Multires Normal Baking Not Baking Normal Data

Question: I smart UV projected a model of the monkey head after subdividing it 5 times and lightly sculpting on it, then baked the normal data based on the multires, but all I get is a flat normal map texture with no directional normal data. How do I fix this?
Answer: Baking normal map from Multiresolution modifier data relies on the difference between the viewport number of Multires subdivisions and the highest level it was subdivided to:

The higher difference in these numbers is (Viewport vs. highest from Sculpt / Render), the stronger effect of the resulting normal map will be.
If your normal map is very light or flat then probably Preview level is set to the same one as Sculpt or Render is. Set it to lower number and choose how much of the normals change you want to bake.
Note that baked normal map should be applied to the low-poly mesh with the same amount of geometry as the mesh had with the chosen Preview level of the Multires modifier.
Comment: I changed the preview back to 0 and kept the sculpt and render values at 4, and it worked! Thank you!
Comment: @WKG Using blender 2.8. it seems sculpt options removed. Render and quality doesn't affect the result but preview. So is that okay to just focus preview number? I'm not sure render and quality are matter anymore in 2.8 when it comes to baking normal.


Broken front driver's side suspension

Question: I have hit a pothole on way home tonight and now driver side is low and arch rubbing on wheel and grinding when I turn left anyone got idea what I broke please
Comment: If you get down low, I suspect you can take pictures of what might have broken.  That would be very helpful.
Answer: Difficult to say without pictures. Based on what you said I would speculate it is definitely suspension related. Badly damaged or destroyed shock absorber-, MacPherson strut (another type of shock absorber configuration), broken coil spring, stabilizer link snapped in two are my guesses. Must have been one hell of a pothole.
Comment: It was and I didn't see it until it was too late  as it was pitch black would you  have any idea what it would cost it's a 06 reg mini
Comment: @Polly - There's really no way to know how much it's going to cost to fix something. It could be a couple hundred to several thousand quid/dollar/denero/juan/[insert currency of choice].

Broken front driver's side suspension


Factors to be Considered for Software Risk Management

Question: What are the risk factors that we need to consider while planning for a software project.
Comment: We used the [Capability Maturity Model](http://en.wikipedia.org/wiki/Capability_Maturity_Model) for the longest time.
Answer:
Is your team adequately trained?
Is your team large enough?
Do you have contingency in case
someone leaves the project, and how
would it affect the schedule?
Is your team too large?
Do they have the resources they need?
Might a competitor bring a product to
market before your project completes?
Can you deal with changed
requirements?
Can you deal with the
project becoming irrelevant?
Do you have buy-in from senior
management?
Do you have any reliances on
suppliers or contractors?
Are you
doing anything in-house that your
team isn't competent enough at?
Do you have budget big enough to meet
the estimated project cost?
Can you meet unforeseen project
costs?
And anything that's specific to your
circumstances :-)
Comment: So even I do share some of your points ;)
Answer: I would add to @Graham's list:

Are some of the requirements out of your control (eg the laws about calculating sales tax) and might they change?
Are you using a tool for the first time and how confident are you the tool will work for you? (It might be brand new, eg Azure, or just new to your team)
Are you relying on a general acceptance by your users of another product (eg writing an iPhone app means you expect your users to have iPhones, writing a BlackBerry app means you expect your users to have BlackBerries etc.)
Can you restore/recreate any lost or wrongly-changed work (not just source control but version control for documents, emails from clients, etc)
Do you have tools and process that enable you to understand progress, lack of progress, and regressions? Does management understand the milestones (I've had projects where at 10% complete the management saw UI prototypes and believed the work was "almost done" then pressured to hurry hurry hurry from then on.)
Do you have testing (automated or not) to demonstrate that a particular set of changes has not broken some other part of the application? Without such tests, could you ever make significant changes such as porting to another language or platform?
Answer: I'd add the following:

Do you know your customer's needs.  If not, has your requirements gathering team adequately determined what it is that the customer wants in the past and been responsive enough to ensure that changes are propagated as quickly as possible to the development team?  Are they adding in gold-plating to the requirements?
Is there an existing product you are competing with and have you determined prior to design just how you will compete with this product?  This is critical as existing products often come out with "I want that feature too" aspects which could make you deviate from original plans.  Is your team/management/target customer able to be side tracked by such an occurrence and do you have contingency plans set-up to handle such an issue?
Is the proposed design of your product relevant to the market?  Halfway through you don't want to discover that while it satisfies your customer's needs it lacks critical aspects to compete in the "new" world.
Answer: Steve McConnell's Rapid Development contains a chapter on risk management, with a usefully long list of potential risks. I've used it as a starting point more than once.
Answer: Do you have the right mix of people? Are all your developers application developers in a data-centric project? Do you need a database designer, a QA person or a UI specialist  instead of only hiring people with the same skill mix?
Do you have adequate hardware to support the project? This is especially true if you are creating a high volume system or if you are too cheap to buy development servers in addition to production servers.
Have you set up backups of your databases? Just having the code to recreate a database is not enough, you need to be keeping the data as well even on dev.
Are your developers working with a small data set instead of one the size that production will be? This almost guarantees production performance issues because queries that work well on a small data set often do not on a large set. I've seen a lot of failed production updates that had to be immediately rolled back due to this particular problem.
Are you defining what to do in edge cases and are you testing them? For instance, I've seen projects where nobody ever defined what happens what an approval is required and the approver says no.
Will you be forced into making bad design choices in order to meet unreasonable deadlines?
In your planning for the project did you consider that people take vacation and sick days, get jury duty, take bereavement leave etc? You need to plan not just for people leaving the project but for the day-to-day time off people get.


Activate a site feature using REST API

Question: I have a workflow which creates a site when an entry is made to a list. I need to activate one of the features at that newly created site using REST API. How can this be done?
Answer: Have you looked at feature stapling? I don't know all requirements, but the feature stapling is another way which can solve your issue.
Comment: Feature Stapling ,I think will not be a feasible option because we have to alter each site templet ONET.xml file manually. And if customer is not technically sound ,and simply create a template for its site  and used it to create a site will surely not have that feature activated.
Answer: The REST URL you can use is this one:
http://sitecollection/site/_api/web/features/add(featureId,force,featdefScope)

Additional information can be found here: http://msdn.microsoft.com/en-us/library/office/jj245237(v=office.15).aspx
If you really want to use REST and you have multiple successive features that need to be activated in order. Be sure to nest each REST action in the success eventhandler of each ajax call.
In other words
function ActivateFeatures() {
   var feature1 = "/site/_api/web/features/add(" + featureId1 + ", false)";
   var feature2 = "/site/_api/web/features/add(" + featureId2 + ", false)";
   var feature3 = "/site/_api/web/features/add(" + featureId3 + ", false)";

   $.get(feature1, function() {
       $.get(feature2, function() {
          $.get(feature3);
       });
   });
}

But I don't recommend using REST. The best way to do this is following Alexander's advice and using a feature stapler.
Answer: function activateFeature() {
$.ajax({
    url: _spPageContextInfo.siteAbsoluteUrl + "/_api/web/features/add('7e2e2482-9007-4db3-8a7f-9bccd986ec4e')",
    type: "POST",
    headers: {
        "Accept": "application/json;odata=verbose",//return data format.
        "X-RequestDigest": $("#__REQUESTDIGEST").val()
    },
    success: function (data) {

    },
    error: function (err) {
        alert("Error: " + JSON.stringify(err));
    }
});

Make a post call on the endpoint web(to activate feature at web level) or site(to activate feature at site collection level) by just passing feature guid in the add method.

Activate a site feature using REST API


What sizes of bricks (building scales) have carried the Lego brand name?

Question: Apart from regular Lego and Duplo, what other sizes of brick have there been that have carried the Lego name? What is the compatibility between the different building scales?
Answer: The sizes are:

Regular Lego bricks.
Duplo. Intended for younger children. Bigger than regular Lego bricks, but compatible with them. Some are branded "Duplo", whereas others carry the "Lego" brand. Still produced.
Quatro. Intended for younger children than Duplo. Bigger than Duplo, and compatible with Duplo. No longer produced.
Primo. Intended for babies. Bigger than Quatro, and compatible with Duplo with special interface bricks.
Modulex. Intended for architectural models and commercial signage. Early sets were branded Lego. Not compatible with regular Lego bricks. No longer produced.
Samsonite Jumbo Bricks. Not compatible with regular Lego bricks. No longer produced.
Lego Soft Bricks. Not compatible with regular Lego bricks.
Lego Storage Bricks are brick-shaped boxes for storing Lego. Some of them can be stacked, so you can "build" with them. However, they're not compatible with other bricks.

There are also various "bricks" used as promotional material, such as the large fibreglass ones you see at the Legoland theme parks. You can't build with them, and they're obviously not compatible with regular Lego.
Although they didn't carry the Lego brand name, Olo and Minitalia were made by Lego for the Japanese and Italian markets. They're the same size as regular Lego, and compatible with it. They're no longer produced.
Answer: Besides Classic and Duplo (2x as big in each dimension, hence the name) there are several more official dimensions of LEGO bricks:

Quatro: 2x as big as Duplo in each dimension, so 4x as big as LEGO Classic: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=48201#T=S&O={}

Modulex: Smaller brick width than Classic LEGO (5/8th), and with a 1:1 relation between height and width, whereas Classic LEGO has a 6:5 relation: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=Mx1111L#T=S&O={}maller

Jumbo: Fits in between Duplo and Quatro, 3x LEGO Classic in each dimension: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=x1446#T=S&O={}

Primo: 2x as big as Jumbo in each dimension, hence 6x Classic LEGO: http://alpha.bricklink.com/pages/clone/catalogitem.page?P=31000#T=S&O={}

There are still several more sizes, reported in Dag Bricks' excellent spreadsheet, but they are not similar to normal bricks in form and/or function, such as LEGO Gears, LEGO Soft Bricks and LEGO Tubs and cups.
Here is a comparison picture between some formats; from top to bottom: Modulex, regular, Duplo, Quatro and Soft Brick:

Source used: http://www.dagsbricks.com/2013/09/lego-techniques-system-sizes-wrap-up.html
Comment: The bottom brick in your last photo looks like a Soft Brick, not Quatro
Comment: The image of the five stacked red bricks does note end with Quatro. It's Modulex, Lego, Duplo, Quatro and the bottom one is 6 times larger than standard Lego. You can easily tell since Quatro uses hollow studs just like Duplo. But I also measured pixels in the picture to make sure. Jumbo Bricks is not in the picture.
I found this page when searching for what Lego called the sizes 6x and 20x the standard brick. My search will go on... Thanks!
Pontus


How to understand "Money Market Purchase" and "Money Market Redemption" transactions in stock account?

Question: In my stock account (TDAmeritrade if it matters), there are many transactions with description "MONEY MARKET PURCHASE", "MONEY MARKET REDEMPTION", "MONEY MARKET REDEMPTION (MMDA1)".  What are they?  Also, strangely some of them have amount as '0.00' or '0.01'.  Why the (nearly) nil amount?
Comment: The broker may be using a money market account as the place to hold money between selling one set of shares and buying another. Ask him or her.
Answer: A money market fund is a type of sweep account.
Brokerages use sweep accounts to take advantage of the cash you let sit there, so they(the brokerage) can make money on the interest. This is done automatically(typically daily) so whatever percentage or thresholds they want to use is automatically applied after you've added or subtracted cash into your account.
In the case with the zero or near-zero amounts being shown, I assume this is for transparency and the result of the automated process to remove the money to their "money market fund" where they have control of it i.e. earn interest on the cash that otherwise be idle. If you were to pull the cash out yourself though you'd have no problem doing so, they'd automatically transfer the correct amount, you just get to see that happening with

"MONEY MARKET PURCHASE", "MONEY MARKET REDEMPTION", "MONEY MARKET REDEMPTION (MMDA1)"

unlike your checking account, though the same concept is being used: stored money is invested to make money on that money at no risk (well FDIC limitations) to the person storing it.
From Investopedia

A sweep account automatically transfers cash funds into a safe but higher interest-earning investment option at the close of each business day, e.g. into a money market fund.
Sweep accounts try to minimize idle cash drag by capitalizing on the immediate availability of high-interest accounts.


Will wireless isolation/AP isolation protect from KRACK?

Question: Will using AP isolation on an Access Point protect connected clients from the KRACK vulnerability on that network?
Answer: Nope.
Wireless/client/AP isolation only provides a means of isolating one wireless client from another. It has no bearing on how 802.11 encryption works or how the WPA2 handshake takes place.
Since KRACK attacks the WPA2 handshake and compromises the encryption between a client device and the access point, it really doesn't care if the wireless client can reach another wireless client.
Comment: Can it at least limit the damage/risk to only one device at a time (If one device is compromised, could the others be protected by isolation at least until they are compromised too, one by one?)?
Comment: @Daniel, it can't limit the damage/risk from KRACK. KRACK doesn't grant access to the network or give control of a client device with a compromised connection. Wireless/client/AP isolation can help to do exactly as you describe if a client device is compromised by other exploits or malicious code (which could be introduced by a KRACK MitM attack or countless other attack vectors). However this is not protection from KRACK.


Were Poltergist and E.T. filmed in the same neighborhood?

Question: Were the two 1982 Spielberg movies E.T. and Poltergeist filmed in the same neighborhood? They were both filmed in tract housing developments during the same year. Were they filmed in the same place in succession?
Comment: Funny, I've wondered the same thing. As a kid I always wanted to buy a house like the one in E.T.
Comment: The exterior of the Poltergeist house was actually in Simi Valley (I lived in Simi from 1977-1990 and my friends and I used to ride our bikes by it frequently to "scare" ourselves in the summer of '82!)
Answer: No, they are not the same place.
According to this site, Poltergeist was filmed in Agoura Hills.

Another page on the same site indicates that the street where they take off on the bike (I assume that's the one you're thinking of) is filmed in Granada Hills.

As a semi-related piece of trivia I found on that same site, in the Charlie's Angel's remake starring Drew Barrymore, there's a scene where she rolls into the villain's backyard, and the house is the same one she and Eliot lived in in E.T.


Can one designate a beneficiary for a savings account in Canada?

Question: For most registered accounts, you can designate a beneficiary in the event of your demise. Is it possible to do the same for a regular bank or high-interest savings account without creating a will? An example might be one is saving up for a large short-term purchase and has tens of thousands of dollars sitting in a savings account as cash.
Answer: In Canada, I had a shared account with my wife at TD Bank. We had the account set up with "right of survivorship". When my wife died suddenly, the bank account became solely mine and did not make up part of her estate. The major advantage here was that I was able to immediately access the bank account to pay for funeral expenses; three and a half months later, I am still waiting on life insurance.
You certainly can grant "power of attorney" over specific bank accounts, but I believe this would allow the person access while you are still alive.
I cannot speak with first-hand authority on designating a beneficiary if the account is not shared, but this is something that my late wife's bank, CIBC, checked when I investigated. Be warned that it can take weeks or months (or, indeed, years, though I hope not) to sort out the paperwork after a person dies.
Comment: I should be clear here, the accounts I was dealing with were savings accounts, chequing accounts, and RRSP savings accounts.


Default.Master for CSS reference

Question: I am trying to find the master page my non-publishing site uses.
The Home.aspx page shows a reference to Default.Master however I dont have a Default.master. I do however have to master pages that have the option to make it the default (V4.master and minimal.master) but its far from intutive as to which master page I need to add my CSS reference too
Answer: Following instructions require you are a "site collection administrator" (SCA)
In Site Settings /_layouts/Settings.aspx there should be a Master page gallery /_catalogs/masterpage which is a library that will contain each master page document.
You mention it is a non-publishing site but you could still enable "SharePoint Server Publishing Infastructure" from the Site Collection Features /_layouts/ManageFeatures.aspx?scope=site (not site featues) in site settings. This would provide 'Master Pages' /_layouts/ChangeSiteMasterPage under 'look and feel' which allows you to see/change the current master page.
Please Note:
Best practice would be to make a copy of the master page which you edit and than set your site to use the new copy you edited/renamed
Comment: However, I dont have a MasterPage option because I dont have publishing on. I am hoping to make these CSS changes without turning on publishing
Comment: Does this basically mean its not possible to make any style sheet changes without Publishing on?
Comment: I don't have a platform available for additional testing but why is it that you cannot enable publishing at the site collection level. The only noticeable changes are the one you want

Default.Master for CSS reference


Sweet potatoes: to cook or not to cook?

Question: I would like to dehydrate some sweet potatoes. Here I found a recipe for dehydrating fresh sweet potatoes in low temperatures without cooking them first. But here they say that fresh sweet potatoes contain toxins and should not be eaten without cooking. So what is the truth? Is it safe to eat dehydrated sweet potatoes that were not cooked first?
Comment: The act of dehydrating will denature _some_ things in the sweet potatoes (in many ways dehydrating/freezing will have the same effect as cooking). I can't say if the enzyme you're worried about will be destroyed (hence this not being an answer).
Comment: How can one ever eat raw sweet potato? Usually pressure-cook it, cook in the steam for consumption. I don't get it, why do you opt to dehydrate?
Comment: @bonCodigo: usually, raw vegetables contain some enzymes and nutrients that are destroyed by cooking. So my default option is to eat raw. However, there are some vegetables that must not be eaten raw because they contain toxins. Hence my question.
Comment: *enzymes rather toxins
Answer: I would prefer cooking them first. Sun-dried sweet potatoes do exist in some parts of Asia as a snack. They are chewy chunks rather than crispy slices as shown in your link. There are also freeze-dried ones around these days. Anti-nutrition contents are not overwhelming in sweet potatoes to my knowledge. So, uncooked should be fine. I think you will get better texture and avoid browning by cooking them first.

Sweet potatoes: to cook or not to cook?


Does an increase in hash/s decrease the time it takes to obtain a block or does it increase the possibilities of solving one?

Question: I am a total noob, and I've been reading the wiki for a long time and have yet to understand the basics... My question here is that if I were to mine at 100GH/s (example), is it guaranteed that I would find a block after a determined amount of time? Or does it just increase the possibility that I am the first to find it?
Answer: Since solving a block is a probabilistic math problem, having more hash power will increase the probability that you will find the right hash and solve the block. You cannot be 100% sure of the estimation given by the profitability calculators.


Can I use Lotus Notes to send mail?

Question: I have to code an app that at some point in time will have to send some reports using Lotus Notes.
My questions are :

Can I send mail through the Lotus Notes client, or something related to Lotus Notes ( a command line tool maybe? )? If so, where could I find information related to this? I would prefer not having to do it in C/C++, but if no other options' present, that would do.
How can I find out the server's address? The GUI is not intuitive, and I can't find the server address. The server's located on another computer on the network.
Comment: What platform/language are you using?
Comment: I'm somewhat language agnostic. Something along the lines of Perl/Ruby/Python/Java/C/C++/C#. Would prefer not to do it in C/C++ though.
Answer: Yes you can send email through a Lotus Notes client.  I've had to do this before in a .NET application because a number of our clients were using Lotus Notes.
Lotus Notes publishes an SDK to do this.
Here's a link.
We used Interop to get the thing working.  Also, be sure that you pick the correct version of the SDK.  It has to match up with the version of Lotus Notes your client uses.  If you use the wrong one then it won't work on their machines.
Answer: I have no idea about Lotus Notes. But for sending email from code i'm not sure why you need a client. In case of Exchange, you just need the server details(or any SMTP server) and then code it in the language you need. You need to go where the Lotus notes client is configured for mail accounts for finding out server details.
Answer: Here's an example of half-a-decade old code to send a Notes mail from Excel VBA using the Notes OLE objects - guess they can be used in most of your preferred platforms:
Dim session As Object
Dim maildb As Object
Dim maildoc As Object
Dim body As Object

Public Sub send(subject, recipient, filename)
    On Error GoTo errorhandler
    Const EMBED_ATTACHMENT = 1454
    Call maildb.OpenMail

    If Not maildb.IsOpen Then Call maildb.Open("", "")

    Set maildoc = maildb.createdocument
    Set body = maildoc.createrichtextitem("body")

    Call maildoc.replaceitemvalue("form", "memo")
    Call maildoc.replaceitemvalue("subject", subject)

    Call body.EmbedObject(EMBED_ATTACHMENT, "", filename, subject)
    Call maildoc.send(false,recipient)
End Sub

Private Sub Class_Initialize()
    Set session = CreateObject("Notes.NotesSession")
    Set maildb = session.getDatabase("", "")
End Sub

The documentation for the various Notes objects can be found here: Lotus Domino Designer documentation
Comment: what are the arguments of maildb.Open?
Comment: Server and database file, but they are not necessary to know: The call to maildb.openmail connects it to the current users personal mail database.
Comment: I'll try the script tomorrow at work and let you if it works.
Comment: Thanks Anders! Based on your script, I was able to write a ruby script that works !
Comment: This answer's so good, I'm always coming back to read it . Thanks!
Answer: try https://rubygems.org/gems/notes_mailer
(disclaimer: i'm the author)
3<
Comment: Thanks. I implemented my mailer using OLE as well, but I didn't publish it :)
Answer: Here is a command line tool for sending SMTP messages.  Just place the SMTP server's IP address in the config file and use command line statements to build an output file that is used for sending.
Remember: if you write code that actually uses the Notes client, the client will need to be installed everywhere this code runs.
http://glob.com.au/sendmail/
As for the SMTP server address, I would suggest contacting anyone in your organization that deals with messaging.  Sometimes companies have a separate internal SMTP server set aside for just this purpose.  Otherwise, you will need to look into the Configuration \ Servers \ All Server Documents section of the Notes Directory to find the SMTP servers address.
Comment: the lotus notes client will be installed everywhere.
Comment: That makes it easier, but I forgot to also mention that the a user will need to be logged in, or the code will need to know which user ID to use and the password.  This may have changed in more recent notes version.
Answer: Need more specifics on the mail options but the easiest are as follows:
1)  Use an @Function - Example @MailSend  This is a built in function in notes that can be used on a form.  Like when you press a button or save a document.  You can open the lotus notes designer and look at help for all the info.
2)  You can use lotus script to create your own custom email send.
Here is a link to the notes forum that will have the answer u seek.
http://www-10.lotus.com/ldd/46dom.nsf?OpenDatabase
Answer: There's the Domino .NET assembly from Notes version 6.5 and above which provides you with fairly easy ways to use Lotus Notes object model in your .NET application (so you can write C# code), however some general knowledge is needed about the object model itself and how to program Notes classes. However you can find many answers on the DeveloperWorks of IBM for Lotus (http://www.notes.net).
You can also put your data to the HDD and create LotuScript local agent to pick it up and send over via email. For this you need some LotusScript knowledge. Local agents can be scheduled easily but Notes client needs to run on that machine all the time.
Server address is not needed when you send emails from Notes code (either .NET app or LotusScript code). All addresses are configured in Notes configuration documents called Locations and Connections. These documents are to be found in the local Address Book application, in the Advanced section. You can also manage locations via the File menu (starting from version 8 I assume). It's rather simple but not "Microsoft style" and that's why you call it "not intuitive".
But normally Notes client is not used to send automated mails unless it's done during the user interaction with Notes application itself. If you need to send mails over you can integrate with the Domino server and send mails from there using scheduled agents. But in case you use .NET code it could also use the client API to do this but you'll need to have Notes client installed on the machine where you run your application that sends mail.
The final option would be to send it over SMTP. This will require SMTP relaying configuration on the server and will not support encryption that is provided "out of the box" by Lotus Notes/Domino.
Comment: Thanks for your answer Alexey. I finally settled on doing this using Ruby & Win32 COM. It works pretty good.
Answer: To answer question 2. You can get the name of the server, which is the lotus notes name by the following:
Private Sub Class_Initialize()

    Set session = CreateObject("Notes.NotesSession")
    dim strServerName as string
    strServerName = session.CurrentDatabase.Server
    If ( strServerName  = "" ) Then
        Messagebox( "This database is local." )
    Else
       Messagebox( "This database is on a server named "+ strServerName +"." )
    End If

End Sub

Can I use Lotus Notes to send mail?


A game on integers

Question: $A$ and $B$ take turns to pick integers: $A$ picks one integer and then $B$ picks $k > 1$ integers ($k$ being fixed). A player cannot pick a number that his opponent has picked. If $A$ has $5$ integers that form an arithmetic sequence, then $A$ wins. $B$'s goal is to prevent that from happening. Who has a winning strategy (after finite number of turns)? Does it depend on $k$?
Comment: Could you clarify whether $k$ is fixed in advance for each play of the game? If not, it seems that B can easily win. So I guess you mean that it is fixed.
Comment: I'm a little unclear on the ending condition.  Does the game end in victory for B after $\omega$ turns, or does the game continue until it is impossible for a player to pick (at which point B wins), or what?
Comment: Joel David Hamkins: The question "Does it depend on $k$?" would seem to suggest that $k$ is a parameter to be fixed in advance.
Comment: @HarryAltman Yes, I also thought so. But I find myself unsettled when something like that is left unsettled. About your question on the length of the game, I had interpreted the game as having length $\omega$, as in the usual Gale Stewart type analysis, but it seems that my answer shows that player A can force a win at a finite stage of play.
Comment: I guess a small modification of my argument in https://mathoverflow.net/questions/129345/n-in-a-row-game-on-mathbbr2/131870#131870 would show that A has a winning strategy, though I would still prefer to see a more explicit approach (but without using nuclear weapons, of course).
Comment: @JoelDavidHamkins I mean $k$ is a fixed integer and I am asking for a strategy that $A$ wins after a finite number of turns. Sorry for the confusion.
Answer: I claim that Player A has a winning strategy in your game, and furthermore, it is a winning strategy for her simply to play the smallest available number.
Let me consider the game along with several natural variations.
Player A wins the original arithmetic progression game. To be a little more specific about the game, let us consider what I should like to propose we call the arithmetic progression game $G_k^n$ for positive integers $k$ and $n$, a two-player game of perfect information. On each turn, player A plays a new integer and player B plays up to $k$ integers, with all played numbers distinct; player A wins if there is an arithmetic progression of length $n$ amongst her numbers, and player B is aiming to prevent this.
In this notation, your original game is $G_k^5$. These are all open games for player A, meaning that any win for player A, if it occurs, will occur at a finite stage of play. It follows by the Gale-Stewart theorem that one of the players will have a winning strategy.
But in fact, we can explicitly describe a winning strategy for player A: let her simply play the smallest available positive integer. I find it interesting that the same strategy works uniformly in $n$ and $k$, and player A doesn't even have to know these game parameters in advance. Further, the strategy doesn't depend on the history of play, but only on the current sets of already-played numbers.
To see that this is a winning strategy, consider any infinite play of the game played according to it. For such a play, the key observation to make is that this strategy ensures that the set of numbers played by A will have proportion at least $1/(k+1)$ in any initial segment of the positive integers. In particular, the set played by A will have positive asymptotic density. It follows by Szemerédi's theorem that the set played by A must contain arbitrarily long arithmetic progressions. So player A will have already won at some stage. So it is a winning strategy.
Let us consider several natural variations of the game.
Player A wins the arbitrarily long finite progressions game. Consider an infinite version of the game, denoted $G_k^{<\omega}$, where play continues through all finite stages, and player A wins such an infinite play if the set of her numbers contains arithmetic progressions of every finite length. The argument above using Szemerédi's theorem shows that the play-the-smallest-available-number strategy is still a winning strategy for player A in this modified game, since she can ensure that her set has positive density and therefore contains arithmetic progressions of any desired length.
Player B wins the infinite arithmetic progression game. If we modify the winning condition of the game, however, to the game $G_k^\omega$, where player A wins only when her set contains an infinite arithmetic progression, then I claim that player B has a winning strategy. The reason is that there are only countably many infinite arithmetic progressions in the integers, since each is determined by its starting point and the difference. Since there are only finitely many numbers played by any given finite stage of play, it follows that player B can block the $n^{th}$ infinite arithmetic progression with a single number played on move $n$. So even when $k=1$, player B has a winning strategy to block an infinite arithmetic progression in A's set.
Player B wins the variant where $k$ is not fixed. Lastly, consider the version of the game where $k$ is not fixed, so that player B is free to play an arbitrary finite set on each move. We may denote it by $G_{<\omega}^n$. For this variant, player B has a winning strategy to block all arithmetic progressions even of length $n=3$ for A. The strategy is simply to fill in all the numbers up to double the current largest number played. In this way, no three numbers played by A can have their differences in an arithmetic progression, since each next number played by A has a larger difference than any two previous numbers. So this is a winning strategy to prevent A from forming an arithmetic progression of length $3$.
Further remarks and questions. In the original $G_k^n$ game, the play-the-smallest-available-number strategy is a winning strategy, but I am not sure how long this takes to win, or whether this strategy is efficient in any sense in winning. Perhaps the finite combinatorics experts can place bounds on how long the game will take. Presumably there is a number $N$, depending on $n$ and $k$, such that player A can force a win in at most $N$ moves, but I don't know how big $N$ will be or even whether there is such an $N$. The existence of such a number $N$ is equivalent to the assertion that this game has a finite game value (but note that not all open games have a finite game value).
Question 1. How quickly can player A win the game $G_k^n$? Does the play-the-smallest-available-number strategy achieve the best bound?
Question 2. For fixed $n$ and $k$, is there a uniform bound $N_k^n$ for the length of play, not depending on the moves of player B?
In the game where $k$ is not fixed, one can imagine the game $G_f^n$, where the function $f:\mathbb{N}\to\mathbb{N}$ is used to specify the size $f(i)$ of the set played by B on move $i$. The argument I gave shows that if $f$ is sufficiently exponential, then player B wins. Meanwhile, constant functions $f(i)=k$ correspond to the original arithmetic progression game.
Question 3. For which functions $f$ does player A still have a winning strategy? For example, if $f$ is linear or even polynomial, does player A have a winning strategy? What if $f=o(2^i)$?
Comment: I added some remarks and questions at the end. Please vote up this comment if you think I should ask a separate MO question with those questions.
Comment: This is a most beautiful answer (speaking as one who played around with this for a little while and didn't come up with anything remotely this clever).
Comment: @onurcanbektas You may have misunderstood the game. If A plays 3, 6, 9, 12, 15, for example, then she has won, even if player B follows your directions, since this is an arithmetic progression of length 5. https://en.wikipedia.org/wiki/Arithmetic_progression
Comment: I've posted such question at https://mathoverflow.net/q/297428/1946.
Comment: I do not yet know Game Theory, but if $k\leq 2$, and if in every move $B$ picks the integers $n-1$ and $n+1$, where $n$ is the integer what $A$ has picked, how can $A$ ever win ?
Comment: Oh, I see. Thanks for pointing out.
Comment: In light of Aaron's answer, I wonder if it might be possible to provide good bounds for the length of play to the win when A follows the strategy of always playing the smallest available number? This is a simple-to-describe winning strategy, but is it efficient at winning quickly? I have no idea either way.
Comment: Note that at that question, I realized that the blocking strategy is certainly not exponential, but $g(i)=i-1$ suffices, since at each move $i$, the new number makes $i-1$ pairs with old numbers, and so only this many blocking moves are sufficient.
Comment: I believe that $A$ wins the finite game for all finite fixed $k$. However I'm more interested in the strategy of $A$. For example, $A$ can always "steal" a turn by picking $0$ first, then after $B$ picks $k$ integers, picking $M$ sufficiently large that no $iM, i\in\mathbf{R}$ has been picked and continuing to pick multiple of $M$. In this way, all $B$'s numbers in the first turn are in vain.
Comment: @Haoran My argument shows that A can force a win in finitely many moves, for any k and n, with the strategy of always playing the smallest available number.
Answer: Joel's answer uses heavy machinery to give a much stronger result. Below is a strong result for $k=1$ using heavy computations (not mine.)
My suspicion is that for the question as asked there might be a relatively simple strategy. However I don't have one.

For $k=1,$ player A can win even with the further restrictions that the progression $1 \leq a,a+d,a+2d,a+3d,a+4d$ must have $d \in \{1,14,15,16\}$ and $a+4d \leq 225$ and that $B$ wins if they get such an arithmetic progression.

This is based on the game Gomoku played on a $15 \times 15$ board. According to the linked article, computer analysis shows that the game is a first player win. Numbering grid intersect $(i,j)$ with $i+15(j-1)$ gives the correspondence. Since humans still play the game in tournaments, it isn't trivial to find a strategy (though there may be rules to even things out).
Allowing arbitrary arithmetic progression gives A many more ways to win, although $k \gt 1$ is also an advantage for B.
Answer: The minimalist strategy for $A$ of "don't think, just pick the smallest unchosen non-negative integer!" has a simple counter strategy for $B$ which is interesting to analyze as to how far it gets before it eventually fails. I wonder how good it is.
The number of turns for $A$ before winning increases exponentially with $k$ (provided $A$ uses this minimalist strategy and $B$ uses the one I will describe.) This is true also for thee term arithmetic progressions.
Consider the game where $A$ needs to get an arithmetic progression of length $m$ to win and $B$ gets $k$ choices each turn. Then I think my strategy for $B$ matched with the minimalist strategy for $A$ will have $A$ win on a turn no smaller than  $k^c$ where $$c=\log_{\frac{m}{m-1}}(m-1).$$
A better strategy (for three term sequences) for $A$ would win in  $k+2$ turns (this could easily be improved to $\frac{k}3$ turns.)  Roughly, on the first $k$ turns $A$ selects available even numbers $a_1,\cdots,a_{k}$ then, whatever choices $B$ has made so far, it is possible to pick an even $a_{k+1}$ so that none of $\frac{a_{k+1}-a_i}2$ have been chosen yet. $B$ must leave one of those unchosen on her turn so $A$ picks that next turn and wins.
How to extend this to longer progressions is not clear however that argument shows that wlog $A$ gets three free moves on the first turn (we could arrange that the entire progression determined by $a_i,a_{k+1}$ is free.)
Below is a strategy for  $B$ if she knows for sure that $A$ will blindly follow the minimalist strategy. The moves are all known in advance so it is just a question of when $A$ wins. For ease of analysis I will allow $k \gt 0$ to be any real number and interpret this as: on turn $t$ if $B$ has previously chosen $m$ integers she has  $\lfloor kt \rfloor-m$ moves available and can make none or some or all and hold the rest for future turns.
The strategy is that she will pick in order the non-negative integers with a $4$ in their base $5$ expansion and let $A$ work up through the rest one at a time. This blocks any $5$ term progressions as long as $B$ stays ahead. However $B$ will save her moves and only pick enough numbers that $A$ will not win on the next turn (which may turn out to take more moves than she has).
When $B$ loses it will because $A$ was able to play a number in some interval $[5^j-5^{j-1},5^j-1].$ This will happen in the event that $$\frac{5^{j-1}-4^{j-1}}{4^{j-1}} \leq k \lt \frac{5^{j}-4^{j}}{4^{j}}.$$ The exact winning move depends on where $k$ falls in that range.
For example, If $k \geq \frac{61}{64} =0.953125$ then $A$ at some point picks $125$ without having won. No problems occur until after the turn when $A$ picks $468=3333_5.$ At this point anything in $[469,624]$ would be a winner for $A$ on the next move. But $B$ has moves in reserve, certainly enough to choose all of $[629,499].$ However to be able to go on and choose all of $[500,634]$ requires $k \geq \frac{369}{256}=1.44140625.$ If so, then everything is good until at least $2499.$

A game on integers


HTTP session fixation

Question: According to wikipedia, Mallory the attacker gets her own SID and then forces Alice to visit a site with the SID.  Why wouldn't Mallory just take Alice's SID, if she could MITM Mallory?  Also, is this attack without MITM only susceptible to SID in query string?
Comment: You assume that the forcing of Alice to visit a page requires MITM.
Answer: Mallory doesn't want Alice's session id.  Mallory wants Alice to perform actions as herself, but while the website thinks she's Mallory.  Like use her credit card to buy something she thinks she'll get, but which will actually be credited to Mallory.
There are several vectors for this attack. The one you mention, cookie-less sessions with the session id in the URL is one.  Mallory having control of a sub-domain and being able to write cookies for a parent domain is another.
Comment: Interesting. But maybe its stealth depends on the website, e.g. if the website did store Alice's name, which would be shown for example in a navbar, she wouldn't notice, but if the site was let's say purely in php and not much JavaScript, her name would change to Mallory, wouldn't it?
Comment: Also the sub-domain is interesting along with the MitM So you could set Mallory's cookie to Alice (by tampering) on a http subdomain and then see her actions on a https domain?
Comment: @Adam Yes, Alice might see a change depending on the website, given the website will think she's Mallory.  It depends on the site and Alice to determine if that's an issue or not.
Comment: @Adam To your second question, Mallory stealing Alice's session token/cookie is not a session fixation attack.  Given the correct configuration you are right that it may be possible, but it's a different kind of attack, and it wouldn't allow Mallory to see Alice's interactions, just to interact with the site as Alice, ala Firesheep.
Answer: Within the scope of the article, the point is that there are 2 different methods by which Mallory gains control over Alice's session. Where the methods differ is when you consider the larger world in which such an attack may occur.

if Mallory can get Alices to click on a link and the target system allows session ids to be set from a URL, then Mallory can fixate the session id.

Here no MITM is required.

a session id supplied to the client over a secure channel cannot be MITMed without breaking the secure channel. There are extensions to tbe http protocol that allow a cookie to be flagged to only be returned over HTTPS connections. But cookies set via HTTP are returned over both HTTP and HTTPS. Hence if Mallory can interfere with Alices HTTP communications, she can fixate the session value which will subsequently be used over a secure channel.

Here there is only a MITM of the unsecured channel.

If Mallory can inject her javascript into any page served up by the target site, by XSS, then she can set the fixate the session id. While this would also allow her to read a cookie with the secure flag and therefore hijackthe session, HTTP has a further option HTTPonly, which hides cookies from javascript. This defeats in-the-browser session hijacking, but not session fixation.

Here the mitigation of using HTTPS, even if enforced with HSTS is inneffective.
Only the cookie name and its value are sent back to the server, not the options it was created with, its path, host, scheme or expiry time, nor anything else about the provenance of the data.
There are also scenarios where hijacking is a more effective attack than fixation.

HTTP session fixation


Audio ads during long breaks in GPS navigation

Question: I am creating a GPS Navigation mobile app and have been struggling to brainstorm an idea to monetize the app. One route would be to have a paid and free version but I feel as though features should not be limited in a GPS Navigation app. The other route would be to have ads which I feel would hurt the user experience. If I chose to use ads I could have popups on every screen besides the navigation screen or I could have audio ads played during breaks in navigation. These ads would only be played if the next advice was not for a long distance such as 5 miles. Would these ads severely hurt the user experience?
Comment: Kind of off topic, but is this model actually competitive with Google Maps and other free alternatives like MAPS.ME which will provide this service (turn by turn navigation) for free?

For reference MAPS.ME (as an equivalent to what you've described) shows ads on its main menu, but not during navigation IIRC.
Comment: @TernaryTopiary Yes it is directed towards a specific clientele
Answer: Yes. The Ads will hurt the UX of GPS navigation system.
These systems use audio to guide the users as they drive, and their subconscious mind is always waiting for the system to guide them (particularly when they are driving on unknown roads).
However, you can use some special tune for navigation advice that will alert the users to pay attention. I will suggest you test the approach with real users and record their responses. If you gather enough positive results, go ahead and implement it.
Do consider users safety. Imagine some Ads speaking about meditation that gives the users a sudden impulse to try it at that moment. I do remember a scene from a British Series Coupling where Jane (who works at Radio Station) says; Hello people, let's begin our day with a deep mediation. So c'mon everyone close your eyes. And all drivers listening to her....... you know what happened :).
Answer: Adding ads to a SW which core functionality is focused on voice and visual navigation will result in poor UX. There is couple of reasons for that.

Navigations in general struggle a little bit with screen estate. If you are designing a mobile app, you need the app to be comfortably controllable with huge buttons, so it can be operated while driving. So taking away space with adds is not a good idea. Just imagine clicking on an add, by accident, when you want to reroute for example. Very bad UX.
As mentioned by Dipak: navigation systems use audio to guide users, highjacking this with ads may result in users ignoring or missing directions. Which is something you want to avoid. Maybe it would be doable if you could select the ads which would run on your app, but still I wouldn't recommend it.

There is couple of ways you could monetise your app.

Have a $X IAP to let users save unlimited locations.
Have a $X IAP to provide day/night themes.
Have a $X IAP for offline mappacks?
Have a $X IAP bundle for all the above?
Have some actor or comedians do the voiceover? As did Yoda for example.


Oraclize a restfullAPI using a specific number represented by the variable z

Question: Hello I made a restfull API on my own (python file jsonify + localtunnel) on a localhost using a specific number (in this case 141) represented by the variable z. This variable should go into DevCoin function balances[msg.sender] and should be displayed on localhost:8080 as: You have 141 DVC. For this purpose I use ganache-cli (Listening on 127.0.0.1:8545) , ethereum-bridge(node bridge -a 9 -H 127.0.0.1 -p 8545 --dev) as well as truffle.js (8545). Using: truffle compile, truffle migrate --development --reset and npm run dev leading to no error. The problem is now, when I connect the index.html(where my variable should be displayed) with a private network on metamask on localhost:8545, I got: You have 0 DVC. I don't know why. If I pass instead of z a number, the chosen number is displayed. Have anyone any idea to help me out?enter image description here
Truffle console:

App.js

truffle.js

2_deploy_contracts.js

index.html
Comment: As you can see via the bridge output, the Oraclize setup is working correctly and returning the `z` of 141 to your smart contract.

So to figure out your issue, first I would use the Truffle console to access your contract on this test-net and query it directly to confirm that `z` is infact updated to `141`.

Then, when you've confirmed that, you'll know that the problem is with the front-end side of your DApp. At that point we can't help further until you post the javascript code that you're using to access the smart-contract.
Answer:
Meta:

You should edit your original question to include the screenshots that you have mistakenly posted as a reply.
You should refrain from posting images of code, and post the actual code instead. Code cannot be copy & pasted from images making it much more work for an answerer to type out a reply.
Answer:
Your issue is that in the javascript, when the balance is refreshed it is querying account[0]'s balance, whereas you are hoping to retrieve the z value from your smart contract.
So to fix this you have two options:
Option 1:

Change the javascript to query the smart-contract for the z variable

Option 2:

Change the smart-contact to apportion the result of the Oraclize query as a balance for account[0].

Code:
An issue with Option 2 is that you'll need to know the address of account[0] before hand, and hard code it into your contract. This isn't ideal, so we'll go for Option 1 instead.

Find the refreshBalance function in App.js and change the line:

return dev.getBalance.call(account, {from: account});

To read:

return dev.z.call();

Now it'll be querying the z variable, and returning the result to the balance span in the html.
Note
The Oraclize query is asynchronous, so please make sure the refreshBalance javascript function is called after the Oraclize query has returned, or else your the value will remain 0.

Edit - Answering follow-up question:
The sendCoin functionality should already work, looking at the code. However, looking at the smart-contract, no account ends up owning any of the coin in order to send any. The constructor function gives the deployer ([msg.sender]) an amount of coins equal to z. However the contract begins life with z = 0, and so ∴ msg.sender also has none.
To rectify this, change the line:

balances[msg.sender] = z;

to:

balances[msg.sender] = 1000000;

Congratulations! [msg.sender], who in this case is Truffle account[0], has a million DVC! Now when you use the send functionality in your DApp, you'll have some coins to send!
Comment: wow thank you very much. It works for the refreshBalance function. How would you change the the sendCoin function, to send some DVC? Greets
Comment: Please accept the answer so other used can know that it provides an accurate solution. As for your other question, I'll edit the answer now...
Comment: Ok I have done it!
Comment: Also, could you add the images you posted in your _answer_, into your question, so that other users can see the full code of your question in one single post? That'd make things much clearer for anyone else experiencing similar issues to yourself! Many thanks!
Comment: No problem & thanks for reorganising your question so now other people can understand the question & answer together!


unable to connect emulator with internet

Question: I am using Android 2.2 . I am unable to connect my emulator to internet .
When I open my web browser in the emulator it shows the message "Web Page not available" . I have set proxy settings in the emulator (settings -> Wireless & Networks ->Mobile Networks -> Access Point Names). Also , I set proxy settings in eclipse (Windows-> Preferences-> Android-> Launch-> Default Emulator Options). I have read many blogs and forums but I haven't found any solution yet .I am really frustrated .
Please help me out.
Abhijeet
Answer: You have to start the emulator from the command prompt and supply the proxy server using something like this -

emulator -avd MYAVD -http-proxy http://proxyname:8000
Answer: The simplest and the best way is to do the following: This has been done for Android Emulator 2.2 1.Click on Menu 2.Click on Settings 3.Click on Wireless & Networks 4.Go to Mobile Networks 5.Go to Access Point Names 6.Here you will Telkila Internet, click on it. 7.In the Edit access point section, input the "proxy" and "port" 8.Also provide the Username and Password, rest of the fields leave them blank.


Who is Er Kishi in Mongol mythology?

Question: Are there any myths about him? I can't find much about him besides the fact that he became a demonic god at some point.
Answer: Tengri, the chief deity of the Turkic pantheon, created Er Kishi to serve as his companion:

In Turkic mythology, Tengri is a pure, white goose that flies constantly over an endless expanse of water, which represents time. Beneath this water, Ak Ana ("White Mother") calls out to him saying "Create". To overcome his loneliness, Tengri creates Er Kishi, who is not as pure or as white as Tengri and together they set up the world. Er Kishi becomes a demonic character and strives to mislead people and draw them into its darkness. Tengri assumes the name Tengri Ülgen and withdraws into Heaven from which he tries to provide people with guidance through sacred animals that he sends among them. The Ak Tengris occupy the fifth level of Heaven. Shaman priests who want to reach Tengri Ülgen never get further than this level, where they convey their wishes to the divine guides. Returns to earth or to the human level take place in a goose-shaped vessel.
Wikipedia contributors. (2020, December 14). Tengri. In Wikipedia, The Free Encyclopedia. Retrieved 13:46, January 7, 2021, from https://en.wikipedia.org/w/index.php?title=Tengri&oldid=994196124

There's a poetic adaptation of the Turkish Creation Story by Eugene Doty you may find interesting.

Who is Er Kishi in Mongol mythology?


How can I make a continuous outline from multiple strokes?

Question: On screen, my creation looks fine, but when I outline strokes or create offset strokes, everything is jacked up.  I have converted text to outlines, adjusted the resulting outlines, but can't figure out how to get AI CS5.5 to convert to a continuous stroke. Suggestions are most appreciated.
Comment: Is this the desired effect? https://i.stack.imgur.com/N62zc.png
Comment: Is your original outline one continuous path? [Which would be *one* problem. I don't see whatever could have happened to get it breaking so bad as in the `/u` and `/e`.]
Comment: WELZ,  thanks for your reply.  Your sample is very close to what I was trying to achieve, but there was still some missing offset on the C and E's, in particular.  The problem seems to be my inability to get the separate line segments to connect.
Answer: Your outline appears to not be one, single path. But a collection of separate segments. You need to make the outline a single path for offset path to work as you are expecting.
You can actually tell where the path breaks by looking at the results...

The S looks correct because it is the only character which is a single path.
If it's all one, compound, path, then the offset will be as you are expecting:

So you merely need to join the separate segments.
Comment: I'm not certain what more I can do to help. You have to join the segments. That may mean zooming and and carefully selecting anchors, or cutting some paths so they can be joined properly to other paths. Or manually tracing the entire outline with the pen tool (which is what I did).
Comment: Man my quickly drawn R and C look pretty bad :)
Comment: What you did is exactly what I was trying to do.  I started out with text, converted to outlines, squished the text together so it would overlap, selected appropriate paths, then used the scissors tool to cut the paths so the overlap would go away.  I'm simply unable to figure out how to get the new paths to join.  Sometimes I can select end points, and click 'command J' with success, but often times, I get an error, or what appears to be an end point is an anchor point.  CS 5.5


Is there any alternative to using capo?

Question: I don't have/want to use capo for my guitar.
Can a specific tuning be applied as an alternative to capo?
Comment: It depends on what you want. Electric guitarists rarely use capos because open strings are less important. If you want ringing open strings in a different key, which tuning you use depends I the key, but tuning between each song means you better have many instruments or great between-song patter.
Answer: It entirely depends what you want to play.
A capo is for transposing a piece up by some number of semitones, without changing the fingering. So let's look at ways to transpose those pieces without a capo -- it will often involve changing the fingering:

If the piece does not contain any open strings, you don't need a capo. Just play the piece with your left hand higher up the fretboard.
If the piece contains a few open strings, you may be able to finger the piece a different way -- whenever the original had an open string, you'll need to fret it. Often you can achieve this with a barre. In this case your index finger is being a "capo" temporarily.
You could tune all your strings up by whatever interval you're transposing. But note that tuning up by more than 3 semitones puts you at risk of breaking strings (and when this happens, cutting flesh), or damaging your instrument's neck.
You could accept different chord voicings. For example, if your original involved strumming the chords D then G, and you're transposing up by 2 semitones, then you could play the chords E then A, including open strings. It will sound different, but it would still be an acceptable accompaniment to a song.

There are transpositions that can't practically be achieved without a capo.
Consider this chord:
<code> %0.7/2.7/3.6/1.0.0
</code>
The fretting is all on the 6th and 7th fret, but there are also three open strings. If you tried to transpose this up by 3 semitones, without a capo or retuning, you'd have to finger the 3rd fret, as well as the 9th and 11th fret. Nobody's hand is that big!
You don't explain why you don't want to use a capo. If you want to achieve what a capo does, then a capo is the best way to do it.
Answer: For the sake of a thorough answer, there are some new electric guitars that have recently appeared on the market that make use of what is refered to as a "digital capo". They can be configured to use built-in digital signal processing to raise or lower the pitch of the strings by digital pitch-shifting, while the actual tuning of the physical strings stays the same. So the notes coming out of your amplifier are different than the acoustical notes played by the strings themselves.
Getting one of these guitars would be expensive as they are rather esoteric instruments. The pitch-shifting technique is not entirely natural-sounding.
Examples are the Line 6 Variax, the Fender-Roland V-Guitar, and the Peavey-Antares Auto-Tune guitar.
Comment: These instruments, at least the Variax and the Fender-Roland, are set up to provide all sorts of alternate tunings, but you can also used them to raise or lower the pitch of all six strings by the same amount at once, acting as a capo.
Comment: I understand this is how Joni Mitchell plays these days, using the box to switch between the outstanding number of tunings she uses, although then it would be "alternative to alternate tunings" instead.
Comment: But there are also pedals like digitech whammy that can do similiar things.
Answer: A set of light strings, tuned a few semitones sharp, will have a similar tension to a set of heavier strings tuned to concert pitch.  Consider the following two sets of strings:
<code>.009 .011 .016 .024 .032 .042 -- A "light" set
.012 .016 .020 .032 .042 .054 -- A "heavy" set
</code>
The "E" string of the first set and the "A" string of the second set would both be interchangeable.  A guitar wouldn't care whether that string was put in the sixth slot and tuned to "E", put in the fifth slot and tuned to "A" [five semitones higher], or put in the sixth slot but toned to "A".  The pattern doesn't quite continue on the higher strings, so tuning a light set up a full five semitones might be a bit of a stretch, but tuning up four semitones should not be at all unreasonable if one is using a light set of strings to start with.

Is there any alternative to using capo?


How to download the monero blockchain testnet?

Question: I want to download the entire monero blockchain on my local node. Where can I find the guide or documentation to download the entire blockchain? Will it run on the bitcore like zcash, litecoin etc...?
Answer: To download the Monero testnet blockchain, you run monerod with the --testnet flag, ie monerod --testnet. The blockchain will start downloading. Note that you will need a current version of the Monero code: either master from github, or the release-v0.12 branch, as of now. The Monero software in 0.11.1.0 is not recent enough to use the current testnet chain.
I'm not sure what you mean by running on the bitcore, but it will run on most machines. If you can run the mainnet, you can run the testnet, and the mainnet and testnet chains are independent. Since Monero is not a Bitcoin descendent, it will handle differently from Zcash and Litecoin, but the principles should be similar.
Comment: Could you give me the link to the current version of monero? If any documentation on how to download the monero blockchain will be greatly helpful.
Comment: The repo is at https://github.com/monero-project/monero. I already said how to download the chain: run monerod (and add --testnet if you want the testnet chain). It is automatic once you run it, no further command needed.


Isn't silent downvoting becoming too much frequent?

Question: Since (earlier last month) I have joined chemistry SE, I have gradually found it to be a very interesting than other QnA sites.
But, of late, I have become a little bit concerned about the usage of Downvoting privilege.
Yes, this privilege should obviously be there for certain reasons, but isn't it being used too frequently?
As far as I understand, this privilege is for closing or giving hint for correction to any post (question/answer) which doesn't comply with the norms of posting in chemistry SE.
But won't a comment pointing out the mistake(s) or suggesting a correction be more helpful than a silent downvote?
Yes, if even after the comments the author remains stubborn to h(is/er) thoughts, then I think it will be the best and high time to cast your Downvote. Won't it?
Please be sure that I am not talking against Downvoting rather Silent downvoting!
And I am seeing this mainly against the newbies. It'll be unfair to expect that every new member will go through all the norms of SE and then will post a question! I think a huge number (even a little 2-3 for the initial times) of downvotes may discourage them to post further freely!
So, I'm just requesting to all the members of this community to have a thought on this.
I mean C'mon Curses(downvotes) can't bring the best out of anyone rather Prizes(upvotes) or Praises(comments) can do
P.S.- If you feel this post useless, you are welcome to downvote, Silently =D
Comment: What you can improve in this post: reduce bold, remove incorrect capitalisation, use paragraphs. Also there's description when you hover mouse cursor over downvote button so they aren't exactly silent.
Comment: I guess I maybe went deeper than you. There's no point in talking with guys who pop in here only once, for their homework done, but new, real users like you should get support.
Comment: Not just related, but the answer is there.
Comment: related https://chemistry.meta.stackexchange.com/questions/3138/reasoning-or-commenting-before-downvoting
Comment: @Mithoron yes related. But I am not asking for any rule that commenting should be made necessary before downvoting. My concern is that our main aim is to enlarge our community and receive more conceptually productive questions, right? Now, if we don't point out the mistake in anyone's post and just downvote and move on, then how are they supposed to understand their fault? That's why I just requested to point out the mistakes and if you wish to downvote even after that, yes do it. But **please do comment something so the author can understand their point(s) of mistake(s)** to improve further!
Comment: Got your point @Mithoron =D. But I am not asking for every post, I mainly emphasizing on those post which can be improved *logically* or *conceptually* and I think orthocresol has aptly pointed out the gist of my this boring large post. So, I hope you'll get my point.
Answer: I agree that leaving a comment is always more helpful than a silent downvote. Yet, there is no way to force people to do so. So once that's out of the way, we come to the idea of encouraging people to leave comments (instead of forcing).
Many of the regulars here try to help as many people as possible, but you must remember that all of us have real life to deal with and we can only leave so many comments. If you see that something gets silently downvoted and want to help, then you can always leave a comment yourself - help to make the change that you want to see.
I will mention though that very few people have lots of patience with posts that grossly violate site policies. Technically, all site policies are available to browse on the help centre, and it is on the asker to read these before posting a question.


How do you release the wires from a push-in wire connector?

Question: I would like to reposition some pot lights - before drywalling the ceiling.  They have been wired using push-in wire connectors.  How do you release the wires from a push-in wire connector ??
Comment: Possible duplicate: [What type of connector is this and how do I remove it?](http://diy.stackexchange.com/questions/21820/what-type-of-connector-is-this-and-how-do-i-remove-it?rq=1)
Comment: If you're referring to the push in connector on the back of a switch/receptacle then this is another possible duplicate: [What kind of electrical outlet is this, and how do I replace it?](http://diy.stackexchange.com/q/20155/2196)
Comment: A photo would be helpful some connectors are not designed to be reusable, some are and a piece of #14 wire or a small screwdriver can be used to remove the wires.
Answer: If you're talking about an outlet - or a similar concept fixture - the best tool I've found is a flat head jeweler/precision screw driver.
The wire is being held in by this:

You can see you'll need to push that "tab" away from the wire, from the back of the outlet you should see a small rectangle hole next to each circular hole that the wires are in:

MAKE SURE POWER/BREAKER IS OFF YOU WILL BE TOUCHING A "LIVE" WIRE
Insert a small jeweler screwdriver in the rectangular hole/slot, use the box as your pivot point and the screwdriver as your level (bring back end of screwdriver towards wire to force "tab" away) and gently pull the wire out.
* If the outlet is old/weak or the wire wasn't inserted in deep you can sometimes get away with just twisting the wire back and forth while pulling.
Comment: Since the OP mentions "pot lights", I don't think that's the type of "push-in" connector they're talking about. Many lighting fixtures (especially recessed fixtures), come with [this type of push-in connector](http://diy.stackexchange.com/a/21821/33)
Comment: @Jason, yeah, but the point is the push-in connectors like those included with recessed lights do NOT have a release function.
Comment: See also: http://diy.stackexchange.com/q/20155/2196
Comment: My pot lights are like this, I just didn't feel like using a ladder and taking pictures.
Comment: I agree with speedy petey most fixtures use wego and those have to be cut off.
Answer: I am guessing you are talking about something like what Halo has seen in the image below.

To get these out you are supposed to just twist like hell and pull out.  I have had to pull a couple out in my basement and it takes a minute.  Also wear gloves because there are a lot of sharp edges around.
If you are going to rewire you need to install a new connector.  Stab connections are not listed for re-use -- once you pull a wire out, their spring is weakened and they cannot be relied on to hold again.  Reusing them violates NEC 110.3b, the requirement to follow labeling and instructions.
Note: My preferred method is to use needle nose pliers and grip about an inch from the connector.  Then just jiggle and pull until it is lose.  I have found jiggling allows me to not have to pull as hard.
Comment: If he needs to install a new connector after pulling the wires out... why not just cut the wire close to the connector and install them into a new one? Much easier and less painful :)
Comment: They are not listed for reuse, twisting or pulling damages the wire and the connector, best to snip and get new ones or wire nuts.
Comment: If shortening the wires is an issue, compound action pliers (like Irwin Vice Grips) might be able to crush and break apart the connectors along the long dimension.
Comment: He doesn't need to, he might.  I have pulled A LOT out.  Maybe 1 out of 6-7 is ruined after pulled.
Comment: @EdBeal : Wouldn't recommend wire nuts; they are not legal in Europe, and I believe that is because they are less reliable than Wago or similar connectors.  (YMMV)
Answer: Just twist the connectors back and forth while pulling them off of the wires. It doesn't require too much strength to do.
Answer: I just did this with my husband.  They absolutely do not pull out once they are in, but he cut the wire off leaving about 1/4" coming out of the connector.  He handed it to me and said, "See what you can do" thinking we'd just have to get a new recessed light fixture.  I googled my question in and came to this website.  When I read the post where someone suggested twisting, I went back, took my needle nose pliers, pulled off the plastic wire covering so I could get a better grip on the wire.  I didn't need gloves...I didn't need to work up a lather and I didn't ruin anything.  I realized that it had threads that kept the wire from pulling out and simply and gently twisted it counter-clockwise and it eased it's way out!  Our mistake was that my husband forgot to put the wire through the punch out holes in the box of the recessed lighting fixture first!  But, he got them through and poked the wire in the appropriate holes of the connector and you couldn't pull them out.
Answer: An additional technique is to remove the insulation and then pull a few of the wire strands out. Then the rest of the strands come out easily.
Comment: The vast majority of wire I see used in such situation is not stranded. In fact I don't recall ever seeing stranded wire used in these cases.
Comment: Most backstabs are not listed for stranded wire and do not play well together.  In fact I recently discovered an excessively warm receptacle, and opened it up to find #12 stranded had been stuffed in a backstab hole intended for #14 solid only.
Answer: After trying this myself and reading the replies, I feel like the best way to handle this is to tear apart the plastic push-in connector and replace it with a proper multi-use WAGO connector. This is not an easy thing to do, but then you end up with completely intact wires which is what you want, and you don't need to shorten the wires by cutting them off. I am going to need to do this 8 times for 4 potlights... very annoying. Honestly, I don't understand why they can't spend 10 cents extra or whatever and include proper WAGO-stype connectors. Maybe it's because they are patented and therefore expensive to include. Who knows.
By the way I read somewhere that the twist on connectors are not less safe than WAGO, they are prohibited in UK for historical reasons because at some point they had some terrible screw-on connectors there that caused a whole bunch of fires. These are not the same as the ones used in modern US and Canada. In any case, for low load WAGO is definitely the way to go. For things that require permanent connection and heavy load the best way based on some advice I got from experts is to twist a long stretch of a wire, put a copper clamp on top (maybe even more than one), and then cover it all with heat shrink. The only way that is better than that is to weld the wires (not solder but actually weld). But that I feel like is a massive overkill for residential applications. Not a pro, just got some advice from pro electricians that work with high voltage industrial-grade circuits.
Answer: A better answer is: don't.
The push in connections are not as reliable as screw connections.  Instead cut the wire keeping as much length as possible, strip, and put it around the screw.
Or, twist and pull.  But expect to have to cut the wire short anyway as it will be all scratched out.
Comment: Agreed, when possible stick with the screws. But you still have to know how to undo the spring connections for those cases where whoever installed the previous unit didn't follow that advice.
Comment: ???  I disagree.  Wago sell their connectors in the UK as suitable for locations where the finished work will not be accessible.  Screw connectors are *not* valid there (screws can work lose over time).
Comment: @Martin bonner, with the specific exemption of nm splices that are approved for in wall all splices in the U.S. are required to be in boxes and accessable, I have repaired replaced hundreds of backstabed devices over the years On outlets and switches only 14 gauge wire can be backstabbed not 12 gauge (I know wago has listed pushins but you won't many Useing them in the U.S.) In industrial panels I have only seen spring loaded terminals 1 time and we had to remove these as the wires kept falling out due to vibration but have no problems with the screw terminals keeping the wire in place.
Comment: If you're going onto screws, the wire being a little scratched doesn't matter.
Answer: I have a surefire method to release the wire.  Just use a drill in the little hole that geniuses can use to free the wire.  Drilling with a drill bit a little larger than the hole with break off a bit of Bakelite and you are most of the way home.  This method ruins the old fixture but they only cost just over a dollar.  You were probably going to replace it anyway.
Answer: The easiest way I have ever found is to just cut the wires and re strip the wires.  If I find an electrician that uses these and is to lazy to wrap the wire around the screw like the old days (needle nose pliers to make the loop) I find a new electrician because it drives the rest of us crazy to have to fix later.
Answer: Just tried pulling wires out of several Utilitech Push-In Connectors, using needle nosed pliers. It worked. Just twisted and pulled at the same time. Didn't take much force.


Are there any aspects of PhD work that do not translate well to distance learning?

Question: In another question about distance PhDs (Do any schools offer teaching or research assistantships via distance education?), I received several comments noting that PhDs on-line are of inferior quality to on-campus PhDs. If what is seen of PhD work from PHD Comics is accurate, PhD students seem to spend much time working independently. So, what aspect of a PhD cannot translate to the on-line format? What aspect of the process cannot be effectively conducted via E-mail or any of the other various forms of on-line communication?
Comment: Are there any aspects of PhD work that do not translate well to distance learning? It's a little flippant to say "all of it." But it's not far from the truth.
Comment: Can you edit to specify whether this is a STEM PhD or a non-STEM PhD you are talking about? I believe that would make a somewhat significant difference for the answers you will get.
Comment: @DumpsterDoofus - sometimes your entire lab can be an average computer.
Comment: @Village: It's an important distinction; in STEM fields, it is basically impossible to do a distance-learning PhD, because you don't have a laboratory, and so you can't do research, and so you can't publish papers, and so you can't create a thesis, and so you can't get a PhD.
Comment: For non-STEM fields.
Answer: A general answer is that a lot of PhD training is informal: it involves things that are taught by example, by osmosis, by noticing someone doing something wrong and correcting them (or right, and praising them). This kind of informal training is much more difficult in online interactions. Some examples are given below...
One specific aspect that does not translate well to online learning is the cross-pollination of ideas via proximity.
A big part of training PhD students involves putting a bunch of smart, talented, hardworking people together and letting them learn from, motivate, support, and bounce ideas off one another. A prerequisite for this is proximity; you just can't have the same kind of interactions over email. Some research centers are explicitly designed to encourage this. At the Bell Labs facility in Murray Hill, NJ,

Some of the hallways in the building were designed to be so long that to look down their length was to see the end disappear at a vanishing point. Traveling the hall's length without encountering a number of acquaintances, problems, diversions and ideas was almost impossible.

(Source: New York Times)
The research center I currently work in was built with a long hallway with this in mind, specifically to foster collaboration between students in different groups!
Another thing that does not translate well is learning scientific communication and mentoring skills. As a PhD student, I have many chances to practice speaking about my work to other graduate students, professors, and undergraduates. I also get to mentor M.S., B.S., and high school students in my lab. These skills are much more difficult to learn over distance.
A third thing that does not work well over email and Skype is learning the etiquette and standards of the field. This is something that isn't explicitly taught (usually) but that students are expected to pick up by osmosis from spending time with other academics and others in their field.
Answer: ff524 provides an excellent answer—although I think there are several other important points that are not discussed there.

Experimental work cannot easily be done via long-distance arrangements, unless one happens to be near another research institution with the necessary equipment and support staff to enable the research to take place.
It is also worth noting that online interactions are still not ideal for rapid development of new ideas and discussions. For instance, suppose during a conversation with your advisor, you want to make a quick sketch and show it to her. If you're meeting in person, you can easily develop the figure on paper or on a whiteboard (or similar), and adjust and make various comments. Such an exchange is extremely tedious online—to the point of being almost counterproductive.
Comment: @Ajasja: If you're in the humanities, or in many other fields, you may be referring to archived documents, original materials, monographs, and other works that are simply not available online in any format. (For one paper I worked on as an undergraduate, I checked out a book from our university library that had not been checked out for __110 years__ prior to my doing so.)
Comment: To experimental work, I would add library research (which will be more relevant for a different set of fields).  Note that there is a huge difference between academic libraries and non-academic libraries for research purposes.
Comment: @MarkMeckes Can you elaborate? I do all my literature searches online...
Comment: @Ajasja: I also do all my literature searches online, but things vary a lot from field to field.  aeismail's comment makes the point I had in mind.
Answer: This is meant to be in addition to your other answers, so will refer to them  a bit.
First let's take your clarifying comment: "For non-STEM fields" I work in a STEM field, but have spent time discussing related issues with postgrads working across the university.  Many of those in non-STEM fields seem or feel rather isolated anyway compared to those of use in a research group which works closely together.  This is partly due to the organisational structure and funding situation leading to fewer PhD positions in some fields, as I understand it, both of which will vary between universities and countries. This could go either way - it could mean that remote working takes away the last vestiges of academic human contact, or it could mean that your tucked away in a corner of your own home alone, rather than a corner of the office. This relates to ff524's answer as well, though I'm coming at it more from the important aspect of getting through a rather strange life for a few years rather than learning academic or transferrable skills.
How much library research (wrt aeismail's answer) is necessary offline will vary hugely with subject - in my case very little, though access to textbooks at all but especially the early stages must not be neglected.  They may not be realistically available for you to buy.  Access to a more local university library as a visiting reader may be possible, but it would be unwise to rely on  this and you may not be able to borrow the books.
You need a supervisor who's not just willing, but enthusiastic about the idea.  I wouldn't want to be a supervisor's first remote student - let someone else iron out the difficulties first.  You need to be on the same wavelength when it comes to collaboration tools, which means in practice you need to be happy to work with the tools your supervisor wants to use.  This is a minor issue when you work in the same building, but becomes critical when you're widely separated.
Answer: I would like to stress a bit more the role of "motivation" as in the answers of ff524 and Chris H., specially in the emotional aspect of it. I would say that doing a PhD has an implicit feeling of isolation: in general, you become an expert at a really narrow field compared to the whole human knowledge (I love how Matt Might explains it in his Illustrated guide to a Ph.D.) and that makes sharing your experiences/thoughts harder (how would you share your troubles and toils with your girlfriend?)
Even if there is no one in your research group doing anything related, the fact of sharing a space (not even talking!) with other people going through the same processes is comforting somehow.
Intuitively, adding a layer of physical isolation on top of the experience would make it less stimulant.


Removing icon from menu-bar

Question: Does anyone know how to permanently remove an icon put in the menu bar by DYMO label maker software?  I can right click it and remove it, or drag it off the menu bar.  However, it returns upon a reboot.
Comment: Have you contacted the maker of the software and asked them how to remove it?
Comment: Check `System Preferences > Users & Groups > Login Items` tab to see if the DYMO software is set to open when you login. If it is there, select it and click the minus sign icon to delete. If you have the original software installer, perhaps there is an uninstall function. Which model of labeler do you have?
Answer: So I downloaded dyno marker software on my Mac for you and I found a simple solution to your problem but before I tell you the solution, make sure of the following:

DYMO label marker app should be quit
Make sure the app is in your Applications folder

After making sure then run the following in terminal app:
rm /Applications/DYMO\ Label.app/Contents/Resources/DYMO\ Label.icns
Then open the app and check if you are still able to see the icon in the menubar.
Comment: I'm having the same issue and this didn't work for me. The Dymo software doesn't even appear in the login items, so how are they making it load at startup? Nobody should download this app. It's terrible.
Comment: Also, Bartender shows DYMO.dls.printing.host in it's list of menu items, but when I search the whole mac I can't find that anywhere.
Comment: Have you tried removing it after installing App Cleaner?  when you delete the app, App cleaner finds related files and offers to delete them too. Maybe this is what you need.
Comment: I finally got it! The Dymo installs the library files directly on the Macintosh HD. When you open a finder window and navigate to "Library", you're actually in the library folder for the user account, not the one on the HD. Finder searches and App Cleaner searches didn't reveal it, even if Finder is told to search "This Mac".

Removing icon from menu-bar


Phone, carrier and country combination

Question: I am interested in getting the Lumia 1520 in eBay or Amazon, the problem is that the 1520 is not officially offered by any carrier in my country. I know I can get any unlocked phone and just put in the Sim card and it will take calls but, will it get the software updates? Anyone can help me with this?
Answer: All Windows Phones will get any updates that are released. Updates are released by the country that the phone was intended for sale in, and carrier lock status; So if you were to import from the US, then you'll get updates in line with when the US end users get their updates, even if you're using your phone day to day in (say) Latvia

Phone, carrier and country combination


partially cooked meats

Question: I am making tomato sauce.  I plan to brown several kinds of meats and poultry today and finish cooking them in my tomato sauce tomorrow.  Is there some health issue I should be concerned with partially cooked meats that will spend over night in the refrig before putting them in my tomato sauce that will be cooking for several hours?
Answer: There really isn't a safety issue here as long as you brown the meat soon after taking it out of the fridge and immediately re-refrigerate it. Just don't leave it out of the refrigerator longer than necessary to do the browning. It wouldn't hurt to save the browned meat in a clean container, not the one that that held the raw meat.

partially cooked meats


Should i write sqlite database file to Documents directory or Library/Caches?

Question: I have read the Data Storage guidelines of Apple and am really confused as to where i should keep the sqlite database files i am creating in my app.  I want to read from the sqlite files even when the app is in Offfline mode. I read that such files created should be kept in the Library/caches with the "do not backup" flag set. Please suggest me the right approach for doing the same.
Answer: The answer depends on how your database files are created:
According to the Data Storage Guidelines page:

Only documents and other data that is user-generated, or that cannot otherwise be recreated by your application, should be stored in
  the /Documents directory and will be automatically
  backed up by iCloud.
Data that can be downloaded again or regenerated should be stored in the /Library/Caches directory. Examples of files
  you should put in the Caches directory include database cache files
  and downloadable content, such as that used by magazine, newspaper,
  and map applications.

This seems relatively clear to me: if your app programatically creates something or generates data that you want saved, put it in the "Caches" folder.  If it's something unique that the customer themselves generate (via typing into a keyboard or something they manually intervened and did), put it in "Documents".
"Do Not Backup" means that the files never get sent up to iCloud and if they get lost, they have to be re-created from scratch (or re-install).
Comment: I have developed a app fully static . I am storing data more than 4 mb of size. With out this content the app will not work. In my case where should i save the local database(documents folder or library folder)
Comment: [Well I see you've already asked this as a separate question](http://stackoverflow.com/questions/16767861/where-to-save-the-local-db-created-for-iphone-app), so either I (or somebody else) will go look up the answer for you
Comment: What about new Extensions and Watch ?
Comment: I am not sure, but I think for a single app, **depending on your database's requirements** you would may be reading some parts of your app from Documents, some parts from Cache and some parts in tmp **simultaneously**
Answer: This may help you. Copying the database to the documents directory will be good enough, The files on bundle is read only, In some situation If you need to update at anytime the better way is copying the database at first if it not exists on the documents directory.
The sample code for copying the database to the documents directory is follows:
<code>-(void) checkAndCreateDatabase {

    // Setup some globals
    NSString *databaseName = @"AnimalDatabase.sql";

    // Get the path to the documents directory and append the databaseName
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDir = [documentPaths objectAtIndex:0];
    NSString *databasePath = [documentsDir stringByAppendingPathComponent:databaseName];

    // Check if the SQL database has already been saved to the users phone, if not then copy it over
    BOOL success;

    // Create a FileManager object, we will use this to check the status
    // of the database and to copy it over if required
    NSFileManager *fileManager = [NSFileManager defaultManager];

    // Check if the database has already been created in the users filesystem
    success = [fileManager fileExistsAtPath:databasePath];

    // If the database already exists then return without doing anything
    if(success) return;

    // If not then proceed to copy the database from the application to the users filesystem

    // Get the path to the database in the application package
    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];

    // Copy the database from the package to the users filesystem
    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

    [fileManager release];
}
</code>
You can refer this Tutorial
The files, contents on documents directory is read, write mode, so you can read the contents  from the database.