iphone Core Data Unresolved error while saving

Question: I am getting a strange error message from the core data when trying to save
but the problem that the error is not reproducible ( it appears at different times when doing different tasks)
the error message:
Unresolved error Domain=NSCocoaErrorDomain Code=1560 UserInfo=0x14f5480 "Operation could not be completed. (Cocoa error 1560.)", {
NSDetailedErrors = (
Error Domain=NSCocoaErrorDomain Code=1570 UserInfo=0x5406d70 "Operation could not be completed. (Cocoa error 1570.)",
Error Domain=NSCocoaErrorDomain Code=1570 UserInfo=0x14f9be0 "Operation could not be completed. (Cocoa error 1570.)"
);
}

and the method that generates the error is:
- (IBAction)saveAction:(id)sender {
    NSError *error;
    if (![[self managedObjectContext] save:&error]) {
        // Handle error
        NSLog(@"Unresolved error %@, %@, %@", error, [error userInfo],[error localizedDescription]);
        exit(-1);  // Fail
    }
}

any idea for the reason of this message ? giving that it appears at random times
Comment: This might help you: "iPhone Core Data "Production" Error Handling" http://stackoverflow.com/questions/2262704/iphone-core-data-production-error-handling/3510918#3510918
Answer: It means there's a mandatory property has been assigned nil. Either in your *.xcodatamodel check the "optional" box or when you are saving to the managedObjectContext make sure that your properties are filled in.
If you're getting further errors after changing your code to suit the two requirements try cleaning your build and delete the application from your iPhone Simulator/iPhone device. Your model change may conflict with the old model implementation.
Edit:
I almost forgot here's all the error codes that Core Data spits out:
Core Data Constants Reference
I had trouble with this before and I realised I unchecked the correct optional box. Such trouble finding out the problem. Good luck.
Comment: This solved it for me. Also note that at least in my experience even though it wasn't saved to the sqlite file, the changes did make its way into the context. So the behavior may be erratic when this happens.
Comment: I couldn't get at the root cause but I managed to make the problem go away by making all properties optional.
Comment: Did you try Charles' code, it would tell you which field are the problem.
Answer: I struggled with this for a little while myself.  The real problem here is that the debugging you've got isn't showing you what the problem is.  The reason for this is because CoreData will put an array of NSError objects in the "top level" NSError object it returns if there is more than one problem (This is why you see error 1560, which indicates multiple problems, and an array of error 1570s).  It appears that CoreData has a handful of keys it uses to stash information in the error it returns if there is an issue that will give you more useful information (Such as the entity the error occurred on, the relationship/attribute that was missing, etc).  The keys you use to inspect the userInfo dictionary can be found in the reference docs here.
This is the block of code I use to get reasonable output from the error returned during a save:
    NSError* error;
    if(![[survey managedObjectContext] save:&error]) {
        NSLog(@"Failed to save to data store: %@", [error localizedDescription]);
        NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
        if(detailedErrors != nil && [detailedErrors count] > 0) {
            for(NSError* detailedError in detailedErrors) {
                NSLog(@"  DetailedError: %@", [detailedError userInfo]);
            }
        }
        else {
            NSLog(@"  %@", [error userInfo]);
        }
    }

It will produce output that tells you the fields that are in missing, which makes fixing the problem significantly easier to deal with.
Comment: Thanks a lot for this code. It makes CoreData problem tracking indeed much simpler.
Answer: I'm throwing this in as an answer, even though it's really more of an embellishment to Charles' snippet. The straight output from NSLog can be a mess to read and interpret, so I like to throw in some white space and call out the value of some critical 'userInfo' keys.
Here's a version of the method I've been using. ('_sharedManagedObjectContext' is a #define for '[[[UIApplication sharedApplication] delegate] managedObjectContext]'.)
- (BOOL)saveData {
    NSError *error;
    if (![_sharedManagedObjectContext save:&error]) {
        // If Cocoa generated the error...
        if ([[error domain] isEqualToString:@"NSCocoaErrorDomain"]) {
            // ...check whether there's an NSDetailedErrors array
            NSDictionary *userInfo = [error userInfo];
            if ([userInfo valueForKey:@"NSDetailedErrors"] != nil) {
                // ...and loop through the array, if so.
                NSArray *errors = [userInfo valueForKey:@"NSDetailedErrors"];
                for (NSError *anError in errors) {

                    NSDictionary *subUserInfo = [anError userInfo];
                    subUserInfo = [anError userInfo];
                    // Granted, this indents the NSValidation keys rather a lot
                    // ...but it's a small loss to keep the code more readable.
                    NSLog(@"Core Data Save Error\n\n \
                      NSValidationErrorKey\n%@\n\n \
                      NSValidationErrorPredicate\n%@\n\n \
                      NSValidationErrorObject\n%@\n\n \
                      NSLocalizedDescription\n%@",
                      [subUserInfo valueForKey:@"NSValidationErrorKey"],
                      [subUserInfo valueForKey:@"NSValidationErrorPredicate"],
                      [subUserInfo valueForKey:@"NSValidationErrorObject"],
                      [subUserInfo valueForKey:@"NSLocalizedDescription"]);
                }
            }
            // If there was no NSDetailedErrors array, print values directly
            // from the top-level userInfo object. (Hint: all of these keys
            // will have null values when you've got multiple errors sitting
            // behind the NSDetailedErrors key.
            else {
                    NSLog(@"Core Data Save Error\n\n \
                      NSValidationErrorKey\n%@\n\n \
                      NSValidationErrorPredicate\n%@\n\n \
                      NSValidationErrorObject\n%@\n\n \
                      NSLocalizedDescription\n%@",
                      [userInfo valueForKey:@"NSValidationErrorKey"],
                      [userInfo valueForKey:@"NSValidationErrorPredicate"],
                      [userInfo valueForKey:@"NSValidationErrorObject"],
                      [userInfo valueForKey:@"NSLocalizedDescription"]);

            }
        }
        // Handle mine--or 3rd party-generated--errors
        else {
            NSLog(@"Custom Error: %@", [error localizedDescription]);
        }
        return NO;
    }
    return YES;
}

This allows me to see the value for 'NSValidationErrorKey', which, when I encountered the issue from the OP, pointed directly to the non-optional Core Data entities that I'd forgot to set before trying to save.
Comment: Also very useful. Specially when you get this raw \n\n\n core data entity description strings.
Comment: Neat. 'message' is unused btw.
Answer: The problem touched me, when I save second record to CoreData.
All not optional fields (relationship) was filled without nil as well, but in the error output I'd notice, that one of fields in first saved object had became nil. Strange a little? But the reason is quite trivial - one to one relationship which nullify first object, when I set it in the second.
So, the scheme is:
"Parent" with relationship "child" One to One
Create Child 1, set parent. Save - OK
Create Child 2, set parent. Save - Error, Child 1.Parent == nil
(behind the scene child 2 did nullify child 1 parent)

Changing the relationship in Parent from One to One to Many to One solved this task.
Answer: I had transient property of type int that wasn't optional. Obviously, when it was set to 0, 1570 error appear. Just changed all my transient properties to optional. Nil-check logic can be implemented in code if necessary.
Answer: I means that your model failed to validate, which could happen for a number of reasons: unused property in your model, missing value that's marked as required.
To get a better understanding of what exactly went wrong, put a breakpoint in a place where you are ready to save your object, and call one of the validateFor... method variants, like:
po [myObject validateForInsert]
More detailed information about the problem is in error description. Successful validation means you will get no output.
Answer: It helped me. Check this one too.
Check the optional box in your *.xcodatamodel objects


What would you call a person who doesn't like questions being asked of them?

Question: My sister says I ask too many questions, such as "What have you been up to lately?"  She is the only person who says that.
What do you call a person who doesn't like questions being asked?
Answer: Another good word would be reticent: inclined to be silent or uncommunicative in speech.
Comment: 'uncommunicative'? (google ngrams says you're right, but still...)
Answer: If you don't want to be critical of her, you could say she's a private person.
If you want to imply she might be hiding something, you could say she is secretive.
Answer: There may be different reasons why questions about oneself are unwanted.
shy people feel uncomfortable being in center of others attention and that includes being asked a lot of questions.
secretive people either have something to hide, or just don't like ttalking about themselves much.
Same goes for silent in the meaning Not inclined to speak; not talkative.
Answer: In this case it sounds like your sister is more indignant than any of the other terms suggested.
Adjective

Feeling or showing anger or annoyance at what is perceived as unfair treatment.
Answer: In answer to your question "What do you call a person who doesn't like questions being asked?", I think of such a person as an authoritarian, self-important, fascist, close-minded, stupid, supercilious, cross-grained, arrogant and imperious fool, dunderhead, or dictator.
But perhaps that's not what you want to know, and perhaps meant to ask, "How should [Maureen] refer to this question-averse aspect of her sister?", which of course I don't know.  However, if previously-suggested shy, silent, private and secretive don't apply, also consider veiled, introverted, taciturn, censorial, no-nonsense, thin-skinned, touchy and untalkative.
Answer: This person is guarded
The ODO proposes this rather good example sentence:

'The question took him by surprise, and his eyes grew guarded and cautious, his own grip tightening as well.'

You might say that she answers your questions guardedly, too.
Answer: If the person being asked the question wishes to conceal something embarrassing or otherwise inconvenient, evasive is a good fit.
If they feel the questioner is overstepping a social boundary, then resentful may be what you're after.
Answer: indisputable/ defensive / unquestionable / unimpeachable / unapproachable / above the law / incontestable
Answer: There isn't a correct answer to your question. Whatever adjective you choose largely depends on your sister's personality traits and life experiences. That said, one might say your sister is shy, introverted, reserved, reticent, secretive, insecure, taciturn or unsociable.  Whichever I choose would be a real guessing game, though.
Answer: Based on analysis of Gardner's multiple intelligences, the faculties of the mind and the characteristics suggestive of the learning disabled: adding inattentiveness or inadvertance, bodily or mindfully impaired and/or lost, visually or aurally illiterate, unfocused, corrupt, unreasonable to be a fool! However, the summarized fool is based off memory and attention issues. He may not like other conversational circumstances. If he doesn't like conversational circumstances entirely he is sociolinguistically (conversationally) incompetent, Noam Chomsky might say. The person who doesn't like answering questions in the worst case would be a fool. This question has helped me to see that incompetence, impairment, mindlessness, illiteracy and foolishness can be a rolling problem. It's only rolling if the worst case scenario fool has memory and attention problems, and the rest aforementioned. Thanks for helping me study for the Praxis PLT with this archetype!
Comment: If your answer is "fool", please put it up front and make your defense clear. This text is nearly word salad.
Comment: You had me at 'Based on..'.
Comment: He had me at 'Based'.


Why did 'r' disappear in English "speak" (compare German "sprechen") and in German "Welt" (compare English "world")?

Question: I cannot help but notice some 'r'-s seem to have randomly disappeared in both German and English. What is going on there?
Comment: According to *A Historical Phonology of English by Donka Minkova* (p121): Sporadic loss of  occurs in some onset clusters: *sp(r)ecan* 'to speak', *sp(r)æċ* 'speech', *p(r)æˉtiġ* 'clever, pretty'.
Comment: Since we have *worship* versus German *Wirtschaft* "economy, establishment" contrast so much, whereas *Weihe* is closer to the sliritual sense, it should be considerable if this was a case of substitution that might apply to *Werald* and *Welt* as well. Between PIE \*wer-, \*werh1-, \*swer-, etc. a reasonable mount of overlapping semantics can be infered as much as for \*wihros "man" > *were* and \*wer-(?) > *warden, warroir*, etc. (cp. further *warranty*, *promis*, Ger. *Versprechen*, *Vorsehen*... Lat. *spect-*?)
Comment: Re: why there is no r in PDE speak - we don't know why it happened. cf.  Anatoly Liberman's remark that "Despite a sizable number of pairs like speak (in Old English, specan coexisted with sprecan: cf. German sprechen), the mystery of the fugitive r has never been solved." https://blog.oup.com/2011/06/pretty-2/
Comment: @"Joyful Sadness", so, the vowel in "pretty" was originally long 'ae'? So, how did it came to be short 'i'? And why was the same phenomenon, the random disappearance of 'r', occuring in German?
Answer: Different reasons.
'they speak/they spoke' in Protogermanic was something like 'sprekanþi/spurkun'. Note the different position of the 'r'. Our forebears made the word more regular with the Germans going for 'spr-' and '-k-'  whilst the Angles going for 'sp-' but also '-k-'.
'world' and 'Welt' are both contactions of 'weraldiz' ('men-age' or 'generation'). Contractions are always fairly irregular. The Germans and the English contracted the word slightly differently.
Comment: Disagree. Simplification of the cluster after contraction from *werald* is imaginable at least if the /r/ was a Upper German alveolar trill/flap next to the lateral approximant /l/. But about *speak*; it is attested besides *sprekan* in OE, maybe a case of different though very similar etyma like *answer* ~ Ger. *Antwort*. See, *sprek-* compares well with *spray*, whereas *speak* might compare to *spuck-* "spit" (cp. *spit it out*, Ger. *spuck's aus*, i.e. "tell me"), or *spüren* "sense" versus *Spuk* or  *fühlen* "feel" (Grimm's law applies), or PIE \*werh1- vs. \*bheh2-, etc.
Comment: @vectory It isn't surprising that both specan and sprecan existed in Old English as it will have been at that time that the regularising was happening. However I'm in good company see Kroonen, Guus "Etymological Dictionary of Proto-Germanic" (Leiden: Brill, 2013) page 469.              You are right that the simplification of /rl/ to /l/ is imaginable in German. Is it a regular sound law?
Comment: It isn't surprising? There's a hefty amount of circular reasoning and false equation in that argument. Is /rl/ > /r/ regular (in German)? Beats me. Comparing Kalle ~ Karl, Polier << Fr. parler, Berlin [bɛɐ̯ˈliːn], [bɛʁˈliːn], (Berlinisch) [bɐ̠liːn], the elision is regular where the underlying backed resonant may be elided in syllable codas, similar to rhotic vowels of AmE rather than the alveolar trill /r/ (as is reconstructed for PGem). This extends into Middle Bavarian, which is an upper German dialect coming from Middle High German, so I don't know where the /r/ can be examined.


iPhone blocked network problem

Question: I recently brought a iPhone 5 from a seller and did the iOS9 update. Everything appeared fine at first, but now the phone won't make phone calls. It keeps saying: "This handset has been blocked on this network."
What does that mean and how do I fix it?
I can send and receive SMS messages as normal.
Answer: This message has nothing to do with the iOS version of your phone, The message : This handset has been blocked on this network means that the handset has been reported as lost or stolen, probably by the previous owner. You need to contact the seller and ask him if the phone he sold to you was not stolen or found.
If you have access to your IMEI (that you can find in Settings --> General --> Information) use this website to check the status of your handset http://www.amta.org.au/pages/amta/Check.the.Status.of.your.Handset

iPhone blocked network problem


socks in java (opening via socks)

Question: how do i add SOCKS support to my application? and where can i get the libs?
Answer: From http://java.sun.com/javase/6/docs/technotes/guides/net/proxies.html
The SOCKS protocol, as defined in RFC 1928, provides a framework for client server applications to safely traverse a firewall both at the TCP and UDP level. In that sense it is a lot more generic than higher level proxies (like HTTP or FTP specific proxies). J2SE 5.0 provides SOCKS support for client TCP sockets.
There are 2 system properties related to SOCKS:
socksProxyHost for the host name of the SOCKS proxy server
socksProxyPort for the port number, the default value being 1080
Note that there is no dot ('.') after the prefix this time. This is for historical reasons and to ensure backward compatibility. Once a SOCKS proxy is specified in this manner, all TCP connections will be attempted through the proxy.
Example:
$ java -DsocksProxyHost=socks.mydomain.com GetURL

Here, during the execution of the code, every outgoing TCP socket will go through the SOCKS proxy server at socks.mydomain.com:1080.
Now, what happens when both a SOCKS proxy and a HTTP proxy are defined? Well the rule is that settings for higher level protocols, like HTTP or FTP, take precedence over SOCKS settings. So, in that particular case, when establishing a HTTP connection, the SOCKS proxy settings will be ignored and the HTTP proxy will be contacted. Let's look at an example:
$ java -Dhttp.proxyHost=webcache.mydomain.com -Dhttp.proxyPort=8080 -DsocksProxyHost=socks.mydomain.com GetURL

Here, an http URL will go through webcache.mydomain.com:8080 because the http settings take precedence. But what about an ftp URL? Since no specific proxy settings were assigned for FTP, and since FTP is on top of TCP, then FTP connections will be attempted through the SOCKS proxy server at socks.mydomsain.com:1080. If an FTP proxy had been specified, then that proxy would have been used instead.
Comment: Will this also cause UDP connections(Dgram) to pass through the specified proxy?
Answer: Since jkd 1.5, you can also configure proxies by Socket programmatically :
For instance :
SocketAddress sa = InetSocketAddress.createUnresolved("mysocksproxy.com", 1080);

Proxy proxy = new Proxy(Proxy.Type.SOCKS, sa);

Socket s = new Socket(proxy);

You might also want to put this code in a SocketFactory.

socks in java (opening via socks)


Find the pairs $(x,y) ; 0 \le x,y \le 18$ such that $19 \vert 3x+4y+5$

Question:
Let $\mathrm S ={(a,b) : a,b \in \mathbb Z,  0\le a,b \le 18}$. Find the number of elements in $\mathrm S$ such that $3x+4y+5$ is divisible by $19$.

I tried using congruences to simplify the problem.
We need $$3x+4y \equiv -5 \pmod{19} \equiv 14 \pmod{19}$$
I wrote $3x+4y \equiv 3(2)+4(2) \pmod{19}$. But I am not able to conclude anything from this. I know that if we find $(x,y)$ such that $x  \equiv 2 \pmod {19}, y \equiv 2 \pmod{19}$ will satisfy the criteria, but will only these? I am stuck here. Please help me with proceeding in this solution
or any other solution will also work.
Thanks!
Comment: @user340297 $3\cdot 7-4\cdot 2=21-8=13$ is not divisible by $19$. Also notice $0\le a,b\le 18$.
Comment: They are $19$ $$(0,\,13),\,(1,\,17),\,(2,\,2),\,(3,\,6),\,(4,\,10),\,(5,\,14),\,(6,\,18),\,(7,\,3),\,(8,\,7),\,(9,\,11),\,(10,\,15),\,(11,\,0),\,(12,\,4),\,(13,\,8),\,(14,\,12),\,(15,\,16),\,(16,\,1),\,(17,\,5),\,(18,\,9)$$
Comment: If $(a,b)$ is in $S$, then $(a+7,b-2)$ is also in $S$. So $S$ is either empty or it has inifinitely many elements.
Answer: Since $19$ is a prime, we have
$$\begin{align}
3x+4y+5\equiv0\mod19
&\iff15x+20y+25\equiv0\mod19\\
&\iff-4x+y+6\equiv0\mod19\\
&\iff y\equiv4x-6\mod19
\end{align}$$
Hence each value of $x$ from $0$ to $18$ gives precisely one value of $y$ in the same range, e.g., $x=15\implies y\equiv54\equiv16$ mod $19$.  So there are precisely $19$ elements of $S$ satisfying the equation.
Comment: Great +1..........
Answer: Write $3x+4y+5=19z$
First we see that $1\leq z\leq 6$. Since $3\mid 19z-4y-5$ we have $3\mid z-y+1$ and so $z-y+1 = 3t$ for some integer $t$. From here we get:
\begin{eqnarray}
y&=& z-3t+1\\
x&=& 4t+5z-3
\end{eqnarray}
So
\begin{eqnarray}
0\leq& z-3t+1& \leq 18\\
0\leq & 4t+5z-3&\leq 18
\end{eqnarray}
Case 1: $z=1$ then $t= 0$ so $1$ solution $x= 2$ and $y=2$.
Case 2: $z=2$ then $-2\leq t\leq 1$ so $4$ solution.
Case 3: $z=3$ then $?\leq t\leq ?$ so $?$ solution.
...
Answer: $$
3x+4y \equiv 14 \pmod{19}
$$
To find a solution we start by searching for a solution of
$$
3x \equiv 1 \pmod{19}\\
4y \equiv 1 \pmod{19}
$$
A solution is given by $x_0=13,y_0=5$. Then the solution of the original modular equation is given by:
$$
x\equiv tx_0 \pmod{19}, \qquad y\equiv (14-t)y_0 \pmod{19},
$$
for $0 \leq t\leq 18$. See relevant post.
For example for $t=0$ we get the pair $(0,13)$ as a solution and for $t=1$ we get $(13,8)$. Can you continue from here?
$$
t=0 \rightarrow (0,13)\\
t=1 \rightarrow (13,8)\\
t=2 \rightarrow (7,3)\\
t=3 \rightarrow (1,17)\\
\dots\\
$$


Labelling large amounts of audio data in automatic or semi-automatic way

Question: I am working on a project, where I have to label the audio datasets which has thousands of data, each audio data is for one second. I have to label where it is in idle or event happening or noise. I used some tool like Audacity and Labelstudio, I can manually label the audio files which is in .wav but thousands of files it is very time consuming is there any alternative method for it, where I could label data efficiently. Now I was trying to write a python script for labelling but there was no luck, was struck in getting it an output viewing format. Could you please share your experience or any other solution for it as supervised learning .
Comment: For the manual labelling, there are good answers here https://datascience.stackexchange.com/questions/55566/tool-for-labeling-audio
Answer: You dataset is unsupervised. I would, first, suggest you try to cluster your dataset, and, then, apply any supervised learning methodology.
I leave you this post for further reading.
Comment: Hey Thank you for the input. I have already have the labelled and clustered data. I want to label inside the each audio data, the waveforms. How to keep an threshold and doing it using python script for it or any other method . Please share your view if you have iany input with this.


Using LVM with two hard drives, 1 Solid State

Question: I am setting up Ubuntu and just got to the option about using LVM to partition the hard drives. My understanding is that if I do this Ubuntu will be able to treat the two drives as one. That's great, but I also want to able to distinguish between the two drives because one is a solid state and one is not. Will I still be able to have a C and D drive with LVM, i.e. can I intentionally save a file to one verses the other?
Answer: You will indeed be able to choose where the logical volumes take their physical extents from.  For illustration (taken from shell history):
sudo lvcreate VG -n LogicalName --alloc cling -L 500M /dev/dev0

The above flags can also be passed to lvchange when the volume already exists. This will move data from one disk to another:
sudo pvmove -n LogicalName /dev/dev0 /dev/dev1

Also, to avoid micromanagement of which file goes on which drive, I recommend running bcache on top of LVM.


.elf or .bin file to be download as application code in ARM cortex M4

Question: I am using a MCU with ARM Cortex M4 processor.
I Have written a bootloader on it.
Using USB CDC ACM class, i am writting the application code in memory address 0x002000.
I have generated both .elf and .bin files of the application code which i want to run through this bootloader.
Which file is required to be write in memory from bootloader?.elf or .bin?
I have generated both .elf and .bin.
Comment: Depends on the bootloader implementation. If you wrote it, you should know what it wants to be fed!  But, most typically, the .bin.
Comment: @pericynthion : Thank you for effort. Currently, in my bootloader, jumping to application code from boot code part is not implemented. For the same reason i want to know that which file is required to write in memory. If .elf is written in memory then how to run the application code from boot code? Similarly, if .bin file is written then how to run the application code?
What steps should be required to follow in boot code?
Comment: Did you ever get an answer? I'm working on a similar problem
Answer: My bootloader is working fine.
I have used .bin file for downloading in flash.
to convert .elf to .bin file use the post building options for GNU gcc compiler as follow :
arm-none-eabi-objcopy -O binary My_project.elf My_project.bin
It converts My_project.elf file to My_project.bin file.


Translation of "cheesy"

Question: What is the best Spanish translation of the English word "cheesy" (something inauthentic, trying too hard to be funny, cheap, shabby, etc.)?
Answer: As I understand "cheesy", the translation is "cursi". And it works in Hispanoamerica too, not only in Spain. "Caseoso" is out of discussion, that's for something related to "cheese".
Comment: I'd say _'cursi'_ would work 75% of the times to accurately translate _'cheesy'_. Options in other answers would suit better in some cases and should be considered as well.
Answer: Terms I've heard:

Cursi

ie.

¡Eres muy cursi!
Comment: I'm pretty sure I've heard *cursi* in Mexico, too.
Comment: Also in Argentina
Comment: Note, that *cursi* would be understood in Spain only.
Comment: Also in Colombia - Cursi is used everywhere.
Comment: Also in Chile .
Comment: Yes, "cursi" is used in México too as Flimzy said.
Answer: Cheesy has another meaning in English appart from "cursi":

Inferior or cheap: "de mal gusto" / "cutre" (slang)
Of a smile: "insincero"

In fact, I've only seen it used as "cutre"
Source: http://www.wordreference.com/definition/cheesy
Comment: I believe _'cutre'_ is Spain only slang.
Comment: No, 'cutre' is slang in Perú too.
Answer: «Hortera» is also a good match
Comment: I'm native, never heard Hortera nor do I know what it means. Wouldn't recommend using it to avoid weird "What?" looks
Comment: In European Spanish is totally common (Google shows 700.000 results)
Comment: Maybe only in Spain, because I'm from south america and never heard of it. For instance, the other suggested translation, "Cursi", has 7.1 million results. Showing it's used more than 10 times more online at least
Answer: I always think of 'cursi' as more like 'twee' really than 'cheesy'.
'Hortera' definitely maps on better.
¡No hay parto sin dolor ni hortera sin transistor!
That was a saying in the 80s-a properly cheesy decade at the time that people now seem to have retro-fitted as cool.
Cheesy is really to do with the gap between self-image/promotion of a person/thing and its reality to the beholder.
So Julio Iglesias was Borat-level cheesy to 70s/80s english ears of a certain age but maybe was an icon of romance to their aunts/mums?
Maybe cheesy is 'masculine-style to excess' and twee is 'female-style to excess'?
Lo que tienen en comun es que en ambos casos se han pasado 3 pueblos.
A  radar for cheesiness is definitely more of an english than a spanish thing though!
Everything in moderation...
Comment: "Twee" is not a very common word at all (at least as far as my linguistic sphere is concerned) and could meaning something more specific, more like cutesy; whereas "cheesy" is extremely common and has a broader use.
Answer: Despende del contexto. Cheesy, también puede significar "mantecoso", "pastoso", "oleoso". Hace referencia a algo denso. No veo la relación con "cursi". Más bién con alguien o algo pesado, medio cargante, difícil de tragar
Comment: Lamento decirte que tu uso de la palabra es ajeno al que le da normalmente (por lo menos en Norteamérica). Signfica normalmente algo dicho/hecho con la intención de hacer gracias, o al que se haya querido infudir de sentimentalismo o de hondura, pero que se quede corto y termine sonando mal.

Translation of "cheesy"


Green's Function - PDE

Question: I am completely stumped on Green's function regarding PDE's. There are barely any examples in my book on how to apply it. For example, if a question asks, "find the Green's function ..." to some specified domain, what am I looking for? What does it mean to find Green's function? Is there a formula to use? Green's function seems so abstract to me. It's just not clicking.
Comment: http://web.stanford.edu/class/math220b/handouts/greensfcns.pdf
Answer: Let $\Omega$ be a domain in the plane (open connected set) and $p$ a point in $\Omega$. A Green function, $G_p$ is a smooth function defined on $\Omega \cup \partial \Omega$ such that:
(i) $G_p$ is harmonic on $\Omega \setminus \{p\}$
(ii) $G_p$ is continuous on $(\Omega \cup \partial \Omega)\setminus \{p\}$
(iii) $G_p$ is zero on the boundary $\partial \Omega$
(iv) $G_p$ has a simple pole at $p$ with reside $\frac{1}{4\pi}$
My Reference is the PDE book by Walter Strauss. His treatment of Green's functions is excellent. You should look him up if you want to understand this topic better.
Comment: Thank you! What do I do in situations where it asks, for example, "Find Green's function for the upper half-ball" or "Find Green's function for the disk of radius a>0" or "Find Green's function for the titled half space" and so on.
Comment: If you are familiar with complex variables you can obtain a Green's function for the disk by using a conformal mapping from the upper half plane to the disk. So if you know one Green's function you can get other types by suitable conformal maps.

Green's Function - PDE


How to change the frequency of Google Play update checks?

Question: Every day I get a notification on my Inc2 that there are app updates available in the market.  Is there a way to change the frequency of these update checks?  I see no reason to be prompted to update my apps on a daily basis and this is a little annoying.  I would like to be able to only have it check for updates weekly.
Answer: You can turn off automatic update checking by pressing menu and than settings in the play store. You can then manually go to my apps to update them. This will not greatly increase the work you have to do, because even if there is a notification once a week it would still require you to confirm the updates. There is no option however to change the frequency of the automatic updates.
Answer: If you go into Settings and check "Auto-update apps" it will download and install the updates without prompting you. If you're worried about data usage, also check "Update over Wi-FI only". I've had my phone set this way for a while now, as I too got tired of constantly having updates to accept.
As Dylan Yaga pointed out, if an apps update changes its permissions, you will still be prompted to update it manually, although this doesn't occur very often.
Comment: Side Note: Apps that change permissions must still be manually reviewed before updating using this method.
Comment: I like being in control of when my apps update.  Daily is far to often to review a list of updates.  I assume that if I auto-update I will still be notified of all of the updates that have occurred.  I have also found that quite a few of my apps update permissions frequently.
Comment: I finally gave in and went this route.  I still don't like apps autoupdating without telling me, but at least my monthly update all doesn't freeze up the device for an hour anymore.


Looking for 90s book title - Pandemic cure causes sterility and children sex change with menstrual cycles

Question: Looking for 90s book title - Pandemic cure causes sterility and children sex change. Plot: There is a pandemic. The cure causes selective sterility mother's must find fathers with different blood types to conceive a child. At puberty, males change to females or females change to males due to menstrual cycles.
Comment: Hi, welcome to SF&F!  Do you have any recollection of what the cover looked like?  Please check out the other [suggestions](https://scifi.meta.stackexchange.com/a/9337/101407) for story-id questions and [edit] in any additional details you might recall.
Comment: No sorry it was a paperback book purchased before 1995. I do not remember any cover details or the author. I remember a blood-type A mother went to a bar to find a blood-type O father. The child conceived was born male then suddenly at puberty changed to female over night. This child would eventually change back to being male if in the presence of a menstruating female. Eventually humanity changed to everyone was two-sexed. When female all of these 'new humans' could conceive a child regardless of the parent's blood-types.
Answer: This might be "The Breeds of Man" by F.M. Busby. With  publication date of 1988, it more or less fits with your memory of a 90s book.
Scientists find a cure for AIDS, but a consequence is that women become infertile to a second pregnancy to men with the same blood type as the first. To fix this problem, the scientists create a second type of human, the Mark II, described on the cover blurb as "a remarkably adaptable breed of man able to survive when normal humans cannot". However, it is discovered that when they hit puberty the Mark IIs cycle between genders every month.
Comment: THANK YOU! It is indeed The Breeds of Man by Busby.
Comment: Glad to help! As you're certain it's correct, can you click to accept the answer? Thanks.


Topology of the product of projective varieties

Question: I can't prove that the closed sets of a product of projective varieties is a zero locus of multihomogeneous polynomials. I'm taking the abstract point of view to the construction of product of varieties, i.e., if $X$,$Y$ are algebraic varieties (ringed spaces locally isomorphic to affine varieties) then we have affine open covers $\{U_i\}, \{V_i\}$ of $X$ and $Y$ respectively, and then we define the topology over $X\times Y$ saying that a subset $C\subset X\times Y$ is closed iff $C\cap(U_i\times V_j)$ is closed in $U_i\times V_j$ for all $i,j$.
Then, my question is: if I have the product $\mathbb{P} ^n\times\mathbb{P}^m$ with the topology induced in the previous form, how I can prove that closed sets of this product are given by zeroes of bihomogeneous polynomials?
Similarly, how I can prove that closed sets of $\mathbb{P} ^n\times\mathbb{A}^m$ are the zeroes of homogeneous polynomials in the first n variables?
Comment: Does the Segre embedding $\mathbb P^n \times \mathbb P^m \hookrightarrow \mathbb P^{nm+n+m}$ help in any way?
Comment: I understand the construction by the Segre embedding, we define a bijection between the product and a closed of $\mathbb{P}^{(n+1)(m+1)-1} $ and then we can transport the whole variety structure to this product, however what I want is to deduce this characterization of the closed sets from the construction that I have detailed above, since this is more general and thus I can understand other closed ones such as those of $\mathbb{P}^n\times\mathbb{A}^m$.
Answer: I believe red_trumpet's suggestion in their comment should answer your question: the Segre embedding $i : \mathbb{P}^n \times \mathbb{P}^m \hookrightarrow \mathbb{P}^{nm + n + m}$ defines a closed immersion of varieties; this implies that all closed subsets of $\mathbb{P}^n \times \mathbb{P}^m$ arise as the pull back of a closed subset of the projective space $\mathbb{P}^{nm+n+m}$. Any closed subset $Z \subseteq \mathbb{P}^{nm+n+m}$ is of the form $$
   V(s_1,\dots,s_r) = Z \subseteq \mathbb{P}^{nm+m+n}
$$ where $s_i \in \Gamma(\mathbb{P}^{nm+m+n},\mathcal{O}(d_i))$ are global sections. The intersection of $Z$ with $\mathbb{P}^n \times \mathbb{P}^m$ will be given by $$
   V(i^\ast s_1,\dots,i^\ast s_r) = i^\ast Z \subseteq \mathbb{P}^n \times \mathbb{P}^m
$$ where $i^\ast s_j \in \Gamma(\mathbb{P}^n \times \mathbb{P}^m, i^\ast \mathcal{O}(d_i))$ are the induced global sections. To conclude I think all you have to do is recognise the pullback bundles $i^\ast \mathcal{O}(d_i)$ on the product $\mathbb{P}^n \times \mathbb{P}^m$ as box-products of line bundles on $\mathbb{P}^n$ and $\mathbb{P}^m$, since their global sections are the polynomials you describe.
I'll describe this in an easy example where the numbers are small; I think the general argument should be clear: denote by $[x_0:x_1]$ and $[y_0:y_1]$ the projective coordinates on two copies of $\mathbb{P}^1$ and $[z_0:z_1:z_2:z_3]$ the coordinates on $\mathbb{P}^3$; the Segre embedding $i : \mathbb{P}^1 \times \mathbb{P}^1 \hookrightarrow \mathbb{P}^3$ is defined on the open patches $$
   \text{Spec}\left(\mathbb{Z}\left[\frac{x_1}{x_0},\frac{y_1}{y_0}\right]\right) \subseteq \mathbb{P}^1\times\mathbb{P}^1 $$ $$
\text{Spec}\left(\mathbb{Z}\left[\frac{z_1}{z_0},\frac{z_2}{z_0},\frac{z_3}{z_0}\right]\right) \subseteq \mathbb{P}^3
$$ by the ring homomorphism given by $$
   \frac{z_1}{z_0} \mapsto \frac{x_1}{x_0} $$ $$
   \frac{z_2}{z_0} \mapsto \frac{x_1y_1}{x_0y_0} $$ $$
   \frac{z_3}{z_0} \mapsto \frac{y_1}{y_0}
$$ and likewise on the other standard affine opens. The gluing data for the line bundle $\mathcal{O}(1) \in \text{Pic}(\mathbb{P}^3)$ on the intersection of standard opens $$
   \text{Spec}\left(\mathbb{Z}\left[\left(\frac{z_1}{z_0}\right)^{\pm 1},\frac{z_2}{z_0},\frac{z_3}{z_0}\right]\right) \subseteq \mathbb{P}^3
$$ is given by multiplication by the invertible section $\frac{z_0}{z_1} \implies$ the induced gluing data for $i^\ast \mathcal{O}(1)$ on the open patch $$
  \text{Spec}\left(\mathbb{Z}\left[\left(\frac{x_0}{x_1}\right)^{\pm 1}, \frac{y_0}{y_1}\right]\right) \subseteq \mathbb{P}^1 \times \mathbb{P}^1
$$ is given by multiplication by $\frac{x_0}{x_1}$ and similarly for the other intersections. If you stare at the formulas long enough you should be able to see that these define the gluing data for $\mathcal{O}(1)\boxtimes \mathcal{O}(1) := \pi_1^\ast \mathcal{O}(1) \otimes \pi_2^\ast\mathcal{O}(1)$ where $\pi_1,\pi_2 : \mathbb{P}^1 \times \mathbb{P}^1 \to \mathbb{P}^1$ are the two projections.
If you want to argue the similar result for the product $\mathbb{P}^n \times \mathbb{A}^m$ I think you can repeat the above argument by restricting the Segre embedding to this open subset of $\mathbb{P}^n \times \mathbb{P}^m$, since this will still define an immersion of varieties.
I'm not sure this was exactly what you were looking for, and I apologise if my explanations were a little too obvious :p I hope I still managed to help somehow :)


Definition of Jets

Question: In Babar experiment they basically observe $\Upsilon(4s)$ resonance which decays to $B^0$ and $\bar{B}^0$ which eventually then decays to Kaon, pions, muons, etc. So, my question is: Is this a two jet event ? Or is it right to talk of jets in this case or just leave it saying that it was a two meson event?
Comment: $\Upsilon$ looks way to much like $\gamma$... Fun fact, if you google $\gamma(4S)$, the first result is the PDG page for $\Upsilon(4S)$. So even Google is confused!
Answer: A jet is created when a quark or gluon is produced with a very high energy and subsequently hadronizes, creating a shower of particles.
The $\rm\Upsilon(4S)$ resonance has a mass of only $10.57~\rm GeV$, which is just barely enough to decay into $\rm B^0 \bar B^0$ in the first place. As such, the mesons are produced almost at rest (in the $\rm\Upsilon(4S)$ rest frame), no hadronization occurs, and you would not call this a two jet event.
You mainly get jets with more massive particles decaying, since there has to be enough energy available to produce multiple hadrons. Decay modes that produce jets will have either free quarks or free gluons listed in the final state. Since colored is confined, this always implies the formation of a jet. For instance, the top quark decays like $\rm t\rightarrow bW$, which will be observed as a jet and whatever the $\rm W$ decays into.
Comment: @kbg I don't know that much about BaBar, but $B^0$ mesons at that energy only travel around a millimeter on average before decaying, so I'd be surprised if they got tracking on them before the decayed. They presumably can reconstruct the vertex of the decay products and figure out pretty much exactly where it decayed, though.
Comment: Also, if you are aware of, do these boosted B meson mostly decay after passing through the first tracking detector so that their decay can be observed or do they decay near the beam pipe and only their decay products(hadrons) are observed by the detector?
Comment: @Chris Do you know if all jets need a hadron to be defined? Are there non-hadronic jets ?
Comment: @partizanos From an experimental point of view, a jet is just a whole bunch of particles concentrated in one place. Hadrons tend to make jets, and other particles do not, but in principle you could have a "jet" with no hadrons.

Definition of Jets


Flush on the board

Question: There was a heart flush on the board ( A K 5 10 and 7 ) of heart. I had the J & 10 of heart in my hand the other guy had none. I was told that it was a split pot. Was I cheated ?
Comment: Yes you were cheated.
Comment: how can the 10 of hearts be on the board and in your hand at the same time?
Answer: More likely you need glasses. Looks to me that you actually had TJ of DIAMONDS. There is only one ten of hearts in each deck, so it wasn't both in your hand and on the board. You'd be surprised, I estimate this actually happens to everybody about once a year if you play regularly. I've seen it hundred of times personally.
Comment: Nicely spotted!
Comment: Many online poker rooms offer the option to use four-colour deck to avoid such misreads.
Comment: I think Mika Caro actually put 4 color decks in L.A. once. Don't think it caught on.

Flush on the board


Logical explanation for '高を括る'? phrase

Question: Just came across this phrase and upon breaking it down it looked like it would have the opposite meaning to what it really has (高を括る-to make light of). Have I missed something and there's actually a good explanation for this phrase? My first thought was that it would mean 'to expect a lot' or something similar.
Comment: @flowsnake the dictionary I checked says the meaning of 括る here is 予想する, so I'm not sure "constrict" plays a part.
Comment: It look like 括 can mean "constrict". Does there need to be more to it?
Answer: 高【たか】 means "yield/amount/quantity" (e.g., of a crop). くくる means "to bind/tie" and, by extension, "to summarize/consolidate". Thus, the literal meaning of 高をくくる is nothing more than something like "to estimate (the capability of someone/something)" or "to assume". However, as an idiom, it has gained a derived implication of "to (wrongly) estimate/assume", and that's why "to make light of something" is a valid translation. When it comes to idioms, you cannot expect their literal meanings are preserved.

Logical explanation for '高を括る'? phrase


How do you switch to a different site template in SharePoint 2010?

Question: If you used a site template (such as the Document Center template) and wish to use a different template (such as a Team Site), how can you accomplish this? More importantly, how do you do this without losing permissions that have been setup on the document libraries, lists, etc?
Answer: This functionality is not available in SP2010. Once a site is setup with a template that is how it is created. That being said, you can simply add the functionality you require to make the site appear to be of another template. By selecting a template, you are simply setting a starting point and not restricted future usage.


What is the physical interpretation of the derivative of a particle field?

Question: I am learning quantum field theory, specifically the quantization of the electromagnetic field. We have this Laplacian
$$
\mathcal{L} = -\frac{1}{2} \partial_\mu A_\nu \partial^\mu A^\nu -j_\mu A^\mu
$$
and I understand why we impose the condition that
$$
\langle \chi|\partial_\mu A^\mu |\chi \rangle = 0 \, ,
$$
but what does it mean?
$\partial_\mu A^\mu$ is an operator (right?), but of what?
What does it measure?
Answer: Let's take the four-vector apart, decomposing it into its components, the electric potential $\phi$ and the vector potential $\mathbf{A}$:
$$A^\mu=(\phi/c,\mathbf{A})$$
Then, contracting with the derivative (and assuming the $(+,-,-,-)$ signature for the metric), one obtains:
$$\partial_\mu A^\mu = \frac{1}{c}\frac{\partial \phi}{\partial t}-\frac{\partial A_x}{\partial x}-\frac{\partial A_y}{\partial y}-\frac{\partial A_z}{\partial z}=\frac{1}{c}\frac{\partial \phi}{\partial t}-\nabla\cdot\mathbf{A}$$
So the physical interpretation is, in some sense, that this operator's observable gives you a comparison of how fast the electric potential is changing as a function of time versus how much the vector potential is diverging in space.
But this calls into question what we actually mean by "physical meaning" when it comes to gauge fields, because the values of both the electric potential and the vector potential depend on the choice of gauge that we apply.
Note that, for one of the common gauges (the Lorenz gauge), we impose the condition $\frac{1}{c}\frac{\partial \phi}{\partial t}=\nabla\cdot\mathbf{A}$, or equivalently that $\partial_\mu A^\mu=0$. As such, in the Lorenz gauge this expression's physical interpretation is trivial - it's simply the statement of the choice of gauge that we've applied. For this reason, probably the most succinct way to interpret this operator is as follows: the expectation value of the operator at a particular point in spacetime gives you a measure of how different your choice of gauge is from the Lorenz gauge at that point.


Is deleting answers you feel are not good answers a suspension-worthy action?

Question: The mods at English Usage are intent on undeleting bad answers, even though I've retracted them. In trying to prune, they give suspensions. What are the rules on that? It's literally only a handful of answers, and of course the accepted answers remain untouched.
Comment: They should have sent a mod message detailing why they suspended you, in which case you could explain what you were doing (as you did here) after which a resolution should have been agreed to.  Did any of that happen?
Comment: It may have looked like a rage quit. Some people try to delete everything they can when they leave. Were they upvoted answers? Any of them the sole answer of the question? These can add to the suspicious look.
Comment: Sounds more directed at English Usage [meta site](https://english.meta.stackexchange.com/) than here. I don't think there's a network wide policy about this and each site has its own appreciation for this.
Comment: Vandalism is _"action involving deliberate destruction of or damage to public or private property."_ Deletion is destructive, since the work is no longer in the sight of the public. Like we've said, it sounds like it looked like a rage quit, like you were trying to "take your ball and go home" because you were removing your contributions. It's just a misunderstanding. The mods are there to help keep the site clean and under control. Someone destroying an odd amount of content needs to be stopped immediately, and the reasoning can be worked out while the user cannot be destructive.
Comment: Not only email. Check your SE inbox notifications. You will see something like Moderator Message
Comment: @RetractedAndRetired there is a contact us link in the footer of every site ...
Comment: @RetractedAndRetired maybe your evaluation of "not good" answer is a bit harsh and as Patrick says in his answer it has triggered an automatic alert. I'm not a English usage mod so I can't tell for them.
Comment: Honestly, without (one of) the mod(s) involved chiming in, everything we're saying here is our best guesses. There may have been something more extreme involved. (As in, something that seriously concerned the mods but to you or me would look completely benign.)
Comment: You will get a mod message in inbox, to which you can reply. Check your inbox. Without a message, they can't suspend you
Answer: Speaking as a moderator on another site, what probably happened was that you recently deleted a number of posts and that triggered an automatic flag. We see these as "possible vandalism: deletions (auto)" flags with a list of recently deleted posts.
If they reviewed the posts and found that they contained content worth saving, the moderators might have undeleted those posts and provided our standard warning about a potential rage-quit in action. That moderator message template reads like the following:

Hello,
I'm writing in reference to your [site] account:
[account]
You have recently removed or defaced a lot of content from your posts.
  Please note that once you post a question or answer to this site,
  those posts become part of the collective efforts of others who have
  also contributed to that content. Posts that are potentially useful to
  others should not be removed except under extraordinary circumstances.
  Even if the post is no longer useful to the original author, that
  information is still beneficial to others who may run into similar
  problems in the future - this is the underlying philosophy of Stack
  Exchange.
Extensive deletions take a lot of effort to repair. I have placed your
  account on hold for 1 day while I reach out to
  you to avoid any further misunderstandings. Once this matter has been
  resolved, your reputation score will be restored and your account will
  resume as normal.
Please respond to this message. I sincerely hope this is just a
  misunderstanding, but if you feel you have an exceptional reason to
  remove this content then let me know. If you'd prefer, you can contact
  Stack Exchange directly through the 'contact us' link at the bottom of
  the site.
Regards,   [site] Moderation Team

By default, the system triggers a one-day suspension to go along with this message. The purpose of that is to prevent any further deletions and give you a chance to respond. We quickly lift these suspensions if someone provides a good reason why this wasn't a rage-quit, a student trying to hide all their homework at the end of a term, or some other kind of vandalism.
If you respond to that message using your on-site account, and explain what's going on, the moderators will see that response and can lift your suspension. Additionally, as suggested in the message, you can use the "contact us" link at the bottom of every page on the site to get a hold of SE employees. They might not be able to respond as quickly as per-site moderators, due to having to develop for and oversee all of these sites.
Answer:
Is deleting answers you feel are not good answers a suspension-worthy action?

Generally not. Sometimes an answer you gave wasn't that good in retrospect. It is fine to delete an answer if you think it should be deleted.
So what happened really? I guess it was something in the line of this: you deleted quite some answers. Your behavior triggered the rage quit warning in a moderator dashboard. The moderator suspended you to prevent more damage to the site.
If the moderator didn't immediately suspend you and just undeleted those answers, and you wanted to override that by deleting the posts again, that would definitely qualify as a reason to suspend.
What you should have done in such a case: ask on the site's meta what to do. Discuss what you want to do and wait on consensus. Or contact the team by using the Contact Us page.
Comment: You have just a few posts there. If you delete more than a few, it will trigger automatic scripts. What should the moderator do then? Wait until you were finished 'deleting everything' and ask then? Not saying that was your intention, but the moderator can't know. They have to act now! That is why you were suspended. You can contact the moderator from the email message you received.
Comment: I don't think they can post on their site meta when suspended.
Comment: I know. He should have before he got suspended and the moderator undeleted posts.


How to query metadata changes in a sandbox based on dates

Question: We are trying to compare our development sandboxes now which have become totally out of sync because of changes done by independant teams for a few releases. Do you guys know of any free apex code which can use the metadata api to query all components in a sandbox and list the name of components which are changed based on a from and to date? I know snapshot can do this but we would like to know if you guys have any utility script which can do this?
Thanks
Buyan
Answer: You can get the created and last modified user and date through the MetadataAPI RetrieveRestult call under the fileProperties object.

You can also parse the audit log to get the last change data of configuration objects but this doesn't provide any information on what the changes were.  I would setup an automated ant task that pulls down the metadata using the force.com migration tool and add those components into a git repository. You can then use native git diff to view the metadata changes. Unfortunately this process would need to be running prior to the org changes.
Answer: Any tool or product which you now use can only get the differences between the two ORGS but cannot give you a revision graph or cannot give you what changes have been made on a from or to date.
Depending upon the size of the company, the recommendation of tools depend.
You can use the above mentioned app it is free.
You can use Kdiff3 which is a free tool and it gives you difference between your two orgs.
You can use free version control tools like SVN, Github, Mercurial and get your two orgs on different branches and do a diff which can show you revision graphs for all the changes.
Answer: You should take a look at this app called Copado.
You can perform Org Diffs (Org Difference analysis) even by date and user.  Then you can add those differences to a deployment to bring the two orgs back into sync.
http://www.copa.do/cms/documentation#orgDifferences
AppExchange link: https://appexchange.salesforce.com/listingDetail?listingId=a0N3000000B3dgGEAR


Set multiple price for single store view in magento

Question: I want to set 3 different currency for a single store in Magento 2.
For e.g i have one store i.e store 1
I want to set 3 currency for this store for e.g Dollar, indian rupee and Euro.
On frontend there will be currency convertor or something similar to that.
Does this can be achieved with default functionality or using any extension.?
My main concern is setting multiple prices for single product in single store view.
Comment: There is a currency converter by default in magento. Also you can set currency rates for different currency. So, if you switch currency it will automatically changes price in all places.set currency rates https://docs.magento.com/m2/ce/user_guide/stores/currency-update.html
Answer: To set 3 different currency for a single store in Magento 2, You have to select the currencies from

Admin->Stores->Configuration->General->Currency Setup

And in Allowed Currency, you can select multiple currencies as you want.

Then you have to set the Currency rates as default currency from

Admin->Stores->Currency->Currency Rates

At last flush the cache and you will see the Currency switcher on the frontend header as below image.

Hope this will help you.


Can rings last around planets indefinitely?

Question: Apparently, Saturn is losing its rings (https://weather.com/en-IN/india/space/news/2023-05-04-saturn-is-losing-its-rings-webb-may-tell-us-how-long-they-have-left) However, is there any way or conditions where the rings around a planet would last indefinitely? Do rings emit gravitational waves that would relax their orbit and eventually make them crash into the planet? Or an axially asymmetric ring around a planet would avoid the emission of gravitational waves?
Comment: Related: https://astronomy.stackexchange.com/questions/34849/are-saturns-rings-stable https://astronomy.stackexchange.com/questions/8616/recent-origin-of-saturns-rings https://astronomy.stackexchange.com/questions/8112/how-long-do-planetary-rings-last
Answer: The rings lose energy due to the Poynting-Robertson effect. Quoting from Wikipedia:

From the perspective of the grain of dust circling a star,
the star's radiation appears to be coming from a
slightly forward direction (aberration of light). Therefore the
absorption of this radiation leads to a force with a component against
the direction of movement.

Basically, small particles lose velocity if you shine light on them.   I suppose the small particles then put a drag on the larger particles.
You ask, how to keep rings around planets going

Move planet away from any starlight.  You not only have to remove the planet from the star, but you need to cool the planet, so that it emits no micron sized infrared light.
Continuously sweep out small particles but let the large ones stay.
Guide all large particles away from each other so there are no collisions (which can generate more small particles).  Or cover them with rubber bumpers.
Replenish the rings by bringing in asteroids at the outer edge and let them crash into each other creating fresh ring material.  This is probably the best option, since nature may be doing this all along.

Another option is to untilt the planet so the rings are always edge-on to the sun.  This reduces the effect by self-shading, but it does not eliminate it completely.
Comment: That goes along with removing the small particles and not letting the large ones turn into small ones.
Comment: I see (+1!) it's the smallest particles that experience angular momentum loss and subsequently remove angular momentum from larger particles via collisions? That explains 1. and 2. But what is the purpose of the "rubber bumpers" in 3.? They change inelastic collisions to elastic collisions between large particles, but how does that reduce angular momentum loss rather than simply lower the "temperature" of the particle motion?


Terminator transparency not showing other opened windows but only wallpaper

Question: Terminator transparency not working after upgrading to Ubuntu 11.10. At zero slider it is  becoming completely black and at max slider its showing wallpaper background rather than background containing other opened windows.
Answer: You need to use real compositing for that. What configuration do you have? If you have a graphics card, installing the Additional Drivers will solve the problem.


Invalid character error on YouTube-API for keywords/tags (when there's no invalid characters)

Question: I've been trying to make a script that uploads YouTube videos to my channel and I wanted to have a progress bar on the upload so instead of directly using the YouTube API I've been trying to modify this script: http://code.google.com/p/youtube-upload/wiki/Readme to allow being called directly from another script instead of command line.
You can view my current version of the script here: http://pastebin.com/3BpTHBXm
The error I get:
Traceback (most recent call last):
  File "youtube_upload.py", line 606, in <module>
    print upload_youtube_video("firstname.lastname@example.com", "password", "This is a test title", "this is a test description", "Games", "test tag, I like tagging, tagging is fun", "/root/test video.mp4")
  File "youtube_upload.py", line 594, in upload_youtube_video
    url = upload_from_script(email, password, title, description, category, keywords, file_path)
  File "youtube_upload.py", line 588, in upload_from_script
    return run_main(parser, options, args)
  File "youtube_upload.py", line 454, in run_main
    url = upload_video(youtube, options, video_path, len(args), index)
  File "youtube_upload.py", line 371, in upload_video
    data = youtube.get_upload_form_data(*args, **kwargs)
  File "youtube_upload.py", line 204, in get_upload_form_data
    post_url, token = self.service.GetFormUploadToken(entry)
  File "/usr/local/lib/python2.7/dist-packages/gdata/youtube/service.py", line 721, in GetFormUploadToken
    raise YouTubeError(e.args[0])
gdata.youtube.service.YouTubeError: {'status': 400, 'body': "<?xml version='1.0' encoding='UTF-8'?><errors><error><domain>yt:validation</domain>invalid_character<location type='xpath'>media:group/media:keywords/text()</location></error></errors>", 'reason': 'Validation Failed'}

I've been trying to figure out what's wrong with it, and from what I can gather from the error message there's an invalid character in keywords, but printing the keywords value just shows the tags as you'd expect. No invalid characters (Youtube documentation says all valid UTF-8 characters are allowed)
I think it MAY be something to do with the encoding. Although I tried converting the string to UTF-8 and it made no difference (but perhaps I was doing it wrong? I used unicode(keywords, "UTF-8")
Another reason I think it might be to do with the encoding is I ran the script perfectly fine on my windows machine yesterday, but it doesn't work on my Linux machine that I'm using at the moment (I don't have access to my windows machine for a few days so I can't confirm whether it still works on the windows machine, I might have accidentally edited the code since then? I don't think I did though). So I'm thinking maybe it's something to do with how Linux encodes stuff compared to Windows? Just a wild guess.
P.S the only thing I edited about the script on pastebin was the username and password, so all the other data is still the same like the title, description and keywords.
Any help is really appreciated, if you need any more information from me just let me know.
Comment: I hate to beg, but does anything have any idea at all? I've been staring at the code for hours and I just don't have a clue where to start.
Answer: Figured it out, just needed to strip the quotation marks.


Is there a way to Change how long the Xbox record time is?

Question: I am making a Xbox gameplay of bendy and the ink machine for my YouTube channel and I need the recording time last longer than 10minutes. Is there a way to change it?
Comment: I found [this article](https://www.thurrott.com/games/xbox-one/108449/xbox-one-tip-record-favorite-gameplay-moments) but it seems to indicate from the screenshots that the max length is only 5 minutes. So not sure if itll be helpful or not. (Disclaimer, I dont own an XB1)
Answer: I think the best option on Xbox would be to use something like Mixer.  Mixer is installed by default, and has the option to record streams.  You will have to change your settings to enable a recording of the stream.
See https://windowsreport.com/save-mixer-streams-xbox/ for details on how to enable recording of your stream.
Answer: To record longer than 10 minutes you are going to need a USB 3 hard drive or stick. Connect it to your Xbox, then go in to settings and change video recording from internal storage to external storage. Then you will be able to record up to 1 hour and it will be saved on the hard drive or stick.


Is upgrading from 11.04 with GNOME3 to 11.10 safe?

Question: I have an 11.04 machine with gnome 3.0 shell and i would like to upgrade it to 11.10. My concern is some sort of conflict between the gnome 3 package i have installed and 11.10 during the upgrade. Anyone got ideas on what might happen if I upgrade? Has anyone tried this?
Answer: I know it's always better for me to back up what I want to keep and install instead of upgrade. I've never had an upgrade go very smoothly. I think most people would tell you to do a fresh install.


What is the risk involved in fedimint?

Question: I want to know the risks involved in fedimint? Fedimint is something that was shared as improving privacy for bitcoiners.
Answer: If implemented as described, Fedimint implements Chaumian E-Cash operated by a Federation. When users deposit funds, the Federation takes custody of the deposit. In return, the Federation issues fungible eCash notes that can only be redeemed once with the Federation. When eCash notes are redeemed, the Federation in exchange issues either a withdrawal or new notes. Beyond each note only being usable once, the notes are not distinguishable to the Federation.
As I understand it:

The Federation operating the Fedimint has full custody of all users funds. They could lose the funds or be forced to turn them over.
Observers of the deposits to the Fedimint may learn about its users per the deposits and withdrawals
The Federation may be able to learn something about some users by logging IP addresses of users and watching spending patterns of eCash notes
The Federation can probably not selectively censor a sufficiently motivated specific user within the system, since the eCash notes are fungible, but could stop redeeming any eCash notes
The Federation could censor withdrawals to specific addresses or Lightning nodes outside of its system
If the members of the Federation collude, they could run off with all user deposits
Answer: Fedimint has a doc on this.

Clearly there is a trade-off from self custody onchain but community custody is not the same as leaving your funds on a large (generally KYC) centralized exchange from either a security perspective or a privacy perspective. To what extent the community is superior to the exchange would be determined by your assessment of the community you are trusting.
With Lightning too there is this concept of a "Uncle Jim" where a trusted relative manages a family's Lightning channels so that not every individual has to worry about liquidity and understanding the intricacies of the Lightning Network. That model might not be for you either but depending on you and your family's skillset that may be of interest.
Christian Decker went through some of the various custodial and non-custodial Lightning node setups at Advancing Bitcoin 2022.
Answer:
Fedimint is an open source protocol and technology stack which makes it easier to deploy and manage community custody solutions.

It is custodial and involves similar amount of risk as an exchange with custody of your funds (bitcoin or other cryptocurrencies)

What is the risk involved in fedimint?


How do I mount ext2 or ext3 filesystems on OSX?

Question: I would like to mount an ext2/3 filesystem on a mac running 10.5.
Answer: http://digg.com/apple/Mounting_Linux_ext2_ext3_using_MacFUSE_under_Mac_OS_X
is recent, and links to http://ekettoz.blogspot.com/2009/06/mounting-linux-ext2ext3-partitions.html
which references http://sourceforge.net/projects/fuse-ext2/
This project has releases from December 2008 to June 2009. I know I have some MacFUSE driver for Ext2 at home, but I am at work right now. I can check which one I have back there. It works well, whatever it is.
Comment: I think whatever your best answer will be, it will use MacFUSE somewhere. I use MacFUSE for accessing my NTFS drives, read and write, without problem (so far - knockonwood).
Comment: That's the right way to do this. I'm using the ext2fsx driver now and it works, but I'll switch to this soon. Nice find.
Answer: http://sourceforge.net/projects/ext2fsx/ appears to do the trick.
I should have asked Google before asking ServerFault. In any case, I'll leave the answer here for others.
Comment: Note that this code hasn't been updated since 2006.  I don't know about you, but I wouldn't trust an open source project that hasn't been maintained in 3 years.
Comment: I had that same thought, Maybe there will be a better solution offered by the someone else. In the meantime, I'll use that one.
Comment: Although, even if it's from 2006, Ext2/3 hasn't changed a whole lot. According to Wikipedia, it was introduced in 1993, so a 2006 driver has 13 years of history (theoretically) behind it. Likewise, 2001 for Ext3.


SoapUI Eclipse Plugin Freezes

Question: I'm using soapUI eclipse plugin.
I open soapUI Navigator and create a new project. On the new project screen, I choose the location of the wsdl to generate test cases from.
After I click 'OK', the plugin starts loading the definitions. This is when it freezes.
I wasn't able to find any thing on the internet besides this 3 year old bug (which is the exact same issue I'm having, you can also see the screen shot of it): http://sourceforge.net/p/soapui/bugs/522/
Does any one know any information regarding what causes it, is there a way around, etc.
I'm inside a corporate network, can access internet fine, but there are firewall restrictions etc.
Comment: I still haven't found a solution for this problem. I ended up using the HTTP Monitor plugins in eclipse, which worked fine.
Answer: I use eclipse Soupui plugin version 4.0.1 and it works fine.

SoapUI Eclipse Plugin Freezes


How to draw laid out glyphs one by one - core text

Question: I have a string that I can paint in Core Text like so:
CGContextShowGlyphsAtPoint(context, 0, 0, glyphs, glyphCount);

Works great.  Now I need to paint each of those glyphs individually, in the same spot as they would end up painted using that nice utility function above.  And I'm not doing it in English, either...sometimes there is a glyph below a glyph below a glyph (diacritic).
Obviously I need something like this:
 CGPoint pt = CGPointMakeZero;
 for (int i = 0; i < glyphCount; i++) {
     CGContextShowGlyphsAtPoint(context, pt.x, pt.y, glyphs[i], 1);

     pt.x += <some quantity>
     pt.y += <some quantity>
 }

Unfortunately I haven't figured out what the "some quantities" are supposed to be yet...some combination of metrics fromCGContextGetAdvancesForGlyphs and/or CTFontGetVerticalTranslationsForGlyphs and/or CGContextGetGlyphBBoxes have been my first guesses, but I haven't got it to work yet.
Anyone have a solution/other ideas?
If you want a test string, try అక్త్రిన్.
(Background: I need to do the painting of glyphs one by one because of customizations to appearances to individual glyphs that I want to make in my app).
Answer: Way late to the party here but this question/answer combo shows how layout is calculated line by line then glyph by glyph.
Core Text calculate letter frame in iOS


Fixing Minolta Sr-1 stuck release button

Question: Just bought a Minolta Sr-1. I was taking some photos until I advanced the lever but the button wouldn't release the shutter. I opened up the bottom and couldn't seem to figure out what was the problem but while closing it the rewind release button also got stuck. There are no details about the Sr-1 online and would like an help possible. It will be much appreciated.
Answer: The SR-1 was launched in 1959. It's possible that your copy could be 61 years old! Even if it was stored in an airtight box, oils and greases will break down over that time and become tacky.
Add actual use, dirt and dust, and that tacky can become gritty. The result is that functions begin sticking and then eventually freeze.
Most people will buy one of these old cameras and use it until it breaks, then toss it and find another. However, if you cherish it, then have a pro clean, lube, and adjust it - usually a couple hundred bucks. If all the parts are good, a clean and relube will get it going for decades more.
If you are mechanically inclined and want to give this a try, then try to find the service manual. I didn't have any luck for the SR-1 but did find this one: http://mattsclassiccameras.com/wp-content/uploads/2016/07/Minolta_SRT_Service_manual.pdf
Obviously, there will be differences but there should also be some similarities to help get you started. The inside of a mechanical camera is more like a watch - don't use a camera as your first foray into fixing devices...unless you are very much okay with breaking it.
Comment: Thank you! You're right about the dirt and dust. As a last ditch effort I opened it up and hit the inner workings with compressed air. Worked like a charm but definately will look into getting it relubed up and what not.


What is singular.php?

Question: From 4.3 we have a new template, singular.php. I tried to understand what is it, but I didn't get it. :)
The page.php for pages.
The single.php for every post types. If we have single-[post-type].php we can use a specific template for the custom post type.. so why we need singular.php?
Answer: It's the nature of the WordPress template hierarchy - point being, if you don't have a page.php, it will use singular.php, same if you don't have single.php, it will fallback to a template lower in the hierarchy.
Ideal for themes that have the same layout for posts/pages, instead of having duplicate code in each respective template.
Answer: singular.php is basically an extra fallback for all post types, regardless if built-in or custom. It comes in straight after single.php and page.php, so you can omit the latter two templates and just have a singular.php template which will be used by all post types in single view.
How useful it will be and the necessity of it will, just as with any other template, depend on the user/site/requirements. The template hierarchy is built such that, regardless of any page being viewed, you will always just need index.php to display any page. So in short, you can have a fully functional theme with only index.php and style.css in the theme folder.
The templates available in the template hierarchy are just there for convenience, and that goes for singular.php as well. You can use any template in context if you need to, but you don't have to use it if you don't need it.
Answer: The single post template file is used to render a single post. WordPress uses the following path:
1.single-{post-type}.php – First, WordPress looks for a template for the specific post type. For example, post type is product, WordPress would look for single-product.php.
2.single.php – WordPress then falls back to single.php.
3.singular.php – Then it falls back to singular.php.
4.index.php – Finally, as mentioned above, WordPress ultimately falls back to index.php.
https://developer.wordpress.org/themes/basics/template-hierarchy/#single-post
The template file used to render a static page (page post-type). Note that unlike other post-types, page is special to WordPress and uses the following patch:
1.custom template file – The page template assigned to the page. See get_page_templates().
2.page-{slug}.php – If the page slug is recent-news, WordPress will look to use page-recent-news.php.
3.page-{id}.php – If the page ID is 6, WordPress will look to use page-6.php.
4.page.php
5.singular.php
6.index.php
https://developer.wordpress.org/themes/basics/template-hierarchy/#page
Comment: `singular.php` is also a fallback for `page.php`
Comment: yes it is a fallback for page.php as well
Comment: added the page.php

What is singular.php?


Doing crunches for month and after that stop doing it effect body shape?

Question: I've done crunches for one month regularly in the gym and after that I stopped exercising. And my stomach came out after two months. So is it because I stop doing crunches ?
What should I do in order to maintain the same abdomen structure?
Comment: Edited your question, feel free to revert it
Comment: No. Crunches do nothing in terms of belly fat. Spot fat reduction is a myth. To reduce fat you need to be in a calorie deficit. You need exercise + nutrition.
Answer: Now the crunches themselves have very little to do with the overall bulging of your stomach. That would be called spot reducing, which does not exist. The fact that your stomach came back is due to the fact that you stopped going to the gym and exercising. You want to be at a caloric deficit to be able to lose body fat.
Answer: yeh, you can't spot reduce its a myth, the first place you gain fat will be the last place u lose it,but targeting certain areas does compress the fat thus making it look slimmer or flatter so yeh if your going to the gym but not doing crèches and your stomach seems noticeably larger it is because your not doing crunches


What is the basic requirement for tzitzit knots?

Question:
There seems to be a lot of different ways to tie tzitzit knots. From the little I understand this is based on various symolism and numeric value (see this question/answer). I would like to know what the basic essential halacha is. Meaning, If I have 8 strings per corner and I tie 5 double knots is that sufficient?
Comment: 7-13 white not 5. Not counting tacheilath.
Comment: Those are specifically for techeles
Comment: Why tie five double knots?
Comment: I was taught there has to be 8 strings and 5 knots. I know knot why ;)
Comment: Related:http://judaism.stackexchange.com/questions/17390/may-an-ashkenazi-wear-yemenite-tzitzith
Answer: The Gemara in Menahot 39a implies that the bare minimum Biblical obligation is only one knot. However, Tosfot there understand that this single knot mentioned by the Gemara is actually (what we would call) a double knot, because a single knot doesn't hold tight. However, there are other traditions of how to make this knot, such as in the example all the way to the right in your picture.
However, the Rabbis have a tradition (quoted in that same place, Menahot 38b-39a) that there must also be 'chulyot', which is usually translated to mean 'windings', which is why you see in the picture that you have a combination of knots and windings. The Gemara (there) states that one should alternate windings and knots, and that there can be anywhere between 7 and 13 windings. (However, it isn't clear if each 'winding' refers to wrapping the string around once, or groups of a few windings, as in most of the examples in your picture.) This may imply that the minimum (Rabbinic) requirement is 7 knots.
Another tradition, quoted by Rashi (Numbers 15:38) and the Midrash Tanhuma (Korach 12) is to make five knots on each corner. Therefore, the minimum Rabbinic requirement would be five knots, which is indeed followed by most Jewish communities, with a few variations on the number of windings (see Shulchan Aruch O.C. 11:14 and commentators there). Therefore, if you were to merely tie five knots, (separated by series of one string wound around the rest at least 7 times) that would almost certainly fulfill the mitzvah according to the Rabbinic requirements.
Comment: I don't follow your last sentance. Shouldn't you need 7 groups of 7 windings each surrounded by double knots (ie 16 knots and 49 windings) to fulfill the mitzva according to the Rabbinic requirements?
Comment: Yes, if the only source to go on is the Gemara, but clearly the custom has been to adopt that of the Tanhuma, that five knots are enough
Comment: thanks, this is a very good answer. where does the tradition of windings come from?
Comment: @deja-jew that same Gemara quoted discusses 'chulyot', which Rashi and Rambam interpret to mean series of windings


Checking version of file in Ruby on Windows

Question: Is there a way in Ruby to find the version of a file, specifically a .dll file?
Answer: For Windows EXE's and DLL's:
require "Win32API"
FILENAME = "c:/ruby/bin/ruby.exe" #your filename here
s=""
vsize=Win32API.new('version.dll', 'GetFileVersionInfoSize',
                   ['P', 'P'], 'L').call(FILENAME, s)
p vsize
if (vsize > 0)
  result = ' '*vsize
  Win32API.new('version.dll', 'GetFileVersionInfo',
               ['P', 'L', 'L', 'P'], 'L').call(FILENAME, 0, vsize, result)
  rstring = result.unpack('v*').map{|s| s.chr if s<256}*''
  r = /FileVersion..(.*?)\000/.match(rstring)
  puts "FileVersion = #{r ? r[1] : '??' }"
else
  puts "No Version Info"
end

The 'unpack'+regexp part is a hack, the "proper" way is the VerQueryValue API, but this should work for most files. (probably fails miserably on extended character sets.)
Answer: What if you want to get the version info with ruby, but the ruby code isn't running on Windows?
The following does just that (heeding the same extended charset warning):
#!/usr/bin/ruby

s = File.read(ARGV[0])
x = s.match(/F\0i\0l\0e\0V\0e\0r\0s\0i\0o\0n\0*(.*?)\0\0\0/)

if x.class == MatchData
  ver=x[1].gsub(/\0/,"")
else
  ver="No version"
end

puts ver

Answer: As of Ruby 2.0, the DL module is deprecated. Here is an updated version of AShelly's answer, using Fiddle:
version_dll = Fiddle.dlopen('version.dll')

s=''
vsize = Fiddle::Function.new(version_dll['GetFileVersionInfoSize'],
            [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP],
            Fiddle::TYPE_LONG).call(filename, s)

raise 'Unable to determine the version number' unless vsize > 0

result = ' '*vsize
Fiddle::Function.new(version_dll['GetFileVersionInfo'],
                     [Fiddle::TYPE_VOIDP, Fiddle::TYPE_LONG,
                      Fiddle::TYPE_LONG, Fiddle::TYPE_VOIDP],
        Fiddle::TYPE_VOIDP).call(filename, 0, vsize, result)

rstring = result.unpack('v*').map{|s| s.chr if s<256}*''
r = /FileVersion..(.*?)\000/.match(rstring)

puts r[1]

Answer: If you are working on the Microsoft platform, you should be able to use the Win32 API in Ruby to call GetFileVersionInfo(), which will return the information you're looking for.
http://msdn.microsoft.com/en-us/library/ms647003.aspx
Answer: For any file, you'd need to discover what format the file is in, and then open the file and read the necessary bytes to find out what version the file is.  There is no API or common method to determine a file version in Ruby.
Note that it would be easier if the file version were in the file name.


Cutting tall grass (2-3ft) to short (2-3in) kill it?

Question: I have some tall grass in my back yard and I would love to cut it but I am worried I could kill it by cutting like more than 80-90% (Hopefully not exaggerating) will kill the plant. Should I try to slowly cut it down to size or would it be fine if I gave it enough water. I would like to not have a brown patch in the back yard, even though it will not be seen to easy.
Answer: The lower parts of the grass probably aren't green right now because they're not getting much light or good air circulation.
It's usually not recommended to cut more than 1/3rd of the grass at a time. So you'd cut it down to 24", wait a few days then cut it down to 16", wait a few more days and cut it down to about 11" and so on. Well take about 6 or 7 cuttings depending how fast it grows in between cuttings.
With grass that high though it still may have other issues.
If it were me I'd just cut it down all in one shot or maybe 2 because it looks bad. Maybe bring it down too about 1ft with a string trimmer then about a week later go through the area with a take to clean up rocks and other debris and hit it with the mower on the highest setting then work down to your desired height.
Try to avoid mowing when the temp is greater than 90f. Start maintaining the lawn after you cut it. Give it some fertilizer and mow it regularly.  Outs not going to l look great right after you cut it but it will recover. In the fall overseed it to help fill in any week areas which you'll undoubtedly have.
There was a similar question recently and you might find my answer to that one helpful as well. https://gardening.stackexchange.com/a/25308/2448
Comment: I'm a little puzzled by the regular info I see on here about not cutting grass by more than a certain amount each time.  Is it because the grasses you grow for lawns there are not the same grasses we grow here in the UK? I have many times  cut long grass down  to 3 inches straightaway - if its really long, it looks brown underneath, but soon greens up and its fine. But that's in the UK, where lawns  are always comprised of the same mix of grasses (fescue, bents,rye and the like), so I'm wondering...
Comment: @Bamboo same types of grass in my area. I've seen lawns go unmaintained that are mowed once or a month or less the overall lawn tends to get weak and more prone to develop weeds and disease. I think when the grass goes to seed it may also introduce some undesirable grasses but that's just based on my observation from afar. I see more bare patches develop too. When the grass gets too high then cut drastically energy is put into shoot development and roots stop growing. Can lead to too much stress when heat comes in without water. See http://ipm.ucanr.edu/TOOLS/TURF/ESTABLISH/onethird.html
Comment: thanks for the info. Agree that cutting infrequently and taking off a lot, or too short, all the time causes problems, but I wonder whether our weather makes a difference - Ive often cut an overgrown lawn right down (in different gardens), but only the once - thereafter, its been properly maintained, and there's been no problem.
Answer: Turf care position: Oh Noes!!! Also, 2" is too short, unless you are going for a golf-green, which is a whole other level of fuss (and even shorter.) 3" is about as short as you should cut normal lawn grass. Among other things, cutting the top too short kills off the roots which makes it less able to get water for itself. Taller grass equals deeper roots.
Practical "whacking the overgrown stuff in the orchard": it will probably live.  I can't say I care much if that stuff turns a bit brown for a while, so I suppose it might. But you might want to put your mower as high as it goes, then give it a week, then cut it back to 3". But hayfeilds put up with "several feet" to "a few inches" multiple times a year without expiring....
Answer: It sounds like you're trying to make hay.
follow these steps:

Cut it down
collect it (so it doesn't cover your good grass)
use it for animal feed, or take it to the compost pile
Answer: No it may look dead for a while but it's fine.  Grass is pretty tough go ahead chop it down and let it get some sun.


If I erase my iPhone, will this erase my iCloud too?

Question: If I erase my iPhone, will my iCloud be erased too?
Answer: No, factory resetting your iPhone will not alter your iCloud. Upon setting up your iPhone again you will be given the option to reconnect to your iCloud account if you desire. iCloud also stores iPhone backups that you can restore your phone from. Apple's apps are really good about storing items in iCloud, however many others are not. If you are worried about losing your content, be safe and make a local backup to a machine through iTunes, just to be safe. Alternatively, I believe you could schedule an appointment at the Genius Bar and have them reset your phone for you.
EDIT: If you have "Find My iPhone" enabled, no one will be able to use that device without your iCloud login credentials.
Answer: No, it won't. Erasing your iPhone has only effect on the device itself. It's even possible to erase your iPhone without an internet connection; how would iCloud then know to erase the data as well?
Answer: When you do a restore, only the stuff on your device storage gets removed. As long as you have access to the iCloud account and the stuff you need is on it, it is ok to restore.
But it is still a good idea to do backups too! :)
Comment: Why was this downvoted?
Comment: another downvote!


Do I need a Schengen transit visa as a US Green Card holder?

Question: I am travelling from  Washington DC to Copenhagen ( layover 4 hours ) then to Newcastle UK. Do I need a schengen visa? I have a green card and 5 year UK visa and am a citizen of India
Answer: As stated in Timatic, the database used by airlines:

Visa required, except for holders of onward tickets transiting on the
    same calendar day if arriving at and departing from
    Copenhagen Kastrup (CPH).

So no, you do not need a visa.


Effect of doubling clock frequency on computer performance

Question: If we double the clock frequency of a CPU, does that translate to a doubling of the CPU performance? Assuming that the number of instructions and CPI are constant, we have an inverse relationship between the clock frequency and computer performance. Thus a doubling of the clock frequency will half the computer performance. Is this correct?
Comment: _"If we double the clock frequency of a CPU, does that translate to a **doubling** of the CPU performance?...  Thus a doubling of the clock frequency will **half** the computer performance."_ - you seem to be very confused. Which is it - double or half?
Comment: No it doesn't - it all depends on what code is being executed and what peripherals are being used and communicated with.
Answer: Yes, but.
Maximum clock frequency is determined by hardware physical constraints like signal propagation time, how fast the transistors switch, etc. So your hypothesis "doubling clock frequency would double performance" is missing critical fine print "as long as it is below the maximum frequency the hardware supports, and the new frequency does not require reconfiguration".
Also, different types of hardware work best at different frequency, for example if you want a faster clock, at some point you'll need more pipeline stages and fancier design, so the hardware for the slow clock frequency is not the same as the hardware for the fast clock frequency and they are not comparable in a simple way.
For example, say your silicon process can make an ALU that needs 2ns to add two integers (forget about all the rest of processor business for now like instruction decoding etc). Without pipelining you can run it at 500MHz (2ns cycle) but if you split it into 4 pipeline stages then maybe you can run it at 2GHz (0.5ns cycle), it will do an operation in 4 cycles, the operation will still take 2ns to complete (neglecting pipeline efficiency for the sake of simplicity) but it can do 4 operations in the pipeline, so it has the same 2ns latency, but 4x higher throughput than the non-pipelined version.
However if you take this 2GHz 4-stage hardware and run it at 500MHz instead of 2GHz, it will have the same throughput than the non-pipelined one, BUT it will have 4x higher latency so it will be a lot slower!... Hardware that runs at high clock frequency, with long pipelines, will have more latency at low frequency than simpler hardware with less pipeline stages that runs fine at low frequency. Say if you took a Pentium-4 and ran it at 10MHz, would it be faster than a 50c Cortex-M0 at 10MHz? That's hard to say because the P4 has a huge pipeline so it reacts to unexpected events like branch misprediction with quite a lot of inertia, whereas the Cortex-M0 doesn't care...
A simpler way to phrase it would be "would halving the frequency make it twice as slow?" because that won't cause problems with maximum clock frequency, and it also makes more sense, since using lower frequency clock is a very common way to trade power vs speed.
If the entire system runs on the same clock, then its performance will be proportional to clock speed. This would be the case in a simple microcontroller for example. In this case halving the frequency will make it twice as slow on the same hardware.
However, in a more complex system like a PC, SoC, or larger microcontroller, different parts of the system will most likely use different clocks. In a PC, there are different clock frequencies for CPU cores, RAM, chipset, various buses, sometimes caches, etc. So "doubling clock frequency" doesn't mean much, although you could say "if all the clocks in the system were scaled by the same factor then performance would scale proportional to that too."
Of course this assumes the processor is not waiting on something that doesn't depend on this clock frequency, for example network data, IO, I2C communication, waiting on an ADC to deliver data, etc. If some part of processing is dominated by timings that don't depend on clock frequency, for example latency due to signal propagation in cables or traces, then clock frequency will influence throughput but not latency. That's what happens with DDR SDRAM timings for example. If you crank up the frequency of your RAM stick you also have to add a bit more latency/wait cycles because the actual time the chip needs to access the data doesn't depend on clock.
That's why I talked about reconfiguration in the first paragraph. If you use half the clock frequency for your RAM, then it will be twice as slow. However, if you reconfigure the latency settings to match the new frequency, then you can keep the same latency (in nanoseconds) which means less cycles of the lower frequency clock. So your RAM will have lower throughput (since clock controls data transfer speed) but latency won't degrade that much. So it will be twice as slow for large sequential access but not for random access. Subtle, huh?
Answer: If we assume the CPU can handle doubling it's clock frequency and everything in the CPU will now work at twice the speed, the CPU will be twice as fast. So if the CPU calculates A+B from it's internal cache memory it will do this twice as fast
BUT that does not take into account the speed of other parts that make up a computer. The CPU might be twice as fast, but the RAM, HDD etc will not. Even RAM is slow compaired to the CPU (and HDDs are at glacial speeds), which means if the CPU get data from the RAM it will have to wait on the RAM. Let's say the CPU at the first speed has to wait 1 ms, which could be 1000 clock cycles, now with the doubling of the CPU clock the CPU has to wait 1 ms, which would be 2000 clock cycles for the cpu.
As you can imagine really hurts your new found performance boost from doubling the CPU clock frequency. Say if you copy some data from the HDD to RAM, the CPU part will be such a tiny part of the time this takes you wouldn't notice anything by doubling the CPU speed. But if you time some program that can run entirely in the cache of the CPU you would see it running twice as fast.
So it really depends on the program you are running on the computer how much of a performance boost you would see by doubling the CPU clock frequency. But it is safe to assume it is less than 2x.
Answer: You will have to define what "performance" means. The other answers here do a good job of defining performance in terms of raw compute potential versus the limits of the operating speed of other components in a system. However these days you have to measure performance in several other ways as well. I will describe two of these here.

An important performance measurement is raw compute potential per watt of energy consumed. This may have to include more than just the CPU in the equation because all the components of the system are energy consumers. This measure translates directly to operating cost that comes in two parts - initial system cost and recurring energy cost.
A second performance measure is based upon the compute task that needs to be done. We can define this compute task as "the workload" that must be executed. The workload requirements will be very specific to each defined task but may very well be dependent upon factors that go out into the   world (maybe even the universe in the extreme case). The important measure here is "how much system cost do I need for my workload?" Raw compute potential may have little to do with getting the job done.


how to connect with pia

Question: i am using elementary os after installing pia from "https://helpdesk.privateinternetaccess.com/hc/en-us/articles/219438217-Installing-the-PIA-App-on-Linux" nether i am seeing any icon beside the clock as said on web page nor i am able to connect what should i do
Answer: Same issue. I am assuming you've followed the directions from the installation guide on the PIA website for 'Linux'.
This works, not the best solution because you have to do this every time you log in to your linux session, but it works.
Open terminal. Enter these commands.
sudo apt-get install openvpn

this installs openvpn (if you didn't have it)
cd /etc/openvpn

this changes your dir to where the program you just installed is located
sudo wget https://www.privateinternetaccess.com/openvpn/openvpn.zip

this downloads a bunch of files you'll need
sudo unzip openvpn.zip

this unzips the zip
ls -l

this shows you a list of the config server files you just unzipped. pick a file to use and then...
sudo openvpn 'filename-goes-here.ovpn'

(e.g. sudo openvpn 'US East.ovpn') make sure you use the apostrophes!
Then it'll ask for your user name and pwd. Put them in and you're running your VPN. When you log out, restart, etc you need to open the term and enter some of the commands again as follows..

cd /etc/openvpn
ls -l
sudo openvpn 'filename-goes-here.ovpn'

There are better ways to do this, but this will get you going in the short term.

how to connect with pia