Physical meaning of cofactor and adjugate matrix

Question: I like the way there a physical meaning tied to the determinant as being related to the geometric volume. Since the determinant can be calculated through Laplace's formula where the cofactor matrix is involved, I'm wondering what would be the physical/geometric meaning of the cofactor matrix? What about the adjugate matrix?
Comment: Similar question: https://math.stackexchange.com/questions/254774/what-is-the-intuitive-meaning-of-the-adjugate-matrix
Comment: I think this might require a long line of reasoning, but it's based on even simpler logic than the Jacobian matrix. I personally find that it's adequate to start with the understanding that the determinant is just the volume of the hyper-parallelipiped. The reason transposition is involved in the adjugate matrix is because its product with the original matrix would represent dot products.
Comment: @Tunococ Based on your comment, I'm going to edit my post. I agree, I should have asked about determinants in general
Comment: I'm not sure if [this](http://math.stackexchange.com/questions/194579/what-is-the-origin-of-the-determinant-in-linear-algebra/194592#194592) would help. Then using the same geometric understanding, Cramer's rule follows easily. You can then think of the adjugate matrix as an application of Cramer's rule.
Answer: As you may know, an interpretation could be as vectors and volumes in the dual space.
But it is not very physically meaningful...
I will give here a geometrical explanation in $\mathbb{R^3}$.
Let $u,v,w \in \mathbb{R^3}$. Call $A$ the matrix with these columns $u,v,w$.
Imagine the parallelotope $P$ generated by $u,v,w \in \mathbb{R}^3$.
The volume of $P$ is precisely $det(A)$.
Consider the cross products $a = u \times v$, $b = v \times w$ and $c = w \times u$.
Let us call $B$ the matrix with these columns $a,b,c$.
Geometrical view: Vectors $a,b,c$ are normal to the faces $(u,v)$, $(v,w)$ and $(w,u)$.
They generate in turn a parallelotope $P'$.
We are going to see that this parallelope $P'$  is a way to "visualize" the inverse of $A$
(I prefer to use the inverse matrix formulation instead of the cofactor matrix or adjugate matrix).
Indeed, by considering the products of lines of $A^T$ with columns of $B$, one gets
$A^TB=k I_3 \ \ \ (1)$
where k is the triple product $[u,v,w]$ which is nothing else than $det(A)$.
Taking determinants on both sides of (1), we obtain $det(A) det(B) = det(A)^3$, from which
$det(B)=det(A)^2$.
In words, the volume of the parallelotope $P'$ generated by $a = u \times v, b=v \times w, c=w \times u$ is the square of the volume of the initial parallelotope $P$ generated by $u,v,w$.
Answer: Let $x_1,...x_n$ be the column of your matrix $M$. Consider the simplex they generate with the vector $0$, (a tetraedron in dimension 3). In the dual of your space (ie the set of line vectors)look at the dual simplex, namely the set of (line) vectors such that $0\leq <x_1,y> \leq 1$. This dual simplex is the convex hull of $0,y_1,...y_n$, with $<y_i,x_j>= \delta _i^j$. So the $y_i$ are exactly the lines of the inverse of $M$, and their coordinates (in the dual base) are the cofactors divided by the determinant.


How to write a drupal cron job to fetch data from a link

Question: How can I write drupal cron job that fetches data from a link and update the database ..? Im new to drupal so unable to understand the working of cron after searching alot. Any help will be appreciated ..
Comment: You should state your Drupal version... is the data of the link formatted in json, xml, csv? or what?
Comment: @No Sssweat Im working on drupal 7.x .. data is coming in json format
Comment: Welcome to Drupal Answers! It's not clear if you are asking how to fetch data from an external source, or which hook you need to implement, but in the first case, the question is too broad, and in the second case the answer can be easily found on api.drupal.org. Just search for [_cron_](https://api.drupal.org/api/drupal/7.x/search/cron) and any of those listed functions give you a hint about what hook to implement.
Answer: Create a simple Drupal 7 module, there are a lot of examples for this (i.e. here). Then hook into cron with a function mymodulename_cron() and inside the mymodule_cron function fetch your json data.
Your mymodulename_cron() will be executed each time, the drupal cron is run. This can be done from outside or from the admin/reports page. Look at /admin/reports/status for info about this.
Comment: thanx @Rainer Feike .. I've created custom module and implemented hook_cron. My hook is working well when I click on run cron from admin interface. I want this hook to execute automatically right after one hour. But im unable to do it. Could you plz guide me how to accomplish this task?
Comment: You can call the cron.php of your site from outside, i.e. use unix-cron and wget. Depends on your deployment env.
Comment: Or you go to /admin/config/system/cron and set the drop-down to 1 hour :-)


Implement File_gets_contents() and image

Question: I want to write a php program, that will take get the images also, the problem is when i do file_get_contents, i only get html excluding the images.How can i go about?
Comment: you question is very vague. get images from where? what are you using file_get_contents() on? what do you mean by "i only get HTML"? overall, what are you trying to accomplish? from your question I have no idea what you are talking about.
Answer: file_get_contents reads the contents of the file and not the contents of the linked files. your script should provide functionality for retrieving the linked files on detecting the links in file being read
Answer: If you are working in a posix environment, you might want to consider invoking wget recursively through shell_exec and let wget do the heavy lifting for you.  There's an article about it on superuser.com.


Keep menu bar even in full screen mode?

Question: Is it possible to keep the menu bar on top of everything and not hide when you open a full screen program? I know you can drag your mouse up and it reveals, but I would like it to stay there all the time.
Comment: What OS/application are you talking about?
Comment: Isn't that just a maximized program?
Comment: Are you talking about Lion? If so, please tag your question as such. (Also, the answer is probably no.)
Comment: Sorry for not being more specific. I'm new to mac and using pixelmator. Just pushing "F" within the program to go full screen.I thought there might be a always keep menubar on top setting somewhere I couldn't find.
Answer: I've found the answer here (Randy6T9's comment to the question):

Add a space to Mission Control: open Mission Control with F3 (or swiping up with four fingers on the trackpad), then click on the '+' button on the top-left corner of the screen.
From Mission Control, drag your application to the new space.
Maximize the application within the space: hold alt+shift and click on the green button of the application top bar.
Comment: Nice. Doesn't quite do the same (most notably, the new space is not named after the window, which I found useful with fullscreen), but it gets of the "you want to click here? Nah, let me shove the menu under the cursor"-annoyance.
Comment: Nowadays: CTRL+Up
Answer: Ctrl+F2 gets menubar focus in the full screen app mode.
Set the F-Keys to standard function keys via keyboard preferences. The default is Ctrl + F2for menubar focus, and Ctrl + F3 for dock focus.
Comment: Typo in this answer, its `Ctrl` + `F3` for Dock focus. Edit to small to be allowed.
Answer: In reality, there are always solutions. It sounds like you're looking for a system level solution to this problem.. I may be able to help point you in the right direction. Here's what I'd try.. Also, I'm going to assume you're not on Lion, which may actually have a preference setting for this kind of thing, sounds like it may from one press release I read, anyway.
1. App-specific config settings
I'd start by exploring all the config options for your specific application. Maybe you even have a friendly gui option for this.. Failing that unlikely event, many apps will store their own preferences inside of their app directory (those icons in /Applications are actually 'executable' directories, there are lots of files inside them). You may also want to look around in your user/home directory - particular under "~/Library/Application Support/[App name]". I've found many games graphics engines have config options you never get a gui for. In a case like this, maybe you could set a lower resolution or some flag that lets the OpenGL (assuming that's what we're really talking about) context run in a window rather than in full screen mode.
2. Explore the defaults system
OSX has a structure that I believe to function much like the Windows Registry.. A kind of database of settings. This is the defaults system. With piles of luck, maybe there's a setting in there?
2.5 Try InsanelyMac forums
I've found the people roaming the InsanelyMac forums to be severely knowledgeable about the plumbing of OSX. I'd head over there and ask for help. They may help you figure out a 'defaults system' solution, or something else.
3. It's a trap! The shield is still up! Pull Up!
It's possible if none of that stuff yields fruit, you may just HAVE to wait for OSX 10.7.. Or hack out some other solution that sort of satisfies your needs. Hopefully it won't come to this, but it does sound to me like a possibility.. Unless you can get your hands on the code for the thing you're wrestling..
Anyway, that's the best I can give ya. Good luck friend!
Comment: I'm now running on OSX 10.10 (Yosemite), OSX handles fullscreen applications far better than it did in previous generations. 10.9 introduced some fairly big improvements in this regard as well. This question is probably going to become quite irrelevant for most OSX users soon.
Comment: BTW defaults only edits plists in ~/Library/Preferences, unlike the registry it's not a database, or centralized. The closest thing OS X has to a registry, is the IORegistry which is regenerated at boot, and only lives in memory.
Comment: @MarcusJ I think the 'defaults system' is extremely similar to the Windows registry in function. Not that I interact with either THAT often.
Answer: You can press shift & alt/option and click on the green maximize button.  This maximizes the screen and keeps the menu bar on top.  Credit: https://forums.macrumors.com/threads/how-to-always-show-menu-bar-in-full-screen.1221766/#post-22753191
Answer: In Monterey (v12.2.1), this is already supported.
In System Settings -> Dock & Menu Bar,
deselect "Automatically hide and show the menu bar in full screen".
Now, the menu bar will always be shown even in full screen, and in mission control, the app will still be named.
To enforce this on existing Desktop windows, exit out of full screen and go to full screen again. Menu bar will always be shown.

Keep menu bar even in full screen mode?


Map signal strength on a free dataset

Question: I'm looking for some kind of tool to generate a map (on openstreemap basis) with (colored) signalstrength points generated from a scan (not related to wlan, but quite similar to gpsmap from kismet). The input data is right now in a .kml file but converting this before won't be a problem. Any hints?
Answer: hm you can use Openlayers (http://www.openlayers.org/)
that understands KML (http://dev.openlayers.org/docs/files/OpenLayers/Format/KML-js.html)
here is an example: http://openlayers.org/dev/examples/kml-layer.html

Map signal strength on a free dataset


How to buy a website

Question: I am in the market to buy a website. I would like to browse a list of websites that are for sale or up for auction. Are there any good services for this?
Comment: What do you mean by 'website'? Do you mean a domain name (www.example.com) or hosting or both?
Comment: I mean both the domain name and the website. Do you know of any?
Answer: If you're looking to purchase both a domain name, and the hosting to put the website online, I'd advise purchasing them from separate companies (personal preference) unless you find a really good deal for both and have read multiple reviews on the quality of their hosting/customer service.
A good place to check out for your domain name first would be GoDaddy or 123reg, as although I personally wouldn't say they're that great for hosting, they do some pretty good deals on domain names and you can find a wide range of extensions available too.
For hosting however, the choices range far and wide. I don't personally know the reputation of hosting companies over there in the USA, but there's one in the UK called TSOHost that I'd recommend - my websites always seem to be up, and if I do have a query they always answer me within a few hours.
All three of the previous companies I've stated provide you the option of using WordPress and other types of plugins if you're interested in getting a website built fast without having to do much of the back-end coding.
Edit
In the case of wanting to buy an already established website, Flippa is probably your best bet.
Comment: Just to make it clear. I am not interested in buying hosting I am interested in buy an actual website - not web hosting. For example, if stackexchange was for sale they would post it on a website selling service so other people can buy the domain and the website. Is it possible to buy a website like this?
Comment: Oh. In that case you can just use https://flippa.com/buy

How to buy a website


Which sensors can be used to feel breeze blowing by the robot?

Question: Am faced with a situation where my robot needs to feel breeze blowing by over its artificial skin. While there exist many types of tactile sensors, nothing seems to fit the bill. I might abandon the idea altogether but just wanted to know for the sake of know how if there exist sensors to do this sort of thing. Given significant advances in MEMS/NEMS, am assuming there are sensors as sensitive or even more sensitive than hair follicles in detecting touch
Comment: Why are you looking at tactile sensors for sensing pressure? Are you specifically wanting to combine tactile sensing with sensing the air flow bear the skin?
Comment: What level of sensitivity do you require?
Comment: @Adam preferably as good as humans/animals....if possible even better
Answer: Microphone chips have been used as a transducer for this due to their low cost. (This being high density pressure measurements)
Comment: Thanks hauptmech that's actually clever....am building a robot to observe physics at work and establish relationships over time. For example when it feels the wind while simultaneously watching leaves of the tree flutter and also hear it rustle, it should conclude that it's due to the breeze..........True AI can't be possible without good sense of smell, taste and touch am assuming
Comment: `For example when it feels the wind while simultaneously watching leaves of the tree flutter and also hear it rustle, it should conclude that it's due to the breeze.` .... this may not be a realistic goal ..... a dog has more intelligence that your robot can ever have, yet a dog is unaware that leaves rustling and fluttering is due to wind (i have two dogs and i'm pretty sure about what i said) ...... also, what should the robot conclude if it is windy and it sees a water fountain or a flock of birds?
Comment: @jsotola I know a dog is way more intelligent than my robot. In fact my robot is no match for a cockroach. The "rustling leaves" thing is intended for use at a very advanced stage. What I realised is while the problem of solving intelligence is hard enough, the bummer is that good hardware(sensors) does not exist yet. Animal ear and nose have high levels of sensitivity able to distinguish and amplify extremely minute changes. Good artificial noses, tongues and skin are still unsolved and still many researchers are trying for AGI


Illegal Knight vs Number 59 Crooked Cook

Question: I just want to know this because I don't think it works.
The effect of Illegal Knight has you target up to 2 cards your opponent controls and summon it to their field and if you did bounce it back to their hand, so if I have Number 59 Crooked Cook on the field would the effect of Illegal Knight to summon on my field and then bounce it back work. I know it will still summon to my field but will it stil bounce my card?
Answer: The ability of Number 59 Crooked Cook has the requirement that it's controller has no other cards on the field, which means that Illegal Knight transferring control deactivates it's protection from other cards' effects.
When resolving effects with multiple steps you re-evaluate the board at each point which means Illegal Knight will return Number 59 Crooked Cook to your hand.
Unfortunately because this happens in the middle of resolving Illegal Knight's ability you cannot activate Number 59 Crooked Cook's (Quick Effect) to destroy Illegal Knight.


Java - How to remove elements from a Point Array and correctly return new fixed Array

Question: Write a method named removeSomePoints. This method takes an array of Points, and returns a new array of points that is the same as the original array, except that it removes all points that have x- and y-coordinates that differ by less than 20. In other words, the returned array will probably have a smaller size than the original array. This method should leave the original array untouched. To clarify: If any of the following points were in the original array, they would not be in the array that is returned.
100 90 (x and y differ by 10)
90 100 (x and y differ by 10)
3 22 (x and y differ by 19)
On the other hand, any of the following points would be in the array that is returned:
100 80 (x and y differ by 20)
80 100 (x and y differ by 20)
2 25 (x and y differ by 23)
My code:
      public static Point[] removeSomePoints(Point[] arr)  {

   int count = 0;
   for (int i = 0; i < arr.length; i++) {
     if (Math.abs(arr[i].getX() - arr[i].getY()) > 19) {
        count++;
      }
     }

    Point[] finalArr = new Point[count];

    for (int i = 0; i < finalArr.length; i++) {
      if (Math.abs(arr[i].getX() - arr[i].getY()) > 19) {
           finalArr[i] = arr[i];
      }

 }

   return finalArr;
}

I've also tried it with this code using ArrayLists:
 public static Point[] removeSomePoints(Point[] arr) {
    ArrayList<Point> pointList = new ArrayList<Point>(Arrays.asList(arr));
    for (int i = 0; i < pointList.size(); i++) {
        if (Math.abs(pointList.get(i).getX() - pointList.get(i).getY()) < 20) {
            pointList.remove(i);

        }
    }
    Point[] finalArr = new Point[pointList.size()];
    finalArr = pointList.toArray(finalArr);

    return finalArr;
}

Neither of the above blocks of code work for what my finished return array should be, many of the points (such as Point(6, 3) are left in when their absolute difference is certainly less than 19).
Can't seem to figure out what is going wrong. It is returning an array but it doesn't change anything. In my main method I have:
    Scanner scan = new Scanner(System.in);
    System.out.print("Please enter name of file containing Points: ");
    String fileName = scan.next();
    Point[] myPoints = readPoints(fileName);
    sortPoints(myPoints); // works fine
    writePoints(myPoints, "sorted.txt");  //works fine up until this point
    removeSomePoints(myPoints)       //doesn't work, effects below method call
    writePoints(myPoints, "sortedAndRemoved.txt");
    new PointDisplay(myPoints, 10, false);  //works fine, pre-written class

I'm asking what is wrong with my removeSomePoints method and what can be done differently. How do I correctly remove and return the Point Array with all points with absolute difference of 19 and lower removed?
Comment: this is a different question - it's asking about hy the rest of the program isn't taking his function into account, not about the function itself.
Comment: Ok, ignore my comment and close vote, I see the OP has moved on to another part of the same question.
Answer: you're returning a new array but not setting the original array to the returned value. You should change
removeSomePoints(myPoints)       //doesn't work, effects below method call

to
myPoints=removeSomePoints(myPoints);       //works now

That should solve your problem.
Note: this is different than sortPoints because you sort the array in-place but you make a new array to remove the points.
Comment: click the green hollow checkmark on the left of this answer to mark it as correct


How does case inflection work on the head noun in internally headed relative clauses?

Question: I have read that some languages use internally headed relative clauses; so, for example, instead of saying "the man that we met yesterday went home today"; they position the shared noun in a relative clause, so they use a structure that literally translates into English as "we met the man yesterday went home today"; but I am wondering how does case declension work in those languages? I know some of those languages have cases (for instance I know Tibetan and Navajo use internally headed relative clauses and Tibetan has cases as well); but what I am wondering is how do they inflect the head noun so that its role in both the relative clause and the main clause is clear? it is easy to conceive of situations in which  the noun although occurring in both clauses does not play the same role in them both; so how do languages with internally headed relative clauses express both cases?
Comment: If you know a certain language has a particular construction, look at grammars and texts in that language to find examples of that construction. The sources where you learn about the constructions should give you examples; otherwise it's just making a claim without evidence.
Comment: the easy to find sources i have come across are a little vague on exactly how cases are expressed in internally headed relative clauses; I am trying to see if anyone has access to better sources on it
Comment: I'm not sure I understand the confusion.  What is it about internal heads that makes this issue unique?  Most languages have something in both clauses referring to the same entity or allow the relative clause to function itself as a constituent.  I think the only difference with internal heads is that they are not fronted.
Comment: nouns usually only take 1 case; so if the clause is internally headed where (if anywere) does the second case manifest? as in a relative clause the shared noun may, for example, by the subject of the verb in the relative clause, and the object of the verb in the main clause; which typically requires distinct cases in languages with case
Comment: Yes, but internal just refers to position.  The same problem exists regardless of position.  For instance, there is the Latin phrase "Bis dat qui cito dat"  (literally, "twice gives (he) who quickly gives."  Does this phrase not have the same issue as what you describe in your question?   How about: "The man she saw left"?  Does not this sentence also have the same surface challenge that "the man" must reflect two different syntactic uses in the two different clauses?
Comment: that is a reduced relative clause; which only relativise objects, never anything else; and the full relative clauses in english use a relative pronoun; which can; if a language has case be inflected for case; so do they just rely on context or subject matter; or is there a way of indicating it?
Comment: In Latin, the "antecedent" can go in either clause or both and usually has coreferential morphemes in each clause.  Sometimes the entire relative clause can act as a constituent without another morpheme.  Sometimes there is "illogical" case attraction between the two morphemes. In the uninflected North Mande languages, relative clauses are matched by a "resumptive" pronoun in the matrix clause.  The surprise in these latter languages is that the relative particle "relativizes" the entire clause in situ without word order changes in the clause.  If any of this is helpful, I can add an answer.
Comment: go ahead; I would love an explanation; I was genuinly curious; so as far as you know; internally headed relative clauses just rely on context and subject matter to convey that?
Comment: As for Tibetan, I strongly doubt it uses relative _finite_ clauses, Tibetan uses relative participial clauses/phrases, something like instead of "the man that we saw yesterday went home today" in Tibetan will be "yesterday by us seen man went home today", with "the man" being in the absolutive case as the subject of an intransitive verb, "man went".
Answer: Hittite puts the noun inside the relative clause, then puts a pronoun in the main clause. The case of this pronoun indicates the role of that noun in the main clause.

ÌR.MEŠ=YA=wa=za ku-ēs dā-s nu=war=as=kan kattanta pehute-t nu=war=as=mu arha upp-i
subjects=my=QUOT=INT which-N.PL take-2S.PST and=QUOT=3P.ACC=MOD away lead-2S.PST and=QUOT=3P.ACC=1S.DAT back send-IMP.SG
"My subjects that you have taken, you have led them away, send them back to me!"

Or in idiomatic English: "Send back my subjects that you have taken and led away!"

nasma=tta URUKÙ.BABBAR-sas ZAG-as ku-is BĒLU maninkuwan nu ERIN₂.MEŠ ANŠU.KUR.RA.MEŠ apē-dani wek-ti
or=2S.LOC Hattusa-GEN border-GEN who-N.SG lord-N.SG near and soldiers chariots that-DAT.SG request-2S
"Or the lord of the borders of Hattusa (NOM) who is near to you, ask that one (DAT) for soldiers and chariots"

Or in idiomatic English: "alternately, ask the border-keeper who is closest to you for soldiers and chariots". The noun is in the nominative since it's the subject of the relative clause; the pronoun is in the dative because it's the indirect object of the main clause.
If necessary, the noun can also be repeated in the main clause; this is helpful when there are several relative clauses in a row, to emphasize which one goes where.

dU-as kuē-dani UD-ti hatuga tethi-ski-t […] ANA ĜIŠGIGIR-ya=kan kuē-dani apē-dani UD-ti ar-hahat […] ĜIŠGIGIR-ya tūriyan apātt=a dāi-r
stormgod-N.SG which-LOC.SG day-LOC.SG fearsomely thunder-ITER-3S.PST […] LOC chariot=MOD which-LOC that-LOC day-LOC stand-1SG.PST […] chariot-ACC harnessed there-and take-3PL.PST
"The day on which the Storm-God thundered furiously, the chariot on which I stood on that day, they took the harnessed chariot"

Or in idiomatic English: "they took the harnessed chariot that I stood on on the day when the Storm-God thundered furiously".
Comment: interesting; that is one approach
Answer: I think the Wikipedia article on relative clauses has a fairly good summary of different types of relative clause.  I will refer to some of its categorizations below, but use them differently.
The term relative clause seems to cover the strategy which most languages can use to pragmatically and syntactically combine two full predications that share a common noun into one sentence.  In many languages, the noun that heads the relative clause remains in the matrix clause.  In other languages, the head noun remains in the subordinate clause.  The latter seems to be what is called "internally headed relative clause" and what Wikipedia calls a relative clause of the unreduced type.  Some languages use both types.
From my somewhat limited knowledge, I have not found any characteristic that is exclusive to internally headed relative clauses.  Languages employing such clauses appear to use more or less the same range of strategies as languages with externally headed clauses.
Somewhat independently of where the head noun remains, different languages have different strategies of semantically combining the clauses: gapping, pronoun replacement, and nominalization.  Syntactically, there may or may not be some additional overt morpheme added to the relative clause to indicate the subordination.
With the gapping strategy, used in Mandarin and English, for example, the listener/reader can recover the function of the noun missing from the relative clause by noticing what is missing.  An example from English is: "I saw the man that I was working on the project for."  The listener/receiver notices the gap appearing after the preposition "for" and knows that what is missing refers to the head noun.
If the referent is low on the accessibility hierarchy, the language may require another strategy to improve "accessibility," such as adding a co-referring pronoun or changing the form of the verb to change its valency.  In English, for example, we can front prepositional phrases that refer to a head noun as in "I saw the man for whom I was working on the project."
With the pronoun-replacement strategy, a co-referring pronoun or related morpheme can replace the shared noun in the other clause to reveal its syntactic role in that clause.  In languages with relative pronouns, these pronouns also indicate syntactic subordination.
Some languages have explicit correlative morphemes, allowing the shared noun to appear in either or both clauses in connection with such morphemes.  Latin, for example, sometimes uses a correlative strategy, but sometimes just has the head noun  in whatever clause is first. (See, Allen & Greenough)  The following is an example of a Latin sentence with an internal head that also uses a gap strategy.  :

quae prīma innocentis mihi dēfēnsiō est oblāta suscēpī; (Sull. 92)
(which first of-an-innocent to-me defense was offered I-undertook)
I undertook the first defense of an innocent man that was offered me.

Such a gapping strategy is necessary in this sentence since suscēpī (undertook) is a transitive verb and is lacking an overt object in the required accusative case in the matrix clause.  The relative adjective quae is in the nominative case and modifies defensiō, the subject of "was offered."  Most commonly in such cases, Latin would have a correlative pronoun in the main clause, especially in cases where the clauses are not so compact.  An example is:

"quae pars cīvitātis calamitātem populō Rōmānō intulerat, ea prīnceps
poenās persolvit " (B. G. 1.12)
(which part of-the-state calamity to-the-people to-the-Roman
had-brought, that first the-penalties paid)
That part of the state which had brought disaster on the Roman people
was the first to pay the penalty.

The words quae and ea are correlatives, sharing the same gender, number, and underlying morpheme.  I think such a strategy is less used in later Latin, but is the norm in Sanskrit.
With nominalization, a language can make use of any of its normal noun modifiers in addition to the basic verbal form that is nominalized to help disambiguate the noun's function in the relative clause.  An example of a noun modifier might by a word or phrase identifying an additional agent, such as in English if we turn "The warrior who killed his enemy..." into "the warrior who, upon his killing of the enemy,...."  An example of modifying the underlying verb form would be to change it from active to passive.  In English we could change "the warrior who killed his enemy" into "the warrior who, with the enemy having been killed by him,...."
According to a grammar I have, Tibetan uses a nominalization strategy to create relative clauses that optionally can result in an internally headed relative clause.  I have only flipped through a grammar of the language, but it seems to use both a gapping strategy and different nominalizers optionally to disambiguate the noun's function in the relative clause.  Some of the nominalizers are derived from nouns that mean or meant such things as "cause" or "place," but can also indicate "agent," for instance.  It seems that normally such precision is not felt to be necessary.  For more details, you can refer to Manual of Standard Tibetan by Nicolas Tournadre & Sangda Dorje that discuss relatives in modern Lhasa Tibetan and in the literary language.
Vai, which can be considered a "northern Mande" language, is spoken in Liberia and Sierra Leone and also uses internally headed relative clauses.  The word order in the language is: (topic) + subject (+ TAM auxiliary) (+ object) + verb + (time/place noun/phrase).  It generally uses a strategy of using resumptive pronouns in the matrix clause and using a relative marker (mú) after the shared noun in the relative clause.  An example using modified IPA (the apostrophes below represent an optional [l/] that is usually unpronounced) might be:

Kpɔ̀ŋ fà'á'à kɔ̀ŋkpɔ́ mú 'á kó'à, à wá tó'à à ɖá 'ɔ̀.
(monkey died [at] nut which {possessive-marker} sake, he/him/it {intensfier} remained [at] he/him/it mouth inside.

(The monkey died for which nut's sake, that remained in its mouth)

The nut the monkey died for remained in its mouth.

In this sentence, the relative clause acts like a topic before the matrix clause.  Notice that the word for nut remains internal to its clause, preceded by a verb and followed by a "postpositional phrase," and that the matrix clause  contains two pronouns.  Notice also that the two identical pronouns (i.e., "à") in the second clause refer to different entities, and yet the pragmatics makes clear which one is the subject of the verb meaning "to remain" (i.e., "tó'à) and which one acts as a possessive pronoun for the inalienable noun "mouth" (i.e., "ɖá").
I am not certain about the situation in Navajo; however, I believe that both independent verbs and verbs in relative clauses in that language have obligatory argument markers that would normally disambiguate the function of the head noun for each verb.  In other words, it obligatorily uses pronoun morphemes in both verbs to co-refer to the noun and disambiguate the syntax that applies to each clause.
One way in which internally headed and externally headed relative clauses may differ is in allowing for different quantification of the noun head.  This linked paper compares such clauses in Navaho (which may not allow externally headed clauses) and Japanese (which can apparently have both types).
Comment: thanks; this is usefull; so it seems to depend on the language; part of why i am asking this is because i am working on a conlang; and my huge stumbling block in putting the option of internally headed relative clauses is how to make case work with them.


Can't select individual objects in object mode– why are they grouping together?

Question: I am very new at using Blender and have a simple scene set up with a table and plane for the floor. I don't know what I did, but now the table and plane move together in object mode, and when I try to select them individually I can't. This is a problem because I need to assign different materials to each thing. What do I do to fix this?
Comment: Related https://blender.stackexchange.com/questions/6184/splitting-pieces-of-a-mesh-into-a-new-object. You can still assign different materials to different parts of one object
Comment: Sounds to me like table and plane are one mesh.  To separate, edit mode, select all, P separate by loose parts.   Adding  a screenshot or two will make your question clearer.
Comment: @batFINGER Before you replied, I messed around with it and for some reason there was a duplicate of the whole setup on top of itself. So I deleted that, and I can now select things individually, but even when I just have selected the table the material applies to the plane (and a few of the table legs apparently). I've attached a screenshot
Answer: I guess you clicked join button in tools while table and chair was selected .It happens a lot if you are messing or trying  stuffs in blender.To fix your project.
select that object which you joined (in your case that chair and table).
then press tab TAB this will lead you to edit mode .
press 'A' to select all everything .
now press p and click on "by loose parts"

press TAB again to go back to object mode.
this will allow you to move individual object but we are not done here you will notice something strange may happen when you will move some object

to fix this you need to reset its origin geometry(sounds tricky but it is really easy)
now select all the object by pressing shift and clicking on object .
now press "SHIFT+CTRL+ALT+C"
click "origin to geometry"
and DONE!!!
hope it help.
next time if you mess things up do not save or close blender . press "ctrl+Z" to reverse your last action .
happy blending ;-)


Increase storage of dual boot system using new drive

Question: I have dual boot system with 240GB of SSD, that is equally divided between ubuntu and windows 10, now I ran out of spaces in both of the partition. I bought a new 240GB ssd and want to install windows and ubuntu into separate ssd,so I can get more space in both of the os, but I did not find any ways. I also tried to partition the new drive to mount half-half on both the system, but ubuntu not reading is as root drive. Can anybody suggest me a good approach to do this to increase partition size of dual boot system with new ssd, or to convert the system to separate ssd to boot from.
Answer: I would run the two OS on separate drives.  You could just do a clean install of Ubuntu to the new drive but if you want to transfer the existing system try the following,  but take serious backups first.

Partition the new disk,  create new root partition and format it.  Possibly also create a new swap partition on the second disk.  Also if using UEFI I suggest you leave space for an EFI partition.
Mount the new root partition to /mnt.
Copy files from old to new root partitions - cd /; cp -axv . /mnt
Edit /mnt/etc/fstab to point root at the new partition.
Reboot,  interrupt the boot and change the root partition to your new partition.
When booted up you need to update grub.  Are you running UEFI?  If so dpkg-reconfigure grub-efi-amd64 should do the trick.
Try rebooting and check you are running the new system.

When you are happy with the new system remove the old root from the old disk and extend the Windows partition to fill the disk.
When the above has settled down you could move /boot/efi to an EFI partition on the new disk.  This would mean the ubuntu system is still bootable if the Windows disk dies.
Comment: Thanks I will give it a try!
Answer: You can uncouple/detach your old harddisk temporary. (As you installed the new drive you know how to do this.) Install Ubuntu onto the new harddisk. Shutdown. Attach the old one again. Boot. Then you have Windows and Ubuntu on the old disk and Ubuntu on the new one. Uninstall Ubuntu from the old drive and partition it as you would like.
Comment: doesn't it delete all the data from my old ubuntu?
Comment: Hi, I did as mentioned by you, but how can I boot into new linux and windows on fresh boot, it always boot into new linux and when I change boot drive it directly boots windows, how to make it change to ask everytime which system to boot
Comment: In that case you have to (re)install grub on one of the disks ( pref. your Ubuntu disk so you don't corrupt your Windows Bootloader). This will get you a menu every time you boot. This page will give you all the information https://help.ubuntu.com/community/Grub2/Installing. Capital 2 is about reinstalling. Check with GParted which disk is which and write down the name, so you install grub to the right disk.


There are Strings in C++?

Question: I have been learning C++ with some books from school that are from the 80's and I'm not really sure if they are strings in C++ or just really long arrays of type char. Can anyone help?
Answer: There is a string class in C++.
Answer: Check out the standard library.
In the STL, you can find the std::string class, as well as a bunch of other useful classes.
The basic documentation can be found here:
http://www.sgi.com/tech/stl/
The string documentation can be found here:
http://www.sgi.com/tech/stl/basic_string.html
The beauty of these stl strings is that they delete themselves; so once you declare them, you can just let them go, and they will handle their own memory.  That's true of other stl classes as well  (Of course, if you declare a vector of pointers, the vector will get deleted, but the memory the pointers point to has to be handled as well; it's not a total panacea, but it works nicely if you keep that limitation in mind).
Finally, I've found that this book is a really good way to learn how to think in STL:
Effective STL
Answer: Yes there are strings in C++, someone's gone along and done all the work and coded them for you. They're not in the actual language but in a library called the Standard Template Library, which is practically always supplied along with the C++ compiler (which you probably already have). Internally they are represented with a char array, but it's done in a special way so if the string gets bigger it discards the small char array and makes a new, bigger one.
You should really get a newer book!
Answer: C++ have a std::string as @mmr points out.
Beside that, almost every class library / framework / toolkit offers (at lest ) one
of it's own.
Besides that, almost every large c++ project you'll get a change to work on will have
an String  library.
All these are needed, because no single size fits all. Some wants lazy copying of data,
some want fast insertion in the middle etc, some want UTF-8 etc..
In all probability, if you project does  any serious  string manipulation, you'll end up
writing one of your own.
Answer: In C++; a null terminated char array IS a string.
Having said that, like many others have pointed out, various libraries also have a string class to handle the common string manipulation functionality.

There are Strings in C++?


outgoing email configuration in sharepoint 2013 with zoho

Question: my email server is configured with zoho.com with SSL.
I had Configured Outgoing E-Mail Settings but OOTB approval workflow give error "The e-mail message cannot be sent. Make sure the outgoing e-mail settings for the server are configured correctly."
Answer: Ensure that the mail server is configured to allow anonymous connections from the SharePoint servers. If this has not been configured, the mail server will reject the connection, which will result in the error you're seeing.
You may need to speak to Zoho to have them configure this for you.
To test, try telnetting to the mail server on port 25 from one of the SharePoint servers to see whether the connection is accepted or refused.


Can I reinstall a single iOS app without losing its data?

Question: I have a single app that needs to be reinstalled. I have tried all tricks known to man in attempts to get it to work, but all have failed. There is a lot of data in this app that I'd rather not lose. It isn't explicitly iCloud-enabled, and it's not a game, so there's no hope of Game Center restoring anything. How, if possible, can I reinstall it without losing my data?
Comment: User data is modifiable and the application itself (I expect) is not. You could have a case of data corruption, and after reinstalling the app with the same data, you may find you have the same problem as before. (I should point out that I'm still not clear on exactly what problem you are experiencing.) I don't know of a way to accomplish your goal. PhoneDisk as mentioned below sounds like a good option and I think you should find a computer where you are able to use that. Just prepare for the possibility that the data is the problem (not necessarily your fault; could be programming error.)
Comment: This is just my opinion, but I'm skeptical that reinstalling an iOS app is the solution. How do you think the contents of the application were incorrectly modified? The way iOS is designed and implemented makes this unlikely.
Comment: Why do you believe that reinstalling it is necessary?
Comment: Which app is it?
Comment: @bneely I've tried everything else.
Comment: @GraemeHutchison "Secret Photo Privacy for iPad." The title's actually about three times that length, but I don't feel like copying it. The bug that's happening is sort of hard to describe, but it involves no photos being visible, including ones I've imported since it happened.
Comment: "data in this app that I'd rather not use" - did you mean lose?
Comment: @bneely yes, I did mean "lose". I'll correct that. As to reinstalling: do you have another solution?
Answer: While I never tried it myself, in theory you could use something like PhoneDisk to open the app's private folder and copy all the content to your computer. Then, after deleting and reinstalling the app, you should be able to copy the content back.
Comment: That's a good answer, but unfortunately I don't have access to a computer which I have admin privileges for, which would be necessary to install PhoneDisk.
Answer: Xcode can reinstall an app. Go to Window -> Devices and click on your device on the left. You can tap the '+' button and browse for an app, or just drag any app you want onto the 'Installed apps' section. You can even drag an app icon straight from iTunes. The app will be reinstalled, over the old one, without erasing any data, documents, caches, etc.
Comment: Worked for me on 10.3.2
Comment: First, you must get the app from iTunes App Store and/or locate it in `~/Music/iTunes/iTunes Media/Mobile Applications` folder. Then, connect your device to the Mac with a USB cable and follow the above instructions. You can also **cross-country** reinstall or update an app, if it is not available anymore in your country's App Store. All you need is an Apple ID registered to another country where the app is available. Then sign in to iTunes with that Apple ID and get the app from the App Store. After that, use Xcode to install the downloaded app over the old one _without erasing any data_.
Answer: Reinstalling the application will almost certainly not solve your problem.  iOS applications are digitally signed.  If even a single byte is changed, iOS will refuse to run it.  What you will be reinstalling will be identical to what you currently have installed.
The problem is far more likely to be with your data or the interpretation of it.  There's probably a bug in the application that has either deleted your data or fails to recognise it.  You should contact the developers to try to diagnose what is happening here.
You can get your data off your device by using a tool like iExplorer, or, if the application has enabled it, iTunes File Sharing (which is available in the Apps tab for your device in iTunes).
Answer: As Hui explained, an app can be reinstalled without the loss of it's data by deleting or renaming the iTunesMetadata.plist file in it's directory.
Terminal works as well as iFile for this purpose, but it's tiny and free.
A Terminal command to accomplish this for Facebook:
<code>rm $(dirname $(find -name Facebook.app))/iTunesMetadata.plist
</code>
I've just had to reinstall after two failed updates and I've had to do this fairly often in the past, everyone suggesting that doing so is unlikely to help with whatever issue timothymh is experiencing might have terrific net connections. No, iOS won't allow the failed installs to run, but it won't let you retry AND keep your data either.
Answer: The only way to reinstall an app is by deleting the app and all it's data and then installing again. Unless you have a way to export/copy the data (for example: in app export/import, iTunes file transfer, DropBox/iCloud sync etc).
I would try to do a full backup and restore of the device to see if that fixes it for you (I don't know if all tricks known to man included this).
Comment: Thanks, but that doesn't help. It doesn't have any export feature, and as a matter of fact a restoring to backup was actually what caused it.
Answer: If your iPhone is jailbroken, you can delete the app's metadata and then re-install the app.
You can use SBSettings to find the app's path, then in iFile go to this directory and delete iTunesMetadata.plist. The App Store will no longer see the app as installed and you can re-install it and keep your data.
Comment: Can you please add some details (maybe using one specific application as a sample) on how to do this?
Answer: I had the same problem so I went to the app's store page thing and updated it from there
Comment: Updating apps is very different from reinstalling, plus that solution only works when there is an update available.


How does learning the moves of chess show up in a neural network?

Question: Is learning the moves a special case or just the same sort of thing that happens as the AI learns strategy? If you take two different neural networks and teach them each how the pieces move, what checkmate is, etc. will the two networks look identical or is there a random element that means that two networks with the exact same number of nodes, running on the same processors, etc. will not look identical even though they both know exactly the same things?
Comment: Perhaps part of your confusion: you generally don't teach the neural networks how the pieces move and what checkmate is. You just teach them directly how to suggest good moves, and an external program is used to ignore illegal move suggestions and pick the best legal move from the net's suggestions.
Answer:
How does learning the moves of chess show up in a neural network?

If you have 2 neural networks that have been initialised in the same way, are trained with the exact same sequence of samples, and there is no other source of randomness, then they will be identical at the end of training.
So, the answer to your question is: it depends on the learning algorithm, how you initialise the neural networks, and how you sample the data and feed it to the neural network. There's no magic!
Finally, what they learn is encoded in their weights and how these weights are used to produce the output (i.e. the architecture). It's not easy to explain intuitively what the neural networks are exactly doing to produce the output (so they are sometimes called black box models), but there are explainable AI techniques that can be used for this purpose.
Comment: would it be possible to look at the network and identify, e.g., this is where the knight move is encoded? how long before the way the knight moves is stored accurately?
Comment: That sort of question is an open area of research in general, though as @nbro mentioned there are techniques for generating explanations (with varying degrees of accuracy), along with alternative interpretable models that may or may not have the same power as blackbox models.


Find Distance Function from Acceleration Function

Question: The (non-constant) acceleration as a function of time, $a(t)$, is defined and known over $[t_0, t_2]$. It is also known that $a(t)$ is integrable. Also, $a(t)=\frac{dv(t)}{dt}$ and $v(t)=\frac{dx(t)}{dt}$, where $v(t)$ is the velocity function and $x(t)$ is the distance function. $t_1$ is a known time within $[t_0, t_2]$. Given $v(t_1)$ and $x(t_1)$, is it possible to find $x(t)$ over the entire interval? If so, how can this be done? Rigor would be appreciated.
Answer: By the Fundamental Theorem of Calculus,
$$
v(t)-v(t_1)=\int_{t_1}^{t}a(s)\ ds.
$$
Similarly,
$$
\begin{align*}
x(t)-x(t_1)&=\int_{t_1}^t v(s)\ ds\\
&=\int_{t_1}^t\left(v(t_1)+\int_{t_1}^{s}a(u)\ du\right)\ ds\\
&= (t-t_1)v(t_1)+\int_{t_1}^t\int_{t_1}^{s}a(u)\ du\ ds.
\end{align*}
$$
Rearranging yields the solution
$$
x(t)=x(t_1)+(t-t_1)v(t_1)+\int_{t_1}^t\int_{t_1}^{s}a(u)\ du\ ds,\qquad t\in [t_0,t_2]
$$
Comment: Yes, that is correct.
Comment: Yes, and the same method also solves $\frac{d^nx}{dt^n}=a(t)$.
Comment: Thanks @pre-kidney for the derivation! To generalize the result slightly, the conditions for velocity and distance can be prescribed at different times (instead of at the same time $t_1$), and we can still determine $x(t)$, right?
Comment: I just realized this problem is a simple second-order differential equation, $\frac{d^2 x}{dt^2}=a(t)$ with two conditions given, and this method can be used to solve any such equation.


Would reaching an elliptical orbit with the same mean altitude as that of a circular orbit require the same amount of fuel?

Question: Would a rocket that wanted to reach an elliptical orbit with a perigee of 100 miles (160 km) and an apogee of 300 miles (480 km) burn the same amount of fuel as a rocket that wanted to attain a circular orbit at 200 miles (320 km) altitude?
Comment: Pretty sure the answer is "no."   Burning the fuel  from x mass to y mass is directly tied to delta-V, and delta-V is tied to changes in spacecraft velocity and momentum, rather than orbital energy.  Burning to a very elliptical orbit with your same periapsis is going to take less delta-v than a bi-elliptic transfer to a high circular orbit with the same semi-major axis.
Comment: You may find this helpful: https://en.wikipedia.org/wiki/Specific_orbital_energy
Comment: @notovny I ain't talking about the same periapsis, but about the same mean value which is 200 mi in a 100 mi x 300 mi orbit. Would it take less delta-v to reach a 100x300 orbit than reaching a 200 mi circular orbit?
Answer: There is no reason to expect the required fuel to be the same.
To show this, we'll produce a simple counterexample with numbers chosen for ease of calculation. We will assume that by "same mean altitude" , OP assumes a perfectly spherical planet, and that "same mean altitude" translates directly to same semi-major axis.
We'll also use generic Distance Units ($\text{D}$) and Time units ($\text{T}$); the equations would work with any consistent  unit system. In the image, assume all orbits to be going counterclockwise.

The central body has Standard Gravitational Parameter $\mu = 1.00\,\text{D}^3/\text{T}^2$
The spacecraft in question is in the circular Parking Orbit O (black), which has a radius of $1\,\text{D}$
We are comparing the delta-V required to go from Orbit O to Orbit C, a coplanar circular orbit with radius $3.00\,\text{D}$ (semi-major axis $3.00\,\text{D}$) and from orbit O to Orbit E, a coplanar elliptical orbit with semi-major axis $3.00\,\text{D}$ but with periapsis distance $1.00\,\text{D}$ and apoapsis $5.00\,\text{D}$
Orbit O to Orbit C:
In this example the radii of the two orbits are close enough in size that the most efficient transfer from Orbit O to Orbit C is a two impulse Hohmann transfer Maneuver;
We fire the engines at the red dot, in the direction of the red arrow to put the spacecraft into a transfer orbit (red dotted orbit), then fire the engines again at the blue dot in the direction of the blue arrow to circularize into orbit C.

Impulse 1
$$\Delta v_{1}=\sqrt{\frac{μ}{r_{1}}} \left(\sqrt{\frac{2r_{2}}{r_{1} + r_{2}}} - 1\right)$$

Impulse 2
$$\Delta v_{2}=\sqrt{\frac{μ}{r_{2}}} \left(1 -\sqrt{\frac{2r_{1}}{r_{1} + r_{2}}}\right)$$

The total delta-V required for the Hohmann transfer is the sum of the above two values.
Substitute in $r_1 = 1.00 \text{D}$ and $r_2 = 3.00\,\text{D}$ and the total delta-V for the Hohmann transfer is:
$$\Delta v_{C} = \Delta v_{C1} + \Delta v_{C2} = 0.22\,\text{D/T} + 0.17\, \text{D/T} = 0.39\,\text{D/T}$$
Orbit O to Orbit E:
To calculate the delta-V requirement to go from Orbit O to Orbit E... Well, in this case, Orbit E is exactly the same as a Hohmann transfer orbit that would take the spacecraft from Orbit O to a coplanar circular orbit of radius $5.00\,\text{D}$ As such we can just use the formula for Impulse 1, but substitute in $r_1 = 1.00 \text{D}$ and $r_2 = 5.00\,\text{D}$, and ignore Impulse 2 entirely.
$$\Delta v_{E} = 0.29\,\text{D/T}$$
Results
In this counterexample case, the delta-V required to go from Orbit O to orbit C is $0.10\,\text{D/T}$ more than for going from Orbit O to Orbit E. As a result, all other things about the rocket being the same on the two different transfers, in this case, the rocket would require more fuel to go to Orbit C.
As a result we can conclude that for two different orbits of the same arbitrarily-chosen semi-major axis, there is no expectation that the fuel costs to reach both  be the same.
Comment: Basically...it's complicated.  To demonstrate  that there's no requirement that the fuel expenditure be equal, I chose an easy-to-calculate situation that showed that the fuel expenditures would be different. With the  infinite number of coplanar elliptical orbits with the same semi-major axis as the circular, there are absolutely situations where getting into the chosen elliptical orbit takes more delta-V.
Comment: So the reason why a circular orbit requires more delta-v is because you have to circularize it in the first place (once you reach apogee)? Isn't it possible to reach a very low (approximately-)circular orbit right away, e.g. at 100 mi (160 km) above the Earth's surface, without the need to adjust a too elliptical orbit? Your parking orbit O could be such a (near-)circular orbit that might be reached right away, couldn't it?
Comment: I love "Basically...it's complicated"!  I must now go use that phrase myself.


Access footer text of PPTX on Visual Studio 2008

Question: team!
I have a MS Powerpoint add-in project in my Visual Studio 2008, in C#. I use the following code to read the text of the footer from a Powerpoint presentation:
String currentFooterText =
Application.ActivePresentation.SlideMaster.HeadersFooters.Footer.Text;

(where Application class comes from the namespace Microsoft.Office.Interop.PowerPoint.Application)
When I load a ppt file (97-2003 Presentation type), the code is able to access the text that was inserted in the Footer property of the Slide (menu View > Head and Footer... > Slide > Footer).
But, when I load a pptx file (Presentation created in Powerpoint 2007 or 2010), the code is not able to access the text that was also inserted in the Footer property of the Slide (menu Insert > Head and Footer... > Slide > Footer). The Text returns a blank text.
Please, does anyone have any idea about that? Is there any incompatibility between these Powerpoint versions for footer access?

Steve!
Thanks for the reply!
In fact, my code is on Visual Studio 2008, for a Powerpoint 2003 Add-in project. And the problem happens when I open a pptx file.
I tried your suggestion, but with brackets instead of the parenthesis, like below:
String s = Application.ActivePresentation.Designs[1].SlideMaster.HeadersFooters.Footer.Text;
But the problem persists, the Text still returns empty for pptx files. It works for ppt, like before. Do you know any programmatic way to use on VS 2008, for a Powerpoint 2003 Add-in project, to access the footer text of a pptx file?
Thank you!
Answer:

Is there any incompatibility between these Powerpoint versions for footer access?

Yes.  In 2007/2010/2013, you'd use:
ActivePresentation.Designs(1).SlideMaster.HeadersFooters.Footer.Text

(Assuming that you want the footer from the first slide master; there can be more than one, as in fact there can be in PPT 2002 and onward)
Comment: Hi, Steve! Thanks for the reply! But it did not work. I answered my question with more information.


Photo stream and iCloud?

Question: I have a new iPhone 4s and an account on iCloud. Is it possible to move an old photo album from my old iPhone 4 to the new iPhone 4S by just using iCloud?
Answer: One way i can think of is using a Mac:

Sync your old iPhone and download your photos to iPhoto.
Activate iCloud and Photo Stream on your mac using your iCloud ID.
iPhoto now will have a Photo Stream folder.
Drag the desired photos/events to the Photo Stream folder in iPhoto.
Make sure you have Photo Stream activated on your iPhone 4S and you are using the same iCloud ID on all related devices.
iCloud on your iPhone 4S should detect via WiFi or your carrier that you have photos in your Photo Stream and will sync all devices under your iCloud ID.

I haven't managed to copy the photos to the Photo Stream Folder on the phone, so maybe it's not implemented yet, but one workaround if you don't have a Mac, is to email/message yourself the photos. Read the mail/message using your new iPhone 4S and save the photos. They will appear in the Photo Stream folder.
Hope that helps.
Answer: You can create a shared photo stream with yourself, copy all the needed pictures into this album and access it again from the new iPhone. See this cnet.com page for an explanation on how to create a shared photo stream.

Photo stream and iCloud?


Accelerating Force on Slipping Tire

Question: I'm wrestling with the problem of a car accelerating from rest whose engine is outputting a torque that would result in a force at the point of contact between the wheel and the ground that is greater than the force of static friction. From my understanding, the wheel would slip, and if the torque remains the same, would do so indefinitely (never gaining full traction). From this, the only force between the contact surface and the tire would be kinetic friction, but is this going to accelerate the car forward? I guess I'm not sure if the car would accelerate at all.
Comment: Why do you think the car wouldn't accelerate forward?
Comment: @DanDan0101, I guess it seems impossible that no matter the torque (as long as it is great enough to exceed the static force of friction) the car would have the same acceleartion
Comment: In that case, the additional torque will simply make the wheels spin quicker and quicker. That's where the extra power is going.
Answer: The car will accelerate with a force equal to the product of the kinetic coefficient of friction and the total normal force on the driving wheels. This force is relatively small as the kinetic coefficient is always much smaller than the static coefficient of friction. The answer, in summary, is that the car will accelerate but relatively slowly while the wheels continue to accelerate under the torque produced by the engine. So the torque of the engine is divided into a component that accelerates the wheel, a component that accelerates the car, and friction losses (if heat is produced and hysteresis is assumed).

Accelerating Force on Slipping Tire


Is "going through the metalanguage" while proving a theorem allowed?

Question: For instance, we want to prove that $\mathsf{ZFC} \vdash \forall x[x \in \mathrm{OD} \implies \phi(x)]$ for some formula $\phi(x)$ of the language of set theory ($\mathrm{OD}$ is the class of ordinal definable sets.) $\mathrm{OD}$ has two definitions which can be proved equivalent, the metalanguage version which quantifies the formulas directly, and the internalized version(Actually I'm not sure that this is right.) I am interested in using the former version to prove the theorem. Let $M$ be an arbitrary model of $\mathsf{ZFC}$. It suffices to prove that $\forall x \in M[M \vDash x \in \mathrm{OD} \implies M \vDash \phi(x)]$. We invoke here the equivalent metalanguage definition to get a formula $\psi$ and ordinals $\alpha_1, \ldots, \alpha_n \in M$ such that
$$M \vDash \forall y[y \in x \iff \psi(y, \alpha_1, \ldots, \alpha_n)]$$
holds, and then prove $M \vDash \phi(x)$ with it. Is this a valid way to prove theorems?
Comment: Can you give a concrete example of $\phi$?
Comment: @AsafKaragila Let's assume that we have proven the correspondense between $\Delta_0$ formulas and Gödel operations(the Gödel normal form theorem). I'd like to see when $\phi(x)$ is "$x$ is in the Gödel closure of $\{V_\alpha: \alpha \in \mathrm{Ord}\}$. With the formula given, we can use the Reflection principle and reletivization freely, so I thought that it is convenient to leap to the metalanguage.
Answer: Yes this is allright. Showing $\mathrm{ZFC}\vdash\forall x[x\in\mathrm{OD}\Rightarrow\phi(x)]$ is by Gödels completeness theorem equivalent to showing that the formula $\forall x[x\in\mathrm{OD}\Rightarrow\phi(x)]$ is true in any model $M$ of $\mathrm{ZFC}$. Now as you mention, if one picks  an arbitrary such $M$, this amounts to showing $M\models\phi(x)$ for all $x\in\mathrm{OD}^M$. By definition of $\mathrm {OD}$, we have
$$M\models \exists\theta\in\mathrm{Fml}\exists\alpha<\beta\forall y [y\in x\Leftrightarrow \mathrm{Sat}(V_\beta, \theta, y, \alpha)]$$
(note that one $\alpha$ is enough since $M$-finitely many ordinals can be coded into one) for such $x$. Now we can pick witnesses $\theta, \alpha, \beta$ for this statement (note that $\theta$ is essentially an $M$-integer, thus $M$-ordinal). This yields a real formula $\psi$ so that
$$M\models\forall y\ y\in x\Leftrightarrow\psi(y, \theta,\beta,\alpha)$$
Now $x$ fits the bill for the kind of sets $z$ for which you have shown $M\models\phi(z)$ and thus $M\models\phi(x)$ as desired.
Comment: Thanks for your answer. Following your method $\psi$ is a fixed formula and works great. But can we also have $\psi$ vary over $x$? I mean, elevating the $\theta$ to a "real formula".
Comment: You only make your life more difficult if you let the formula $\psi$ vary, so that works too. Just be careful that you cannot assume that the $\theta$ is a real formula immediately, (nonetheless it can be replaced by a real formula with the argument above).


Blocking DC power to active GPS antenna

Question: I would like to connect two GPS receivers to a single active antenna letting the DC voltage form only one receiver to reach the antenna. In this blog post the guy made his own RF part by putting a capacitor into a male to male SMA adapter which is a very low-cost solution. I wonder whether there are similarly working low-cost parts readily available off the shelf so that I do not have to build it myself. The cheapest GPS antenna splitter I could find is a Tallysman TW150 for $85 while the solution with a custom capacitor must cost much less.
Answer: The component that you want is called a "DC block". You could also get a "bias tee" and leave the bias connection disconnected. Don't forget that you will also need an RF power divider that works at the frequencies you're trying to receive, and please note that not all power dividers will pass through DC. If you get one that doesn't, then you'll need to add the DC back in with a bias tee.

Blocking DC power to active GPS antenna


When is it acceptable to use roughness without a map input in the Principled BDSF node?

Question: For a PBR material setup, one usually have map inputs for the color, roughness, normal nodes. If a material has an undefined roughness, but it's not perfectly smooth either, is it okay to use the roughness slider as a substitute for a map input? Would such a technique have an impact on the photo realism of the object?
Comment: The title has a mistake in it - there is no such thing as 'roughness node'. You are talking about roughness input. It shouuld be something like 'When is it acceptable to use the roughness input without a map for it in Principled BDSF node?'
Answer: It is perfectly normal to use a single value for roughness in all the cases when roughness is uniform across the surface for example with smooth clean objects made of the same material.


How to test for randomness using FIPS 140-2

Question: I designed a PRBG which produced 20000 bits. Please help me here. How do I test for randomness using FIPS 140-2 suit. I know what each test entails. Question is, can I get like a program/software/code that implements these test on a .txt file of the 20000 bits. Thanks in advance.
Comment: I'm voting to close this question as off-topic because code requests are off topic, we require concise questions, not requests for help.
Answer: A few points:-

The FIPS 140-2 tests are wrapped up within the rngtest program, available in Linux as package rng-tools5.  I'll produce something like:-

rngtest: starting FIPS tests...
rngtest: entropy source drained
rngtest: bits received from input: 8388608
rngtest: FIPS 140-2 successes: 419
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=340.598; avg=2424.694; max=6357.829)Mibits/s
rngtest: FIPS tests speed: (min=35.585; avg=73.032; max=84.396)Mibits/s
rngtest: Program run time: 115567 microseconds

If you appreciate the nature of those tests, you'll know that a small number of failures are to be expected (even though I didn't get any above).

20,000 bits isn't a lot of bits, RNG wise. Randomness needs to be appreciated within the context of the sample size.  One block will be insufficient for anything other than checking for catastrophic failure.  The tests are very slack, and a strongly compressed file will pass it. There are stronger tests that require many more bits.
rngtest is predicated on binary data, not ASCII which will cause the test to fail badly. You simply need to tweak your PRBG to produce bytes and not characters.
I assume that there is some form of cryptographic primitive within your PRBG as this test cannot prove security.
Comment: thank you. I will try this out!
Comment: hi. please I need help tweaking the code to produce bytes. It produces characters at the moment and the rngtest fails woefully. I am programming on matlab.
Comment: @TakuAngwaOttoCHE Sorry Taku,  I don't use matlab, but does anything like [this](https://uk.mathworks.com/matlabcentral/answers/155689-how-to-convert-text-into-binary) help? Remember that a binary version of equivalent text will be smaller as an ASCII file doesn't fill up all of the available bits in the bytes (depending on the locale). So you 'll need to make a lot more than 20,000 characters. Maybe 8 times as much. And don't forget any carriage returns etc...
Answer: The trivial selftests for the (deterministic) RNG are listed in the standard, don't think there is a external testsuite for those.
However the approved algorithms from SP 800-90A also have Test excessive testing and documentation requirements, but mostly for the deterministic part.  NIST offers in 800-22 statistic Test Suite documentation for their tooling.
And you find the validation program here: https://csrc.nist.gov/projects/cryptographic-algorithm-validation-program/random-number-generators
Comment: thanks. I will check it out too


Output ordering in Oracle 10g

Question: I am using Oracle 10g and the output returned from a SELECT command is in a zig zag format. How I can arrange columns in correct order? Is there any command?
Comment: Could you provide an exemple with the command you use and the output you would like to obtain ?
Comment: What tool are you using to query the database?
Answer: If you are using sqlplus you can control output formatting via "COLUMN" commands.
I suspect the zigzagging has something to do with the size of your terminal and the length of the columns you are selecting.
If you first format each column to an appropriate length and then do your select, you should see better output.  You can refine it from there.
Google "sqlplus reference" you will find more details about how to use sqlplus.
Comment: ok. But in postgresql, it will come in correct format as given below.
 pki_under_clearance_id | uvc_code | dt_uc_date | vc_order_type | f_amount | txt_remarks | vc_invoice_no | dt_invoice_date | fki_branch_id | fki_financial_period_id
------------------------+----------+------------+---------------+----------+-------------+---------------+-----------------+---------------+-------------------------
                      0 | _BLANK   | 2008-01-01 |               |        0 |             |               |                 |            76 |                      17
Answer: And perhaps you might be interested in reseting, "pagesize" and "linesize" parameters.
SQL> set pagesize 30
SQL> set linesize 90

Output ordering in Oracle 10g


When shipping electronic components, can I reduce static by using dryer sheets or sprays?

Question: Can I use dryer sheets, or anti-static spray on polyurethane foam to reduce static between the foam and the polypropylene container the foam is in? I need to ship some ESD sensitive electronics overseas by air freight. The most sensitive electronics are in ESD bags, then placed in custom-cut holes in the foam. But it isn't feasible to enclose all the electronics in ESD bags. I wanted to further reduce static by using anti-static foam, but that isn't available in my area and I would have to wait weeks to have it delivered. So do you a reasonable substitute could be lining the inside of the container with anti-static dryer sheets (then putting in the foam), or spraying the polyurethane foam with anti-static spray (e.g. Downy Wrinkle Releaser)?
Comment: What is the most conductive, most flexible material you can think of? You probably have a roll of it in your kitchen.
Comment: @ignacio are you saying I should cover the inside of the polypropylene container with aluminum foil? Should I cover the top (the bottom of the container lid) too, or is that unnecessary?
Answer: Think of it another way - how impressed will your customers be when they see some packaging that clearly doesn't look right even though you meticulously ensured that the "method" you used was perfect.
So they phone you up and say - hey this wasn't packaged up in anti-static stuff, how can you explain that. So, you spend ten minutes on the phone telling them what you did. Hey guess what, they think you are full of BS!!
The whole idea seems wrong to me. Use the correct stuff or expect disillusioned customers.
Answer:
So do you [think] a reasonable substitute could be lining the inside of the container with anti-static dryer sheets (then putting in the foam)

Absolutely not.  This will only equalize the charge on the outside of the foam.  As soon as you slide an unprotected board in, it is the mechanical rubbing which creates triboelectricity.  Which is to say, it occurs at the point of contact (the two rubbing surfaces), not on the outside of the foam.
If the foam was ESD foam, then it would have a very slight conductivity to it, such that sliding a board in may still generate some voltage, but this is quickly spread out to the entirety of the foam. Then everything near the board is at the same potential, therefore is safe.  And if you were touching the foam, then you're at that potential also.

or spraying the polyurethane foam with anti-static spray (e.g. Downy Wrinkle Releaser)?

This might actually work, somewhat, in that the sprayed area will have a slight conductivity.  But unlike the ESD foam, this only works on the sprayed area.  Meaning, no conductivity to you, so the sprayed area is free to keep increasing in voltage.  This is not guaranteed to work at all, but if it did work at least a little bit, it still would not be as good as ESD foam.
Consider a metalized plastic bag.  These are available all over, are pretty cheap, come in many sizes, and often have a reclosible seal.  If no seal, just fold the edge over and use (little pieces of regular) packing tape.


How to install Pure-FTPd and configure FTP server to transfer files?

Question: I want to install Pure-FTPd and configure FTP server for transfer files. How can I do this? I am using Ubuntu 13.04.
Comment: Apparently PureFTPd is peculiar in it's configuration method, any reason you need it in particular? In any case, the Ubuntu help site has a guide: https://help.ubuntu.com/community/PureFTP
Answer: Install Pure-FTPd
root@www:~# aptitude -y install pure-ftpd

run as a daemon
root@www:~# echo "yes" > /etc/pure-ftpd/conf/Daemonize

prohibit Anonymous
root@www:~# echo "yes" > /etc/pure-ftpd/conf/NoAnonymous

enable chroot
root@www:~# echo "yes" > /etc/pure-ftpd/conf/ChrootEveryone

only IPV4
root@www:~# echo "yes" > /etc/pure-ftpd/conf/IPV4Only
root@www:~# /etc/init.d/pure-ftpd restart
Restarting ftp server: Running: /usr/sbin/pure-ftpd -l pam -E -A -8 UTF-8 -B -O clf:/var/log/pure-ftpd/transfer.log -u 1000 -4 -B

Answer: I developed a guide to installation of PureFTP, MySQL and TLS on Xenial since I had some difficulties, maybe it will help.
http://ajoliveira.com/ajoliveira/uk/software/pure-ftpd-mysql.php
or in Portuguese
http://ajoliveira.com/ajoliveira/pt/software/pure-ftpd-mysql.php
The reason I installed PureFTP is explained in the guide I published, too many problems with proftpd, which became unusable after Trusty (passive mode, TLS) and had problems before (crashes). I found this package easy to install and working with no apparent flaws.

I used ProFTPd for a long time. However on the previus Ubuntu LTS
  (Trusty) ProFTPd was already buggy, shutting down by itself, which I
  corrected with a script.
On Xenial the situation become worse, with the product stopping but
  not shutting down. On the other end I could never setup ProFTPd for
  passive ftp transfers and TLS never worked properly since MLSD command
  failed with TLS authentication.
So, I decided to give PureFTP a try. I had to search for information
  on many different sites since the main site has no information on the
  obscure files used in the configuration directory. Those are
  transcriptions of the command-line options with a distinct syntax.
I found out that the installation is straightforward and repeatable
  when you know the steps to take and the product works like a charm, so
  I decided to share the installation process with the community.
I assume you will use phpMyAdmin in what MySQK operations are
  concerned and are familiar with it, so I will be providing an sql file
  for the single needed database, and assume InnoDB or other
  transactional engine. If you are using MyISAM, just comment the last
  sentence on the provided mysql.conf(MySQLTransactions On). All bash
  commands must be preceded with sudo or you may start a root session
  with su.

Install the software.
sudo apt-get install pure-ftpd-mysql

Setup user and group.
sudo groupadd -g 2001 ftpgroup
sudo useradd -u 2001 -s /bin/false -d /bin/null -c "pureftpd user" -g ftpgroup ftpuser

Setup the database.
Now using phpmyadmin on the server tab create an user called pureftpd, note the password you choose and click on "Create database
  with same name and grant all privileges.".
Load this file and unpack it.
On the left-pane go to the pureftpd database just created and click on "Import". Select the file you just unpacked. You should end
  up with a populated database with a single table where:
• User is the user name
  • status is 0 inactive 1 active
  • Password is the password, encrypted in MD5 (choose MD5 after you enter the password on the varchar(64) dropdown. Change the password on
  the test user provided or it will never work
  • uid and gid will be 2001 (created on steps above)
  • dir should point to the dir where you have the files. Either that dir is set to be owned by the user/group created (chown ftpuser.ftpgroup "dir") or you might just add ftpuser to your
  www-data group if we are talking about apache-served files.
  • ULBandwidth and DLBandidth are the limits in kb/s for the upload/download maximum bandwidths, 0 means no limit.
  • comment should serve your internal purposes for user identification.
  • QuotaSize is the maximum space an user is allowed to upload.
  • QuotaFiles is the maximum number of files an user is allowed to upload.
sudo cp /etc/pure-ftpd/db/mysql.conf /etc/pure-ftpd/db/mysql.conf.old

Configure PureFTP.
Load this file and unpack it.
  Copy the mysql.conf inside the db directory to /etc/pure-ftpd/db/
Please change the string my_password on the mysql.conf file, MYSQLPassword field, to the password you defined when you created the
  user with mysqladmin
Load this file and unpack it.
  Copy all files inside the conf directory to /etc/pure-ftpd/conf/
It is assumed in these files that passive ports are 50000-50010 (PassivePortRange), no passive mode forcing (no ForcePassiveIP file,
  if you want that create one and leave your IP there in a single line),
  no automatic creation of user home directory (CreateHomeDir), no name
  resolution (DontResolve), no display of hidden files
  (DisplayDotFiles), no local user authentication (PAMAuthentication). I
  increased the maximum number of files per folder and the maximum
  directory depth (LimitRecursion) to 5000/50. If you want to change
  those refer to the documentation.
sudo aptitude install openssl

Install ssl certificate.
sudo openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout /etc/ssl/private/pure-ftpd.pem -out /etc/ssl/private/pure-ftpd.pem chmod /etc/ssl/private/pure-ftpd.pem

-days 3650 will create you a certificate for 10 years...
sudo chmod /etc/ssl/private/pure-ftpd.pem

Putting it to work
sudo service pure-ftpd-mysql restart

Well, it should work...
Installation of the above is entirely at your risk.
Comment: While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference.  Link-only answers can become invalid if the linked page changes. - [From Review](/review/low-quality-posts/794481)
Comment: I see you did it already and I agree, nevertheless link will stay there, page is up for 14 years now. The advantage of link answers is that when you want to make a correction, there is just one place to go.
Comment: The imported text contains different wording than the original, I spotted at least a different word (MySQK instead of MySQL), I do recommend potential readers to read the original.


loading encrypted shared objects using the rtld / free loader/linkers

Question: I am doing some research in encryption/software protection. I want to link dynamically encrypted shared objects (Linux, x86 Architecture, ELF32/64 format)

The code to be protected is contained (encrypted, no valid ELF) in the shared object.
The object itself is a valid ELF-file, containing an init method
The decryption should be started, dependend on a available license in the init function called by the loader.
After encryption the code is present as valid ELF-file in memory.

There were some further requirements:

The decrypted code must not be stored (even temporarily on disk) - prevent easy object dump and code reuse
The protection algorithm must not be published, so I may not use parts of the GNU code (even people do a great work there!)

I think the hard way is to reimplement a loader/linker providing the needed functionality... Perhaps there may be a way to use the Linux rtld, or parts of it, other linkers?
Is there an easier way?
Thanks for every idea/hint
Some related links/Infos

a packer solving a similar kind of problem: http://www.upx.org/
(did not work for one of my test shared objects)
Some details about loading shared objects http://smilax.org/135/dsohowto.pdf
Answer: A long time ago, Phrack featured an article on ELF encryption. Also a long time go, there was a program called BurnEye to encrypt ELF binaries.
Comment: I was told that there also exists a tool called burndump available at [link](http://www.securiteam.com) stripping the protection...
Answer: Take a look at Shiva if you're interested in this. There was no source code released to the public but the theory is still there.


nuclear fission and half life

Question: Why is the alpha, beta or gamma decay of an unstable nucleus unaffected by the chemical situation of an atom, such as the nature of the molecule or solid in which it is bound? The chemical situation of the atom can, however, have an effect on the half life in electron capture. Why is this so?
Answer: The cross-section for electron capture depends (among other things) on the likelihood that there is an electron in proximity to a proton.
Orbital states with angular momentum other than 0 (that is all states except s-states) have a node at $r=0$ and because the nucleus is several order of magnitude smaller than a typical atomic orbital this means that electrons from those states have essentially no chance to be in proximity.
However, all s-states have a local maximum at $r=0$, and therefore have non-trivial probability to be available for capture. Now if an outer electron that in an atomic context was in a s-state is instead involved in a molecular bond, then it probably does not have a high probability of being in the nucleus and the total rate for the process can be expected to go down.
The other decay processes you list don't depend on the presence of an electron.
Answer: A qualitative argument:
The $\alpha$, $\beta$ or $\gamma$ decay are phenomena that are associated with the weak nuclear, and strong nuclear forces which rule in the nucleus. The electromagnetic force, although it plays an important part in the stability of the nucleus, it does not completely determine what and how will happen inside the nucleus. The $\beta$ decay is determined by the weak nuclear force which goes something like this:
$n\rightarrow p+e^-+\bar\nu_e$
$p\rightarrow n+e^++\nu_e$
The $\gamma $ decay results from a rearrangement of the nucleons form higher to lower energy shell configuration, with the emission of the excess energy as $\gamma$ light. The energies involved here are from several eV (Th-229) to several MeV (Co-60).
The events that take place in the outside the nucleus part of the atom/molecule is simply rearrangements of the electrons in the various energy levels. Very low energy involved. If you can understand that the electromagnetic interaction of the protons inside the nucleus cannot have an effect in a $\beta$ decay, then you can understand why the electrons outside the nucleus do not have any effect on what is going on inside the nucleus.
Comment: The process called "[electron capture](http://en.wikipedia.org/wiki/Electron_capture)" is not one of the ones you list. It means $p + e^- \to n + \nu_e$.
Comment: @dmckee Thank you for reminding me of this very interesting process. You have covered this possibility very well in you answer. The only comment I would like to make, is to mention the exceptional case of Be-7 which decays purely by electron capture (energetically more favorable.) But this is interesting from astrophysics point of view where Be-7 is under immense pressure. You were most likely talikng about nuclei under "normal conditons." Correct me if I misred your answer.

nuclear fission and half life


How do I generate a report of where multiple specific fields are being used in an org?

Question: I want to generate a report of where multiple specific fields are being used in my org. I know that Salesforce has a 'Where is this used?' button for each field which shows where that particular field is being used. Is there a way to generate a report for this instead of visiting each field manually?
Comment: There is no standard reporting for this, you'll need to use a 3rd party metadata search tool on AppExchange.
Comment: Thanks, @DavidCheng. I was able to find a 3rd party tool for this purpose.
Answer: As David mentioned there is no standard process,  You can use 'Field Trip' which helps analyze and report on which fields from which object in your organization are used consistently and which fields are left unused. The Field Trip report provides the percentage of utilization of each field. This helps to get field utilization report results and to conclude if we can delete the fields which are not in use.
Thanks
Comment: Thanks for the reply. I tried another app called 'FieldPro' and it helped with this.


Using AudioFileStreamParseBytes to parse bytes by reading from a file does not call kAudioFileStreamProperty_ReadyToProducePackets

Question: I am trying to parse bytes by opening a audio file (M4A), reading 2048 bytes in a loop and passing it to AudioFileStreamParseBytes. This does not call the callback with the property kAudioFileStreamProperty_ReadyToProducePackets. But the property kAudioFileStreamProperty_FileFormat is being successfully called. (So I know the callback mechanism is working.)
Questions :

Can I use AudioFileStreamParseBytes to parse audio data by reading from a local file ? Most examples show how to use AudioFileStreamParseBytes by parsing HTTP stream data, but not reading from a local file.
Has anyone tried to do the above and has been successful processing audio files ?

NOTE : The reason I am not using AudioFileOpenWithCallbacks to open the m4a file is that the api call is failing to open the following file after downloading it locally ( http://www.arsenal-music.com/podcast/arsenal-podcast-05.m4a ). This m4a file has images embedded in it and AudioFileOpenWithCallbacks is not able to parse the file. At the same time I have used Matt Gallagher AudioStreamer code that opens this file, parses it and plays it fine. So I am leaning towards using AudioFileStreamerParseBytes by reading data from a local file. (As far as I understand there should be no difference whether the data is coming from HTTP stream or a local file. But I could be wrong.)
I do not see any errors in the any API calls (just in case someone asks me this question). I can paste the code if needed, but all I want to know is if the approach of reading from file and passing it to AudioFileStreamParseBytes will work or not ?
Answer: After some testing I found that one can use AudioFileStreamParseBytes to parse bytes that are read from a local file. Data need not come from a Http stream.


Removed the skirt of the siding now the subflooring is exposed. What should I do?

Question: The skirt boards for the siding were partially covered in soil and rotting so I removed them. Now it looks like I exposed the subflooring. How do I prevent them from rotting now that they are exposed? The first picture shows what I removed but on a different part of the house.
Comment: A better photo of the actual detail would be great.
Answer: Without a better picture, it appears to be a 2X plate that is attached to the concrete and not subfloor. If it is a home built within the past 30 or 40 years or so, it may be pressure treated (PT) to resist rot. If it is not pressure treated, it is doing pretty good, for where it is.
To fix the issue it will only need a piece big enough to cover over the concrete by no more than an inch. I could be a piece of pressure treated 1X4 or something of that nature. If you go that route, it will need to be nailed or screwed with fasteners approved for contact with PT material. They are available anywhere hardware is sold. The box will be marked " compatible with ACQ" or PT or "copper azole" lumber.
Depending on the thickness of the added piece, or maybe not you will want to add a flashing, so falling weather cannot go between the gap  of the siding and the added piece.

If you can get the nails out that are in the way, it will be easy to separate the siding just a fraction to get a space big enough the slide the flashing in first. Then add the 1X4 under the flashing, that is if 1X4 is tall enough to cover over the concrete the 1", it may take 1X6. The hope would be is that you can use a piece to cover the problem, without it going into the dirt again. Using PT or not, it is never a good idea to let any kind of siding go below grade.
Comment: Wow this is incredibly helpful. Thank you so much!!!


What software can be used to create a restorable drive image?

Question: Not sure what Linux software I would use for this. I'm looking for something like Acronis True Image for Windows, but for Linux. The rule is that we are keeping Windows out of the equation, I want to be able to rely solely on Ubuntu to handle the management and restoration of backup images.
Answer: Clonezilla is fairly popular though I've never used it. I would imagine you should be able to install it to its own partition and hack it into grub so it's there as a boot option (which I assume is what you're going for).
But most people just boot to it on CD or USB.
Answer: A simple solution is to use the dd command.
To back up a drive partition (eg. /dev/sda1), run this command:
dd if=/dev/sda1 of=~/sda1_backup

and to restore:
sudo dd if=~/sda1_backup of=/dev/sda1

For more information on the dd command, see man dd.
To reduce the space used by the backup images, you could use gzip, bzip2 etc. to compress the images. If you do this, you will need to decompress the images before restoring.
Answer: Personally I use these:

clonezilla
g4l
systemrescuecd
Answer: A somewhat newer tool is FSArchiver, which is included on the SystemRescueCD and supports restoring to partitions smaller than the original as long as there is enough space for all files.  It works with most filesystems that linux supports, can preserve both "basic" and "extended" attributes (e.g. for SELinux), can compress the archives with lzo, gzip, bzip2 or lzma, and can store the archives encrypted.


Is it a good idea to deposit directly into a service when withdrawing from another?

Question: I have two accounts on different Bitcoin broker services. I want to withdraw from one and deposit into the other. Is it necessary to first withdraw to my own Bitcoin wallet, or can I just withdraw from one service and deposit into the other directly, bypassing the wallet altogether? What are the advantages and disadvantages of either approach?
Comment: I see some close-votes on this topic citing this to be a "customer support issue". I voted to keep this question open, because I don't think this is a provider specific issue. "Should one withdraw directly from a service to deposit into another? What are the advantages and disadvantages of doing so?" appears to be a perfectly reasonably general issue with using Bitcoin.
Answer: Many services explicitly warn users against this practice, including in their withdrawal terms clauses like "you may only withdraw to an address which is controlled by you." This is likely to be due to the details of procedures used in the case of dispute resolution, but I've never seen any explicit justification for it.
The advantages of withdrawing directly are (1) saving the network fee associated with the transaction from your intermediate wallet to the receiving service; (2) overall the transaction would be faster.
The disadvantage is potentially violating the terms of services and the associated risk.
I admit to having taken this shortcut occasionally, but I would tend to avoid it for large transactions.
Answer: I've done that, successfully, but only with negligible quantities of low value alternative crypto assets.
I would never do that for high quantities or valuable assets such as Bitcoin, in order to help easier issue tackling in case everything that could go wrong goes wrong.

Imagine something went wrong at the destination exchange and your deposit isn't recognized.
If the destination exchange wants (for some reason) send the funds back to the exact same invoice address (weird, because reusing invoice addresses is universally discouraged, but...), it would be better that invoice address to be yours than of the source exchange. Maybe the source exchange isn't well wired into recognizing source funds in that invoice address automatically.
If the destination exchange wants some kind of source ownership proof from you, a simple problem will go through a solution unnecessarily contrived compared to if the ownership is yours.

Fees maintain the network alive. Save in headaches, save the network, pay fees.
Answer: If you want to deposit or withdrawal bitcoin then you will definitely need a btc wallet. Usually when you create a broker account you get a wallet and address with it.
Now if you want to transfer btc from one broker account to another then you will just need the address of the second account and you will be good to go.


Rendering of objects visible in viewport only!

Question: how do I render the objects visible in the viewport only ie. only the objects with the open eye  in the object outliner.
Thank you
Answer: By default only the eye icon to hide the object in the viewport is shown in the outliner, but you can add other icons including one to prevent the object being rendered.  Click on the Filter icon above the outliner then on the camera icon in the menu that appears. Hover over each icon for a description of what it does.

You'll then find another column of camera icons in the outliner which you can use to prevent the object being rendered as shown below.
Answer: You would have to move the unwanted rendered objects to a collection. Select objects >>> m >>> 'move to new collection'. There is a box left of the archive. Uncheck the box for it not to show in render. Check the box for it to show in the render. This could be useful for storing backup models in case anything goes wrong. Or properly organizing your objects. The eye does not affect the render, only the box does.
Comment: Thank you parm k,
Comment: Is there a way to disable the camera icon (render) automatically when I click on the eye icon
Comment: I am assuming your  asking if you can hide objects in a render with the eye. I am not 100% sure if there is a way. The eye only soul purpose is to make your viewport cleaner and faster. Again, I may be wrong.