The regular logo is shown in the         But when going to a  it's cut off:        I use Chrome.

I can't see the complete 'en español' underneath the Spanish Stack Overflow logo on user profile pages. Nothing changes when I scroll, but when I go to the , the logo gets shifted up a bit and it looks fine. The same thing happens on the  site.  You can tell that the logo is the correct image but shifted downwards because the top of the 'in [language]' text is visible:    I'm on Vivaldi 2.0 for Windows 10 and on Chrome 69.0.3497.100 for Windows 10. It happens only when you don't have an account for that site, both when you're anonymous and when you have connected accounts on other sites.


Say if I have an array:   a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])  I want to create a new array which takes a and an increment, and creates a new array, for eg: If I want increments of 2, then my new array would look like: [1, 3, 5, 7, 9]  or if I want increments of 3, then: [1, 4, 7, 10]  Is there any functions in numpy or python in general which allows me to do this? Instead of having to create a for loop which iterates through and creates a new array?

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


If sequence$\frac{A}{B}\rightarrow \alpha\neq 0$, show if A is summable, B is summable.  I was trying to use contrapositive of the statement suppsoe A converges to L and B to M.$If M\neq 0 then \frac{A}{B}\rightarrow \frac{L}{M}$   But it didn't work out well since we do not know if B has a limit or not. How do I show B converges?

We had the following theorem in class:     Let $(a_n)$ and $(b_n)$ be sequences and $b_n>0$ and $\lim_{n\rightarrow\infty}\frac{a_n}{b_n}=L$ with $L\in\mathbb R\backslash\{0\}$. Then $\sum a_n$ converges if and only if $\sum b_n$ converges.   So by recapitulating the lecture I've tried to prove it but I didn't get it. It's obvious that you have to use the comparison test, but how? Can anybody help? Thanks a lot!


I'm currently trying to add an index to my .tex file but it never appears in my pdf document.  \documentclass[11pt]{book} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsthm} \usepackage{graphicx} \usepackage{dsfont} \usepackage[dutch]{babel}  \usepackage{cases} \usepackage{color}   \newtheorem{stell}{Stelling}[section] \newtheorem{gev}{Gevolg}[section] \newtheorem{lemm}{Lemma}[section] \theoremstyle{definition} \newtheorem{defn}{Definitie}[section] \newtheorem{vb}{Voorbeeld}[section]  \usepackage{hyperref} \hypersetup{     colorlinks,     citecolor=black,     filecolor=black,     linkcolor=black,     urlcolor=black }  \usepackage{makeidx} \makeindex  \usepackage{fancyhdr} \pagestyle{fancy} \fancyhf{} \fancyhead[L]{\nouppercase{\leftmark}} \fancyfoot[C]{\thepage}   \title{Book}  \begin{document} \maketitle \tableofcontents \chapter{First chapter} \section{First section}\index{first section}  \printindex \end{document}   Edit I had forgotten to add the `\printindex' in my message. But it was allready in my tex-file.

I have a document that has \usepackage{makeidx} and \makeindex in the preamble and \printindex inside the document body. An .idx file is created when I compile, no errors are signalled, still there is no index listing in the PDF document that is produced. There used to be one until all my files were deleted except the .tex file, after that I could not get the index to appear in my output. How can one troubleshoot this thing? I have changed all the "%bm" with "%tm" wherever I could find it in the build profiles (Tools -> Options -> Clean), as Thorsten Donig suggested on this website (in an answer to another posting regarding problems with the index creation). It did not solve my problem. I am using the TeXnicCenter editor on Windows XP, with the MiKTeX 2.9 distribution.


I recently learnt that pressure in a Fluid depends only on depth and not mass of a Fluid (in any orientation). In my textbook the pressure has been derived by considering an infinitesimally small cylinder with a small pressure pressure difference between the two faces. Equilibrium condition was then applied to the cylinder (Weight+Force due to liquid above=Force due to liquid below). This gives pressure as a function of depth.  Examples are also given in my book which show different orientations of the fluid in which  pressure is calculated at a point at the same depth from the free surface.  The example which confuses me is the Fluid in a skew cylinder. The free surface of the Fluid is at the same height as in the other examples and the pressure is calculated (At the bottom face) by using the vertical height from the bottom surface. But for the Fluid to be at the same vertical height some more Fluid should be added to the pipe (as volume changes) right ? (As compared to a right vertical cylinder having the same height).   If some more fluid is added the  the mass of the Fluid above the bottom face will change and so should the pressure.  So does pressure not depend on the mass and only depends on height ?

Fluid pressure is calculated as  $$\rho = hdg$$  where $\rho$ is fluid pressure, $h$ is depth from surface, $d$ is density of fluid and $g$ is acceleration of gravity.  It used to make sense to me for square or rectangle shaped containers since pressure means force per unit area.  $$Pressure = \frac{Force}{Area} = \frac{Fluid \space Weight}{Container's \space Bottom \space Area}$$  and  $$h \times d \times g= \frac{h\times m \times g}{v} = \frac{h\times m \times g}{h \times s} = \frac{m \times g}{s} = \frac{Fluid \space Weight}{Container's \space Bottom \space Area}$$  where $m$ is mass, $v$ is volume and $s$ is bottom area.  I thought that pressure being dependent on $h$ and not $m$ would be acceptable since $m$ is also dependent on $h$ since fluids can't go higher when they have spaces to their sides.  One big obvious mistake I made was to assume that all containers would be squares or rectangles. So, now I can't wrap my mind around the concept that pressures on tennis balls in the following image are equal.    Why are they equal when the weight (and mass) of fluid above them is obviously different?


It seems that the diffuse_color definition has changed in Blender at some point as older scripts in which it was defined by the struct with 3 parameters now it requires the struct with 4. Does anyone know what is the meaning of the fourth parameter?

I am attempting to create a plane and set the color; the following code throws an error at this line:    bpy.data.materials['RSgreen'].diffuse_color=(0,0,0)   the error is:  ValueError: bpy_struct: item.attr = val: sequences of dimension 0 should contain 4 items, not 3  which makes no sense to me; diffuse_color calls for 3 parameters in the .  bpy.ops.mesh.primitive_plane_add(size=4,enter_editmode=False,location=(-2,-2,0.01)) bpy.context.active_object.name='Plane2' bpy.ops.material.new() bpy.data.materials[1].name='RSgreen' bpy.data.materials['RSgreen'].diffuse_color=(0,0,0) bpy.context.object.data.materials.append(bpy.data.materials['RSgreen'])


I am searching for a long time tool that can runs as CLI on linux machine and identify which RAID configuration is defined on the disk or disks ( according to the list from lsblk )  the reason for that we cant showdown ( Production machines ) the linux machine and look on the RAID controler when OS id down   I am just cant understand why it is so difficult to capture the RAID conf when OS is up , must be somewhere tool that identify the RAID configuration

we want to verify if raid1 is configured on out linux machine  so we found the answer on -   but from the output -  how we can be sure that raid1 is configured?  and how to understand it from the command: dmesg | grep raid  when non raid , and when raid1 is configured ?


I'm specifically interested in estimating the growth of the coefficients $(a_n)_{n\in\mathbb{N}}$ of the Taylor series of $$\exp(1/(1-z))$$ centered in $0$: knowing that $\limsup_{n\rightarrow+\infty}|a_n|^{1/n}=1$, what I'm trying to figure out is whether the growth of $(a_n)_{n\in\mathbb{N}}$ is at most polynomial or super-polynomial... I tried to calculate explicitly the coefficients in order to find some regularity in the sequence of the coefficients, but I quickly got lost in the process.  Thanks in advance for any answer or suggestion.

Let $\sum u_n z^n$ denote the power series of $e^{1/(1-z)}$.  As our radius of convergence is $1$, it follows that $u_n$ exhibits sub-exponential growth.  On the other hand, $\{u_n\}$ must grow supra-polynomially, else transfer theorems like those found in  would then imply that the singularity at $z=1$ is regular.  Heuristically, it would appear that $$u_n \sim \alpha n^{-3/4} e^{2\sqrt{n}},$$ for some $\alpha \approx .162982$.  This opinion is echoed, without support, as a comment on the OEIS page for . Note: The sequence considered therein is the generating function of $e^{z/(1-z)}$, which has $\mathbb{Z}$ coefficients after scaling $u_n$ by $n!$  How would one derive asymptotic results such as these?  (Edited for spelling.)  Note: I've posted my own solution in the answers below.  In short, the saddle-point method applies.


I'm trying to solve a problem from my Group Theory course. It goes like this:  Being $S_n$ the symmetric group of order $n$. Find the number of index 2 subgroups of $S_n$.  I'm not pretty sure how to start. I guess it would have something to do with the normal subgroups of $S_n$, since any index two subgroup of a group $G$ is normal to $G$. But I don't know how to compute this number of subgroups, I just know that $|S_n|=n!$. Any help will be appreciated.

How to prove that the only subgroup of the symmetric group $S_n$ of order $n!/2$ is $A_n$?  Why isn't there other possibility?  Thanks :)


I have found some solutions but what I want to do is I want to become a root user "permanently". When I restart computer I still want to stay as a root user. I don't want to use termanial everytime to become a root user. Is there any idea?

I've often come across posts on forums or other websites where you see people joking in such a manner about running/logging in as root as if it's something awful and everyone ought to know about it. However, there isn't much that a search reveals on the matter.   It may be widely known to Linux experts, but I really don't know why. I remember always running as root when I first tried Linux years ago (Redhat and Mandrake) and don't remember running into any problems because of that.   There are actually some distros that have a bright red background with alert signs all over it as wallpaper for the root user (SuSe?). I still use the "Administrator" account for regular use on my Windows installation and haven't ever run into any problems there either.


I'm reading about sufficient statistics, and have come across two definitions which seems unrelated, and I'm trying to understand their connection.  The first definition is from      A statistic $t = T(X)$ is sufficient for underlying parameter $\theta$ precisely if the conditional probability distribution of the data $X$, given the statistic $t = T(X)$, does not depend on the parameter $\theta$   $$ \operatorname{Pr}(x \mid t, \theta) = \operatorname{Pr}(x \mid t) $$   Wikipedia also provides the following equivalent statements, which I assume is due to bayes theorem $$ \operatorname{Pr}(\theta \mid t, x) = \operatorname{Pr}(\theta \mid t) \\  \operatorname{Pr}(\theta, x \mid t) = \operatorname{Pr}(\theta \mid t)\operatorname{Pr}(x \mid t) $$  The other is an informal description of the theorem, also from      Roughly, given a set $\mathbf {X}$ of independent identically distributed data conditioned on an unknown parameter $\theta$, a sufficient statistic is a function $T(\mathbf{X})$ whose value contains all the information needed to compute any estimate of the parameter (e.g. a maximum likelihood estimate).   which I would understand as $\mathcal{I}(\theta \mid t,x) = \mathcal{I}(\theta \mid t)$ for some information measure, i.e. that the information of $\theta$ given $t$ is the same as if we were given $t$ and $x$, so $t$ is sufficient.  The page on  shows that the same Fisher information can be inferred from $X$ and $T(X)$, but Fisher information is not mentioned on the page on sufficient statistics. It is not clear if this is the only formal definition of information, or if this holds for other kinds of information.    As there is already a question on the intuition behind the equivalence of the statements, an answer to this question should contain the answer to:   How is information defined in this context? Is it Fisher information or something more general? How may one demonstrate using the definition of information and the definition of sufficient statistic, that the two statements are equivalent? (or not?)   A proof of equivalence should preferably be as rigorous as possible, but not incomprehensible.

I've just started studying statistics and I can't get an intuitive understanding of sufficiency. To be more precise I can't understand how to show that the following two paragraphs are equivalent:  Roughly, given a set X of independent identically distributed data conditioned on an unknown parameter θ, a sufficient statistic is a function T(X) whose value contains all the information needed to compute any estimate of the parameter. A statistic T(X) is sufficient for underlying parameter θ precisely if the conditional probability distribution of the data X, given the statistic T(X), does not depend on the parameter θ.  (I've taken the quotes from ) Though I understand the second statement, and I can use the factorization theorem to show if a given statistic is sufficient, I can't understand why a statistic with such a property has also the property that it "contains all the information needed to compute any estimate of the parameter". I am not looking for a formal proof, which would help anyway to refine my understanding, I'd like to get an intuitive explanation of why the two statements are equivalent. To recap, my questions are: why the two statements are equivalent? Could someone provide an intuitive explanation for their equivalence?


If we shake a electron back and forth I understand how it radiates electromagnetic wave. But I do not understand how a charge going in circular path or accelerating in a straight line radiates. Please answer it and do not mark it as duplicate. Does only electron in simple harmonic motion radiate?

Let's consider it case by case:  Case 1: Charged particle is at rest. It has an electric field around it. No problem. That is its property.  Case 2: Charged particle started moving (it's accelerating). We were told that it starts radiating EM radiation. Why? What happened to it? What made it do this?  Follow up question: Suppose a charged particle is placed in uniform electric field. It accelerates because of electric force it experiences. Then work done by the electric field should not be equal to change in its kinetic energy, right? It should be equal to change in K.E + energy it has radiated in the form of EM Waves. But then, why don't we take energy radiated into consideration when solving problems? (I'm tutoring grade 12 students. I never encountered a problem in which energy radiated is considered.)


I'm currently reading this document by the University of Texas in Austin about Predicate Logic, and got stuck on the following:   Note about nested quantifiers: For predicate P (x, y): ∀x∀yP (x, y) has the same meaning as ∀y∀xP (x, y). ∃x∃yP (x, y) has the same meaning as ∃y∃xP (x, y).  We can not interchange the position of ∀ and ∃ like this!  Example: U = set of married people. True or false? 1. ∀x∃y[x is married to y] 2. ∃y∀x[x is married to y]  I'm doubtful about the answer to this example. Also, some explanation about ordering of ∃ and ∀ operators would be appreciated.

I am reading nested quantifiers. I am confused in between two cases,   1. Existential Quantifier before Universal Quantifier  2. Universal Quantifier before Existential Quantifier   I would be very thankful if someone highlights the difference between them and also give an example.   Thanks in advance.


After the last figure of each chapter adds an extra line for me is bad. How I can fix?  Attached my configuration.  Thank you.  \documentclass[letterpaper,11pt,twoside,openright]{book}  \usepackage[english, spanish]{babel} % espanol \usepackage{inputenc} % acentos  sin codigo \usepackage[pdftex]{graphicx} %imagenes \DeclareGraphicsExtensions{.png,.jpg}  \usepackage{geometry} %  margenes para encuadernacion \geometry{bindingoffset=2cm} \geometry{textwidth=390pt}  \usepackage{color} % para el color de fondo y letras \definecolor{gris}{gray}{0.5} \usepackage[table]{xcolor}  \usepackage{verbatim} % para la letra tipo consola \setcounter{secnumdepth}{3} % para que ponga 1.1.1.1 en subsubsecciones \setcounter{tocdepth}{3} % para que ponga subsubsecciones en el indice  \usepackage[T1]{fontenc} \usepackage[scaled]{uarial} \renewcommand*\familydefault{\sfdefault} %% Only if the base font of the document  \pagestyle{headings} % establece el estilo como book \pretolerance=10000 % se usa para no separar palabras se-pa-ra-cion \tolerance=10000  \usepackage{longtable}  %longuitud de las tablas (tabla 4.1 muy ancha)  \usepackage{hyperref} \hypersetup{     colorlinks=true,%     citecolor=black,%     filecolor=black,%     linkcolor=black,%     urlcolor=black }  \usepackage{amsmath,amsthm} \RequirePackage{wboiboites} \definecolor{itcrtxtcolor}{RGB}{255,255,255} \newboxedtheorem[boxcolor=gray,                   background=gray!15,                   titlebackground=gray!5,                  titleboxcolor = black]                  {Ejemplo}{Ejemplo}{thm}  \addto\captionsspanish{% Sirve para cambiar las traducciones que vienen en LATEX \def\bibname{Referencias}% \def\tablename{Tabla}% }  \begin{document}  ...

I am using the book documentclass and have a list of figures. After  I noticed that there is a blank line to separate figures that are in different chapters, but not if they are within the same chapter. Since I changed the numbering of my figures to be {1, 2, 3, etc.} instead of {2.1, 2.2, 3.1, etc.} this looks silly and I'd rather have a blank line between each figure, no matter what.  How do I do that?  Similar:


I mostly used conventional sneakers for cycling  and never wore bicycle shoes in my life. At this moment of my life I decided to level up a bit. I've built myself a road bike and now I'm looking into proper footwear. It's a whole new world for me and I'm completely lost. My first impression is that there are several types of pedals, cleats and shoes and you have to choose the right ones in order to fit them all together.  I'd really appreciate a brief consultation on how to choose a proper footwear gear. Which pedals play good with which shoes and/or cleats and how to buy the right combination?  Thanks guys! You're the best!!

I am looking at buying a pedal/shoe system as the clips and straps I am using are hurting my feet again.  It's been a long time since I have bought a road pedal / shoe system, and I have forgotten the differences between SPDs, Look pedals and all the others.    Can someone give a short comparison of each pedal system with pros and cons of each? My usage is/will be mainly city street cycling and then road cycling (recreation, not racing).  I'd prefer if people would give the pros and cons of each and not their opinion on the "pedal system war".  :) However, "I use them because I find XYZ and it helps in ABC ways" is very useful.


Example sentence:  "As the concert ended, the atmosphere was all but ecstatic."  Replace words with synonyms:   all = everything but = except   The sentence would appear:  "...the atmosphere was everything except ecstatic."  Meaning, "the concert was not ecstatic". It was all feelings except ecstatic.  I regularly hear similar sentences used in the way where "all but" means the exact opposite of my interpretation. The last straw of "curiosity : need-to-know" ratio broke when I heard it used in Band of Brothers--which very clearly implied the use of "all but" as a similar meaning to "very".  There's undoubtedly a hole in my logic.  Edit:  Band of Brothers quote: "He was just one more casualty in a war that was supposed to be all but over."

Here's two ways I've seen the "all, but" idiom used:  "Close all tabs but this one" (Any modern application with a number of tabs might have this as an option.) It means "close all the tabs, but not this one".  "With that goal, the championship is all but decided". This seems to mean "you can say/do whatever (all) you want, (but) it won't change who wins the championship."  Is one of these usages more correct than the other?


I am working in an environment with strict bandwidth requirements, and we need predictable bit lengths of the stuff we send. We need to broadcast ECDSA public keys, and we are using OpenSSL to generate them.  So will the prublic key lengths vary from private key to private key? Or will they be constant?  I noticed there are many output formats, like DER, and one with base4 encoded public key wrapped in headers. I would like the shortest possible public key, possibly in bit format, with predictable length. What is the best way?

I am working in a very bandwidth restricted environment where I from time to time have the need to distribute public keys. The distribution happens in bit format, so there is no need for encoding, at best I would like all my data "raw".  It is my understanding that the public key, in compressed form, takes up the space of the curve size+1, e.g. 160 bit curve gives 161 bit public key. However, the output from OpenSSL gives me a much larger key size, e.g. 904 bits for the secp160r1 curve. I reckon there must be a lot of metadata involved.  Edit: I removed the "--- Public key starts here ---" etc and that almost cut the file in half ahem. But still there are 60 bytes/480 bits, a lot more than what I would think of as necessary.  Can I somehow reduce this size, getting rid of metadata? For example extract the key components of the signature and reassemble it in a compatible format on the receiver side? I assume DER encoding also adds overhead, but hardly this much?  Here arethe commands I use, in Cygwin:  $ openssl ecparam -out private.pem -name secp160k1 -genkey $ openssl ec -in private.pem -pubout -conv_form compressed -out public.pem


Consider these two sentences:   How many people came?  Quite few. How many people came?  Quite a few.   The first means few people came (less than expected), the second means many (more than expected).  Why the difference, and what exactly is the "a" referring to?

I have few friends.   I have a few friends.      I thought "few" means just one, two or even none. "A few" typically means more than two. However it seems to me some people say "few" when they really mean "a few", am I right?


I have several ESXi hosts that running vSphere version 6.0 standard licenses. Now, I have a plan to upgrade all of that to vSphere version 6.5. I'm not sure to upgrade to vSphere 6.5 for free. Can I upgrade to 6.5 for free?

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I take screenshots very often. I have a dedicated folder for screenshots, but I have to select it each time I take a snapshot with Ubuntu's default screenshots tool. How can I set the default folder to save them to?

Are there any sort of configuration options for specifying the default save location for gnome-screenshot, or is this hard-coded into the source code? It used to be ~/Desktop, which seems to have changed to ~/Pictures (in 12.04). The only possible solution I've seen is about  (as it includes time stamp information now instead of simply 'Screenshot#'), but that solution doesn't really seem ideal to me. Also,  post suggested that the last save location is remembered the next time you take a screenshot, but in my experience, this doesn't seem to be the case. And in any case, following on from that, that entry in gconf-editor doesn't even seem to accurately reflect the last location, so more than likely an entry related to an older version of gnome-screenshot. Table of contents:


I'm just about to download and install UBUNTU but I'm confused by the descriptive paragraphs for these versions; It says that the 12.04 LTS version has support to 2017 But that the latest version 13.04 is only supported for several months!!!!  Which should I download?

What are the differences between an Ubuntu Long Term Support release (LTS) and a normal release?


I know this subject brought out several time already, but the posts are old. Is there anything new in this area? Are there any APIs that can verify that?

If I want my app to behave differently on a jailbroken iPhone, how would I go about determining this?


What is the difference between . script.sh  ./script.sh  and source script.sh  ?

What's the difference between executing a script like this:  ./test.sh  and executing a script like this:  . test.sh?  I tried a simple, two-line script to see if I could find if there was a difference:  #!/bin/bash ls   But both . test.sh and ./test.sh returned the same information.


Lets get this out of the way, I did something stupid. Yes, stupid. Very stupid. I am well aware of how stupid this is. I am embarrassed and I regret doing it. Please help. I was installing a program, while also watching TV, and somehow managed to remove /usr/bin from path. NOOOOOO.  I'm using ubuntu 16.04. I added the new program bin to path by typing:  sudo nano ~/.bashrc   The new path was added, but then I tried to update using sudo and I got this error:  The command could not be located because '/usr/bin' is not included in the PATH environment variable.   However, the bin still exists:   Command 'sudo' is available in '/usr/bin/sudo'   nano in available, ls is available - its all available - but not in path. So, simply trying:  sudo nano ~/.bashrc   and trying to add /usr/bin to path is not an option. Without sudo I dont have permission to open  bashrc. I can cd into /usr/bin, but I cant ls anything, and I have no idea how to access sudo or nano once I'm in there. ./sudo, sudo.sh ./sudo.sh all returns "command not found".   How do I add /usr/bin to path in the event I remove it?  EDIT  I found the solution here:   I replaced the PATH with the path of the program I added to my path. So, typing this into a terminal gave me access to sudo and nano again:   export PATH=$PATH:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Whatever I try to run, I get the error:   The command could not be located because '/usr/bin' is not included in the PATH environment variable.   I had some modification in my .bashrc file but then removed the two additional lines afterwards. However somehow the PATH variable seems to have been destroyed.


I remember reading a long time ago a scifi short story about an official who has to go and close down the last zoo. The zoo was just a few pet animals and I think they had to be exterminated which precipitated the owners suicide. Any idea of title and author?

I'm hoping someone can help me as this is driving me nuts! Context and Chronological info I'm trying to find the title/author of a short story that I read in some or other anthology ages ago. I couldn't give you an exact date but I'd say it was probably 50s/60s. Plot The human population has increased to the point where input and output of resources on Earth is in exact equilibrium. As such, no other living matter can be permitted to exist, as its use of resources would throw this equilibrium out of balance. One man in a vast tower block has managed to hide some flowers, and, I think, one or a few small animals - perhaps a mouse. These are detected by the relevant authorities, and the story ends when an official arrives at the apartment and requires the man to destroy them - the last non-human living things on Earth.


For example   "Adam and Eve" is (almost) never said as "Eve and Adam". Making tea: "milk or sugar", but rarely "sugar or milk". Elevator: "up or down" is more common than "down or up".   Some groupings are equally common in both orders:   "coffee or tea" / "tea or coffee" "time and space" / "space and time"    Is there a word to describe this order?

Is there a word or phrase for two nouns or adjectives joined by a conjunction (usually "and") in a fixed sequence?        alive and well           fast and furious   hat and gloves   pen and pencil   law and order   wit and wisdom   salt and pepper   bacon and eggs   horse and carriage   Adam and Eve   ladies and gentlemen   loud and clear   heads or tails   yes or no   dead or alive


<?php  $dob = $_SESSION['dob']; $month = $_SESSION['month']; $s = $_POST['present']; $p = "1";  if ($stmt = $mysqli->prepare("UPDATE atten SET total = ? WHERE name = ?"))  {     // Bind the variables to the parameter as strings.      foreach ($s as $name)      {         $stmt->bind_param("ss", $p, $name);          // Execute the statement.         $stmt->execute();      }      // Close the prepared statement.     $stmt->close(); }   This is the error message I'm getting when I try to execute the above code:     Call to a member function prepare() on a non-object.   Any ideas why?

So I'm refactoring my code to implement more OOP.  I set up a class to hold page attributes.  class PageAtrributes  {   private $db_connection;   private $page_title;      public function __construct($db_connection)      {         $this->db_connection = $db_connection;         $this->page_title = '';     }      public function get_page_title()     {         return $this->page_title;     }      public function set_page_title($page_title)     {         $this->page_title = $page_title;     } }   Later on I call the set_page_title() function like so  function page_properties($objPortal) {         $objPage->set_page_title($myrow['title']); }   When I do I receive the error message:     Call to a member function set_page_title() on a non-object   So what am I missing?


I'm new to java and new to stackoverflow. Here is a code from my textbook:  public static void main(String[] args) {     Circle circle1 = new Circle(1);     Circle circle2 = new Circle(2);      swap1(circle1, circle2);     System.out.println("After swap1: circle1 = " +      circle1.radius + " circle2 = " + circle2.radius);      swap2(circle1, circle2);     System.out.println("After swap2: circle1 = " +      circle1.radius + " circle2 = " + circle2.radius); }   public static void swap1(Circle x, Circle y) {     Circle temp = x;     x = y;     y = temp; }  public static void swap2(Circle x, Circle y) {     double temp = x.radius;     x.radius = y.radius;     y.radius = temp; }   class Circle {     double radius;      Circle(double newRadius) {         radius = newRadius;     } }   The output reads as "After swap1: circle1 = 1.0 circle2 = 2.0" "After swap2: circle1 = 2.0 circle2 = 1.0" My question is how does this work? Why isn't the first print statement the same as the second? Are you not allowed to swap two different objects? Thanks in advance.

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


So I went to my biometric appointment and I have all my paperwork set up. I bought my shipping label on the VFS website and now I am trying to unlock it through the confirmation email. I type in the correct password and it denies me. I have called the UK, I have emailed VFS but they take 2 days to respond. Has anyone had this issue? What did you do?

I purchased the round-trip courier service through VFS Global. In the instructions, it states that you will receive in a separate email the shipping labels for this courier service. I receive Registration Details and Transaction Details only. No Shipping labels. I have called VFS Global in NY,NY and no human being access to ask questions, just an insane phone tree that does not answer my questions on how to get shipping labels that were never sent. I have called the British Consul in Atlanta and she could not answer my questions then transferred me to the same phone tree message that I receive through the British Consulate. I have sent emails to customercare@vfsglobal.com, info.vfsnewyork@vfsglobal.com, NYscanhub.escalate@vfsglobal.com, DLUKVInewyorksensitive@fco.gov.uk and I have received no response from anyone.  Frustrated. I do not know what to do. Please help me!!


Recently I received a email from London Journals Press.  Dear Dr. Po-Wei Huang, ... Taking note of your research interest that matches with our journal scope, I would like to welcome you to associate with us. To follow this, our Editorial Board has agreed to recognise you under "Quarterly Franklin Membership" (Membership ID#XC11296). ... Also I encourage you to have your upcoming research article/paper published in our international, peer-reviewed, refereed journal, London Journal of Engineering Research (LJER) and confirm your review slot before 15th of the coming month for the next issue. ...  At first, I ignored it. But after few days, he sent a follow up email like the following,  I’m writing this as a follow-up for my email which I sent few days ago. I think that you had a glimpse of our Franklin Membership email and our proposal for your membership ID #XC11296. I did not hear back from you since then. If you have any queries regarding the Quarterly Franklin Membership honored to you, I (or my support teammate) would be grateful to provide you with further information. I hope you don't find this outreach uncomfortable. I was simply wondering if you are still interested in joining our member community. I truly feel that someone like you who is involved in many great research works is ideal for connecting.  I find that London Journals Press is not on the list of . So , is there Any recommendation? or should I ask my advisor directly?

. While the reasons for his doing this are not yet public, this is a real loss of a valuable service. Does anyone know of similar services available to the general public?  Edit:  is definitely relevant, but that approach is more appropriate for finding top journals rather than identifying bottom ones. I.e., following that method would probably exclude lots of valid, lower-tier journals. Are there any approaches to easily identifying a predatory publisher?


This happened just a few days ago and I've been making do but it has really started to bother me.   When I click F12 on startup and select my Ubuntu it loads fine and I sign in but once I'm signed in for some reason I cannot see any toolbars, for instance the 'tray' with the time and battery left, etc nor can I see the slide bar on the right that has your favorites, nor can I resize any windows?   I can navigate through things using the terminal because I know how to but I can't even close windows, and they all stack up on the top left corner of the screen and since I cannot close or move these windows I am having a hard time.   Maybe I pressed some shortcut to like, lock my windows? or something any help would be great

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


You may have confused with the topic. So let me explain it.  In most of the computing languages , we have for and while loop. But in my example , I will declare the loop in c#.  When you decalre a for loop and while loop like this.  1.For loop   for(i=0;i<10;i++)    {      //do something    }   2.While loop   int i=0;  while(i<10)    {      //do something      i++;    }   From the 2 loops. When it comes to the complier , do they complie the same things?(except the int i that was declared outside the while loop.) If they don't , which one is better or more efficient?  Thanks in advance

for (i=0 ; i<=10; i++) {     ..     .. }  i=0; while(i<=10) {     ..     ..     i++; }   In for and while loop, which one is better, performance wise?


I am very interested in physics and I want to improve my basics especially in mechanics. I have only started high school (junior) so I don't know much about calculus, which is used in most of the books. I am only looking for a conceptual books explained basic concepts nicely.

What are some good books for learning the concepts of Kinematics, Newton laws, 2D Motion of Object etc.?


Here’s all I remember about this: it was a shorter book [150 pages max? Couldn’t have been more]—~20 years old at most? with kinda surreal illustrations. There was some sort of civilization of microscopic people [people??] that lived within this massive person. They might’ve been centered in the kidney/liver. One person has to go on a voyage to the eye, perhaps motivated by the illness go a family member [maybe mother?] and goes to various other body parts before reaching the eye including the nipple. One detail that struck out in particular was that, at the nipple, there’s a little hole through which these people can view the world outside this person they’re stuck in. The book ends with these people having reached the eye—now they can see the world outside of this large person they live in.

So the story is sort of post apocalyptic in that there is an entire city that for some reason is living in a (spaceship?) shaped like a horse.  The main character is a man with a wife and teenage son. The guy is weird. At one point he says,      call me (something) call me (something) but don’t call me late to   dinner!   I don’t remember why but for some reason this man believes there is a third eye of the horse and I think you can see outside from it. He goes on a mission to find the third eye.   This story is weird as heck but I can’t stop thinking about it and really want to read it again.


I want to have upright-shape subscripts while in math mode and that by default, i.e. I want to redefine the underscore _  I have found a solution for that here  but it will also overwrite _ when it is not used in math mode and cause problems, for example when including a figure that has an underscore in the name.

I've been using Hendrik Vogt's answer to my earlier question , in which he explained how to make the underscore character active and assign a macro to it so that it can be redefined to produce roman type in subscripts:  \catcode`_=\active \newcommand_[1]{\ensuremath{\sb{\mathrm{#1}}}}   The solution works like a charm in maths and text environments, however I've run into trouble when I use it in 'literal' environments, such as file names or references, where making _ active breaks things.  Question: How can I make the underscore produce roman subscript, yet still function as a normal character in file names, labels, references and the like? I only need the subscript function in maths environments.  MWE:  \documentclass{article}  \catcode`_=\active \newcommand_[1]{\ensuremath{\sb{\mathrm{#1}}}}  \begin{document} $D_H$ \label{sec_a} % This causes a "! Missing \endcsname inserted." error \end{document}


I have an Update statement which update several columns. Some of those columns are nvarchar(max) type and not always need to be updated.   I would like to avoid updating unnecessary columns, so, the simplest solution I come up is the following:   UPDATE table1 SET column1 = @col1, Column2= @col2, ... TextColumn = CASE SomeVar WHEN 0 THEN @NewVal ELSE TextColumn  WHERE idTable = @idTable   Does any one know if SQL is smart enough to avoid updating the TextColumn if it is going to be updated with itself?  The second option is just to split the Update as follows:      UPDATE table1 SET column1 = @col1, Column2= @col2 ...     WHERE idTable = @idTable     IF Condition      UPDATE TextColumn = @TextVal WHERE idTable = @idTable        I do not know if there is a better alternative, maybe it is possible to dynamically choose the columns in the update sentence.  I will appreciate any suggestion about this, my main target is improve the performance of the Update   This question is similar to . However, that question does not address the posibility of spliting the Update statement in two sentences in order to avoid unnecessary updates. Moreover, in this case the column to update is nvarchar which involves a large amount of text which brings other performance considerations.

If I have an UPDATE statement that does not actually change any data (because the data is already in the updated state). Is there any performance benefit in putting a check in the WHERE clause to prevent the update?  For example would there be any difference in execution speed between UPDATE 1 and UPDATE 2 in the following:  CREATE TABLE MyTable (ID int PRIMARY KEY, Value int); INSERT INTO MyTable (ID, Value) VALUES     (1, 1),     (2, 2),     (3, 3);  -- UPDATE 1 UPDATE MyTable SET     Value = 2 WHERE     ID = 2     AND Value <> 2; SELECT @@ROWCOUNT;  -- UPDATE 2 UPDATE MyTable SET     Value = 2 WHERE     ID = 2; SELECT @@ROWCOUNT;  DROP TABLE MyTable;   The reason I ask is that I need the row count to include the unchanged row so I know whether to do an insert if the ID does not exist. As such I used the UPDATE 2 form. If there is a performance benefit to using the UPDATE 1 form, is it possible to get the row count that I need somehow?


I forgot to close my laptop or lock the screen before I went to work the other day, and when I came home my laptop was stuck on a black screen. I should also mention I have a cat who loves to walk and sit on my keyboard and I feel like she was probably the cause of this(I left bash open). I can get to grub when I restart, but if I try to boot with Ubuntu I just get the black screen again. I can't access the login page. I also have Windows 8.1 installed and I can boot that with no problem.  Any help would be greatly appreciated :)  Edit: I think it may be an issue with my drivers for my graphics card. I have an AMD Radeon HD 8510G. I haven't been able to bypass the black screen to update my drivers though. There was another post about this but the instructions weren't working for me. I tried changing quiet splash to nomodeset and radeon.modeset=0 but I still get the black screen when I boot.

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


Why is abc undefined in first output, then printed out in the final console.log ? I would expect hello world hello...    var abc = 'hello';  function test() {   console.log(abc);    var abc = "world";   console.log(abc);  }  test(); console.log(abc);

What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?


I have read similar questions on various websites but haven't solved my issue. Thanks in advance for your help.   I installed Ubuntu on a Dell server with Windows 10 pre-installed as dual boot.  During booting, Windows 10 is not in the GRUB boot menu.  However, I can still boot into Windows by pressing F12 during booting to get into BIOS? then choosing Windows BootMgr.  $ sudo ls /boot/efi/EFI BOOT  ubuntu  $ sudo efibootmgr -v BootCurrent: 0001 Timeout: 1 seconds BootOrder: 0001,0000,0008,0009,000A,000C,000D,000E,000F Boot0000* Windows Boot Manager  HD(1,GPT,1a291e8a-bf72-4171-adb6-6244b30625ee,0x800,0x145000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...e................ Boot0001* ubuntu    HD(5,GPT,015d35bf-e5ff-4267-8fe3-d0b70583083f,0x7286c800,0x1ad000)/File(\EFI\ubuntu\shimx64.efi) Boot0008* Onboard NIC (IPV4)    PciRoot(0x0)/Pci(0x1c,0x3)/Pci(0x0,0x0)/MAC(e4b97af857c8,0)/IPv4(0.0.0.00.0.0.0,0,0)..BO Boot0009* Onboard NIC (IPV6)    PciRoot(0x0)/Pci(0x1c,0x3)/Pci(0x0,0x0)/MAC(e4b97af857c8,0)/IPv6([::]:<->[::]:,0,0)..BO Boot000A* Diskette Drive    BBS(Floppy,,0x0)..GO..NO[.......+.D.i.s.k.e.t.t.e. .D.r.i.v.e.........................rN.D+..,.\...........BO Boot000C* Hard Drive    BBS(CDROM,,0x0)..GO..NOS.......+.H.a.r.d. .D.r.i.v.e.........................rN.D+..,.\...........BO Boot000D* USB Storage Device    BBS(PCMCIA,,0x0)..GO..NOc.......+.U.S.B. .S.t.o.r.a.g.e. .D.e.v.i.c.e.........................rN.D+..,.\...........BO Boot000E* CD/DVD/CD-RW Drive    BBS(USB,,0x0)..GO..NO........o.C.D./.D.V.D./.C.D.-.R.W. .D.r.i.v.e....................A...........................>..Gd-.;.A..MQ..L.Z.K.J.P.E.3.1.J.2.5. .7. . . . . . . . ........BO Boot000F* NetWork   BBS(Network,,0x0)..GO..NO........g.N.e.t.W.o.r.k.........................rN.D+..,.\...........8..Gd-.;.A..MQ..L.K.i.l.l.e.r. .E.2.4.0.0. .B.o.o.t........BO   Under Linux, failed to find bootmgfw.efi with sudo find . -name "bootmgfw.efi"

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


as per Java Doc, The finalize method is never invoked more than once by a Java virtual machine for any given object.  i'm trying to call finalize on an object which is newly created and holds reference.   // Java program to demonstrate requesting  // JVM to run Garbage Collector public class Test {     public static void main(String[] args) throws InterruptedException,Throwable     {         Test t1 = new Test();         Test t2 = new Test();                 t1.finalize();                 t1.finalize();         // Nullifying the reference variable         t1 = null;          // requesting JVM for running Garbage Collector         System.gc();           // Nullifying the reference variable         t2 = null;          // requesting JVM for running Garbage Collector         Runtime.getRuntime().gc();      }      @Override     // finalize method is called on object once      // before garbage collecting it     protected void finalize() throws Throwable     {         System.out.println("Garbage collector called");         System.out.println("Object garbage collected : " + this);     }  }   output is : something like below :  Garbage collector called Object garbage collected : Test@232204a1 Garbage collector called Object garbage collected : Test@232204a1 Garbage collector called Object garbage collected : Test@232204a1 Garbage collector called Object garbage collected : Test@6fffd0ea   I can't understand the behaviour of GC how its working, and what is happening if i'm calling finalize() method.

If I call finalize() on an object from my program code, will the JVM still run the method again when the garbage collector processes this object?  This would be an approximate example:  MyObject m = new MyObject();  m.finalize();  m = null;  System.gc()   Would the explicit call to finalize() make the JVM's garbage collector not to run the finalize() method on object m?


This is my first time with Ubuntu (or any Linux distro for that matter).  I installed Ubuntu 14.04 alongside windows 7. The initial install went flawlessly without any errors. After the install, I was able to login with the user I created, and then it booted up to a blank purplish screen. The only thing showing is my cursor. Left or right clicking doesn't bring up any options. I left it for an hour thinking it is still installing. Still has the blank screen. I reloaded the DVD thinking I will get a 'repair' option, but only get 'Try Ubuntu' and 'install Ubuntu'. This is on a dell laptop. Can anyone please give me a detailed step by step fix? My first experience with Ubuntu isn't going too well.

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.


I am seeing this plot  a lot in machine learning literature. But how to read it? In general I know $\lambda$ is increasing from left to right, and we are getting larger coefficients. But  What are the x and y axis? and two scales of each axis?

I'm looking at this example for LASSO regression in R: .  It mentions "step size" and "best_step".  And, the documentation  also mentions this idea of a "step".    I have never heard of a step size being applied to LASSO regression.  Can someone please help me understand where this is coming from?


I have a problem regarding hanging indentation of second line in bibliography did not align with a first line. My MWE was adopted from Legrand orange book template. What I want is making the same alignment for bibliography.  I try using \setlength{\bibhang}{0pt} but didn't work. If I remove numbers from options, the alignment looks normal but I prefer to have author-year and number format as modern book bibliography style.      \documentclass[12pt,twoside]{book} \usepackage{tikz} \usepackage{geometry}  \geometry{ paper=a4paper, % Paper size, change to letterpaper for US letter size top=3cm, % Top margin bottom=2.8cm, % Bottom margin left=2.5cm, % Left margin right=2cm, % Right margin headheight=14pt, % Header height footskip=1.0cm, % Space from the bottom margin to the baseline of the footer headsep=10pt, % Space from the top margin to the baseline of the header %showframe, % Uncomment to show how the type block is set on the page } \makeatletter \renewcommand*{\@seccntformat}[1]{\csname  the#1\endcsname\hspace{1em}} %CHAPTER HEADINGS \newif\ifusechapterimage \usechapterimagetrue \newcommand{\thechapterimage}{}% \newcommand{\chapterimage}[1].  {\ifusechapterimage\renewcommand{\thechapterimage}{#1}\fi}% \newcommand{\autodot}{.} \def\@makechapterhead#1{% {\parindent \z@ \raggedright \normalfont \ifnum \c@secnumdepth >\m@ne \if@mainmatter \begin{tikzpicture}[remember picture,overlay] \node at (current page.north west) {\begin{tikzpicture}[remember picture,overlay] \node[anchor=north west,inner sep=0pt] at (0,0)  {\ifusechapterimage\includegraphics[width=\paperwidth].  {\thechapterimage}\fi}; \draw[anchor=west] (\Gm@lmargin,-8cm) node [line  width=2pt,rounded corners=15pt,draw=black,fill=white,fill  opacity=0.5,inner sep=20pt]{\strut\makebox[17cm]{}}; \draw[anchor=west] (\Gm@lmargin+.3cm,-8.1cm) node{\huge\sffamily\bfseries\color{black}\thechapter\autodot~#1\strut}; \end{tikzpicture}}; \end{tikzpicture} \else \begin{tikzpicture}[remember picture,overlay] \node at (current page.north west) {\begin{tikzpicture}[remember picture,overlay] \node[anchor=north west,inner sep=0pt] at (0,0)  {\ifusechapterimage\includegraphics[width=\paperwidth].  {\thechapterimage}\fi}; \draw[anchor=west] (\Gm@lmargin,-8cm) node [line  width=2pt,rounded corners=15pt,draw=ocre,fill=white,fill  opacity=0.5,inner sep=20pt]{\strut\makebox[17cm]{}}; \draw[anchor=west] (\Gm@lmargin+.3cm,-8.1cm) node  {\huge\sffamily\bfseries\color{black}#1\strut}; \end{tikzpicture}}; \end{tikzpicture} \fi\fi\par\vspace*{220\p@}}} %200 = space below the picture  \def\@makeschapterhead#1{% \begin{tikzpicture}[remember picture,overlay] \node at (current page.north west) {\begin{tikzpicture}[remember picture,overlay] \node[anchor=north west,inner sep=0pt] at (0,0)  {\ifusechapterimage\includegraphics[width=\paperwidth].  {\thechapterimage}\fi}; \draw[anchor=west] (\Gm@lmargin,-8cm) node [line  width=2pt,rounded corners=15pt,draw=ocre,fill=white,fill  opacity=0.5,inner sep=20pt]{\strut\makebox[17cm]{}}; \draw[anchor=west] (\Gm@lmargin+.3cm,-8.1cm) node  {\huge\sffamily\bfseries\color{black}#1\strut}; \end{tikzpicture}}; \end{tikzpicture} \par\vspace*{220\p@}} \makeatother \usepackage[numbers, sort&compress, comma]{natbib} \usepackage[sectionbib]{chapterbib} \usepackage{lipsum} \begin{document} \usechapterimagefalse \include{chap1} \end{document}   \chapter{Chapter 1} \section{Section 1} \lipsum[2] \nocite{*} \bibliographystyle{apalike} \setlength{\bibsep}{0pt} \setlength{\bibhang}{0cm} \linespread{1.0}\selectfont \bibliography{TestBib}

I prefer the apalike bibliography style with the number in brackets in front (see also  and ). However what I am curious about is how to align the first and subsequent text lines neatly next to the number in brackets.    Does anyone know how to do this?


I saw this formula $$\frac{p_n}{n} < \log n + \log \log n \quad\text{for } n \ge 6$$ on this Wikipedia site . I needed a proof so I checked the sources. I couldn't find a proof... If there is, please tell me on what page and I apologize deeply. If not - please send me a link to a proof.

In  I have found that the bounds for $n$-th prime is given by, $$n(\ln n+\ln \ln n)>p_n>n(\ln n+\ln \ln n-1)$$ for all $n\ge6$. Are there even stronger bounds for the $n$-th prime?   If possible (of course if the answer is affirmative) in the answer (or comment) please give the link of the paper in which it first appears.


Before asking any questions I'd like to say that I'm not an economist, investor, entrepreneur etc. I just want to know how the world works.  My first question is why would giant companies (Apple, Google, Samsung...) issue dividends?As far as I know only small and medium companies issue them (or at least should) to attract investors, but companies that don't need investments don't have a reason to waste their money.    Second question - why are Google's stocks so expensive and they don't even issue dividends (and they probably don't have a reason to)?

If a company can lower the dividends and even stop paying them at all during hard times, why would they re-install them at all?  If I understand correctly a company pays dividends so that investors that buy stock from that company have a bigger motivation to do it and then get more people to invest in the company. But once the stock is sold and no more stock is being issued, what does the company gain by paying dividends? It seems paying dividends would only raise the price of the stock, what does a company gain by raising it? Would it make more sense to lower it and buy that back?


I want to create spring coil. If I try to create it by manually extruding the edges it will probably look weird and deformed. Is there a way to create a spring coil procedurally so that it is even and symmetrical?

I need to model a simple spiral shape. I imagine the best way to do this is with curves, but I am unsure how to create a perfect spiral shape with curves. What's the best/easiest way to make a spiral tube?


I'm learning about regular expression, and they are divided into basic and extended.  Basic Regular Expression(BRE) uses meta-character [ ] ^ $ . *.  It's works on grep command well. But, when we use ls, echo or something else command, it works well, too.(For example, ls -al [abc]*.txt)  But, when I learn section about pathname expansion, it uses BRE's metacharcter.  So, I think they are same. Am I right?

I wrote a regular expression which works well in a certain program (grep, sed, awk, perl, python, ruby, ksh, bash, zsh, find, emacs, vi, vim, gedit, …). But when I use it in a different program (or on a different unix variant), it stops matching. Why?


Error on hibernate "not enough swap space for hibernate". swapon -s reports Filename              Type        Size     Used   Priority /dev/dm-1             partition  1003516    240388  -2  Can I increase the swap partition size using gparted ?

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


Denote by $F(X,Y)$ the set of all functions from $X$ to $Y$. For sets $A$, $B$, and $C$ prove that a. $F(C,A\times B)$ is in one-to-one correspondence with $F(C,A)\times F(C,B$).  Let's give this bijective function between $F(C,A\times B)$ and $F(C,A)\times F(C,B)$ a name, for example $M$. If you start out with a function $g$ which maps out every $c$ to some ordered pair $(a,b)$, then $M(g) = (x,y)$ where $(x,y)$ is an ordered pair of functions. $x(c)$ = $a$ and $y(c) = b$.  In other words, $M$ looks at the behavior of the input function $g$ for every $c$, and splits $g$'s behavior across two functions.  I cannot seem to prove that $M$ is a bijection. Could someone please lay out how I can start with this since we are dealing with a function that maps a function to an ordered pair of functions.  Also, how would you do: F(C , F(B , A)) is in one-to-one correspondence with F(B × C , A).  Because, C maps to a function.

I'm going through the book Proofs and fundamentals, by Bloch, and it doesn't include a solution manual for it's examples. It doesn't have many examples on notation and proof strategy for certain cases, so I needed a little help.    Although I understand the idea, and can draw it out, I'm not sure how to write it in decent proof notation. Any help would be appreciated!   Edit: apologies, my idea is this: theres some function in $F(C,A\times B)$ such that theres some $x$ within $C$ that means $g(x)$ is within $A\times B$. Similarly, the second two imply that for some function within $F(A,C)$ there exists a value $x$ such that $g(x)=C$. and similarly for the third part from $B\rightarrow C$. It's easy to see with drawing it out that these two are the same because one will have a part within A and the other will lead to a part within $B$, so their cross will be the same. I wanted to go about proving it by setting a function $f$ within $F(C,AxB)$ and then working from there, but I really have no idea where to start or the notation.


I am using Ubuntu 14.04. When I run sudo apt-get update, I get the following error:  W: Failed to fetch   Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file) E: Some index files failed to download. They have been ignored, or old ones used instead.  How do I correct this error?

I am using Google Chrome 48.0 32-bit. Today when I launched Google Chrome, I got this message:    This computer will soon stop receiving Google Chrome updates because this Linux system will no longer be supported   I thought Ubuntu 14.04 is supported for five years, what's exactly happening here?  And on 64-bit Ubuntu, I get an error from Update Manager and apt-get update:  Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)   Some index files failed to download.   They have been ignored, or old ones used instead.


I'm fairly new on PHP. I'm trying to sanitize my input before UPDATE it on myqsql. If my string is something with apostrophe, like  " I'm new on Php" it not works with this code $description = $_POST['description'];  $description = htmlspecialchars($description);  $description = mysqli_real_escape_string($description);  $description = trim(preg_replace('/\s+/', ' ', $description));  It didn't work: my field in table result empty If i use $description = $_POST['description'];  $description = htmlspecialchars($description);  $description =  str_replace("'","\'", $description);  $description = trim(preg_replace('/\s+/', ' ', $description));  It works. Why  $description = mysqli_real_escape_string($description) won't work ?

Is there a catchall function somewhere that works well for sanitizing user input for SQL injection and XSS attacks, while still allowing certain types of HTML tags?


I have a directory icontaining a large number of files. I want to delete all files except for file.txt in Solaris. How do I do this?   I tried doing -->  rm !(UsageRequest.csv)  But it didn't worked. Solaris is throwing error as "Unexpected Token - '('  ".

I have a directory containing a large number of files. I want to delete all files except for file.txt . How do I do this?  There are too many files to remove the unwanted ones individually and their names are too diverse to use * to remove them all except this one file.  Someone suggested using   rm !(file.txt)   But it doesn't work. It returns:  Badly placed ()'s    My OS is Scientific Linux 6.  Any ideas?


I've attempted to prove this proposition and would appreciate some critique. N.B: I've taken for granted that $g \circ f$ injective $\rightarrow f$ injective.  Specifically, for functions $f:A\rightarrow B$ and $g:B\rightarrow C$ show that ($g \circ f$ injective $\wedge $ $f$ onto) $\rightarrow g$ injective. I tried to prove the contrapositive statement $\neg$($g$ injective) $\rightarrow$ $\neg$($g \circ f$ injective $\wedge $ $f$ onto) $\leftrightarrow$ ($\neg g \circ f$ injective $\vee \neg f$ onto) $\leftrightarrow$ ($\neg g \circ f$ injective $\wedge $ $f$ onto) $\vee$ ($g \circ f$ injective $\wedge $ $\neg f$ onto).   We can have $\neg g$ injective with $g \circ f$ injective if $\neg f$ onto because then there may exist $b \in B$ s.t. $f(a) \neq b\forall a\in A$ so the case might be that there are no $a_1 \neq a_2 \in A$ s.t. $(g \circ f)(a_1) = (g \circ f)(a_2)\leftrightarrow (g \circ f)$ is injective. We can have $\neg g$ injective with $f$ onto if $\neg g \circ f$ injective because then there exists $b_1 \neq b_2 \in B$ s.t. $g(b_1) = g(b_2)$ with corresponding $a_1 \neq a_2 \in A$ s.t. $g(f(a_1)) = g(f(a_2)) \leftrightarrow \neg g \circ f$ injective. However, we cannot have $\neg g$ injective $\wedge$ $[g \circ f$ injective $\wedge f$ onto$]$ because, by the injectivity of $g$, there will exist $b_1 \neq b_2$ with corresponding $a_1 \neq a_2$, since $f$ is well-defined, s.t. $(g \circ f)(a_1) = (g \circ f)(a_2)$ rendering $g \circ f$ not injective.   Q.E.D.  A secondary question, which should perhaps be considered separately, is about how I've (correctly, I hope) manipulated the logical statement of the question. I've considered $\neg$(g injective) $\rightarrow$ $\neg$($g \circ f$ injective $\wedge $ $f$ onto) like an 'equation' with $\rightarrow$ acting like $=$. Then, intuitively, I thought I could separately operate on both sides with ($\wedge g \circ f$ injective) and ($\wedge f$ onto) to get the two separate statements $\neg g$ injective $\wedge g \circ f$ injective $\rightarrow \neg f$ onto and $\neg g$ injective $\wedge f$ onto $\rightarrow \neg g \circ f$ injective which I attempted to show in parts 1. and 2. above. Is this valid reasoning?

How can one show that if $g(f(x))$ is injective and $f$ is surjective then $g$ is injective?  Here is my attempt:  $g(f(x))$ is injective, so  $$g(f(a))=g(f(b)) \iff f(a)=f(b).$$  $f$ is surjective, so $f(x)=y$.  So $y=y'$ such that $f(b)=y'$.  So $g$ is injective.  Is my proof correct?


The other day one of my spellcasters conjured  so his team could sleep in peace:  A 10-foot-radius immobile dome of force springs into existence around and above you and remains stationary for the duration. The spell ends if you leave its area. Nine creatures of Medium size or smaller can fit inside the dome with you. The spell fails if its area includes a larger creature or more than nine creatures. Creatures and objects within the dome when you cast this spell can move through it freely. All other creatures and objects are barred from passing through it. Spells and other magical effects can't extend through the dome or be cast through it. The atmosphere inside the space is comfortable and dry, regardless of the weather outside. Until the spell ends, you can command the interior to become dimly lit or dark. The dome is opaque from the outside, of any color you choose, but it is transparent from the inside.  I had assassins waiting for them for an ambush. One of my assassins was a Druid who transformed into a Earth Elemental and earth glided underneath the tiny hut to get inside. My thought was that if the earth elemental burrowed underneath and reappeared inside the tiny hut it would break the hut because it's a Large elemental. Will this happen, or does it not count because it wasn't included during the casting time?

In a session today we were camped out in a Leomund's  and the DM determined that since it is described as a dome, the bad guys (Wraiths, so they are incorporeal) could enter the area from below. I went with it and it was a fun encounter, but I wondered what other people think about it. I can see two arguments.  His argument: It is described as a dome. So only the semi-spherical outside prevents things from happening. A dome doesn't (necessarily) have a floor, they can enter no problem.  My argument: The intent of the spell seems to be to prevent baddies from coming in. The rest of the wording simply talks about the "area", not a barrier.  Has anyone thought this through or seen a ruling anywhere?  Note: Given that I'm playing a 3-foot tall gnome, we decided that on subsequent castings I'd do two.  One is the normal one and the other is an inverted on with a "floor" about five feet in the air, that extends into the earth. The overlap allows for protection.


Will Google crawler find a page that is not linked to? I.e. pages accessible by manually modifying the URL, like http://www.example.com/node/1/[secret keyword]. Note that it is only secret in that there are no links to it; this "secret" path should't hold sensitive information.

We have a system hosting many websites for our customers, and inside that system there is a method that non-live customers can view their sites before we turn them on.  Say the link is something like this: ourbigcompany.com/customer/domain=thisisanewsiteurl  Those links are not linked to anywhere outside a secure login - they are only sent to the customer via email. They are publicly viewable, as they have to be, but that's not the real problem.  The real problem is that somehow Bing is getting hold of them and trying to crawl the sites.   I know how to stop the crawling, but that would be like treating the symptoms without fixing the problem.  We log the traffic and there is no referrer - so that is not helpful.  If I change the querystring value for a site, Bing has it within hours. I need to figure out where Bing is getting the links from so that I can close what is obviously a security hole, but I am not sure how.   Any ideas on how to figure that out?


How to prove for any complex numbers $a$, $b$, $c$, the inequality $$|a|+|b|+|c|+|a+b+c| \geq  |a+b|+|b+c|+|c+a|$$ is correct?


Is it necessary to hyphenate the words "hard-to-find" together when referring to things which have a property of being not readily located?  Example:     Adam locates hard-to-find items.

Some compound words are written without hyphens (nonaggression, nonbeliever), some with hyphens (well-intentioned), and others with spaces (post office).  Is there a rule or good guide as to which option should be used?


How do I delete LVM partitions and start installing ubuntu from scratch?

I want to reinstall Ubuntu, but I also want all information and settings to disappear. So everything looks like the first time I installed it. Is it possible to do so via Terminal? Or what are the steps I should follow?


I have a question about Androids onCreate method. I understand that the Activity is extended and that onCreate() is implemented as android developers guide states (Class Overview at ). But why do we use @Override? And also if i want to refer to that method what word should i use? Should i say that onCreate() is Overrided or that onCreate() is implemented ?    public class MainActivity extends Activity {      @Override      protected void onCreate(Bundle savedInstanceState) {             super.onCreate(savedInstanceState);             setContentView(R.layout.activity_main);      }

What are the best practices for using Java's @Override annotation and why?     It seems like it would be overkill to mark every single overridden method with the @Override annotation.   Are there certain programming situations that call for using the @Override and others that should never use the @Override?


In a sentence reading peri- and post-stimulus is the first hyphen necessary?    If not, what alternative structure should be used?

If multiple hyphenated terms share the same latter half, and I wish to list them without repeating that latter half, how should the hyphens be placed?  For example:     I will be investigating control issues in ground-based, water-based, and air-based robots.   If I do not want to repeat based, could I write:     I will be investigating control issues in ground-, water-, and air-based robots.   Is it correct to just leave a hyphen dangling after ground and water?  If not, how should it be written? I know the original sentence doesn't sound too bad, but I really just want to know the punctuation rule (or the convention in American English if there is no rule).


It is easily proved that prime gaps can be arbitrarily large by constructing the sequence of composites $(n+1)! + 2, (n+1)! + 3, \dots, (n+1)! + (n+1)$, which are divisible by $2, \dots, n+1$ respectively. It is also easily proved that prime gaps of size $n$ do not exist generally: if $n > 1$ is odd, $p_{i+1} - p_i$ is the difference of two odd numbers and is thus even, so $p_{i+1} - p_i \not = n$.   My question is if it is known, generally, whether for even $n \in \mathbb N$, there exists an $i$ such that $p_{i+1} - p_i = n$, and if so how it may be proved.

The nth prime gap is defined as $p_{n+1} - p_n $, [sequence A001223 in OEIX] (). What values can occur as a prime gap?  Clearly with the exception of $1 = 3 - 2$, all the prime gaps must be even. We also know that this sequence must contain infinitely large numbers, since there are no primes between $n!+2$ and $n! + n$.   Is it true that every even number occurs as a prime gap?


I have a string and I wrote following code to extract "NewUsers19" from that.    function getNoOfUsers() {    var noSpace = "UserRejectedOrderCount25NewUsers19FundedNewUsers14DepositAmount($)43165.23DepositCount75WithdrawAmount($)53510";   var regex = /(?:NewUsers)([0-9]+)/;   var value = regex.exec(noSpace);   return value;    }     The regex worked fine in online editors but I don't know why it does not work in Google App Script. Any help will be appreciated.

I want to match a portion of a string using a  and then access that parenthesized substring:  var myString = "something format_abc"; // I want "abc"  var arr = /(?:^|\s)format_(.*?)(?:\s|$)/.exec(myString);  console.log(arr);     // Prints: [" format_abc", "abc"] .. so far so good. console.log(arr[1]);  // Prints: undefined  (???) console.log(arr[0]);  // Prints: format_undefined (!!!)   What am I doing wrong?    I've discovered that there was nothing wrong with the regular expression code above: the actual string which I was testing against was this:  "date format_%A"   Reporting that "%A" is undefined seems a very strange behaviour, but it is not directly related to this question, so I've opened a new one, .    The issue was that console.log takes its parameters like a printf statement, and since the string I was logging ("%A") had a special value, it was trying to find the value of the next parameter.


Context: I'm trying to convince a friend to switch to using parameterized queries to prevent SQL injections and other malicious attempts as that is the standards these days but he has this mentality of "If it's not broken, don't fix it."  Here's the code he currently uses:  function sql_safe($text) {     return str_replace("'", "''", $text); }   Is there a way for me to break this function to illustrate to him that this approach is not advisable anymore? I've been trying but I can't break it myself so now I'm turning to you guys for help.  Additional Info  It's being used as a general means to protect the system from SQL injections so that user inputs are escaped properly. But I feel like his approach could break at certain scenarios which I haven't figured out yet.

I realize that parameterized SQL queries is the optimal way to sanitize user input when building queries that contain user input, but I'm wondering what is wrong with taking user input and escaping any single quotes and surrounding the whole string with single quotes. Here's the code:  sSanitizedInput = "'" & Replace(sInput, "'", "''") & "'"   Any single-quote the user enters is replaced with double single-quotes, which eliminates the users ability to end the string, so anything else they may type, such as semicolons, percent signs, etc., will all be part of the string and not actually executed as part of the command.    We are using Microsoft SQL Server 2000, for which I believe the single-quote is the only string delimiter and the only way to escape the string delimiter, so there is no way to execute anything the user types in.  I don't see any way to launch an SQL injection attack against this, but I realize that if this were as bulletproof as it seems to me someone else would have thought of it already and it would be common practice.    What's wrong with this code? Is there a way to get an SQL injection attack past this sanitization technique?  Sample user input that exploits this technique would be very helpful.    UPDATE:  I still don't know of any way to effectively launch a SQL injection attack against this code. A few people suggested that a backslash would escape one single-quote and leave the other to end the string so that the rest of the string would be executed as part of the SQL command, and I realize that this method would work to inject SQL into a MySQL database, but in SQL Server 2000 the only way (that I've been able to find) to escape a single-quote is with another single-quote; backslashes won't do it.  And unless there is a way to stop the escaping of the single-quote, none of the rest of the user input will be executed because it will all be taken as one contiguous string.  I understand that there are better ways to sanitize input, but I'm really more interested in learning why the method I provided above won't work. If anyone knows of any specific way to mount a SQL injection attack against this sanitization method I would love to see it.


I've got an app where users can place orders for recurring delivery of a particular service.  The orders table has columns service_id and state, where service_id links to the service the user has ordered and state can be active or inactive, reflecting whether the user currently wants to receive that service or not. Users can toggle orders on and off as they please.  When a user turns an order on or off (active/inactive) I need to track this, and I need to be able to query for whether an order was active or inactive on a given date.  My question is: What's the best way to to model something like this, specifically so that I can easily write a query like "all orders that were active on (date)"?  I've thought about making a orders_states table with order_id, state, and date, where each change create a row with the state that was set and the date it was set, but I'm not 100% sure about how I'd query it to get the past state on an arbitrary date, or if there's a better way to model this.  I'm testing / prototyping on this now, but I'm obviously not a SQL expert and would love some suggestions from the pros here. Thanks!  (I'm using Postgres 9.4.1.2 in case that matters, but I figure this is more of a generic SQL modeling question)


While hammering a nail (before it is in the wall) it is pretty evident that the tip of the nail is going to be applying a force directed along th axis of the nail, then why is it said that pressure is always non directional ?

I have a final exam tomorrow for fluid mechanics and I was just looking over the practice exam questions. They do not provide solutions. But pretty much I have to define pressure at a point and also say why pressure is scalar instead of a vector.  I am thinking pressure at a point is $P=\lim_{\delta A \to 0} \frac{\delta F}{\delta A}$. Please let me know if I am wrong.   But I do not know at all why pressure is a scalar instead of a vector. I know it has something to do with $d \mathbf{F}=-Pd \mathbf{A}$


I have an all titanium wire mesh underneath my eye due to a car accident. It is supposed to be MRI and X-Ray safe and I have traveled with it once before. I usually avoid informing security beforehand in order to avoid additional security checks and confusions.   Is there something I should be worried about health-wise at airports or at security checks wherein it would be a better decision to inform them beforehand rather than running into some medical issues?

I had an operation some time ago and now I have small screws in my shoulder which will not be removed anymore. When I decided to fly for vacation, I supposed that these will may bring me into trouble at the airport when going through the metal detector.  So I asked my doctor and at the hospital if there is any kind of "passport" or something similar which confirms the screws in my shoulder so that I do not get into many problems. Unfortunately, they told me such things do only exist if you get a new knee or something, not if you just have a few screws in your body.  When I flew from Vienna to Amsterdam and back, my fears were confirmed: The security staff inspected me very precise, and I had to explain them my story. Thank god I have some scars left so they believed me!  However this is not a permanent solution for the future. Is there any international "passport" which my doctor and hospital do not know about? If not, what else are my possibilities?  I am not that afraid when travelling within the EU, however I fear that this situation might get quite dangerous when I'm in other countries...


I have a dynamic form that I want to append some other html in, but when I want to use the event of my appended html I should include that script in that first script but also I want to add another html in the second script but I don't know how to deal with quotation tags:        $(document).ready(function(){     $("#registerNums").on('click',function(){       var inputnums = parseInt($("#inputnums").val());       alert(inputnums);       var outputnums = parseInt($("#outputnums").val());       alert(outputnums);       var rulenums = parseInt($("#rulenums").val());       for(var i=1; i < inputnums + 1; i++){         var inputmems =         '
'+           '
'+             '
'+               'Enter the number of your input'+ i +' membership functions:'+               '<input type="text" class="form-control" id="inputmems'+ i +'" name="inputmems'+ i +'" placeholder="Enter inputmems">'+             '
'+             '
'+               'Enter the name of your input'+ i +' membership functions:'+               '<input type="text" class="form-control" id="inputname'+ i +'" name="inputname'+ i +'" placeholder="Enter inputname">'+             '
'+             '
'+               'Enter the range of your input'+ i +' membership functions:'+               '<input type="text" class="form-control" id="inputrange'+ i +'" name="inputrange'+ i +'" placeholder="Enter inputrange">'+             '
'+             '
'+               '<input type="button" class="btn btn-primary" id="registerMems" value="register mems">'+               '

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I have a question similar to an existing one. I would comment, but my reputation is too low. How do I participate to that question? Should I answer, edit or start a new question that may be marked as duplicate?

I've been trying to break the 15 barrier for about 2 years now (much less the 50 barrrier!), and I want to try and answer this question:    But the question needs some clarification before I can answer it. How can I get this clarification if I can't post a comment? Or do I just have to sit this one out?


The way to resize via terminal on Ubuntu, is little complicate.  So, would like to learn which are these commands for resizing this directories (/usr & /root) and how to do it.

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


What exactly is  difference between them?   form2.Opacity = 0   and  form2.Visible = false

If so, does it effectively deprecate the visibility property?  (I realize that Internet Explorer does not yet support this CSS2 property.)


I am at a complete loss at this point. I have tried many ways to get this to work but I am still having trouble. I am building a simple script to add or delete movies to a mariaDB database. The adding a movie part is easy enough but I am having trouble on the deleting part. I can't figure out what I am doing wrong. elif choice == "2":     print("What movie do you want to remove?")     remove = input("Movie Title: ")     del_movie = "DELETE FROM movies WHERE title = '?'"     cur.execute(del_movie, remove)     conn.commit()     print(remove,"has been deleted!")     print(cur.rowcount, "record(s) deleted")  The command goes through and I don't get an error anymore, but when I query the database none of the rows have been deleted.

Using SQLite3 with Python 2.5, I'm trying to iterate through a list and pull the weight of an item from the database based on the item's name.  I tried using the "?" parameter substitution suggested to prevent SQL injections but it doesn't work. For example, when I use:  for item in self.inventory_names:     self.cursor.execute("SELECT weight FROM Equipment WHERE name = ?", item)     self.cursor.close()   I get the error:     sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 8 supplied.   I believe this is somehow caused by the initial creation of the database; the module I made that actually creates the DB does have 8 bindings.  cursor.execute("""CREATE TABLE Equipment      (id INTEGER PRIMARY KEY,      name TEXT,     price INTEGER,      weight REAL,      info TEXT,      ammo_cap INTEGER,      availability_west TEXT,     availability_east TEXT)""")   However, when I use the less-secure "%s" substitution for each item name, it works just fine. Like so:  for item in self.inventory_names:     self.cursor.execute("SELECT weight FROM Equipment WHERE name = '%s'" % item)     self.cursor.close()   I can't figure out why it thinks I have 8 bindins when I'm only calling one. How can I fix it?


I understand that if the same message is sent to 3 people with $e=3$ that even with different public keys, the message can be decoded using the Chinese Remainder Theorem. I have tried to figure out the steps to do so, but I am unable to actually lay it out even using small numbers. How would one decrypt a message $m$ = 10, for example with $n_1=6$, $n_2=35$, and $n_3=143$, with $e=3$?

I have three different 1024-bit public keys with common exponent $e$ but different moduli. A message $m$ is encrypted (without padding) using the three keys, which results in three different encrypted messages.  Given the three pairs of public keys $(N_i,e)$ and the encrypted messages $c_i=m^e\bmod N_i$ , how do I decipher the original message $m$ ?


I'm trying to install new files from Synaptic Package Manager however, after marking all the files and clicking on "Apply", I subsequently get this error message:  E: The method driver /usr/lib/apt/methods/https// could not be found.  E: Unable to lock the download directory   How do I fix this?

sudo apt-get update E: The method driver /usr/lib/apt/methods/https could not be found. michael@Ubuntu:~$ sudo apt-get clean michael@Ubuntu:~$ cd /var/lib/apt michael@Ubuntu:/var/lib/apt$ sudo mv lists lists.old michael@Ubuntu:/var/lib/apt$ sudo mkdir -p lists/partial michael@Ubuntu:/var/lib/apt$ sudo apt-get clean michael@Ubuntu:/var/lib/apt$ sudo apt-get update E: The method driver /usr/lib/apt/methods/https could not be found. E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? michael@Ubuntu:/var/lib/apt$ sudo apt-get update E: The method driver /usr/lib/apt/methods/https could not be found.   Why am I getting these errors when doing an apt-get update?


What will occur if one digs a hole in some moon/dead-planet without an atmosphere (and without a Lava Core), such that this hole shall have a 1 meter diameter and will be so deep that shall go through its core and appear on the other side of the moon?  Then one shall jump (or drop a ball) into that hole.  Will the object simply reach the other side of the planet/moon at speed of 0? Thus a harmonic motion from side to side of the planet?  Addition: Differences from :   This is vacuum (no atmosphere) I drop an object and do not jump inside the hole

...And you jumped in.  What would happen when you got to the middle of the Earth? Would you gradually slow down, until you got to the middle and once you were in middle would every direction feel like it was up?


Is mathematical practice:   an act of discovery of eternal objects and ideas independent of human existence; an intuition-free game in which symbols are manipulated according to a fixed sets of rules; or a product of constructions from primitive intuitive objects, most notably the integers?   I would like someone to explain what schools of thought are behind these definitions, what is relation between them, can all be equally valid, is there the most accurate definition among them, and all related questions...  I am just a laymen interested in philosophy.

What would it mean to say that mathematics was invented and how would this be different from saying mathematics was discovered?   Is this even a serious philosophical question or just a meaningless/tautological linguistic ambiguity?


import java.util.*; import java.lang.*; import java.io.*; class Main { public static void main (String[] args) throws java.lang.Exception { Scanner sc = new Scanner("(10,{10,9,6,5}),(12,{5,6})"); String s=sc.nextLine(); String[] strArray = s.split("[(,{})]"); for(int i=0;i <strArray.length; i++) {     System.out.println(strArray[i]); } int[] intArray = new int[strArray.length]; for(int i = 0; i < strArray.length; i++)  { if(strArray[i]!=" ") {     intArray[i] = Integer.parseInt(strArray[i]); } } System.out.println(strArray.length); } }   /*Output:    Runtime error ......  10  10 9 6 5  12  5 6    When printing on different lines there is blank spaces in between.  When printing on same line output:10109651256.  length of splitted array is 14.  What are these spaces blanks or NULL?  Why aren't they printing on the same line?//

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I wanted to replace a string : 'li\\oa' by 'ext' but I get this error     error: octal escape value \505 outside of range 0-0o377   I know that the problem is: string containing these chracters '\\', so the question is : How can i read these backslashes as a string.   df['col']= df['col'].replace(['li\\oa'],['ext'], regex=True)

I have a string that contains both double-quotes and backslashes that I want to set to a variable in Python. However, whenever I try to set it, the quotes or slashes are either removed or escaped. Here's an example:  >>> foo = 'baz "\"' >>> foo 'baz ""'   So instead of baz "\" like I want I'm getting baz "". If I then try to escape the backslash, it doesn't help either:  >>> foo = 'baz "\\"' >>> foo 'baz "\\"'   Which now matches what I put in but wasn't what I originally wanted. How do you get around this problem?


The problem is to find the number of irreducible quadratics in $\Bbb Z_p[x]$, where $p$ is a prime number.  To solve this, I wish to find first the number of reducible quadratics of the form $x^2+ax+b$, then the number of reducible quadratics, and subtract this from the total number of quadtratics.  I know that each reducible quadratic that is of the form $x^2 +ax+b$ is a product $(x+c)(x+d)$ for $c,d\in \Bbb Z_p$.  So, I don't know what to do next. Please help me solve this problem.  Thanks for the help!

Can some of you help me with my homework?     I had to count the irreducible, quadratic, monic polynomials in $\mathbb{F}_p[X]$ for arbitrary $p$.    I will show you what I tried myself.  Research effort  First of all the set $\{X^ 2 + bX +c : b, c \in \mathbb{F}_p \}$ contains $p^2$ elemenst. We need to substract the amount of elements that is reducible. These elements are exactly the set $A = \{(X+c)(X+d) : c, d \in \mathbb{F}_p \}$. There are $p(p-1)$ pairs of $(a,b) \in \mathbb{F}_p \times \mathbb{F}_p$ such that $a \neq b$, and there are $p$ pairs such that $a=b$.     When $a$ and $b$ are unequal, whe know that $a$ and $b$ can be swapped without changing anything to the polynomial $(X+a)(X+b)$, so I obtained that $|A| \leq p +(p-1)- \frac{1}{2}(p-1)=p-\frac{1}{2}(p-1)$.  In other to find out these are the elements, or that there are still less, I thought I had to assume that $(X+c)(X+d) = (X+\gamma)(X+\delta)$, to deduce some information about the realation between $(c,d)$ and $(\gamma, \delta)$, but this led to taking square roots in $\mathbb{F}_p$, and I am not familiar with that.  Could you please provide me some more information?


I worked a file to be printed on a 4 x 10 feet banner. I set up the file size to 48 inches x 120 inches, at 300PPI.  My file was really large (7g), and it was smooth, no apparent pixel when zoomed to print size. Although, when I received the banner, it was ugly and we can see all pixels and the printer said we were bad graphic designers. Can somebody explain if I really did something wrong?   I don't think it should have been printed with a that bad resolution looks.

For wall-sized graphics and large banners (e.g. 3m × 5m), what is an acceptable PPI for print? As I understand it 300 ppi is the typical for 'small' artworks (esp. for clean text resolution). However, for small artworks, the audience usually engages at a much closer distance. Therefore, in the interests of keeping a bitmap file down to a reasonable size, can you get away with a much-reduced PPI for a large format/banner print?


I have accrued better than top 5% in one site. Here on the site that discusses mechanics and operation of that site and others, I don't have the simple option to downvote a post because the "association bonus" rep is below that threshold.  A specific example is the MIT license changeover. It overwhelmingly affects Stack Overflow where I have plenty of rep points, yet the thread was moved to this site where I do not have enough to record a downvote.   I get that it should probably not work in the opposite direction. But I think that there should be some allowances granted in permission specifically for this and other meta sites so they take into account a member's standing on the site that is the target of discussion.  EDIT: I did search for this for a few minutes and didn't find the linked question, so I'll take that as a whoops on me.

I'm a member of the community (StackOverflow).  This community is here to discuss that community.  Why, even though I'm a 10k+ user on the real community, am I treated like a second-class citizen here?  It seems kind of cliquey.  I want to volunteer my time to StackOverflow, but not usually through meta discussions.  But when something hinders my ability to work on SO, I want to be able to discuss it here without being stifled.  I also understand that this community has unique considerations from a moderation standpoint.  An SO moderator might not make a good meta.SO moderator.  I suggest we draw a line between permissions that facilitate participation and those that facilitate moderation.  Here are the ones I think primarily facilitate participation:   Leave comments Vote up Flag offensive Edit community wiki posts Vote down Show total up and down vote counts (because it allows you to guage the actual popularity of an opinion).   Allowing anybody to leave comments was a great first step.  My proposal is that the above permissions would either be granted to all people who have the equivalent permission on SO (or even another sister site?) or to all people (i.e. no rep requirement).  Incidentally, since votes in SO often are used to guage the popularity of a suggestion, I don't think there should be penalties for downvoting but that's another, related topic.  It just makes no sense to me that you can have people that have full participation rights on meta.SO even though they have never really participated on SO, meanwhile I'm a very active member on SO and am hindered from talking about it here.  It's like having a town hall meeting but only inviting the people who hang around town hall.    To sum up some of the comments, in reality much of what I'm talking about you already get from account association so I'd be totally satisfied if we lowered the vote down and vote split rep requirements to 100.


What is the simple way to find the file extension in php, if the filename is filename.jpg.txt?

This is a question you can read everywhere on the web with various answers:  $ext = end(explode('.', $filename)); $ext = substr(strrchr($filename, '.'), 1); $ext = substr($filename, strrpos($filename, '.') + 1); $ext = preg_replace('/^.*\.([^.]+)$/D', '$1', $filename);  $exts = split("[/\\.]", $filename); $n    = count($exts)-1; $ext  = $exts[$n];   etc.  However, there is always "the best way" and it should be on Stack Overflow.


Hello fellow Ubuntu users, I'm in a bit of a situation here where I cannot make the Kernel's built-in penguin logo display on top of the boot messages. I don't understand why because I compiled and installed a customized kernel with that specific option enabled and I can confirm it in uname -r. I saw something about framebuffers on what is seemingly the only other forum post on earth about this, from 2011. I couldn't really make sense of the link that the guy posted because it redirected to an Arch Linux wiki page with instructions that do not work for me (big surprise Arch isn't Debian wow).  Example: pic    Thank you in advance.  Edit: I run Ubuntu MATE 20.04 LTS, I have Plymouth disabled and want to use the feature built into the Kernel.  Edit 2: Yes I have the correct settings on in the config and I have seen that post. In fact, it's the one I'm referencing to not have helped me all that much. I'll check Gentoo wiki. Here's my config:  CONFIG_LOGO=y # CONFIG_LOGO_LINUX_MONO is not set # CONFIG_LOGO_LINUX_VGA16 is not set CONFIG_LOGO_LINUX_CLUT224=y   I obviously chose the 224-color one.

On Knoppix-based distros, you get a nice Tux logo on the left of the screen during text boot. Is this possible to get on Ubuntu?


I have a home server running ubuntu 10.04 that is running two services:   an SSH service a dockerized gogs service   I would like to essentially reverse-proxy incoming SSH connections based on the subdomain.  For instance, I'd like for ssh connections made via ssh user@mydomain.com to be forwarded to port 2222 and those made via ssh user@gogs.mydomain.com to be forwarded to port 10022.  In essence, I'd like something analogous to nginx for SSH traffic.  How can this be achieved?

I've grown quite fond of HTTP reverse proxies in our development environment and found the DNS based virtual host reverse proxy quite useful. Having only one port (and the standard one) open on the firewall makes it much easier for management.  I'd like to find something similar to do SSH connections but haven't had much luck. I'd prefer not to simply use SSH tunneling since that requires opening port ranges other than the standard. Is there anything out there that can do this?  Could HAProxy do this?


I am new to Drupal. I have been trying to make a slide show on the front page but I am facing an issue on how to upload images of my choice in the slide show. I.e. the images that I have in my computers folder.  I have created a view and placed an image field in it, everything is set. I have also added the block to the main page content. All I can see on the front page is the slider title obviously since i have not been able to add any images.   Can any body tell me how to set my own images to the slider?  I don't want to use fixer slider.  I have used views slide show and some other js files for cycle.  Edit: Here is a screenprint of the view I defiined so far:


What is the name for an endomorphism $f$ of a category such that $f\circ f=1$?  Note that I work with category $\mathbf{Set}$.

I can think of several examples of functions such that twice application of the function is equivalent to no application of it.   Additive inverse Multiplicative inverse Fourier transform Complex conjugation Any group built up from $\mathbb{Z}_2$, applying (one of) the $\mathbb{Z}_2$ parts' operation.   "Idempotent" came to mind, but that's wrong. It means $f(f(x)) = f(x)$, not $f(f(x))=x$.  What is the word for this "flip-flop" property?