I'll be using them for, but I know I'm going to have questions if 0.1*10 comes out to 1.00000000000000001)
Answer: Oracle's BINARY_FLOAT stores the data internally using IEEE 754 floating-point representation, like C and many other languages do.  When you fetch them from the database, and typically store them in an IEEE 754 data type in the host language, it's able to copy the value without transforming it.
Whereas Oracle's FLOAT data type is a synonym for the ANSI SQL NUMERIC data type, called NUMBER in Oracle.  This is an exact numeric, a scaled decimal data type that doesn't have the rounding behavior of IEEE 754.  But if you fetch these values from the database and put them into a C or Java float, you can lose precision during this step.
Answer: The Oracle BINARY_FLOAT and BINARY_DOUBLE are mostly equivalent to the IEEE 754 standard but they are definitely not stored internally in the standard IEEE 754 representation.
For example, a BINARY_DOUBLE takes 9 bytes of storage vs. IEEE's 8. Also the double floating number -3.0 is represented as 3F-F7-FF-FF-FF-FF-FF-FF which if you use real IEEE would be C0-08-00-00-00-00-00-00. Notice that bit 63 is 0 in the Oracle representation while it is 1 in the IEEE one (if 's' is the sign bit, according to IEEE, the sign of the number is (-1)^s). See the very good IEEE 754 calculators at http://babbage.cs.qc.cuny.edu/IEEE-754/
You can easily find this if you have a BINARY__DOUBLE column BD in table T with the query:

select BD,DUMP(BD) from T

Now all of that is fine and interesting (maybe) but when one works in C and gets a numeric value from Oracle (by binding a variable to a numeric column of any kind), one typically gets the result in a real IEEE double as is supported by C. Now this value is subject to all of the usual IEEE inaccuracies.
If one wants to do precise arithmetic one can either do it in PL/SQL or using special precise-arithmetic C libraries.
For Oracle's own explanation of their numeric data types see: http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/datatype.htm#i16209
Answer: Oracle's Number is in fact a Decimal (base-10) floating point representation...
Float is just an alias for Number and does the exact same thing.
if you want Binary (base-2) floats, you need to use Oracle's BINARY_FLOAT or BINARY_DOUBLE datatypes.
link text
Answer: Bill's answer about Oracle's FLOAT is only correct to late version(say 11i), in Oracle 8i, the document says:

You can specify floating-point numbers with the form discussed in
  "NUMBER Datatype". Oracle also supports the ANSI datatype FLOAT. You
  can specify this datatype using one of these syntactic forms:
FLOAT specifies a floating-point number with decimal precision 38, or
  binary precision 126. FLOAT(b) specifies a floating-point number with
  binary precision b. The precision b can range from 1 to 126. To
  convert from binary to decimal precision, multiply b by 0.30103. To
  convert from decimal to binary precision, multiply the decimal
  precision by 3.32193. The maximum of 126 digits of binary precision is
  roughly equivalent to 38 digits of decimal precision.

It sounds like a Quadruple precision(126 binary precision). If I am not mistaken, IEEE754 only requires b = 2, p = 24 for single precision and p = 53 for double precision. The differences between 8i an 11i caused a lot of confusion when I was looking into a conversion plan between Oracle and PostgreSQL.
Answer: Like the PLS_INTEGER mentioned previously, the BINARY_FLOAT and BINARY_DOUBLE types in Oracle 10g use machine arithmetic and require less storage space, both of which make them more efficient than the NUMBER type

ONLY BINARY_FLOAT and BINARY_DOUBLE  supports NAN values

-not precise calculations

Oracle Floats vs Number


Using standard edit pages in Force.com Sites

Question: I want to create a form which is available externally, and allow unauthenticated users to create records.  Is there a way to use standard edit pages in a Force.com site, or can you only display VF pages?
Comment: Is it a custom object data? provide edit access to the object for guest user profile
Answer: The standard detail and edit page are not available in Force.com Sites for guest (unauthenticated) users.
If you want to create a form to submit records (something like your own Web-to-Case) you'll need to create a Visualforce page and then add the page to your site.


Are praying and listening to stories supposed to make dwarf non-idle?

Question: I use the idle count to check if I need to re-assign some dwarfs to a intensive task that is currently on the queue, but that number lately is <10 so I was presuming that my dwarfs are all being productive... nope, they aren't. I counted 24 of my dwarves listening the amazing tale of how a dwarf ceased being the manager of some fort. Apparently it was interesting. Anyhow, are dwarf listening histories and the like supposed to be counted as non-idle?
Comment: Thought the new bits/activities added this last release were supposed to fall under the same logic as breaks or parties.  So, yeah, not idle, but wasting time, in the usual fashion.  Not actually played this release yet though, so not certain.
Comment: Looks like it might be bugged as there's two worship jobs. 'Worship' which actually reduces the need for worshipping, and 'Worship!' which doesn't work correctly and so the dwarfs are never satisfied. Source: http://www.bay12forums.com/smf/index.php?topic=154219.0 - Basically if they're stuck with the second one, the dwarfs will never finish. Otherwise worshipping will be a quick task like having a drink or eating I'd presume.
Comment: @djsmiley2k interesting. I saw a few of them also "Listen story!", but since the story teller ended they stopped doing it. Through, then they moved to "Socialize!".
Comment: Yup, some 'event!' items split into multiple branches appently, and this is what's breaking. The 'Praying' job doesn't do this (and maybe Listen Story!' too).
Answer: Yes, the idle counter is meant to show you how many dwarves are sitting around waiting to do something. The new "jobs" like listenting to stories are essentially the new way that dwarves sit around and socialize so the idle counter has become less reliable than it used to be because of how much more common socializing is. My guess is that toady will eventually change it to include socializing dwarves to be a better measure of how many dwarves are working.


What's The Most Dangerous Chemicals I Can Make From Air?

Question: Let's say that I have a special sword that has macroscopic maximum thickness, and has a minimum thickness of 1 atom. It's also incredibly wear-resistant, which would make it usable. Let's say that I swing it about through Earth's atmosphere, which is 78% nitrogen, 21% oxygen, and contains trace elements like carbon dioxide and water. The sword is 2 m long, and light enough to be lifted. With a blade that cuts chemical bonds, what's the most dangerous chemicals I can produce with that sword alone?
Comment: I'm reasonably confident that the sword wouldn't cut molecular bonds. The molecules will elastically rebound from a blade even an atom thick. After all, the molecules are themselves an atom thick in profile, and colliding with atom-thick particles at great speeds all the time. It's not impossible, but stretching it. Any free atoms that were released would be highly reactive, so you might generate a few stray free radicals, but no more than sunlight.
Comment: Let's put a bound on "Dangerous"- most corrosive? Chemically Reactive? Explosive? Lowest LD50? Rack up the most insurance claims?
Comment: just because the blade can cut chemical bonds does not mean the wielder can see or hit chemical bonds well enough or frequently enough to get anything of any quantity.
Comment: @ChristopherJamesHuff That's the point I'm trying to make. An atom-wide sword isn't going to be able to cut molecules like the OP's question seems to indicate. Unless you start adding in magic, the chemistry & physics just don't work. I didn't have exact speeds, but knew it was crazy-fast compared to a sword.
Comment: What do you mean by "cutting" chemical bonds? Do you think that chemical bonds are made of pieces of string, which can be mechanically cut with a knife?
Comment: @DWKraus in fact, under typical room conditions, the average velocity of a molecule of air is around 500 m/s, 1.45 times the speed of sound. And they're some of the smallest atoms in the periodic table. The edge of the sword would be among the bluntest, slowest moving things they run into.
Comment: Not disagreeing, just adding some detail. @AlexP: mechanical scission of molecular bonds is a real thing, it just takes rather different circumstances. For example: https://www.ameslab.gov/news/polystyrene-waste-is-everywhere-and-it-s-not-biodegradable-scientists-just-found-a-way-to This is just a case where the bonds are particularly strong and the forces not effectively applied to breaking them.
Answer: Awesome, wimpy power.
There aren't many bonds in normal air to cut: O-O, N-N, maybe H-OH if there's some humidity.  So you get isolated neutral O and N atoms, and maybe H and OH on occasion.
The isolated atoms have more energy than bound ones, so the most striking thing about your sword is that it's a perpetual motion machine.  Either that or it has to pay the energy cost, in which case it has more resistance to swinging through the air than any other sword in the entire history of brutes with pointy objects.
But how much of an effect is this?  Well, air at a comfortable temperature is 1 mol per 24 liters... oh, forget that, we don't need it.  You cut bonds in maybe an angstrom slice of air ($10^{-10}m$).  (Molecules can be wider than that, but you'll hit many edge on)  For each mighty swing that averages a meter of distance times a meter of sword, you create $1m \times 1m \times 10^{-10}m = 10^{-7}L = 10^{-4}cm^3 = 0.1mm^3$ of monooxygen/nitrogen/etc.  A tenth of a cubic millimeter ... I'm quaking in my shoes.  The energy produced (or required) is $0.1uL / (1 mol /22.4 L) \times (946 kJ/ mol N2 bond) = 4.22 mJ$.  (Oops, we did need it)  That's about $1/250$ of a watt-second (like a kilowatt-hour but smaller), or 1 millionth of a food "Calorie", so your swordsman doesn't need to stock up on energy drinks to swing that thing around.
If it can cut nuclei in half, then we might have something.  Random subsets of protons and neutrons from O and N nuclei probably make some pretty spectacular radiation, and it wouldn't take very much... oh wait, I've been reminded that the sword would have to cut the nucleus, which no matter how sharp it is, is still absurdly unlikely.
Comment: @Nosajimiki Sure, but if the cutting part is the width of an atom, that's still ~4.5 logs wider than the nuclei. That's like trying to split a hair lengthwise by swinging the Washington Monument at it
Comment: [Nuclear diameter](https://en.wikipedia.org/wiki/Atomic_nucleus) is on the order of 10^-15m for small elements. Using your formula, adjusting by a factor of 10^-5 and plugging in the nuclear binding energy (5.3 * 10^10 kJ/mol), you're still looking at...62J?  [Equation source](https://www.chem.purdue.edu/gchelp/howtosolveit/Nuclear/nuclear_binding_energy.htm)
Comment: Oh.  Then there's that.  I should have remembered the area the blade had to strike would get smaller. :)  Can we get a redesign where you can swing the broad side of the blade and any nucleus in the area gets taken up and rearranged for zero energy?  Thanks.  :)
Comment: "macroscopic maximum thickness, and has a minimum thickness of 1 atom" <- The OP seems to already allow for a sword of normal width, just give it billions of parallel mono-molecular edges and you should be able to sweep a 2-3mm wide path even without cutting on the flat of the blade.
Comment: Re: spectacular radiation. Yes, but not as much as you want. Air is not very dense, and neither are atoms (though the definition starts to break down at that scale). The cross-sections of N and O are very small, so you probably wouldn't have enough interactions to produce any radiation noticeably above background. Also, I suspect a lot would be alpha, which would be shielded by the simple expedient of having skin
Answer: Just chemically breaking down the elements in the air is not that big of a deal, Mike's answer does a good job of outlining why... but let's pretend the sides of you sword also contain complex mono-molecular geometry, something similar in shape and function to RNA, then it could take those loose elements and reform them into new molecules. Since you have the technology to make a monomolecular blade, I will assume you can do this as well. Now your sword is its very own a chemistry lab activated by the kinetic energy of your swing.
Because thermodynamics is always ruining every world builder's fun you can not use your swing to form a significant amount of high explosives or anything fun like that because the energy you store in any created molecular bonds can not exceed that of your sword swing.
This leaves you with toxins.  The two deadliest toxins in the world by volume are Botulinum toxin and Maitotoxin, but both of these contain elements that you would not abundantly find in the air, but the 3rd deadliest toxin is Batrachotoxin (C31 H42 N2 O6).  This toxin could theoretically be synthesized from Carbon Dioxide, Nitrogen, and Water Vapor which are all relatively abundant in the air.  A lethal dose of Batrachotoxin is just 136 μg.
Since no cut has truly perfect edge alignment, even a monomolecular blade can sweep a few millimeters width of air as it moves.  If you you swing your blade around carelessly, it will accumulate this poison on the flat of the blade kind of like condensation.  That said, the really deadly part will be when it actually cuts into a person.  Flesh has a much higher molecular density than air, so just passing through a couple of mm of skin will liberate relatively large amounts of the elements you need to poison and kill your opponent.
Comment: @jdunlop The same could be said for any monomolecular blade. Frankly, a blade capable of triggering RNA like chemical reactions is IMO more plausible than one that can kinetically cut through molecular bonds. We can already make nano-materials from proteins; so, being able to make proteins from nanomaterials should not be that far fetched.
Comment: A sword that turns its victims to poison. Nice!
Comment: @TysonDennis - with the understanding that this blade is straight-up magic.
Comment: Nosajimiki - The lack of a power source would make chemical assembly difficult.  That said, yes, that's my point.  There's no `magic` tag in @TysonDennis's post, but pretty much _all_ of the answers are actually describing magic swords, because monomolecular edges wouldn't last.
Answer: Let's set aside the plausibility of a blade really cutting atomic bonds, and let's take for good that it happens. Any singlet atoms that you would produce is not exactly friendly, considering that it will desperately try to recombine because chemistry. Considering both abundance and reactivity, I would say that the nastiest thing that you will produce is atomic oxygen

An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.

Molecular oxygen is already reactive, atomic oxygen is even more reactive than that.
Answer: Not much most of the time
Air is really close to local energy minimum. So Expected would be many momentary bond cleaving events just to have them re-form as they were shortly thereafter.
Sword will likely rust into dullness
So to create say monatomic oxygen momentarily might cause some interesting reactions but I would expect re-combine into standard diatomic oxygen most often. Second often would be reacting with the sword to rapidly rust away the edge until the chemical bond cleaving stops.
It is a catalyst
The sword is essentially just a very good non specific catalyst. So what does a car's catalytic converter produce? Generally it reduces that amount of dangerous chemicals, same with this sword.
The most dangerous I would expect out of this setup would be things like:
Carbon monoxide, ozone, nitrogen oxide. And those would be in very small  quantities.
Not the right conditions
If you think it would spontaneously create H-N=N-N=N-N=N-H or some such? No, for same reason as shattered tea-cups don't spontaneously jump into your hand complete with tea.
Comment: Had to look up azidotriaziridine (H2N6). I think it's dangerous. Can someone prove that?
Comment: I just made up a long chain of N because I could type it in and the longer the chain the more unstable and dangerous. It is almost guaranteed to be explosive. It is in the difficult and dangerous to create category so would be hard to find literature.
Answer: This is a sort of follow-up to Nosajimiki's answer.
Poison is not a useful thing in melee.  Batrachotoxin is indeed very deadly, but it isn't instantly lethal or debilitating.  Someone cut with and poisoned by a Batrachotoxin blade could continue to fight for a minute or more.  Plenty of time to run you through with his own blade before he died.  Poison doesn't help you win a sword fight, it just lets you turn a defeat into a Pyrrhic victory.  The best thing about your fancy monomolecular sword will be its amazing cutting properties, it should go through bone like butter.
If you absolutely have to use this poison idea, put it on an arrowhead or something, so you can run away and wait for the poison to take effect.
Comment: This assumes it is an unarmored dueling sword.  As a battlefield weapon, they make a lot more since.  Cavalry often favored swords for doing pass-by attacks. Here you are already not sticking around for a counter attack; so, instant kills don't matter so much. Armored infantry benefit even more. Armored infantry battles often dragged on for many hours with very few people suffering more than superficial wounds until one side either got too tired or broke formation. If both sides have have swords that can nick you through armor, but not fatally penetrate it, poison becomes very useful.
Comment: And even if you turn a defeat into a Pyrrhic victory on an individual level, doing this many times over the course of a battle can turn the whole course of the conflict in your favor.  Because if the first guy in your formation dies having only scratched his opponent, that opponent is now going to be much easier for your second guy to take out.
Answer: From Wikipedia's article on the atmosphere, there are five main compounds that you can cut in the air are:

Nitrogen (78.08%) -- Will be cut into atomic nitrogen, which likely just wants to recombine back into N2

Oxygen (20.95%) -- Will cut into atomic oxygen, which may just react with almost anything.  Likely it will react back into O2 gas

Carbon Dioxide -- Cutting one of the chemical bonds will get you carbon monoxide and a free oxygen atom.  The lone oxygen atom will react with something and be begging to do so.  Not sure if it would be able to just react back into CO2 or not.  Due to its linear bond structure, it is likely impossible to cut both oxygen atoms from the Carbon.

Methane -- Possessing 4 C-H bonds in a sort of caltrop-like shape, cutting them will basically strip a number of hydrogen out of the gas, leaving an incomplete hydrocarbon behind.  Likely, it will be cut into a CH3 group and an hydrogen atom.

Water Vapour -- One of the H-O bonds get cut here, not unlike with CO2.  This nets a hydrogen atom and an hydroxide unit.  Unlike with CO2, the molecule is not a straight line, so there might be a slim chance to slice both hydrogen atoms off the water molecule.

The other major components of the atmosphere are the noble gasses, and they will not form molecules that can be cut under normal conditions, so that is roughly 0.934% of the atmosphere that has no bonds to cut (Argon mostly).
From that list above, the most dangerous thing is probably the nitrogen or the oxygen, but likely it will just react with itself again.  That typed, there are plenty other trace materials that are in the atmosphere in minute quantities.

Dust, Pollen, and Spores probably won't cut into anything super deadly.  However, is is likely the most interesting thing that you could cut the bonds of.  The larger molecules of organic matter offer up more ways to be cut.

Chlorine and Fluorine could be present in trace amounts and be cut, but like with atomic oxygen, the halogens will likely react before they pose any real danger to anything or anybody.  Fluorine in particular just wants an electron and will mug almost anything to get it.

Sulphur compounds can be present, with hydrogen sulphide and sulphur dioxide being the two common ones that get thrown into the air.  Due to the angled bond in the molecule, the same premise as with water works for them.

Now the answer is that the most dangerous thing you an probably make is atomic oxygen on a regular basis.  You wouldn't really be able to make enough carbon monoxide to be dangerous, and anything truly nasty is only there in trace amounts
Now if your sword could store what it cut, or gave you control over what it cut meaning that you the wielder has control over how the cut molecules recombine, that would be a different matter entirely.
Answer: As others have shown, it's not going to do anything relevant.  It's not organized so you can't make a toxin with it, all you can do is chop off radicals.
L.Dutch came up with the most aggressive radical that will be produced in any quantity but there's another that you'll get on occasion that makes a lone O look downright friendly:  A lone F.  There's no fluorine gas in the atmosphere but there are fluorine-bearing compounds on particles at the parts-per-billion level.
Comment: "It's not organized" <- If you mean the blade geometry, the OP made no such stipulation. In fact, since you can't exactly "cut" molecular bonds anyway, I think it's safe to assume that it would have to be very organized in order for it to chemically break air molecules as it passes.  So much so that the same technology could inherently also be used to assemble molecules too.
Comment: @Nosajimiki No--I was saying the chopping isn't organized.  You can chop off pieces but you can't control how they reassemble.
Comment: Given the concentration of fluorine compounds, and the reactivity of free fluorine, you're not going to have a loose F for long enough for it to be a threat - and you're not going to make _enough_ of it to present a risk to an opponent.
Comment: @jdunlop Quite true.  Since there's no way to make anything that's actually a threat with the blade I was trying to get the technically most dangerous.
Answer: It's probably not the worst thing that could be created, but your blade is probably going to produce at least some cyanide gas as a byproduct. As your magic sword cuts CO2 and N2 in the atmosphere, you're going to have some C4+ and N3- ions that are going to be really, really eager to combine with each other and reach an electrically neutral state, and will end up forming CN- ions, and will then probably bond with an H+ ion for good measure to produce gaseous hydrogen cyanide.
Now, I don't know what percent of carbon and nitrogen ions cut by the sword will end up joining with one another, or how much cyanide gas will end up being produced (let alone if it will be enough to be lethal), but's its something that will end up being produced in some amount just assuming random atomic collision.


PCV Valve hose question

Question: What is a PCV Valve Hose made of? Can any rubber hose replace it? Like the rubber hoses used for gas lines in lawnmowers? Does it need to be made of some type of plastic? From what I understand, the hose just moves gases developed in the cranckcase from blowby to balance out the pressure in the cranckcase right? So considering it is only gases that the hose is moving, can it be replaced with a rubber hose? I would much rather spend $5 for a rubber hose than $36 for the actual part (part number 6758 on fordparts.com). However, I am curious to know if the gases will eat away the rubber material or not (if I need the actual ford part or not).
Answer: Yes, you could use any fuel and oil resistant hose. They are typically made of silicone, polyurethane or rubber. This will ensure longevity of the replaced hose. Have a look at silicone automotive hoses.
One thing to consider is, on many modern systems the hoses are molded to a particular shape to clear surrounding components in the bay. If this is the case, you'll be better off using the correct part to avoid kinking or straining the universal hose.
If its quite simple, you can make sure the hose is secure and less prone to making contact with other parts such as belts, manifolds, etc.
Of course, use hose clamps at each end.
Answer: The part you use should withstand high temperatures and must not collapse under vacuum. I think if you use garden hose, it will just collapse and also melt down.
The only hands on experience I have is changing the PCV hose with a silicone one in a jaguar s-type v6 3.0. It worked fine there, but that doesnt mean that you will have similar results.
You can get reinforced vacuum silicone hoses cheaper than your garden hose at aliexpress for example. (you need to know what size/length you need)
Answer: I found a reference from Motor Week saying NOT to use fuel line or vacuum hose as a substitute for PCV hose.  Quote:

The vacuum hose won't stand up to the oil that comes through this
  [PCV] system. The fuel hose is designed for internal pressure. It will
  collapse under the vacuum of the PCV system. PCV hose is designed
  specifically so it won't collapse. So insist on PCV hose, never fuel
  hose or vacuum hose.

http://www.motorweek.org/features/goss_garage/clearing_up_pcv_valve_problems
Answer: Not only should you absolutely use PCV hose material, be sure and get a good one.  I bought a PCV hose (aftermarket) that collapsed in less than a year on a 2008 Corolla S.  When you hear the results of a collapsed hose, you understand the constant and large amount of pressure/vacuum flowing through it.  I have a check engine light on (P0171 code) and one possible reason is a faulty PCV hose.  It can affect the fuel/air mixture.

PCV Valve hose question


Is a composition of a major triad constant in a key

Question: If you have a C major triad with a root, 3rd and 5th in the key of C major, would a G major triad still be composed of a root, 3rd and a 5th?
Answer: Yes, the G major triad would be root, major 3rd and perfect 5th. This isn't only for the major triad; it works the same way in the minor, augmented and the diminished ones. You just change the formula. Most of the common chords used in Western music are built on thirds. So, if you are in the C major scales, you can have 7 chords:

C major: root, maj third, fifth
D minor: root, min third, fifth
E minor: root, min third, fifth
F major: root, maj third, fifth
G major: root, maj third, fifth
A minor: root, min third, fifth
B diminished: root, min third, diminished fifth
Answer: This really depends on which root, third and fifth we are talking about.
Rule: a triad consists of a root, third and fifth - the (as yet unqualified, because that will depend on the type of triad) third and fifth being relative to the root note. These are the chord tones.
A major triad will consist of the root, a major third and a perfect fifth (again, intervals measured from the root note).
When considering chords in a key, we will be looking at the scale tones, or degrees that are used to make up the chord. Thus, in C, the C major chord will be composed of the first, third and fifth degree (tone) of the C major scale.
What about G major? Assuming we're still in C, its root note is the fifth degree of the C major scale (G), its third is the seventh degree (B) and its fifth is the ninth/second degree (D). If we were in G, then the chord tone/scale tone correspondence would be the same as for C major in C.
In other words, there is a bit of an ambiguity of terminology, when we use words like third or fifth with regards to chords in a key.
Comment: So when casually referring to the composition of G major in the key of C, we would still use **root, third and fifth** while **fifth, seventh, and ninth/second** are technical terms?
Comment: If you're looking at the tones of the chord in relation to itself, you would use the chord tones (root, third, fifth). If you're looking at the tones of the chord in relation to the *key*, you would use scale tones (fifth, seventh, ninth). The second scenario is most commonly used when discussing voice leading - that is, how to join two chords in a key together. For example, the seventh scale tone (third of G major) resolves to first (root of C major)
Comment: @AZNPNOY2000 the root,third,fifth are the terms if you start counting from G, whereas fifth,seventh and ninth are the terms if you start counting from C.
Answer: Just to clarify. The ROOT is the actual LETTER NAME of a chord, regardless of which key something is in. The THIRD of that chord is either a maj. or min., 4 or 3 semitones higher than that root, and the FIFTH is 7 semitones higher than the root (for a perfect 5th).
Comment: It's not uncommon for the key to influence the letter name of the chord.  For example in the key of F, you would not see a A# chord but instead a Bb due to the key.
Comment: @Dom - very good point. You obviously don't play with the same guitarists I sometimes do...  I've seen loads of A# in F !!


How to dodge homing missile?

Question: There is a missile guidance algorithm called proportional navigation. Is there an opposite algorithm for missile avoidance? Something that tries something other than escaping in the direction of a homing missile that doesn't work when the escaping object has a little less power?
Comment: Chuck out a load of window.
Comment: Here's a guide from a (fairly realistic) game that's relevant if you're just getting started: https://forum.warthunder.com/index.php?/topic/493540-guide-to-dogfighting-and-dodging-missiles-at-103/
Comment: This paper is also highly relevent: https://scholar.afit.edu/cgi/viewcontent.cgi?article=4693&context=etd
Comment: @Drew from a game? Wow. My suggestion came from what the dambusters did as one of their sorties...
Answer: Short answer: if there was one on the target, it would basically seek to be unpredictable, i.e. random (but within bounds of wanting to close the distance)
Long answer:
If the target is ahead of the interceptor, and they are both flying in approximately the same direction, a faster/more agile interceptor will eventually intercept the target, unless the target does something like release chaff or the interceptor runs out of propellant.
If they are head-on, closing distances, then the relative agilities makes a difference. If the interceptor has a relatively small maneuverability envelope, then the target may be able to dodge the interceptor, and then fly past.
From these examples above, we see that the evasion strategy implemented by the algorithm must take into account the relative speed and agilities of itself, and the interceptor. I'm not aware of any air-to-surface, air-to-air, ballistic or other missile, that is capable of detecting and discriminating what interceptors are launched against it, and plan an evasion route accordingly.
Usually what is done is the route to the target has features that make the target hard to intercept en route, such as a terrain following, hypersonic velocities or random course changes.
Specific answer:
Let the:
Interceptor be I
Missile be M
Target of missile be T
Bearing of M to be BM
Bearing of I to be BI
Essentially you want M to close the distance with T in the most direct route possible. In 2D space without obstacles, if T is fixed then you just need a bearing, BM.
M may assume that I will use proportional navigation to intercept it, and will follow BI. Plotting a course for M to hit T will therefore be a compromise between the shortest path, and the path that evades interception.
How I would code the algorithm is to let M have a random evasion time interval, RT, specified by an average + variance. Every RT, M makes a random course change.
The random course change is itself defined by another Gaussian distribution with the average = BM and the variance an "evasiveness parameter".
Hope this helps.
Comment: There any  known alghoritms about that? My case is simplest possible, 2D without gravity, terrain, obstacles or etc, like in space. Only two, interceptor and escaping one.
Comment: Answer updated with a simple pseudocode. Hope it helps.

How to dodge homing missile?


AD Migration from SBS 2003 to SBS 2011

Question: I am looking at doing a cross forest AD migration from SBS 2003 to SBS 2011. I have a new server that runs SBS 2011 with a new domain name and am looking at moving all the user profiles from say old.local to new.local.
There's only around 12 users so this is not a big move.
I was going forward with using ADMT, and upon setting up trusts between SBS 2003's forest and SBS 2011's forest I found out SBS 2003 does not support trusts with other domains. It therefore appears I cannot use ADMT as it tells me "ADMT is unable to connect to domain controller" "Access is denied. (0x80070005)" which I believe is due to cross forest trusts.
The reason I wanted to migrate AD was that I was under the assumption with migrating AD I can preserve the user's SIDs and therefore when they log on their PC in a new domain they will use the same user profile on the PC after a domain change. All of their Desktop/Documents/Settings/Etc will not have to be copied between profiles under C:\Users. I also don't like having profiles names under C:\Users\ such as 'account' and 'account.new' which you get when a users logs in with the same account name but new SID to my understanding.
I only need to copy users as the Security Groups have been completely redone, and Exchange mailboxes I can do manually between the servers with export/import (unless there's a faster way).
Is it possible for me to migrate all the users between the servers? Or should I simply recreate the user accounts on the new server and manually copy their profiles at all of their desktops?
Answer: I might suggest a migration of AD from SBS 2003 to SBS 2011 rather than just migrating security principals (retaining the existing AD domain rather than migrating to a new AD domain). Microsoft has documentation to assist in doing this, but I've found the SBS kits at www.sbsmigration.com are rather inexpensive and easier to follow than Microsoft's documentation.
http://www.sbsmigration.com/pages/selected_kit/SBS-6/230/
http://www.microsoft.com/download/en/details.aspx?id=14570
Comment: The new server is for the most part set up and configured with a new domain name. The new domain name is essentially required because the company is changing its name.

AD Migration from SBS 2003 to SBS 2011


Help modeling this dome

Question: I am very new to blender and still using 2.78, I have this idea in my head and but can't think of how to model a dome shape with a cross on top if that makes sense. I attached a sketch of how I want it to be, sorry if it is hard to understand. I don't care a lot about size or measurements.
Answer: I've tried this. It's made with bevels, mirror, extrusions, join and knife. I corrected the final extrusion as, as Lemon has pointed out, it looks like I inverted the cross.
Comment: ooh ok, actually I thought it was flat, but anyway it's the same process  ;)
Comment: I think you have inverted the extrusion of the cross
Answer:
Have tried to do it in a minimalistic way.
First noticing that the shape is a double mirror (and that helped to make regular edge loop or knife cuts when needed):

From that, the mesh is the following:

The main point is the pinched extremity of the cross. The cross was extruded first, then the extremity has been merged to the edge it was extruded from. We so first obtain a triangle.
Edges are then marked as creases, and the creases (pink edges) are supported by edge loops as visible below.

The base mesh and how to set the mirror modifiers:

Above, from left to right:

Add a plane
Poke the face (menu 'face/poke face' in edit mode)
Select all and bevel ctrlB
Add edge loops at the diagonals CtrlR for each diagonal
Keep a quarter
Split the quarter in half

From the image above, the mirror modifiers setting (left and right):

Add a simple (default mirror on X)
Then add a second mirror on X and Y and base the mirroring on an empty placed at the origin (which has not moved so far, normally)
Rotate the empty 45 degrees.

Extruding and give the base shape

From left to right:

What we have done before
The cross extruded
The extremity down and merged with the base
The global shape for the not extruded part

From that, add some loops, mark the crease, add some loop agin and cuts as described above.

Help modeling this dome


How To Install Phatch 16.1 Version on 16.04

Question: The Problem
I run Ubuntu 16.04. The latest Phatch version for 16.04 (0.2.7.1-3.1) stops loading at the splash screen. I have read that version 0.2.7.1-4 for 16.10 works fine and should work on 16.04.
The Question
How can I install 0.2.7.1-4 on 16.04?
What I've Tried

I've checked Ubuntu Software for other versions but apparently only
the latest version of software per Ubuntu version is available.
sudo apt-get install phatch (installs 0.2.7.1-3.1)
sudo apt-get install phatch=0.2.7.1-4 (says it's not found)

I tried applying the 16.04 patch as recommended but terminal just paused and seemingly did nothing until I killed it.
sudo patch /usr/share/phatch/phatch/lib/pyWx/wxPil.py < phatch.diff
If it's not possible to install the 16.10 version on 16.04 I will spend an hour and refresh myself on the ways to do stuff (apply it) manually.
Answer: Patching works. I did it as explained in ubuntuusers.de wiki, that is:

Save the patch file phatch.diff to your Downloads folder.
In a terminal:sudo patch -b /usr/share/phatch/phatch/lib/pyWx/wxPil.py < ~/Downloads/phatch.diff


Using the move from the matrix as a fighting technique

Question: How practical is it to dodge punches by leaning back table top like similar to how Neo did in the first matrix movie during a boxing match and also counter from that position. It has always been one of my favorite scenes in media and I have seen it being used in fictional boxing media of watch and read such Hajime no Ippo and the Boxer. I know that trying to copy moves you seen in fantasy is generally looked down upon and can be unsafe and generally not realistic. But it seems at least somewhat possible so I'd to see to what degree just for the sake of my curiosity.
Comment: An interesting question from a tactical standpoint may be "If I end up in this position, how can I fight from it?" It's not a smart position to seek out, but you may end up falling or being pushed backwards onto a surface and having to fight from there to regain position.
Answer: You can dodge punches but doing so by leaning backwards is usually a really bad idea.
I believe I have seen some boxers do it when against the ropes, but only really to show off.
The issue is that you risk taking a punch to the stomach that you can't easily see.  Also you are obviously off balance because physics will apply to you in a way it doesn't in the matrix movie.
It's bad structurally and it's bad for your view of the opponent.  There is no payoff other than looking cool (and you won't look cool when you get hit).
Comment: @PipperChip I agree but I'm not going to spend more time on this question.  Feel free to write a better answer and get fake internet points.
Comment: This answer would be improved by explaining the idea of structure: what it is and why breaking it is bad.
Answer: I can give you an example where leaning back is used in actual sparring, although it is a slight lean, not even close to what you see in The Matrix:
In modern Taekwondo Olympic sparring, athletes are taught to keep a slight lean back stance.
When defending, this helps against high kicks, where leaning back a bit further will be enough to avoid being hit. When attacking it helps avoiding high counter kicks, such as the spinning hook kick, that used to be responsible for most KOs
This leaves the arms available to protect the torso, with minimal arm move.


Why mAh is constantly going higher?

Question: I am kind of new in electricity, I bought a USB tester - KWS1902C. I can see my laptop voltage is constant 20 V (or around 20) to be more precise. Amperes are changing in sleep mode 0.002 when working depending on the load from 1 to 2 amperes. So far so good. One thing I do not understand is why mAh is constantly rising. Reading on the internet, mAh is the capacity. But why my capacity is rising all the time when battery is 80% (I set max to be 80%) on my laptop?
Comment: Cheap Chinese toy can not be used for precise measurent. Algorthm is unknown. Usually that devices calculate left energy by the voltage but the have to be calibrated for each battery.
Comment: what do u mean by algorithm, which one should be used ?
Comment: The device has microcontroller inside. Microcontroller run by some programm which is implement some algorithm. If it has some user interface, you can programm it. Battery voltage depends on remain power, but measured in some conditions. Briefly, the device is a toy, not a precise instrument.
Answer: The mAh reading on your meter is a measure of the total energy used since the meter was last reset.  It does not indicate the capacity of your battery.
Answer: mAh measures the total charge which has passed through some point over all time. It is like a turnstile counter for electrons.
So mAh is a great way to keep track of capacity, just the way a turnstile counter is a good way to measure a stadium's total capacity if you reset it when the stadium is empty and then look at its value once it is full.
In other situations it is just measuring the charge which has "passed through".
It's almost the total energy, but you need to multiply it by the voltage first: electrons can pack a different punch depending on their voltage.
Note that the detail is somewhat more complex particularly with regard to the role of voltage and potential and fields, and also exotic carrier types etc, but this will do you.

Why mAh is constantly going higher?


Is it permissible to hang out with my best friend and wife together

Question: I am a male and have a male best friend. The question I have is: is it permissible to meet and hang out or For example, walk in the park with my wife and also my best friend? If you can answer my question and refer to Hadith or teaching that would be appreciated
Answer: Yes it is permissible for a wife to go anywhere she wants under the security of her husband. Though your friend is non-mahram to your wife. So you should keep your wife with you. Not close and alone with your friend. A non-mahram should not stay with a girl alone more than 10 minutes. So u should check these things. They can also talk with each other but unnecessary talk is not allowed. So you should spy these things that both don't talk to each other unnecessary or touch each other because this is considered as a sin. You can hangout with your wife and best friend anytime you want. Sorry! U couldn't find a hadith. But this is the answer in my knowledge.
Comment: Where do you get the 10 minutes time limit from?
Comment: 10 minutes? why not 11 minutes?


allowing space in encoding function (Sage ShiftCryptosystem)

Question: I am using sage to implement an encryption function that takes in plain text and converts it a cipher text ignoring space and non alphabetic characters(including them in encoded text). the encoding function however, removes all spaces and ignores non alphabetic characters(not including them in encoded text). I could not find any documentation on the function. Any help?
Answer: Is this what you are looking for?  The examples make it pretty clear that this is what is intended.
Sage documentation on the ShiftCryptoSystem
Also, note that
<code>sage: ShiftCryptosystem?
</code>
will take you the same place in the command line or notebook interface.  Double question marks start getting you source code, hopefully that will lead you somewhere.  Keep in mind that these cryptosystems are intended for pedagogical use.


Determination of the speed and angular velocity of 4 rolling cylinders between planks

Question:
According to the picture, there are four identical cylinders, with radius R, that are rolling without slipping at every contact point. The upper plank is moving with speed 2v (m/s) towards the right, while the lower plank is moving with speed v (m/s) towards the left. My question here is, what is the speed at point P? It seems intuitive to conclude that Vp = 2v but if we ignore the lower plank and cylinders, shouldn't the displacement of the 1st upper cylinder + displacement of the 2nd upper cylinder = displacement of the upper plank? I'm pretty confused at this part. Also in this configuration is the velocity of the center of mass of each cylinder not equal to (angular velocity)*R anymore?
Answer: Starting with a lower cylinder (and assuming that the given v and 2v are measured relative to the base), it is clear that the center of mass is moving to the left with a speed of v/2.  Combine that with a tangential velocity of v/2 to get v at the top and an angular velocity of v/(2R).  For an upper cylinder $v_c$ + $v_t$ = 2v  and $v_c$ - $v_t$ = -v. (Where $v_c$ is the speed of the cylinder to the right, and $v_t$ is the tangential speed.


Does the skills boost percentage stack with 2 rings?

Question: There are rings that boosts skills, for example a Earth Shaker ring boosts ability by 30%. I assume this is 30% more damage. If I have 2 of these rings, does the boost stack?
Comment: @MadScientist can you give me a link for what you said?
Comment: From what I read, many of those rings are broken anyway and don't do anything. And they generally only increase durations, not damage
Comment: @Huangism I was wondering if rings stack too, and I found [this reddit post](https://www.reddit.com/r/dragonage/comments/2nw4q7/ability_rings_30_and_why_you_shouldnt_use_them/) about how the ability rings don't work (what Mad Scientist was mentioning I guess), but apparently whatever problem they had got fixed. Still though, I would be itnerested in getting an answer as to whether ability rings stack or not.
Comment: @DarthPizza That thread says this: "(LARGE BUG) - Stacking rings will often cancel the original effect (if it has not already been cancelled.) However, if the original bonus does apply, removing both rings can actually drop your base ability lower than it's original strength. The system only gives you the benefit of one ring in a best case scenario -130% dmg. Removing one ring drops it back to 100%, removing the second can drop it to 70%. Luckily, these changes are also cleared by moving to a new location, loading a new game, etc." But then an edit says everything works properly after patches
Answer: It appears to depend on the type of ring.  By Earth Shaker I assume you mean this?  Assuming that all the bugs have been fixed (which they almost certainly aren't) and rings now function as they are supposed to I think a user from this thread says it best:
"Ability improvement rings work by setting an abilities properties to a 30% higher number all other rings add a bonus to stats. You can see this in the abilities tooltip the damage or duration number there changes on equip. Using 2 ability improvement rings has no use but 2 heal on kill rings for 10% each gives you 20% of your max HP with each kill and 2x20% crit damage gives +40%. This is the same in single and multiplayer."
I managed to find 2 instances here and here where people had actually done methodical tests on stacking rings.  In both cases they found that stacking rings had no effect but equally there are plenty of people saying that they're sure stacking does work.
I would say that with the bugs and stacking (maybe) working with some rings and not others the only way to be sure would be to do a test yourself whenever you find yourself wanting to stack rings.  Equip them and see if anything changes on the tooltip or your attributes screen, then also maybe also do a damage test with 1 equipped and then with both.  My feeling is its probably not worth it.  Just use different rings.


Shouldn't there be an HTML5 tag?

Question: Apparently HTML5 isn't a tag. Should it be created?
Comment: The thing to do would be to point to some questions where you feel the tag is warranted - that gives folks something to discuss. Right now, "Should we have [x] tag?" just leads to "Well, I don't know, where would we use it?" - so some examples would be very helpful.
Comment: I just posted a question for which it was relevant (Video tag). I couldn't use that tag as I don't have a high enough rep.
Comment: @jchwebdev If your question is the only one that should be tagged with it, then this tag is useless. If you can point out a dozen or two questions like that, then OK, tag may make sense.
Answer: Your original question isn't actually about HTML5 (or Drupal actually, it's about a relative path issue), you just happen to be using an element that wasn't available before that version.
I don't think adding a tag is a good idea since it doesn't apply to the question. If there are (let's say) half-a-dozen or more other questions that are clearly about HTML5 in conjunction with Drupal, then yes, it would make sense to add it. I haven't come across any such questions, if you have some examples please edit them into the question.
Comment: There are a handful of questions about the new HTML5 form elements, and related (like `placeholder`).  But, I am too busy to search for them.
Comment: @jchwebdev if you think html5 is obvious for all modern Drupal questions, then you just prove html5 tag would be useless - if it applies to everything, you can't effectively use it for filtering. And filtering is the main (if not the only) purpose of tags.
Comment: @MPD actually http://drupal.stackexchange.com/search?q=html5 returns pretty nice list, but I will not dare to decide which is *really* about html5, and which only happens to mention it, but is not truly version dependent.
Comment: I can only say that, regardless of the relevance of my particular example, an HTML5 tag seems like an obvious choice for -any- web development platform.
Answer: I don't think we should create the tag. Essentially, because we actually have a specific close reason for that type of question

Questions on programming, PHP, SQL, etc. that do not relate directly to Drupal are off-topic here, but can be asked on Stack Overflow.

HTML would fit nicely into that list, as would HTML5. If a question really is about html 5, it's actually off-topic on the site! So no, I don't think the tag should be created.
In addition, had the tag truly been needed, it would have organically been created anyway. There's almost 1000 users with high enough reputation to create the tag, and those users, (since they have higher rep) are the most active on the site. Despite that, not one of them appears to have had need for the tag.
Comment: You could be right, I could be wrong. Here's a challenge for you: What is a good HTML5 question, that is specifically Drupal related? I loaded up http://drupal.stackexchange.com/search?q=html5 and looked through the first page of 15 question. I found exactly 0 that would be appropriate to tag html5. Either they were about a Drupal api (form or filter), or they were unclear on the question. I challenge you, start by finding a single good question, and we have something useful to discuss.
Comment: @jchwebdev You're missing the point somewhat - we don't create tags until they're required for a question. As we still don't have a list of questions that would benefit from this tag, it hasn't been created yet. That's it. It has nothing to do with the greater community's 'vocabulary', of _course_ we've all been using HTML5 for a long time now. I'm sure we all use angular for our frontend, too, but that doesn't mean we have to create a tag for it. I think you're just unfamiliar with what we use tags for
Comment: One last thing and I'm done. Where you wrote, "it would have organically been created anyway." I disagree. Novices don't know what they don't know. And experienced people don't ask. From what I've seen, the Drupal community is not exactly the most 'tech-forward' group of guys (how many sites still run D6?) If you limit tags to what is common, you can miss out on innovations. In fact, I am surprised that HTML5... which has been around for a good while now... is -not- a bigger part of the community's vocabulary. No offense intended.

Shouldn't there be an HTML5 tag?


Is there any way to switch Platinum and Gold in the world?

Question: In Terraria, when you create a world, there are only certain materials that generate in that world, specifically ores. Platinum and gold are examples. Can you change the ore a world generates?
Answer: You can not change the ore a world is set to generate, however, I have come up with two solutions that do me quite well.
Using the Extractinator: Farming Silt and Slush
With an Extractinator, you can convert Silt and Slush into any number of useful materials. While completely random, you will commonly receive coins, jewels and ore. Before creating my off-world mines, this was a stable source for silver, gold and platinum. I also found it to be the quickest way to earn gold. I understand I got very lucky in finding one so early in the game, with ice chests having only a 5% chance to contain one, however until you're as lucky, just make sure you're putting all that silt and slush away, and don't destroy it.
Generate Mining Worlds
Once I pulled my character up a bit to take on the underworld, I got myself kitted out with Mining Gear. The helmet, alone, gives you a free light source. With the other two pieces, you gain a 30% increase to mining speed.
I then generated a new world, and proceeded to turn it into an "off-world mine". Dig tunnels through the world, until you find the materials you are after. Dig out a bit, to reach lower levels that contain higher-value ores, and dig out tunnels in a checkered pattern - it just makes it easier to navigate back to the farthest reaches. If you take a spare bed with you, you often find the odd underground house you can use to set up a safe re-spawn.
Off-world mines are still limited to the ore they generate; however, they can also be a very good source of silt and slush, to which I direct you back to heading one.
Comment: Note since 1.3 extractinators are much easier to find, as it may appear in fishing crates or found already placed in underground desert cabins.
Comment: Another option is to fish for crates-- Crates have an equal chance to get gold and platinum ores and bars.
Comment: not sure what you mean by a checkered pattern, are you referring to branch mining?
Comment: The question isn't "How do I obtain x ore?"... So to be completely honest, nothing but the first half line of your answer is really relevant :\
Answer: Short answer: No
The world will be generated with only one of these ores (chosen at random) and once generated, you cannot change the world other than through standard gameplay.
Without using a world editor, a world cannot contain natural ores of a type it didn't generate with. Though people could still bring ore mined from another world in and place it.
If you specifically want a world with one type rather than the other, your best option is simply to generate a few worlds and wait until you get one with the ores you want.


How does one recall the current context properties for MIDI effects in Lilypond?

Question: After setting the a context property for a MIDI effect, for example \set Staff.midiChorusLevel = #2, how would I save this value into a variable inside a Scheme function, should I want to temporarily change this value in the function and then reset it to the value that was there before?
Answer: First let me give you a short overview of how Lilypond thinks: When you invoke Lilypond on a file it is first parsed. The parser essentially transforms the text file containing Lilypond code, scheme code &c. into scheme objects representing music, organized in books &c.
This is then translated into a set of graphic objects (grobs) which are then spaced and output.
Now we need to keep in mind that the whole concept of contexts only exists during this translation step, but most of our code is executed in the parsing step. This means we do not actually have access to the value of these context properties at the time our code is executed.
One solution to this would be to define your own variables to keep track of the value, but this is dangerous, as the setting will not be done in score order but in parsing order.
But instead we can use the hooks Lilypond provides to us to execute code at a later time. In fact, if we use commands like \set or \override these actually create special music objects that will then be interpreted in the translation phase. You can use \displayMusic to actually see what these things turn into.
Now Lilypond does also provide a hook to let us execute any function of a context within the current context using \applyContext fun or if we want a specific parent context \context ... \applyContext fun or even \context ... = ... \applyContext fun.
This way we can write a function that stores previous values and allows step by step unsetting of values like this:
#(set-object-property! 'store 'translation-type? list?)

#(define ((tset sym val) context)
   (if (eq? sym 'store) (ly:warning "Do not use tset to set 'store Property!")
       (let* ((store (ly:context-property context 'store))
              (this-store (assoc-get sym store '()))
              (current-val (ly:context-property context sym))
              (new-store (cons current-val this-store)))
         (ly:context-set-property! context 'store (assoc-set! store sym new-store))
         (ly:context-set-property! context sym val))))

#(define ((rset sym) context)
   (if (eq? sym 'store) (ly:warning "Do not use rset to reset 'store Property!")
       (let* ((store (ly:context-property context 'store))
              (this-store (assoc-get sym store '())))
         (if (null? this-store)
             (ly:context-unset-property context sym)
             (begin
              (ly:context-set-property! context sym (car this-store))
              (ly:context-set-property! context 'store
                                        (assoc-set! store sym (cdr this-store))))))))

\new Staff {
  % Remove beam exceptions so we see an effect
  \set beamExceptions = #'()
  8^"Default" 8 8 8
  \applyContext #(tset 'beatStructure '(2 2))
  8^"Override" 8 8 8 |
  \applyContext #(rset 'beatStructure)
  8^"Reset" 8 8 8 8 8 8 8

  \break

  \set beatStructure = 2,1,1
  8^"Different default" 8 8 8 8 8 8 8
  \applyContext #(tset 'beatStructure '(2 2))
  8^"Override" 8 8 8 8 8 8 8
  \applyContext #(rset 'beatStructure)
  8^"Reset" 8 8 8 8 8 8 8

  \break

  s1
  \applyContext #(tset 'clefPosition 2)
  2^"Voice context (does not work)"
  \context Staff \applyContext #(tset 'clefPosition 2)
  2^"Staff context, does work"
}

Of course we could turn this into Music functions to get syntax more similar to \set Staff.something = something. By the way you can also use this to create differential functions for midi, like let's say \faster or \faster perc.
Answer: As far as I have understood your problem, you have
\set Staff.midiChorusLevel = #something
...
\customFunction { ... }
...

and you would like \customFunction to set midiChorusLevel temporarily and reset it to the previous value afterwards.
Now, LilyPond does not provide a ready-made tool for that, but depending on what you're trying to do exactly, there could be simple solutions.

If you just need it to set midiChorusLevel at one point in time and reset it just afterwards, use \once \set midiChorusLevel = ....

If you want a general default for midiChorusLevel on the staff context, i.e. the value to restore will always be the same, use

\new Staff \with {
  midiChorusLevel = #something
}
{
  ...
  \set midiChorusLevel = ...
  ...
  \unset midiChorusLevel
  ...
}

This \unset construct resets the property to its default in the context, which is established (in priority order) by \with blocks, \layout { \context { ... } } blocks, and LilyPond defaults.
In the general case, LilyPond provides no way to restore the previous setting, because it does not remember it. (It does remember settings using a stack for grob properties, and there is a \temporary command for those, but not for context properties.) However, as @Lazy demonstrated, you can use the \applyContext hook to implement it. My approach would be slightly different from his solution, using a closure to store the property value:
\version "2.22.2"

#(use-modules (ice-9 match)
              (ice-9 receive))

resetAfter =
#(define-music-function (path mus) (symbol-list? ly:music?)
   (receive (context property)
     (match path
       ((c p) (values c p))
       ((p) (values 'Bottom p)))
     (let ((val #f))
       #{
         \context #context
           \applyContext
             #(lambda (context)
                (set! val (ly:context-property context property)))
         #mus
         \context #context
           \applyContext
             #(lambda (context)
                (ly:context-set-property! context property val))
       #})))

\new Staff {
  % Remove beam exceptions so we see an effect
  \set beamExceptions = #'()
  8^"Default" 8 8 8 8 8 8 8
  \resetAfter beatStructure {
    \set beatStructure = #'(2 2)
    8^"Set" 8 8 8 8 8 8 8 |
  }
  8^"Reset" 8 8 8 8 8 8 8

  \break

  \set beatStructure = 2,1,1
  8^"Different default" 8 8 8 8 8 8 8
  \resetAfter beatStructure  {
    \set beatStructure = #'(2 2)
    8^"Set" 8 8 8 8 8 8 8
  }
  8^"Reset" 8 8 8 8 8 8 8
}

Answer: Take a look at the StackOverflow post Static Variables in Scheme/Racket, which explains how to simulate static variables in Scheme.
The gist of the solution is that within your scheme function, there is a lambda expression that stores the original value of the midi property and returns that value when invoked.
Comment: That is not really what the question is about.


iPhone 4s search sometimes stays blank

Question: Search page works very well except when it doesn't work at all. In those cases it just stays blank. What's the fix for that?
Comment: I have the same problem and would like to know if there is a fix or an update to fix this problem. Happing on my iPhone 4s and my wife's as well.
Comment: mine ocasionally stops functioning and I have been able to get it started again by shutting down and restarting the phone, and typing in just the first letter for the search. Also worked when I pressed and depressed the shift button on the keyboard before typing in the first letter. Weird, but it seems to work.
Answer: This happens to me too. A temporary "fix" is to turn off mail search in Spotlight. (Found on the Apple Discussion Board)
Comment: Do you know if mail is the cause, or just making any arbitrary change to the rules will jumpstart the stuck process?

iPhone 4s search sometimes stays blank


Using ExchangeService to Add Appointment Occurances

Question: The target is someone's Exchange Calendar (2007). I want to add a simple "Appointment Occurance" to someone's calendar. This code works (I am using the Microsoft.Exchange.WebServices.dll):
<code>service = new ExchangeService(ExchangeVersion.Exchange2007_SP1);
service.Credentials = new NetworkCredential("supervisor", "password", "DOMAIN.COM");
service.AutodiscoverUrl("<email@example.com>", ValidateRedirectionUrlCallback);
appt = new Appointment(service);
appt.Subject = "<subject>";
appt.Body = "<Body Text>";
appt.Start = _DateFrom;
appt.End = _DateTo;
appt.Sensitivity = Sensitivity.Private;
appt.Save(WellKnownFolderName.Calendar);
</code>
However, there are problems with this code:

The appointment target is the employee. When adding the appointment, the appointment shows up for the employee (yay!) but also for the supervisor (boo!). Am I supposed to use the employee's credentials? If so, what if I do not have access to that - only the supervisors, am I out of the game already?
The appointment shows up in Outlook as a "Meeting Appointment" and not and "Appointment Occurrence". So, the box to input meeting attendees is showing (with no one in it of course), and is irrelevant in my scenario.
appt.Body does not respond at all to Environment.NewLine or "\r\n" - I haven't tried HTML yet.
Answer: Instead of WellKnownFolderName.Calendar
You should use new FolderId(WellKnownFolderName.Calendar,"firstname.lastname@example.com")
So the last line becomes
appt.Save(new FolderId(WellKnownFolderName.Calendar,"email@example.com"));
Also having problems with the newline, this is only since version 1.1 so it probebly is a bug