I have a discrepancy between the bib keys I write inside my LaTeX editor and the printed bib keys.   See my MWE please:  \documentclass[fontsize=12pt,a4paper,oneside,  listof=totoc,                   % Tabellen- und Abbildungsverzeichnis ins Inhaltsverzeichnis bibliography=totoc,             % Literaturverzeichnis ins Inhaltsverzeichnis aufnehmen titlepage,                      % Titlepage-Umgebung statt \maketitle headsepline,                    % horizontale Linie unter Kolumnentitel %abstracton,                    % Überschrift beim Abstract einschalten, Abstract muss dazu in {abstract}-Umgebung stehen DIV12,                          % auskommentieren, um den Seitenspiegel zu vergrößern BCOR=0mm,                       % Bindekorrektur, die den Seitenspiegel um 6mm nach rechts verschiebt. geometry package überschreibt diesen Wert ]{scrreprt}  \usepackage[ngerman]{babel}     % deutsche Trennungsregeln und Übersetzung der festcodierten Überschriften \usepackage[style=authoryear, backend=biber, isbn=false, doi=false, maxcitenames=2, uniquename=false, maxbibnames=10]{biblatex} %sorting=none if not alphabetically, maxcitenames, maxbibnames  \begin{filecontents}{\jobname.bib} @misc{OReilly.2005,  author = {O'Reilly, Tim},  year = {2005},  title = {What Is Web 2.0: Design Patterns and Business Models for the Next Generation of Software} } @misc{OReilly.2005b,  author = {O'Reilly, Tim},  year = {2005},  title = {Web 2.0: Compact Definition} } \addbibresource{\jobname.bib} \end{filecontents} \begin{document}     \cite{OReilly.2005} \cite{OReilly.2005b} \printbibliography \end{document}   My first citation points to the second bib entry inside the compiled pdf and vice versa. Reading the compiled pdf is no problem in this case but it confusing the heck out of me when I write.   I guess biblatex is doing this because it is sorting the bib entriey alphabetically... I would expect this behavior:   \cite{OReilly.2005} => OReilly 2005a  \cite{OReilly.2005b} => OReilly 2005b  Is this changeable without a lot of effort or am I doing something wrong here?

I have the following problem illustrated by a simple example: If I cite the paper of an author T. Coven in my document, the outcome is 'Coven (2004b)'. If I cite the appendix to this paper, the outcome is 'Coven (2004a)'. Now the appendix pops up much less frequently than the original paper, therefore I would like to reverse the order (exchange 'a' and 'b' in the citations). Is this possible?  I am using Biblatex. Here is the bib-file of the above example (named: lib.bib):  @article{co:2004, author = {T. Coven}, title = {Title A}, journaltitle = {The X Journal}, date = {2004} } @article{coapp:2004, author = {T. Coven}, title = {Appendix to Title A}, journaltitle = {The X Journal}, date = {2004} }   MWE:  \documentclass[a4paper, 12pt, headsepline, headings=small,]{scrreprt} \usepackage[backend=bibtex8,     style=authoryear-icomp,     dashed=false,     autocite=footnote,     maxcitenames=3,     mincitenames=1,     maxbibnames=100,     firstinits=true,     sorting=nty     ]{biblatex} \bibliography{lib}  \begin{document} \cite{co:2004} and \cite{coapp:2004} \end{document}


I've just encountered a situation playing this with my daughter where she has played the Finger of God and there's a Play All card in the table. Does this mean she can keep Playing Finger of God until there are no more Creepers on the table? Seems to be a loop.

In Monty Python Fluxx, there are keepers that kill creepers.  Can they be played and also kill in the same turn, or is it 1 turn to play them and 2nd turn to kill?  Also, can they be used over and over again?


For cynical people, the word "cynics" is commonly used. For example, , one of the definitions is      cynical: (adjective) of or relating to the Cynics or their doctrines.   Is there a similar term for naive that can be used in a similar fashion? For example, something like     of or relating to the Naives or their doctorines.

Are there idioms (or single words) in English for people who behave like they have come from another world where everything is perfect and know nothing about the reality? They usually come up with ideas that can never work, but look attractive if you don't analyze them properly. They know nothing about science, and it seems they don't know that people lie, cheat and get violent. PS in Russian we usually use the word "эльфы" (elves) for such people, and they are supposedly visiting our world from the "world of elves". It's usually considered pejorative.


Perception is the organization, identification, and interpretation of sensory information in order to represent and understand the environment.  What if our sensory perception is faked by a Matrix-like computer game designed by aliens, as ?

I recently read  that suggested we might be able to determine if we are part of a computer simulation run by our descendants.  The idea seemed far-fetched, but after looking around, I see that it has been argued for by at least one philosopher.  Notably, this abstract from :     This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.—Nick Bostrom. Philosophical Quarterly, 2003, Vol. 53, No. 211, pp. 243-255.     points out:     The concept is reminiscent of '  but posits a more futuristic .    As I think about it, however, I can't think of any material difference except that the generic "demon" (which is a stand-in for any powerful being) is replaced with a specific candidate: our own decedents.  While it certainly makes for some wonderful science fiction (and even seems inspired by it), there doesn't seem to be anything about the ontological and epistemological aspects of the theory that weren't anticipated by Descartes.  Is there some aspect of the Simulation Argument that improves on the Evil Genius?  Would not the same limitations on proving (or disproving) this sort of existence apply equally to both?


I am new to GeoServer and I want to overlay Google Maps to my OpenLayers in GeoServer, I don't know how to start, do suggest me how to begin.  I want know which file to access, file extension, and what language is being used to incorporate it in GeoServer?

İ have added a shapefile to geoserver and generate a WMS page. I want to add google satellite  as a base layer but i can't do it.  Any hint on how to add google satellite as a base layer?


i have a server with ip adrress 192.168.11.xx and i have DNS server with ip address from isp 203.174.12.xx  and i build a mail server with postfix and dovecote, with ip address 192.168.11.xx same with ip my server, with domain domain.xx.xx , mail server mail.domain.xx.xx but i just can send mail from localhost,  :~# telnet localhost 25 Trying ::1... Connected to localhost. Escape character is '^]'. 220 ns1.domain.xx.xx ESMTP Postfix (Ubuntu) mail from:root 250 2.1.0 Ok rcpt to:imam 250 2.1.5 Ok data 354 End data with <CR><LF>.<CR><LF> this data . 250 2.0.0 Ok: queued as E4832181A08   if i use telnet with 192.168.11.xx  :~# telnet 192.168.11.xx 25 Trying 192.168.11.53... Connected to 192.168.11.xx. Escape character is '^]'. 220 ns1.ns1.domain.xx.xx ESMTP Postfix (Ubuntu) mail from:root 250 2.1.0 Ok rcpt to:imam 451 4.3.0 <imam>: Temporary lookup failure if i use telnet with mail.domain.xx.xx  :~# telnet mmail.domain.xx.xx 25 Trying 192.168.11.xx... Connected to mail.domain.xx.xx. Escape character is '^]'. 220 ns1.titan.biz.id ESMTP Postfix (Ubuntu) mail from:root 250 2.1.0 Ok rcpt to:imam 451 4.3.0 <imam>: Temporary lookup failure   and for imap and pop3 i can't telnet it  :~# telnet localhost 143 Trying ::1... Connected to localhost. Escape character is '^]'. Connection closed by foreign host.  :~# telnet localhost 110 Trying ::1... Connected to localhost. Escape character is '^]'. Connection closed by foreign host.   please help me :)

I have a mail server, postfix and dovecot. I started both as a service:  : ~ # /etc/init.d/postfix Start [Ok] Starting postfix (via systemctl): postfix.service. : ~ # /etc/init.d/dovecot Start [Ok] Starting dovecot (via systemctl): dovecot.service.   But when tried to telnet can not send mail:  : ~ # Telnet 192.168.xx.xx 25 Trying 192.168.xx.xx ... Connected to 192.168.xx.xx. Escape character is '^]'. 220 ns1.xx.xx.id ESMTP Postfix (Ubuntu) ehlo mail.xx.xx.id 250-ns1.xx.xx.id 250-Pipelining 250-SIZE 10.24 million 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250-DSN 250 SMTPUTF8 mail from: tes@xx.xx.id 250 2.1.0 Ok RCPT TO: admin@xx.xx.id 451 4.3.0 <admin@xx.xx.id>: Temporary lookup failure   When trying to telnet to IMAP/POP3:  : ~ # Telnet 192.168.xx.xx 143 Trying 192.168.xx.xx ... Connected to 192.168.xx.xx. Escape character is '^]'. Connection closed by foreign host. : ~ # Telnet 192.168.xx.xx 110 Trying 192.168.xx.xx ... Connected to 192.168.xx.xx. Escape character is '^]'. Connection closed by foreign host.   I check postfix:  : ~ # Postfix status postfix / postfix-script: the Postfix mail system is running: PID: 1523  : ~ # Postfix check postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./lib postfix-util.so.1 postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./lib postfix-tls.so.1 postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./lib postfix-master.so.1 postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./lib postfix-dns.so.1 postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./sbi n / lmtp postfix / postfix-script: warning: group or other writable: /usr/lib/postfix/./lib postfix-global.so.1 postfix / postfix-script: warning: group or other writable: / usr / lib / postfix / sbin / ./lmtp     :~# postconf -n  alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases append_dot_mydomain = no biff = no compatibility_level = 2 home_mailbox = Maildir/ inet_interfaces = all inet_protocols = all mailbox_command = mailbox_size_limit = 0 mydestination = txx.xx.id, mail.xx.xx.id, localhost.localdomain, localhost mydomain = xx.xx.id myhostname = ns1.xx.xx.id mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128, 192.168.11.53/24 myorigin = /etc/mailname readme_directory = no recipient_delimiter = + relayhost = smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtpd_use_tls = yes virtual_alias_domains = xx.xx.id virtual_alias_maps = hash:/etc/postfix/virtual   :~# dovecot -n  # 2.2.22 (fe789d2): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.13 (7b14904) # OS: Linux 4.4.0-34-generic x86_64 Ubuntu 16.04 LTS disable_plaintext_auth = no mail_location = maildir:~/Maildir namespace inbox {   inbox = yes   location =   mailbox Drafts {     special_use = \Drafts   }   mailbox Junk {     special_use = \Junk   }   mailbox Sent {     special_use = \Sent   }   mailbox "Sent Messages" {     special_use = \Sent   }   mailbox Trash {     special_use = \Trash   }   prefix = } passdb {   driver = pam } protocols = imap imap pop3 userdb {   driver = passwd }


Are there consequences that are typically enforced when an author puts the publisher’s PDF on a personal website or social media (e.g. ResearchGate) in violation of the publisher’s policy? I see many journal policies which prohibit uploading the final-version PDF on repositories (see ). But at the same time, I see many final-version PDFs freely available if you look on ResearchGate, Academia.edu or an author’s website.  If these are cases of technically breaking the publisher’s rules, are there typically consequences for researchers?

I know that some publishers sometimes send copyright infringement emails to researchers putting their articles on a personal website. How often do publishers actually sue researchers for copyright infringement for putting their articles on a personal website? (assuming the authors didn't have the legal right to do so)  I am mostly interested in United States-based authors, but I am curious about other countries as well.


How does one go about exactly summing this series   $$\sum_{n=1}^{\infty}\frac{(-1)^nn^2}{3^n}$$  Stuck on this and not sure how to proceed. Appreciate any assistance!

I'd like to find out why  \begin{align} \sum_{n=0}^{\infty} \frac{n^2}{2^n} = 6 \end{align}  I tried to rewrite it into a geometric series  \begin{align} \sum_{n=0}^{\infty} \frac{n^2}{2^n} = \sum_{n=0}^{\infty} \Big(\frac{1}{2}\Big)^nn^2 \end{align}  But I don't know what to do with the $n^2$.


I want to launch application on another workspace without changing current workspace.  For example I am on Workspace 1 and want to launch Chromium on my second Workspace.  Currently I am using the command below :  chromium-browser & wmctrl -r chromium-browser -t 2   or   wmctrl -s 2 chromium-browser   but I want to launch chromium on the second workspace while I am on the first workspace.  When I switch to the second workspace, I expect Chromium to be launched.

I'd like to write bash script that starts certain application on startup. I would like to have for example Firefox opened in first workspace, Slack on second, spotify on third. I know how to start these applications, but don't know how to place them in specific workspace. Is it possible in Ubuntu 17 with GNOME?


Would it be "a (incorrect) report" or "an (incorrect) report?"

When a/an precedes a parenthetical aside (sometimes seen in informal/conversational writing), should the vowel rule depend on the first word in parentheses, or the next word in the "regular" flow of the sentence?     I need a (memorable) idiom (preceding an m word; use a)   or     I need an (memorable) idiom (preceding an i word; use an)


Broadly, the steps involved in establishing a full implementation can be separated as follows: analysing the application to be accelerated; understanding the logic, compute, and data dependencies; and then enabling this on a chip given the constraints of real hardware.   Is this correct usage of semicolons? I'm not concerned about them following the colon; I'm only concerned about using it in a list where only one individual element - as far as the semicolons are concerned - is itself comma-separated. Also slightly concerned about how the list being sequential affects the sentence flow.   Many thanks in advance for any help/advice.

Are semicolons required (rather than commas) in a list after a colon when the list is not bulleted? I was told that it was a rule, but I can find no authoritative prescriptive source.   Consider the example sentence below.     The following are unclear: whether a change in Rule C is regarded as a violation; whether it is possible to add conditions to rule D in Category 5 when submitting a report to the Committee; and whether Rule G and Rule H satisfy the professional requirements.    If there is no potentially confusing internal punctuation in the list elements, and if parallel construction (e.g., whether . . . whether . . . whether) shows clear demarcation, are commas not sufficient?


So I remember reading this book in the early 2000's, and I'm pretty sure it was placed in my classroom, so it was obviously geared toward young adults. It was about a girl who wakes up one day with a birthmark (I think it might have been crescent-shaped).  At some point, it is revealed that she was either cloned or genetically engineered and that there are several duplicates of her, all with the same birthmark.  Its possible that the bad guys (who cloned/bred/grew her) want her back and try to take her from her parents, but I'm not sure. One thing I do remember is that the girl finds one of her twins or duplicates or whatever, and she's a Russian ballet dancer. I think it was a pretty short book, part of a much longer series that I couldn't find at the time, and I'd love help digging it up again.

Story is a YA book, involving a high-school super soldier.  Facts I recall from the story:   The super-soldiers were girls, IIRC all clones Super soldier research project had a half moon as its symbol Some genetic engineering was involved in the gene line Somehow, this genetic engineering also gives the girls skills Super-soldier project was shut down and some of the researchers took a couple of girls each to raise as their own. Protagonist's adoptive mother was one of the researchers. The girls are all "defective" in some way, protagonist is one of them and is hard of hearing. Protagonist has some (2,3?) non-super friends at her high school.   Scenes I recall:   First scene, protagonist is in classroom, and reflects how she prefers it when her teacher shaves, since then she can lip-read what he's saying. Protagonist and other super soldiers get captured and brought together. IIRC this is the first time the protagonist meets other super soldiers, or at least the first time she meets some of them.  The girls receive half-moon pendants from their captors, with implanted hidden microphones. Someone has an allergic reaction to a metal (IIRC, in a bracelet). They get around this by coating the metal in clear nail polish to avoid contact.  This scene gets called back to after the capture, as the protagonist recalls the trick and uses the same idea to disable her pendant microphone. When escaping her captors, the protagonist unlocks her (latent) lockpicking skills.   Looking this up just for nostalgia's sake, IIRC it wasn't that good. Originally read it in Dutch in the early 2000's, but I don't recall a precise date.


I have 2 dictionaries with identical keys.  d1 = {'Dog':[7,2],'Cat':[5,2]} d2 = {'Dog':1,'Cat':4}   Is there a good way of combining them so that I can have one dictionary that looks like this?  d = {'Dog':[7,2,1],'Cat':[5,2,4]}

I have two Python dictionaries, and I want to write a single expression that returns these two dictionaries, merged (i.e. taking the union).  The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place. >>> x = {'a': 1, 'b': 2} >>> y = {'b': 10, 'c': 11} >>> z = x.update(y) >>> print(z) None >>> x {'a': 1, 'b': 10, 'c': 11}  How can I get that final merged dictionary in z, not x? (To be extra-clear, the last-one-wins conflict-handling of dict.update() is what I'm looking for as well.)


So this is my first try with cycles and I was wondering what can I do to make the image clearer?

I know that this question is a bit old or maybe overdone, but I'm running the latest edition of Blender and when I use the Cycles engine I get really fuzzy results and I can't find a simple, non-compromising solution to the quality.  I don't know exactly what I'm doing wrong here, but I'm sure others share my frustration.  Leaving everything in default settings, I started a new project and switched to the Cycles render.  I duplicated the cube and set colors for two Diffuse BSDF shaders, then went ahead and made walls and a floor all sharing the same diffuse shader.  I made two windows to emit blue light.  The screenshot has gaps between the walls because of the setup:  I'm aware that it's considered very incomplete and many have come to terms with some amount of noise, but is this normal?  Furthermore, with default settings or not, I can't change the amount of noise produced.  Supposedly, using "progressively refine" in the rendering tab should make it refine itself indefinitely, however Cycles only counts to 10 refines and then stops, creating a render which is a pixel-perfect match of the ordinary rendering method when it's completed.  I understand that there are tricks that can be used to reduce noise, but at the cost of extra processing time and usually small quality conflicts, like blurring.  My question essentially boils down to is this Cycles' current limit?


I know that to create array in C++ use new []  and delete this array use delete []  I wonder if I create a object and delete this with delete []  Test * a = new Test; delete [] a;   Well... it works... but is it safe? should I use delete without bracket?

Alright, I think we all agree that what happens with the following code is undefined, depending on what is passed,  void deleteForMe(int* pointer) {      delete[] pointer; }   The pointer could be all sorts of different things, and so performing an unconditional delete[] on it is undefined. However, let's assume that we are indeed passing an array pointer,  int main() {      int* arr = new int[5];      deleteForMe(arr);      return 0; }   My question is, in this case where the pointer is an array, who is it that knows this? I mean, from the language/compiler's point of view, it has no idea whether or not arr is an array pointer versus a pointer to a single int. Heck, it doesn't even know whether arr was dynamically created. Yet, if I do the following instead,  int main() {      int* num = new int(1);      deleteForMe(num);      return 0; }   The OS is smart enough to only delete one int and not go on some type of 'killing spree' by deleting the rest of the memory beyond that point (contrast that with strlen and a non-\0-terminated string -- it will keep going until it hits 0).  So whose job is it to remember these things? Does the OS keep some type of record in the background? (I mean, I realise that I started this post by saying that what happens is undefined, but the fact is, the 'killing spree' scenario doesn't happen, so therefore in the practical world someone is remembering.)


I want my bibliography in Dutch. I use natbib IEEE. How can I ajust this so everything is in Dutch?

I'm encountering a problem when using Overleaf. I've used \usepackage[dutch]{babel} and my table of contents and header of my bibliography is all Dutch, which is great. However, my bibliography itself, is in English.  For example when I quote a chapter in a book, the bibliography says chapter 582 or first edition, whereas it should say hoofdstuk (Dutch for chapter) 582 and first editie (Dutch for edition).   I've tried \bibliography{bib.bib}{dutch} , but that did not work.


having failed to post the first question in a clear way, I will try to be more specific.  I have two 2d matrices, one with 5 columns (let's call it data) and the other with 7 (let's call it BMU). Let's call the 5 column submatrix photometry and the last two columns respectively z and z_err.  What I would like to do is, excluded the last two columns of BMU, calculate all the euclidean distances between the data objects and the BMU objects, then for each data objects find the closest k BMU objects. (here I rearrange the distance matrix and so I can't associate a distance to a specific BMU object)  Done so, I would like to retrieve this closest k objects in the BMU matrix and use the 6th and 7th column to perform some operation.  In order to store and retrieve all these informations that I need, I was trying to create some sort of dictionary. So, when I calculate the distances, I can use an ID to associate the particular distance to the features of the BMu object (photometry, z and z_err) even if I have to rearrange them.   thanks for any help :)

Imagine that you have the following list. keys = ['name', 'age', 'food'] values = ['Monty', 42, 'spam']  What is the simplest way to produce the following dictionary? a_dict = {'name': 'Monty', 'age': 42, 'food': 'spam'}


I "lost" my iPhone at work, could not find it anywhere. I reported it lost, and got another through the insurance. A month later, I found it hiding in a file in one my desk drawers. The phone is just less than a year old, in near new condition, and it seems a waste to discard it. What has to be done to be able to sell it to someone who needs a working phone?

I was curious about the things that we need to do before selling your iPhone or even before giving it back to Apple (Apple has a program where they will refund you some money if you want to get a new iPhone).   Quick googling show: .  I'm interested in all aspects. What to do in the iPhone itself, the associated Mac/iTunes and your account at Apple/iCloud.


Given a string $A$.  Definition: Two strings are said to be equal if after applying following operation, they become equal(equivalent).  Operation: Given two strings, you can swap any characters in the string at most one time in any string. eg - $abc$, $bac$ are equal(equivalent) since in $bac$, we can swap $b$ with $a$.  Now we need to calculate the number of "ordered pairs" after permuting the $A$ string such that they are two strings that are not equal.  Note: Characters in string can be repeated.  Example: Let string A is $abc$. No of permutation of string $A$ is 6 which are $abc$,$acb$,$bca$,$bac$,$cab$,$cba$. There is no $ordered$ $pair$ of strings such that both string are not equal(equivalent). Like in pair ($acb$,$bac$) both can be made equal(equivalent) because we can $c$ with $b$ in $abc$ and $a$ with $b$ in $bac$. So answer is $0$.   Thanks

We are provided with a string A (may contain repeated characters as well ). One needs to make all possible permutations of A , and find out how many pairs of strings chosen from these permutations are not similar.  Two strings are similar if we can make both of them exactly same by carrying out at most 1 swap in each of them .  Example :- if we are provided with string abcd  , then for permutation abcd , the permutations which are not similar to it are bcda , bdac , cadb , cdba , dabc , dcab . Similar is the case for other permuations as well. So overall number of desired pairs are 24*6=144 .  I tried solving it for each possible pair by approach mentioned here     But as the permutations can be large enough , I need a better approach of solving this.


I have an AMD Radeon R9 M265X gpu in my laptop. I downloaded the latest (2015) ubuntu drivers (fglrx-core_15.302-0ubuntu1_amd64_ub_14.01.deb) for the card from the AMD Page (). At first it gave me an error for not having libqtcore4 installed. I managed to install that and now it just gives me this error: ERROR: Cannot create report: [Errno 17] File exists: '/var/crash/fglrx-core.0.cr ash' Error! Bad return status for module build on kernel: 5.4.0-42-generic (x86_64) Consult /var/lib/dkms/fglrx-core/15.302/build/make.log for more information. dpkg: error processing package fglrx-core (--configure): installed fglrx-core package post-installation script subprocess returned error exit status 10 Errors were encountered while processing: fglrx-core E: Sub-process /usr/bin/dpkg returned an error code (1) I tryed the linux universal radeon-crimson-15.12-15.302-151217a-297685e.zip installer, but after unziping in /tmp/ and running sudo ./amd-driver-installer*.run (as seen in this tutorial: ) it gaves me this error: error: Detected X Server version 'XServer 1.20.8_64a' is not supported. Supported versions are X.Org 6.9 or later, up to XServer 1.10 (default:v2:x86_64:lib32:XServer 1.20.8_64a:none:5.4.0-42-generic:) Installation will not proceed. Does anybody know a fix or something? Thanks.

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


My Work: $$\lim_{n\to \infty} \sum_{k=1}^n \frac n{n^2+k^2}$$ $$\lim_{n\to \infty} n\sum_{k=1}^n \frac 1{n^2+k^2}$$ $$\lim_{n\to \infty} n(\frac1{n^2+1^2}+\frac1{n^2+2^2}+\frac1{n^2+3^2}+...+\frac1{n^2+(n-1)^2}+\frac1{2n^2})$$  I'm not really sure where to proceed from here, or if this even is the correct direction that I should take this problem. My math Analysis class has covered up to Riemannian integrals, but I'm not sure that they will be entirely helpful in this instance.

I'm asked to prove that $$\lim_{n \to \infty}\left(\frac{n}{n^2+1}+\frac{n}{n^2+4}+\frac{n}{n^2+9}+\cdots+\frac{n}{n^2+n^2}\right)=\frac{\pi}{4}$$ This looks like it can be solved with Riemann sums, so I proceed:  \begin{align*} \lim_{n \to \infty}\left(\frac{n}{n^2+1}+\frac{n}{n^2+4}+\frac{n}{n^2+9}+\cdots+\frac{n}{n^2+n^2}\right)&=\lim_{n \to \infty} \sum_{k=1}^{n}\frac{n}{n^2+k^2}\\ &=\lim_{n \to \infty} \sum_{k=1}^{n}(\frac{1}{n})(\frac{n^2}{n^2+k^2})\\ &=\lim_{n \to \infty} \sum_{k=1}^{n}(\frac{1}{n})(\frac{1}{1+(k/n)^2})\\ &=\lim_{n \to \infty} \sum_{k=1}^{n}f(\frac{k}{n})(\frac{k-(k-1)}{n})\\ &=\int_{0}^{1}\frac{1}{1+x^2}dx=\frac{\pi}{4} \end{align*}  where $f(x)=\frac{1}{1+x^2}$. Is this correct, are there any steps where I am not clear?


I have one player and many enemies. The enemies are following my player through the navigation mesh. Sometimes enemies get stuck because there is another enemy in-front of them. You can say both are in line.   Is it possible that when one enemy collides with other enemy in-front of it to change direction so that it avoids colliding with one another?

I'm implementing a multi agent A* algorithm on a tile map. Agents move only in the X and Y axes. I avoid collisions between them by checking where the others are when calculating paths.  It works fine except the situation where agents have to pass the same tile from different directions. In situations like this, an optimal solution would be for one agent to wait for the other to pass:    Also, if there's no northern corridor, then pathfinding fails.  How could I implement such an algorithm?


I have the following code, trying to match if there is a speed using PhraseMatcher, eg., "44 mph" in a sentence.     import spacy from spacy.matcher import PhraseMatcher import re  nlp = spacy.load('en_core_web_sm') speed_flag = lambda text: bool(re.search(r'(?i)\d+\s?mph', text)) IS_SPEED = nlp.vocab.add_flag(speed_flag)  matcher = PhraseMatcher(nlp.vocab) matcher.add('MPH', None, [{IS_SPEED: True}])  doc = nlp(u'Car was going 44 mpH.') matches = matcher(doc)  print(matches) for match_id, start, end in matches:     span = doc[start:end]     print(span.text)   This returns an empty list, however, re.compile(r'([M-m][P-p][H-h])') returns the right answer for "Mph", "mpH", "mPh", etc. and re.compile(r'([0-9]+)') returns any digits in my document.  I am using the example here to construct this: ... also, I tested my regex pattern, ([0-9]+) ?([M-m][P-p][H-h]) in a python interpreter and it does work.   I realize the original example is done using Matcher and I am trying to use PhraseMatcher, which does not accept the correct input (viz., a list of dictionaries) to do this.  Any idea as to how to achieve this.

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


I saw  but I still do not understand:     What is the difference between ideal and principal ideal?     At my homework I had to prove to things about $I=\left\{p(x)\in \mathbb{Z}\left[X\right]:2\mid p(0)\right\}$: 1. That $I$ is an ideal. I prove it... 2. That $I$ is not a principal ideal.    Now how can I prove 2.? Why $I$ isn't a principal ideal?   Thank you!

Hi I don't know how to show that $\langle 2,x \rangle$ is not principal and the definition of a principal ideal is unclear to me. I need help on this, please.   The ring that I am talking about is $\mathbb{Z}[x]$ so $\langle 2,x \rangle$ refers to $2g(x) + xf(x)$ where $g(x)$, $f(x)$ belongs to $\mathbb{Z}[x]$.


I have some bash scripts, one which has the following content:  #!/bin/bash source $(dirname ${BASH_SOURCE[0]})/script.sh   while the other one has the following content:  #!/bin/bash source "$(dirname ${BASH_SOURCE[0]})/script.sh"   How do these scripts behave differently and why? What is the difference?

I can write  VAR=$VAR1 VAR=${VAR1} VAR="$VAR1" VAR="${VAR1}"   the end result to me all seems about the same. Why should I write one or the other? are any of these not portable/POSIX?


I have a very confusing exercise in my workbook. There are 4 options. This is the question: I wouldn't like _____ in bed until noon, although I enjoy _____ 1) to lie, to sleep  2) lying, sleeping  3) lying, to sleep  4) to lie, sleeping I have no idea. Hopefully you can help me.  Greetings

I bought this book titled 2 Hari Taklukan Grammar, written by Edward Rahardian in Bahasa (Indonesian language) and mostly talk about gerund and infinitive. And these are some examples of the gerund sentences that I found.        His mother suggested having lunch before we leave.     I will try studying harder.     The car needs washing.     Your hair needs washing.     My teacher disliked me coming late.        Somehow those words sound unnatural for me because I've never heard those in daily conversations. As a learner, I only get exposed with English by watching TV series and any other entertainment resources.  So in my thought, they sound more natural like this:        His mother suggested to have lunch before we leave.     I will try to study harder.     The car needs to be washed.     Your hair needs to be washed.     My teacher disliked me to come late.       Are those sentences in the first group grammatically correct? And, is it normal for one to say them in normal/daily conversations?


I'm trying to prove this combinatorially. $$k\binom{n}{k} = n\binom{n-1}{k-1}$$ I know the first step is to relate a question to the equation. My question was if you have $n$ friends how many ways can you choose $k$ of them. I know this isn't correct because that would be the question if the left side wasn't being multiplied by k. Can anyone help me figure out what multiplying ${n \choose k}$ by $k$ means?

I am looking for the combinatorial argument for the identity:  \begin{equation} k\binom{n}{k} = n\binom{n-1}{k-1} \end{equation}  This is easy to show algebraically as:  \begin{equation} \binom{n}{k} = \dfrac{n(n-1)(n-2)(n-k+1)}{k(k-1)!} \end{equation}   What is the combinatorial argument? What are some general ideas to get started?   Here is a clarification of 2. From what I have seen so far, proving (combinatorially) an identity with an addition sign usually implies that we need to partition a set (this makes sense because of the addition rule and provides a nice visual). On the contrary, the previous observation leads me to believe that multiplication in identities can be resolved with the multiplication principle, but what is the "visual/interpretation" for this? Could someone provide such an interpretation for the example identity given above?


is one of the many videos on youtube showing how a cornstarch and water mixture can become very hard when put under stress. I haven't found a good explanation of why it behaves the way it does. Is there any paper that has been published on this that explains the weird properties of the liquid? If not, could someone here try to explain what is going on?

You can dip your hands into a bowl of non-Newtonian fluid but if you are to punch it, it goes hard all of a sudden and is more like a solid than anything else.   What is it about a non-Newtonian fluid that makes it go hard when having a force suddenly exerted on it? How does it go from being more like a liquid to a solid in such a short amount of time? Does it change its state as soon as the force has made contact with it?


My professor gave us these properties very fast in our class and I can't find a proper explanation for them, can someone help me please?  (1) - The cardinal of the set of naturals is the same of the integers and the same of the rationals and these are enumerable sets (how is this possible? Don't the rationals have all the integers (and also other elements) and the integers have all naturals (and also other elements)??)  (2) - The cardinal of irrationals is bigger than the one for naturals and this is a non-enumerable set (this one kinda makes sense)  (3) - The cardinal of irrationals is equal to the cardinal of a set [a,b] (wait, how? Doesn't [a,b] have may more elements than the irrationals?)  Anyway, maybe the problem is that I'm not understanding the key concepts of cardinal and enumerable set... Can someone explain me please?

Possible Duplicate:          We previously proved that $\mathbb{Q}$, the set of rational numbers, is countable and $\mathbb{R}$, the set of real numbers, is uncountable. What can you say, then, about the cardinality of the irrational numbers?  I would say that the cardinality of irrational numbers is uncountable. That would be because the set $\mathbb{Q}$ is a subset of $\mathbb{R}$. The irrationals is also a subset of $\mathbb{R}$. Basically, my thought is that the continuum is composed of irrationals and rationals (only two subsets of reals). Because we can prove that the rationals are countable by Cantor's proof, then the remaining subsets of $\mathbb{R}$, the irrationals, has to be uncountable for $\mathbb{R}$ to be uncountable. My concern is how to go about the prove this (rigorous, intro level).


I would like to know what a conformal mapping from the unit disk onto an interior ellipse is. Thank you.

I was originally looking for a conformal map that maps a punctured unit disc to unit disc. The only answer I can find lead to  resource.  The final step of the answer given rely on a conformal map that maps an ellipse to a unit disc. Although we know such a map exist by Riemann Mapping Theorem, is there any way to write down the map explicitly (let's say, length of axes are given)?  The only related formula I can find is Joukowski transformation which does the other way around.


Is the sentence "There was a large number of students in the auditorium," or "There were a large number of students in the auditorium," correct? I am unsure because I believe if you consider, "... a large number..." which is singular, then you would use "was," but if you considered "students," which is plural, then you would have to use the plural verb "were". Is "was" or "were" correct in this sentence?

Formally, is it correct to write:     A number of questions has been asked here.   or:     A number of questions have been asked here.   As a non-native speaker of English, I would prefer the former: the subject seems to be "number", therefore the verb ought to be singular, I'd say. However, the latter seems more common, and therefore I believe that my gut feeling is just plain wrong — but I would really like to have a definite answer.  Moreover, is it the same for "a myriad of", "a plethora of", and so on?


I'm trying to prove, given only that one sequence $B$ is bounded and the other sequence $A$ is convergent to zero, that their product also converges.  My work probably wouldn't be considered a formal proof but I'm curious if my strategy/thought process is on the right track.  My work:  Since $A$ converges to zero, there exists a point in this sequence where all terms are between $-1$ and $1$. In this case, whatever behavior $B$ has will be dictated by the terms of $A$. If $B=0$, then the conclusion is trivial. Thus, $AB$ converges to zero.

Let $a_n$ be a null sequence and let $b_n$ be a bounded sequence. Prove that $a_n \cdot b_n$ is a null sequence.  I tried using the product rule of sequences but cannot because $b_n$ is not necessarily convergent and may not have a limit. How do I go about answering this?


How to find this limit;  $$\lim_{n\to \infty}\left[(n+1)\int_{0}^{1}x^n\ln(x+1)dx\right]$$  What techniques can I use here? Thanks for reading and help.  This question was asked in  2008.

Evaluate the following limit : $$\lim_{n\to \infty}\left[(n+1)\int_0^1x^n\ln(1+x)\,dx\right].$$   We have , $$\lim_{n\to \infty}\left[(n+1)\int_0^1x^n\ln(1+x)\,dx\right]$$ $$=\lim_{n\to \infty}\int_0^1\ln(1+x)\,d(x^{n+1})$$Now put , $x^{n+1}=y$. Then , $$=\lim_{n\to \infty}\int_0^1\ln\left(1+y^{\frac{1}{n+1}}\right)\,dy$$Let , $\displaystyle g_n(y)=\ln\left(1+y^{\frac{1}{n+1}}\right)$.     Edit  :      Then , $\displaystyle g(y)=\lim_ng_n(y)=\ln 2$ in $(0,1]$.       Now , $\displaystyle \sup_{x\in (0,1]}|g_n(y)-g(y)|=\sup_{x\in (0,1]}\ln\left(\frac{1+y^{\frac{1}{n+1}}}{2}\right)=0$. ( As , $y^{\frac{1}{n+1}}$ is monotone increasing function in $(0,1]$ , so $\ln\left(\frac{1+y^{\frac{1}{n+1}}}{2}\right)$ is also monotone increasing in $(0,1]$ and so it attains its maximum value at $y=1$ . ) So , $\{g_n(y)\}$ converges uniformly to $\ln 2$.   Then ,we can show that $g_n(y)$ converges uniformly to $\ln 2$ in $(0,1]$ and hence the given limit is $\ln 2$.     Is this correct ? Does there any other technique to evaluate the limit ?


My Lenovo Thinkpad laptop came with a Type-C charger that has multiple output specs. The output specification of the Lenovo charger is: 20V/3.25A, 15V/3A, 9V/2A, 5V/2A. Can I use this charger to charge my Macbook Pro 2019? The output specification of the Apple Type-C charger that came with my Macbook is: 20.3V/3A, 15V/3A, 9V/3A and 5.2V/3A

I've just bought a portable battery, but the portable battery don't comes with an adapter for the house current; it only comes with a USB cable so I can charge it with my laptop. My mobile phone came with a charger, and I want to know if is safe to use that charger with the battery without problems, even though the output has a higher amperage. These are the specifications:  Battery input: 5V, 1A Charger output: 5V, 2A  Will the output only give the quantity that the input is requesting, or will the input overheat because it cannot handle all the current it receives?


Show that a group $G$ is abelian if $(gh)^3 = g^3h^3$, $(gh)^4 = g^4h^4$, and $(gh)^5 = g^5h^5$ for all $g$ and $h$ in $G$.   I have tried many manipulations but I keep getting stuck as I am not even able to see why it is true. Every other exercise I tried seemed routine or manageable, but this one in particular I need a hint.

If $G$ is a group in which $(a\cdot b)^{i} =a^i\cdot b^i$ for three consecutive integers $i$ for all $a, b \in G$, show that $G$ is abelian.  Proof: Let $x$ be the smallest of the 3 consecutive integers. Then, we have   $(1)(a\cdot b)^{x} =a^x\cdot b^x$, $(2)(a\cdot b)^{x+1} =a^{x+1}\cdot b^{x+1}$ and $(3)(a\cdot b)^{x+2} =a^{x+2}\cdot b^{x+2}$.  Using $(2)$ and multiplying $a^{-1}$ on the left and $b^{-1}$ on the right, we get $baba...ba = a^{x}b^{x}(4)$ whereby there are $x$ number of $a$ and $x$ number of $b$ on both sides.  Using $(1)$ and multiplying both sides on the right by $ab$, we have $\overbrace{abab...ab}^{(x+1)ab} = (a^{x}b^{x})ab (5)$.  Substitute $(4)$ into $(5)$, we get $\overbrace{ab...ab}^{(x+1)ab} =\overbrace{ba...ba}^{(x)ba}ab(6)$.  Using $(3)$ and multiplying $a^{-1}$ on the left and $b^{-1}$ on the right, we get $\overbrace{ba...ba}^{(x+1)ba} = a^{x+1}b^{x+1} = \overbrace{abab...ab}^{(x+1)ab}(7)$.  Combining $(6)$ and $(7)$, and multiply $a^{-1}b^{-1}...a^{-1}b^{-1}$ on the left, we get $ab = ba$. Hence $G$ is abelian.


This is what I see on the right under Related questions on meta:    As you can see, all numbers over 99 break into two lines.

The score for the 4 questions are 111, 1218, 261 and 5 respectively, but they display 2 digits per line. This is an obvious bug in design.


How to get size of an object of a class/struct in C#.  hello h = new hello(); Base b = new Base(); Console.Write(Marshal.SizeOf(h) + "," + Marshal.SizeOf(b)); Console.Read();   I tried above code, but it gives error. ERROR:     Type 'Virtual.Base' cannot be marshaled as an unmanaged structure; no meaningful size or offset can be computed.   THanks!

I have a class, and I want to inspect its fields and report eventually how many bytes each field takes. I assume all fields are of type  Int32, byte, etc.  How can I find out easily how many bytes does the field take?  I need something like:  Int32 a; // int a_size = a.GetSizeInBytes; // a_size should be 4


I'm writing my Master's Thesis in LaTeX, using the bookclass (maybe I should have used the memoir one, but now it's too late) with the twoside option.   I thought the larger margin was that in the bindings side in order to balance the space lost because of the bindings. However, I've figured out it is exactly the opposite.   I'm afraid the text is going to seem very off-center. Do you think I should change the default margins for a Master's Thesis? Unfortunately, my university doesn't provide any template.  Thanks.

Shouldn't the twoside option produce a wider margin at the binding/spine edge, rather than the other way around? I'm using \documentclass[twoside]{report}.


Have a large amount of junk contacts that are not part of any data extensions that need to be deleted (400k) from the marketing cloud instance. What is the easiest way to go about doing this? If there is an option to delete all contacts and start with a fresh instance this is also an option we are considering.

We have duplicates in our all contacts in Marketing Cloud. To solve this, we want to delete all contacts (audience builder).   We use the Marketing Cloud connector, and send emails to synchronized data extensions. Because of this connector the all contacts will be filled with fresh data after 15 minutes right?  Is there any reason not to do this? What can go wrong?


i am running my procedure using help pf ref cursor like  SQL> variable rcq refcursor; SQL> DECLARE amount NUMBER; BEGIN Getresults('null',1,1,1,1,1,1,1,40,1,'  ','NameWithDates',amount,:rcq); dbms_output.put_line(amount); END; /   PL/SQL procedure successfully completed.  SQL> print rcq   do we save this result any xls file or (txt file in correct format)

I need to retrieve certain data from an Oracle 11g release 1 database and provide it as one or more CSV files. The data resides in multiple tables and/or views. All this should work via the command line. What would be the best approach to this?


I was editing in material preview, but when I switched to solid view, most of my scene did not show, just the parts that fell into a dark rectangular pyramid.  The pyramid itself is positioned and rotated arbitrarily.

When looking at my objects in 3d view I'm seeing a gray cone that seems to be hiding other objects.   Can anyone help me turn this off and explain what it is please.  Screenshots attached.


I would like to use a formula to identify if a cell in a group of cell contains a specific word.  Example, I'd like to search if a cell has the content X  The formula's response could be 1 if found, 0 if not found.

First off, I'm not that advanced of an Excel user. I'm certain Excel can do what I'm about to ask, but I've yet to find a way in any of my attempts or searches.  My question is very similar to  except that A) the answers there didn't work for me, and B) even if it did, it's not quite the correct output I need.   Basically, I have 2 columns. Column A contains URLs (16388 rows). Column B contains URL slugs (202 rows).   I want to search to see if any of the values in column B are contained within any of the values of Column A. If they are, I want to return the value TRUE in column C.   From what I've read, VLOOKUP ought to work for this, but for the life of me I can't get it to work. I also tried in the answers in the link above that use COUNTIF and MATCH, but in both of those cases, all I got were FALSE returns, when I know that there are values in Column B that are contained in a URL in Column A.   Does that make sense?  EDIT: Both answers are providing results (thank you!), but I suspect I may not have asked the question correctly. In both of the answers, I'm getting TRUE results, but it looks like the TRUE is correlating to the slug in Column B rather than the URL in Column A. Let me put it this way:  I'll move the slugs from Column B to C so that B can be used for the TRUE responses. What I want the fomula to do is:   Look at URL in A1 Are any of the values in Column C contained within the URL in A1? If yes, then return TRUE in B1. If FALSE, leave it blank.    So I will be able to see which of the URLs contain the slugs I am searching for. I apologize for not being clearer in my original ask (though I feel like it's only a slight tweak from the answers I've already been given.)


I am using the WinEdt QuickGuide.tex as a template to write a document, however, when I try to include the bibliography like:  %======================================================================================== %   Bibliography %========================================================================================  \usepackage[style=alphabetic,sorting=nyt,sortcites=true,autopunct=true,babel=hyphen,hyperref=true,abbreviate=false,backref=true,backend=biber]{biblatex}  \addbibresource{C:/Superstar/Desktop/Joe/ModernControl/References/chap1.bib}% BibTeX \defbibheading{bibempty}{}   I get the error:    ! No room for a new \count . \ch@ck ...\else \errmessage {No room for a new #3}                                                   \fi   can you tell me how I can go about putting the references correctly in this template?

I have this error message:  ! No room for a new \dimen . \ch@ck ...\else \errmessage {No room for a new #3}                                                 \fi   which I can not find a cure for.


I want to test   $$H_0: \mu  \leq 0 \,\,\,\,\,\, vs \,\,\,\,\,\, H_1: \mu >  0.$$ I am using a t test, so the statistic $T$ has $\nu$ degrees of freedom which depend on the sample size.  What is the difference between testing $H_0: \mu  \leq 0$ or $H_0: \mu  = 0$ vs $H_1: \mu >0$?  Is it possible to test only $H_0: \mu  \leq 0$?  In R command t.test(), it seems that this is equivalent to specifying alternative =  "greater", but there seems to be no distinction between the two hypothesis?

I saw a lot of times claims that they have to be exhaustive (the examples in such books were always set in such way, that they were indeed), on the other hand I also saw a lot of times books stating they should be exclusive (for example $\mathrm{H}_{0}$ as $\mu_1=\mu_2$ and $\mathrm{H}_{1}$ as $\mu_1>\mu_2$) without clarifying the exhaustive issue. Only before typing in this question I found somewhat stronger statement on the  -- "The alternative need not be the logical negation of the null hypothesis".  Could someone more experienced explain which is true, and I would be grateful for shedding some light on the (historical?) reasons for such difference (the books were written by statisticians after all, i.e. scientists, not philosophers).


Assume I have a Theorem with number 1.2 in my paper. After that some other numbered content follows. Now, in a new section I want to cite Theorem 1.2, i.e. want to make some kind of copy paste. How would you do this?

Suppose I have some theorem in the paper  Section 1 Theorem 1.1. Let ...  And then later in the paper I want to recall the theorem by reprinting it  Section 4 We recall Theorem 1.1: Theorem 1.1. Let ...  What's the proper way to do this?


macOS Sierra system is using over 200 GB of storage space on my 250 GB hard drive. I've removed Time Machine backups to no avail. How do I free up space? My current usable space being less than 50 GB is getting quite problematic.  Edit:  The culprit has been found. Imagemagick is creating tons of temp files for some reason.

Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?


Let's say that you're in a very controlled environment, there is no hurry to get the shot, and you're shooting manual.  In order to correctly expose the photo, what order should you alter the ISO (if shooting digital), shutter speed and aperture; and why?

Suppose we have time to shoot with an DSLR. Before actually shooting, some settings have to be adjusted to get a picture. Suppose we have a brand new DSLR in hand and every setting has to be defined.  Of course, getting the right picture depends on the subject, the context, the personal taste, etc. but I don't matter on the artistic point of view, just on the order (if such a determined one exists) and the importance of all the required technical step.  As a debutant, I imagine it could be this (rather simple) one:   ISO, depending on the current lightness ; white balance, depending on the light color ; aperture, depending on the desired depth of field ; composition, depending on the subject ; shutter speed, depending on the desired exposition ;   and finally...   SHOOT!   Is this a correct way to handle things? Is such an order (this one or another) very typical or does it change for each picture? If different, what's yours, and why?


Until now, I only used the Auto mode on my el cheapo .  I read up about the non-auto modes (P/Av/Tv/M)… but, considering the camera, was wondering if they're actually worth using.  Thank you.

I'm very new to digital photography, so I still haven't gotten the hang of all this exposure and ISO stuff, etc. I have a Canon EOS T3.   My question is how big of a difference does it make using manual settings rather than auto settings for everything? I've taken some pretty nice photos with all auto settings, and I'm not sure if it could have turned out any better using manual settings. I know that there are some people who have been in the game for years upon years, and to them they can notice the difference between photos taken with manual vs auto settings, but for my situation, do you think it really makes a difference? Is my camera smart enough to determine the best settings for me?  Also, lets say manual settings are better (which I'm sure they are, since they give you greater control). How often are you supposed to adjust your settings? Between every shot, considering they are unique shots? Or does it not matter about the object, but rather the lighting environment? So if I'm in a forest at 2:00 PM on a sunny bright day and I take photos for one hour, should I be constantly adjusting my settings between every unique shot to get the best out of it? Or do I usually just find one setting that works for the environment I'm in?


$f(x)=|x+\frac{\pi}{2}|-2|x|+|x-\frac{\pi}{2}|$  After using Fourier transformation I get  $a_0 = \frac{\pi}{2}$  $a_n = \frac{8}{\pi n^2}sin^2(\frac{n\pi}{4})$  $f(x)= \frac{a_0}{2} + \sum_{n=1} ^{\infty} a_n*cos(nx)$  After this of I substitute n=2k and k=2h+1 I can get values but not for the sum in question. Is it even possible to solve this?

As I have heard people did not trust Euler when he first discovered the formula (solution of the ) $$\zeta(2)=\sum_{k=1}^\infty \frac{1}{k^2}=\frac{\pi^2}{6}.$$ However, Euler was Euler and he gave other proofs.   I believe many of you know some nice proofs of this, can you please share it with us?


I'm converting a project from Java to C#. I've tried to search this, but all I come across is questions about enums. There is a Hashtable htPlaylist, and the loop uses Enumeration to go through the keys. How would I convert this code to C#, but using a Dictionary instead of a Hashtable?   // My C# Dictionary, formerly a Java Hashtable. Dictionary<int, SongInfo> htPlaylist = MySongs.getSongs();  // Original Java code trying to convert to C# using a Dictionary. for(Enumeration<Integer> e = htPlaylist.keys(); e.hasMoreElements(); {     // What would nextElement() be in a Dictonary?      SongInfo popularSongs = htPlaylist.get(e.nextElement()); }

I've seen a few different ways to iterate over a dictionary in C#.  Is there a standard way?


If $G$ is a finite group of order $n$ and $p$ is the smallest prime dividing $|G|$, then prove that any subgroup of index $p$ is normal.  This falls under the category of Cayley's Theorem, but i have difficulty in proving this. Please help me out!

Generalizing the case $p=2$ we would like to know if the statement below is true.  Let $p$ the smallest prime dividing the order of $G$. If $H$ is a subgroup of $G$ with index $p$ then $H$ is normal.


Sharpshooter A hits the target 1/4 of the time. Sharpshooter B hits the target 2/5 of the time. If they both shoot, what is the probability that at least one sharpshooter will hit the target?

A coin is tossed three times. The probability of zero heads is 1/8 and the probability of zero tails is 1/8. What is the probability that there is at least one head and at least one tail?  So, if P(zero heads)= 1/8 , then that should be the same of p(all tails)?  We would use the complement rule and Multiplication Rule?   P(at least one head) = 1 - P(no heads) = 1 - 1/8= 7/8 P(at least one tail) = 1 - P(no tails) = 1 - 1/8= 7/8  would I multiply the two values?


So when I do sudo -s in my terminal I get into root mode, and after I do whatever I wanted to do, I do 'exit'. Now If I do 'sudo -s' again, the terminal does not ask for any password and enters root mode directly. Is this a normal behavior? I use ubuntu 16.04.  as I remember this was not the case 3-4 days ago,I think something has changed today,cant figure out what.  If this is not normal, how do i rectify it.

Just installed a minimal ubuntu 12.04, then installed xfce4 and xinit from the command line after first boot.  Totally vanilla installation afaik.  I'm noticing that sudo caches the password until I issue sudo -k to clear it.  This is unexpected behavior in my mind.  I've run xfce4 before and don't recall credential caching being on, nor have I experienced it in the many previous ubuntu installs I've had over the years.  Is this a new feature of Ubuntu?  Is this something that's the result of the minimal install?  Is this an xfce default that's been added recently?


Let $p$ be a prime. Let $A = \{a,2a,3a,\ldots,(p-1)a \}$, where $\gcd(a,p)=1$. Show that there is exactly one element in $A$ congruent to $1$ modulo $p$. My attempt: It is suffices to show that for each $a \in \{1,2,3,\ldots,p-1\}$, there is exist exactly one $b \in \{1,2,3,\ldots,p-1\}$ such that $ab \equiv 1 \pmod{p}$. Suppose there is exist an element in $A$, say $c$, such that $ab \equiv ac \equiv 1 \pmod{p}$. Then, \begin{equation*} b \equiv 1\cdot b \equiv (ac)b \equiv (ab)c \equiv 1\cdot c \equiv c \pmod{p} \end{equation*} Hence, $b$ is unique and we're done. Am i true? If not, how to show it?

Say we have two integers $n$ and $k$, such that $0 < k < n$ and $gcd(n, k) = 1$.  Why is it that if we take every integer $x\in\{0,\dots, n-1\}$ and compute $k\cdot x \ (mod \ n)$, we get as remainders all numbers from $0$ to $n-1$, with no repeats?  In other words, why is $\ f:\{0,\dots,n-1\}\rightarrow\{0,\dots,n-1\}$, $\ f(x)=k\cdot x\ (mod\ n)$ a bijection for $k,n\in\mathbb{N},\ gcd(k,n)=1$?


I have looked at the  and do not understand why there is a maximum on the amount of reputation you can offer as a bounty.

Why can't I give more than 500 reputation as a bounty at a time? The system won't let me choose an option more than 500.  Also, how were some users able to do so? On  the OP has given a single bounty worth 550 rep, but at the moment I have 844 rep and I can't give any more than 500 rep on a bounty.  Can you please tell us if this is a bug or not?


I'm trying to recover stuff after I accidentally formatted an ext4 partition. I'm running the system from a Live USB, and following  to mount a backup superblock. However, I get an error when I'm trying to mount it. Here's what I get:  ubuntu@ubuntu:/$ sudo dumpe2fs /dev/nvme0n1p4 | grep -i superblock dumpe2fs 1.45.3 (14-Jul-2019)   Primary superblock at 0, Group descriptors at 1-31   Backup superblock at 32768, Group descriptors at 32769-32799   Backup superblock at 98304, Group descriptors at 98305-98335   Backup superblock at 163840, Group descriptors at 163841-163871   Backup superblock at 229376, Group descriptors at 229377-229407   Backup superblock at 294912, Group descriptors at 294913-294943   Backup superblock at 819200, Group descriptors at 819201-819231   Backup superblock at 884736, Group descriptors at 884737-884767   Backup superblock at 1605632, Group descriptors at 1605633-1605663   Backup superblock at 2654208, Group descriptors at 2654209-2654239   Backup superblock at 4096000, Group descriptors at 4096001-4096031   Backup superblock at 7962624, Group descriptors at 7962625-7962655   Backup superblock at 11239424, Group descriptors at 11239425-11239455   Backup superblock at 20480000, Group descriptors at 20480001-20480031   Backup superblock at 23887872, Group descriptors at 23887873-23887903 ubuntu@ubuntu:/$ sudo mount -o sb=32768 /dev/nvme0n1p4 /mnt mount: /mnt: wrong fs type, bad option, bad superblock on /dev/nvme0n1p4, missing codepage or helper program, or other error. ubuntu@ubuntu:/$ sudo mount -o sb=98304 /dev/nvme0n1p4 /mnt mount: /mnt: wrong fs type, bad option, bad superblock on /dev/nvme0n1p4, missing codepage or helper program, or other error. ubuntu@ubuntu:/$ sudo mount -o sb=23887872 /dev/nvme0n1p4 /mnt mount: /mnt: wrong fs type, bad option, bad superblock on /dev/nvme0n1p4, missing codepage or helper program, or other error.   What am I doing wrong here?

When I was installing Mint Debian edition unlike the classic edition, the installation automatically formated my home partition when I did not specify to format.  So the formatting previously was ext4 as is now. I believe the data is still there as it was a quick format.   I have now booted the computer up on a live USB to prevent writing on it.  Ran testDisk. Is there anyway to recover to a previous superblock so i can recover my data?


If $\{u_n\}$ is a sequence of real numbers and the series $\displaystyle\sum_{n=1}^{\infty}u_n^2$ is convergent, prove that the series $\displaystyle\sum_{n=1}^{\infty}\frac{u_n}{n}$ is absolutely convergent.  I have proved the series $\displaystyle\sum_{n=1}^{\infty}\frac{u_n}{n}$ is convergent, but how to prove it is absolutely convergent?

Let $a_1,a_2,a_3,\ldots$ be reals. Prove that if $\sum_{n=1}^{\infty} a_n^{2}$ converges, then so does $\sum_{n=1}^{\infty} \frac {a_n}{n}$.   For this I have shown the case for when $ a_n^{2} \le\frac {|a_n|}{n}$ $\Rightarrow$ $ |a_n|\le\frac {1}{n}$ $\Rightarrow$ $\frac {|a_n|}{n} \le \frac{1}{n^{2}}$ and we know that $\sum_{n=1}^{\infty} \frac {1}{n^{2}}$ converges and hence $\sum_{n=1}^{\infty}\frac {a_n}{n}$ converges by the comparison test. Now considering $ a_n^{2} \ge\frac {|a_n|}{n}$ $\Rightarrow$ $\frac {|a_n|}{n} \le a_n^{2}$ $\rightarrow$ combining the two cases for any n we have: $\frac {|a_n|}{n}\le\frac{1}{n^{2}}+a_n^{2}$ Hence using the comparion test again we know that $\sum_{n=1}^{\infty} a_n^{2}$ converges and $\sum_{n=1}^{\infty} \frac {1}{n^{2}}$ converges hence the sum converges so we can conclude that $\sum_{n=1}^{\infty} \frac {a_n}{n}$ is absoluetly convergent $\Rightarrow$ convergent.  Not to sure if this is correct, any help would be much appreciated, many thanks.


I noticed Milk of the Poppy is offered every time some is near death.  Most people refuse it.  Is it refused because it will make you fall asleep and die?

I've been rewatching Game of Thrones and have noticed that everytime someone is offered milk of the poppy they refuse it, If memory doesn't fail me, some examples would be: King Robert, Jaime Lannister and Maester Luwin.  Why do characters refuse milk of the poppy? I thought it was some form of anesthetic? Does it have nasty side-effects? Can it make you die? Or is it just to make the characters look tough?


I'm currently populating a div with jquery but need to format the output with a thousands separator and to two decimal places whilst also keeping the output as a number.  FYI I'm currently populating the div using:  var prev_count = 120; var new_count = 20.50;      var count_till = prev_count < new_count ? new_count : new_count - 1;     jQuery({ Counter: prev_count }).animate({ Counter: count_till }, {         duration: 600,         easing: 'swing',         step: function () {             jQuery("#count_div").text(Math.ceil(this.Counter));         }     });   Starting variable is 120 and this is meant to count down to 20.50 however it ends on 20, not 20.50, is this possible if so how would i go about it?  Here is my

I would like to format a price in JavaScript. I'd like a function which takes a float as an argument and returns a string formatted like this: "$ 2,500.00"  What's the best way to do this?


I am a doctor and I want to give my plab 2 exam in the UK.  As I am a recent graduate my father is supporting me financially. He is a retired government officer who gets pension, rents from his properties and interest from his fixed term deposits. Please tell me that how should I maintain his bank statement for 6 months, and is my employment necessary to get a visit visa as I heard from many guys that it shows ties back to your country.

The UK Visas and Immigration Directorate publishes  that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine).  Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available.  These must clearly show that you have access to the funds, such as:  bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided   The first item is "bank statements" and this ties in with the , which says...  evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months  (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?


The picture I uploaded is too large... Is there a way to limit the size (width & height)?

Is it possible to resize an image in an answer? For example,  has  that should have the image in the answer, but it's too big.  Is there a way to handle resizing?


I am planning to spend around 100 days in Leipzig, Germany, this summer. I want to get a prepaid data plan. 1 GB should be more than enough.  My Questions are:    Which service providers have suitable data plans? Prices? Are there service providers that offer support all over Europe? I might go to Prague, Milan, or Amsterdam on weekends and I will need access to the internet there.

Next month I am traveling to country X, where I would need Y minutes of calls, Z text messages and most importantly Q megabytes of data. How can I find the cheapest/most reliable SIM card for my needs?


I recently used deluge to download a torrent but forgot to set the location as a USB drive so my hard drive had 0bytes remaining, I deleted the file and used force quit to kill deluge as it was hanging. Unfortunately I pressed the mouse too soon and killed unity which caused the system to crash. Now I can't boot, I get a "couldn't get size" error on a black screen. In recovery the hard drive is showing as "103gb - 98% used, 0% free". I don't think I removed the file from deluge and normally if you delete a file from a hard drive but don't delete it from your torrent client, the free space does not show up, it only shows up when you remove it from the torrent client. So I figured this could be the problem. I removed deluge from root shell prompt, hoping it would free up the missing 5gb but it didn't. I've used clean and fcsk but I can't free up any more space, I did free up 167mb of space by removing un-needed packages but I still don't have any free space. I tried running Nautilus to remove any remaining files from deluge, but it won't run, can't remember what the exact error was but it couldn't run a display server or something, I guess cos of the lack of space ? I've been trying to fix this for days, can anyone help ? Thanks

I'm using Ubuntu 11.04 and I want to free up some space in my root directory, which is overloaded. I especially want to change the path used for installing applications (they are getting installed directly to the root drive).  Another consideration is that I'm working on a MySQL database server. The server is installed in the root directory itself, so I don't want to  risk losing any data.  Please give me some tips to help sort out this problem.


On Mac OS X, some applications will display a notification that appears briefly in the upper-right corner (e.g., when I receive email).  Is there a way to generate a notification from the command-line?  In other words, is there a command-line program I can run to display a custom notification, with text of my choice?  Ideally, I'd love to be able to run something like  show-notification "Hello world!"   from a shell script and have a notification appear showing the text "Hello world!".    I discovered I can use  to display a dialog box in the center of the screen that the user has to click "OK" on, but I'm looking for a notification not a modal dialog box.

I'd love to be able to take advantage of 10.8's Notification Center features in AppleScripts and shell scripts I write.  Is there a built-in command or a third-party library I can use from either an AppleScript or shell script?  Ideally the type and icon of the notification could be controlled, but even just the ability to trigger a basic banner with a stock icon (but custom text) would be appreciated.


I would like to understand how to you the word me and I in a sentence using correct grammar.  The difference between you and me :  The difference between me and you The difference between you and I  :  The difference between me and I

When the phrase is used as an object, why so many native speakers are saying "you and I" instead of "you and me"? I'm not a native speaker but I thought "you and me" is correct. Not sure if this falls into the same category, but "Just between you and me" sounds more natural than "Just between you and I".


In certain books like David Griffiths electrodynamics , he treats current as a vector in some places. Moreover certain problems like current in a strip are often dealt with by taking current components. I am having a difficult time understanding this.  After going through books and dealing with problems,i think that when current flows in a wire, of negligible dimensions, it is bound to flow along a line, so we treat it as scalar. But when we talk about current in a strip or in a volume, we can take components of current.Is it so?

Current has both magnitude and direction. As per the definition of vector , current should be a vector quantity. But, we know that current is a scalar quantity. What is the reason behind it?


I really need help in some theorems of real analysis. I don't even know where to start them. If someone know any of the following theorems, then please either give the proof or direct me to any good cites where I can find them because I couldn't find them anywhere. Theorem: Let A, B be subsets of R, let f: -> R be continuous on A, and let g: B -> R be continuous on B. If f(A) is a subset if B, then the composite function g o f: A -> R is continuous on A.  Theorem: Let $A\subseteq\mathbb{R}$, let $f:A\to\mathbb{R}$, and let $|f|$ be defined by $|f|(x) := |f(x)|$ for all $x\in A$.  If $f$ is continuous at a point $c\in A$, then $|f|$ is continuous at $c$. If $f$ is continuous on $A$, then $|f|$ is continuous on $A$.   and  Theorem: Let $A\subseteq\mathbb{R}$, let $f: A\to \mathbb{R}$, and let $f(x) \ge 0$ for all $x\in A$.  We let $\sqrt{f}$ be defined for $x\in A$ by $(\sqrt{f})(x) = \sqrt{f(x)}$.  If $f$ is continuous at a point $c\in A$, then $|f|$ is continuous at $c$. If $f$ is continuous on $A$, then $|f|$ is continuous on $A$.

Suppose $f$ and $g$ are functions such that $g$ is continuous at $a$, and $f$ is continuous at $g(a)$. Show the composition $f(g(x))$ is continuous at $a$.  My idea: Can I go straight from definition and take $\delta=\min\{\delta_1,\delta_2\}$, where $\delta_1$ is used for the continuity of $g$ at $a$ and $\delta_2$ is used for f being continuous at $g(a)$. In my proof I just treat $g(a)$ as a point when referring to the composition. So it goes like this:  Proof: Given $\epsilon>0$, take $\delta=\min\{\delta_1,\delta_2\}$. Then $0<|x-g(a)|<\delta$ which implies $|f(g(x))-f(g(a))|<\epsilon$.


I'm just about to optimize a website. Now I would like to know from where Google obtains these links:   Why? I also want some links to appear on the search-result for my homepage

My website used to have sitelinks and now it doesn't. It's very possible that it's due to changing the website to a sidebar design instead of having an "interstitial" type landing page which limited the number of choices, but I'm not sure.  Here is how sitelinks might look for a site:    What are some things that I can do to improve my chances of getting sitelinks?


Prove that every $m \times n$ matrix of rank $1$ has the form $A=XY^t$, where $X,Y$ are $m$- and $n$-dimensional column vectors. How uniquely determined are these vectors$?$  My attempt: I thought about using the dimension formula somehow. I know that nullity $+$ rank $=$ dim $A$. We know dim $A=mn$ but this got me nowhere. Then I tried doing an example. I took $$ A=\begin{pmatrix} 1 & 3 \\ 0 & 0 \end{pmatrix} $$  which has rank $1$. Then I can choose $$ X=\begin{pmatrix}1 \\ 0 \end{pmatrix}, Y=\begin{pmatrix} 1 \\ 3\end{pmatrix} $$ or I could choose $$ X=\begin{pmatrix} 1/2 \\ 0 \end{pmatrix}, Y=\begin{pmatrix}2 \\ 6 \end{pmatrix} $$ so that they are not uniquely determined. However, I can interchange the entries of $X$ and $Y$ to get ''different'' $X,Y$. But one the entries of $X$ (or $Y$ are chosen) then entries of $Y$ (or $X$) are then forcefully chosen. So I believe the final answer for that will be that they are not unique but choosing one vector determines both.  However, this method works for matrices $A$ with only one nonzero row and certainly many $A$'s have rank $1$ with many nonzero row. I know that $A$ has rank $1$ means I can use a series of elementary matrices to place it in the form I used above, but am unsure of how to use this since I'm not sure how to reconcile this with my ''choices'' for $X,Y$. Is there a way to do this or am I on the wrong track.  Note: I do not need nor want solutions but rather hints or thoughts on how I should proceed.

Let $A$ be an $n\times m$  matrix. Prove that $\operatorname{rank} (A) = 1$ if and only if there exist column vectors $v \in \mathbb{R}^n$ and $w \in \mathbb{R}^m$ such that $A=vw^t$.    Progress: I'm going back and forth between using the definitions of rank: $\operatorname{rank} (A) = \dim(\operatorname{col}(A)) = \dim(\operatorname{row}(A))$ or using the rank theorem that says $ \operatorname{rank}(A)+\operatorname{nullity}(A) = m$. So in the second case I have to prove that $\operatorname{nullity}(A)=m$-1


Hello guys the below given php code is mine i need to know it is vulnerable or not  $sql = "select Email,Password       from user where Email='$emailid'"; $ctr=0;              try     {        $result = $con->query($sql);        foreach($result as $row)        {                  $ctr++;      $pword = $row['Password'];      }    } catch(PDOException $e)   {       $errTyp = "danger";     $errMSG = "Something went  wrong, try again later...";   }  if($ctr == 0) { $errTyp = "danger"; $errMSG = "Invalid Username |  Password"; }  else {  if( $pword==$password ) {           $_SESSION['Id']=$emailid;    Here is my php login page code Just to confirm, how vulnerable is the above code to sql injection?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I had reset my css with a reset css (likely normal) but recently im using a wysiwyg plugint (textarea plugin) and everytime I insert an ul or ol list the disc or numbers dont appear, because the list-style:none; I have added a new div surrounding the textarea and making in the css file something like  .divsurrondig ul{list-type:disc; border:1px solid red;}   the red color appear everytime I insert a new list with the widget but no! bullet appear, do you know how can I reset the list style for show the bullets/numbers?

I've got a stylesheet that will not, for whatever reason, apply list-style-type to a UL element. I'm using YUI's Grid CSS with their reset-fonts-grid.css file, which I know strips that out as part of the CSS reset.  After calling YUI, I call the stylesheet for the website and in there have a block for UL:  ul {list-style-type: disc;}   I've also tried setting it via list-style but get the same result. I know that the above CSS block is getting read as if I add things like padding or margins those do get applied. The style-type isn't showing up in either Firefox or IE.  The only other CSS I've applied to UL's are in a #nav div but that CSS doesn't touch the list-style-type, it uses the reset that YUI provided, and YUI and the site style sheet are the only two CSS sheets that are called.  I've also got FCKEditor on the admin side of the site and that editor does show the bullet styles so I know it has to be something with the CSS that isn't being filtered by FCKEditor.


I'm trying to find $$\lim_{(x,y) \to (0,0)} \frac{x^2+y^2}{\sqrt{x^2+y^2+1}-1}$$  Book says answer is $2$, though nothing I tried gave me a $2$. I did $y=mx, y=0, x=0$, all ways learned in classes, but only find $0/0$ and $0$ as answers.

$$ \lim \limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 1} $$  According to my textbook the limit equals $2$.  What I have tried:  Using the squeeze theorem:  $$ \lim \limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1}} \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 1} \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 2} $$ $$ 0 \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 1} \le 0 $$  I have also tried to use the squeeze theorem with two other equations and obtained different values:  $$ \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2 - 1}{\sqrt{x^2 +y^2 + 1}} \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 1} \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2 + 1}{\sqrt{x^2 +y^2 + 1} - 2} $$ $$ -1 \le \lim\limits_{(x,y)\to (0,0)} \frac {x^2 + y^2}{\sqrt{x^2 +y^2 + 1} - 1} \le -1 $$


I have a string with len of 2 or 3 s1 = 22 s2 = 27 s3 = 102  I want to return a string with 3 chars. If orig string was len of 2 - add 0 at the begginig. So output will be: "022" , "027", "102".  Is there an elegant/one liner to do it in Python?

What is a Pythonic way to pad a numeric string with zeroes to the left, i.e. so the numeric string has a specific length?


In windows the OS know the type of file by using extension: exe,doc,ppt,pdf ....  etc    In Linux as we know that the extension is useless.   My question is how can Linux know the type of file it is dealing with: shell script, audio file,video file .... etc or is it dealing with all the files in the same way?

In windows we can associate a file's extension with programs. E.g. a file test.pl can be run by the installed Perl interpreter due to the pl extension. In linux though it needs #!/usr/bin/perl as the first line. Is this because there is no association between file extensions and programs in Linux?


"this is my string".myfunction(argument)   This is very simple in javascript. With the keyword this i can access to my string directly. Is that possible with python?

Ruby can add methods to the Number class and other core types to get effects like this:  1.should_equal(1)   But it seems like Python cannot do this. Is this true? And if so, why? Does it have something to do with the fact that type can't be modified?  Update: Rather than talking about different definitions of monkey patching, I would like to just focus on the example above. I have already concluded that it cannot be done as a few of you have answered. But I would like a more detailed explanation of why it cannot be done, and maybe what feature, if available in Python, would allow this.  To answer some of you: The reason I might want to do this is simply aesthetics/readability.    item.price.should_equal(19.99)   This reads more like English and clearly indicates which is the tested value and which is the expected value, as supposed to:  should_equal(item.price, 19.99)   This concept is what  and some other Ruby frameworks are based on.


Consider two sentences -  1) I didn't know that X is a Russian. 2) I didn't know that X was a Russian.  My question is, under the condition that X is still Russian, can sentence 1) be used ?  Thanks.

I know the past tense carries the past tense in every dependent clause, but referring specifically to places or to things that are eternal, like the Earth, seems a bit weird and therefore we sometimes (I believe incorrectly) say     He didn't know that New Jersey was actually on the East Coast.   Because it still is. Or     He thought the Earth was round.   So is it square now?  Logically speaking, would you consider the use of past tense here a bit confusing in a day-to-day speech in these examples? Would you instinctively opt for using the present tense?


Good day everyone! I am building a hotel booking application on android, my problem is when I select a date in the check-in editext via datepicker, the month in check out reservation shows the next month in the datepicker. How can I resolve this problem? Thank you. Here is my line of code for date picker.      etin = (EditText) findViewById(R.id.etcheckin);     etin.setInputType(InputType.TYPE_NULL);     etout = (EditText) findViewById(R.id.etcheckout);     etout.setInputType(InputType.TYPE_NULL);      etin.setOnClickListener( new View.OnClickListener() {          @Override         public void onClick(View view) {              showTruitonDatePickerDialog(view);         }     });      etout.setOnClickListener(new View.OnClickListener() {          @Override         public void onClick(View view) {              showToDatePickerDialog(view);         }     }); }  public void showTruitonDatePickerDialog(View v){     DialogFragment newFragment = new DatePickerFragment();     newFragment.show(getSupportFragmentManager(), "datePicker"); }  public void  showToDatePickerDialog(View v){     DialogFragment newFragment = new ToDatePickerFragment();     newFragment.show(getSupportFragmentManager(), "datePicker"); }  public static class  DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener{     public Dialog onCreateDialog(Bundle savedInstanceState){         final Calendar c = Calendar.getInstance();         int year = c.get(Calendar.YEAR);         int month = c.get(Calendar.MONTH);         int day = c.get(Calendar.DAY_OF_MONTH);          DatePickerDialog datePickerDialog = new DatePickerDialog(getActivity(), R.style.Theme_AppCompat_DayNight_Dialog_Alert, this, year, month, day);          datePickerDialog.getDatePicker().setMinDate(c.getTimeInMillis());         c.set(2018,11 ,31);         datePickerDialog.getDatePicker().setMaxDate(c.getTimeInMillis());         return datePickerDialog;     }      public void onDateSet(DatePicker view, int year, int month, int day) {         // Do something with the date chosen by the user          Calendar cal = Calendar.getInstance();         cal.setTimeInMillis(0);         cal.set(year, month, day, 0, 0, 0);         int mont = month + 1;         etin.setText(mont + "/" + day+ "/" + year);         // etin.setText((etin.getmonth + 1) + );     } }  public static class ToDatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {     // Calendar startDateCalendar=Calendar.getInstance();      @Override     public Dialog onCreateDialog(Bundle savedInstanceState) {         // Use the current date as the default date in the picker          String getfromdate = etin.getText().toString();         String getfrom[] = getfromdate.split("/");         int year,month,day;         year= Integer.parseInt(getfrom[2]);         month = Integer.parseInt(getfrom[0]);         day = Integer.parseInt(getfrom[1]);         final Calendar c = Calendar.getInstance();         c.set(year, month, day + 1);         DatePickerDialog datePickerDialog = new DatePickerDialog(getActivity(), R.style.Theme_AppCompat_DayNight_Dialog_Alert, this, year, month, day);         datePickerDialog.getDatePicker().setMinDate(c.getTimeInMillis());          c.set(2018,11, 31);         datePickerDialog.getDatePicker().setMaxDate(c.getTimeInMillis());         return datePickerDialog;     }     public void onDateSet(DatePicker view, int year, int month, int day) {          Calendar cal = Calendar.getInstance();         cal.setTimeInMillis(0);         cal.set(year, month, day, 0, 0, 0);           etout.setText(month + "/" + day + "/" + year);     } }

In java.util.Calendar, January is defined as month 0, not month 1. Is there any specific reason to that ?  I have seen many people getting confused about that...


With the new website, it seems impossible to find the svn builds. Where can they be obtained now?

I know that  provides downloads for official releases. I see on forums that people use newer versions of Blender. Where can I get newer version of Blender (nightly builds, alpha versions... etc).


After examining the 5e PHB on healing (pg 197) and perusing through various healing spells, I have found no reference to willingness as a required component for HP to be restored. The context for this question is a PC or NPC who, having been reduced to 0HP, wishes to die rather than be captured alive.  Can an unconscious player character or NPC reject healing from a potion? Please note that I am not referring to any form of resurrection, strictly to healing from potions.   Is there any core rule which states that the healee must 'opt in' to potion effects, or does RAW, by its silence on the matter, indicate that the unconscious PC/NPC in my case could be forced back to consciousness by the potion?

Imagine you have contracted lycanthropy, and you do not want to be cured. A cleric within touch range attempts to use Remove Curse on you. You are not a willing recipient of the interaction, and you perceive this as a spell-based threat:     A saving throw—also called a save—represents an attempt to resist a spell, a trap, a poison, a disease, or a similar threat.   Is there any form of resistance to this other than just not letting the dude get into touch range?


A black hole, neutron star or any object that has accumulated an accretion disc, sometimes features opposing jets, positioned perpendicular to the accretion disc.  I understand that these jets are produced by magnetic fields created by the enormous amount of electrically charged plasma located on the "equator" of the gravity source. Please correct me if I have this either plain wrong or under-simplified it.   My question is: where does the material,  either electron-ion jets or electron-positron jets, come from?   If it comes from the accretion disc itself, is it made up of particles that have a slight velocity vector component inwards, normal to the gravity source, which then get caught up in the central magnetic field and forced into the outrunning jet? Alternatively,  is it matter that is preexisting around the poles of the gravity source. Assumption 1 seems far more likely to me, but I would appreciate  any explanation.   EDIT: There are  duplicate type  questions listed below but 1. The answer to my question postulated the possible creation of material at the base of the disc, and 2. I wanted to know could the jets occur from existing material in the jet region? Neither of these points,  in my opinion, were dealt with in the previous questions.  END EDIT

How are they formed? And why are they so bright?


So, I want to jailbreak my iPhone, I know my options but lack the resources or knowledge.  Here's what I've got: Windows 10 64 bit PC, iPhone 6+ 128gb on iOS 12.4.6, MACOS High Sierra vbox machine.  First option: Use Checkra1n jailbreak on my vbox machine and directly solve the issue.  First Problem: I cannot connect my iPhone directly to the VM as it detects the device as a USB 3.0 and not an actual phone. I have the vbox extension pack installed, 'USB 3.0' USB controller and the iPhone filter applied but checkra1n will never detect the phone in order to apply the jailbreak.  Second option: Downgrade the iPhone to the jailbreakable, unsigned iOS 12.4 version using itunes and ipsw's and use the unc0ver app on the phone.  Second problem: 12.4 is unsigned. Can't downgrade as far as I know.  Third option: You tell me. Please.  What I'm asking is to let me know how to solve the problems listed above or supply a working alternative method to the circumstance  Thank you.

This is a canonical question   How do I jailbreak an iPhone or iPad (to install a package manager like Cydia or Sileo for tweaks) on:   iOS/iPadOS 13 iOS 12 iOS 11 iOS 10 iOS 9 iOS 8


Is there ANY difference in the following two ways of defining a functions?  METHOD 1)  var printName = function(name){     return("Hi! My name is ",name) }   VS  METHOD 2)  function printName(name){     return("Hi! My name is ",name) }   and I mean ANY, I'm new at JS and want to lay down my understanding of functions and Objects before I advance as I feel these 2 features are the 2 I'll use the most.

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


If electron (or other charged particle) is accelerated by gravity (a very weak force), it should emit electromagnetic radiation. Is there any experimental evidence that gravity does indeed cause such emissions?

A charged particle undergoing an acceleration radiates photons.  Let's consider a charge in a freely falling frame of reference.  In such a frame, the local gravitational field is necessarily zero, and the particle does not accelerate or experience any force. Thus, this charge is free in such a frame. But, a free charge does not emit any photons. There seems to be a paradox. Does a freely falling charge in a gravitational field radiate?


I'm trying to parse filters for a search command I'm coding. The user can search using one or more arguments. The values can have spaces (if so, must be wrapped around double quotes). Also, there are several "operators" I've declared, these are: = (for equals), := (for starts with), =: (for ends with) and * (for contains). For example:  name=John name:="John Doe" name*"ohn Do"  Must match: name=John, name*"John Doe", name*"ohn Do" I've tried using Regex (C#) but it won't match the string when it doesn't contain quotes. This is what I came up with so far: Regex.Matches(input, "(name(=|:=|=:|\\*)([^\"](\\S+)) | (name(=|:=|=:|\\*)\"([^\"]*)\"))", RegexOptions.IgnoreCase);  Which is basically match the word "name" followed by one of the operators followed by anything up to a space, or the same but up to the closing double quotes. But it doesn't match anything. In reality I'm replacing "name" with a few keywords inside a foreach, but for the sake of simplicity, let's just match the word "name". Anyway, any ideas what I might be doing wrong?

I would like to update a large number of C++ source files with an extra include directive before any existing #includes. For this sort of task, I normally use a small bash script with sed to re-write the file.   How do I get sed to replace just the first occurrence of a string in a file rather than replacing every occurrence?  If I use  sed s/#include/#include "newfile.h"\n#include/   it replaces all #includes.   Alternative suggestions to achieve the same thing are also welcome.


I don't understand what does the dollar sign do. Especially in this context:  for url in  $(cat   example.txt);   do  host    $url;

There are two syntaxes for command substitution: with dollar-parentheses and with backticks. Running top -p $(pidof init) and top -p `pidof init` gives the same output. Are these two ways of doing the same thing, or are there differences?


It is my turn and I have  on the battlefield and  in my hand. During the Beginning of Combat my opponent uses 's ability on my Bristling Hydra.  Can I then play  or activate the Hydra's ability to fizzle the Deadlock Trap? And does it matter which I use, or would either one work?

If I play an instant that grants target creature "indestructible," can an opponent use an instant in response to destroy said creature? Would the stack resolve their ability first? If so, would I be allowed to change target for indestructible? If not, do I still pay the mana cost?


There are three doors. Behind the doors, there are 2 goats and 1 car. But we don't know which thing is present behind which door. Our target is to get the car by guessing. Afterwards, we select a door (let the 1st door). Keeping the selected door closed, another door (let the 2nd door) is open which has a goat.Now, is it beneficial to change the selection so that we can get a car?  I have known about an answer where it is said that it is beneficial to change/switch the answer.It suggested to use probability saying that, the probability of the unselected door (3rd door) increases after opening the 2nd door.But the probability of the selected door (1st door) remains unchanged. But how does it happen?

I have recently learned of the Monty Hall problem, where given three doors, you choose one with a 1/3 probability of choosing the correct door, and then switching to the other door changing the probability of choosing the correct door to 1/2. I am confused because wouldn't staying at the same door have an equal probability at 1/2 because by staying at that door you are effectively choosing that door in the smaller sample space?  Thanks for the help!


I have had many teachers who have told me that zero is a natural number but then there is those teachers who say its not. why is that ?

Is there a consensus in the mathematical community, or some accepted authority, to determine whether zero should be classified as a natural number?  It seems as though formerly $0$ was considered in the set of natural numbers, but now it seems more common to see definitions saying that the natural numbers are precisely the positive integers.


\documentclass[12pt,titlepage]{article}  \usepackage{setspace}  % Single-spacing, double-spacing, e.g., \setstretch{1.0} \usepackage{ifthen} \usepackage{booktabs} \usepackage{array} \usepackage{multirow} \usepackage{tabularx} \usepackage[font=bf, labelsep=period]{caption} \usepackage{changepage} \usepackage{amsmath} \usepackage{graphicx} \usepackage{epstopdf} \usepackage{endnotes} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Document Dimensions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \setlength{\textwidth}{6.2in} \setlength{\textheight}{8.6in} \setlength{\topmargin}{-0.1in} \setlength{\oddsidemargin}{0in} \setlength{\parskip}{2mm} \newcommand{\otoprule}{\midrule[\heavyrulewidth]}  \setstretch{1.6}   \date{}  \begin{document}          \begin{titlepage}  \title{some title}  \author{blah\thanks{blah}, blah\thanks{blah}, blah\thanks{blah}, blah\thanks{\textbf{Corresponding author:} blah}, and blah\thanks{blah}}   \textbf{Keywords:} Performance Measure, Performance Manipulation, Return Smoothing  \textbf{JEL Classification:} C10, G10, G20  \maketitle   \end{titlepage}    \end{document}   The above produces the following:      However I want to have the text that says JEL classification and Keywords right ABOVE the author affiliations on the title page, but when I compile I keep getting them on separate pages. How can I make them appear on the same page?

I want my page to look something like this (using \documentclass{article}):     text       title       text   but I can't get it right, it puts my title on the next page leaving my first text paragraph on separate page. What should I do?