Ok, I answered  for a user some 10 minutes back and it helped him so he thanked me and upvoted my answer. I politely asked him to mark it as an answer also. Is that rep-whoring ? Also, he thanked me a couple of times and i know that SO states that we should refrain from making unnecessary comment but in this case i felt obliged to respond.

I've had a couple of answers today where the OP indicated via a comment that I solved their problem, but the question wasn't upvoted or accepted.  In both cases the person probably wasn't able to upvote since they were new, but they could have accepted my answer. I felt a little guilty asking them to accept the answer, but since it solved their problem I felt that it would help others who stumbled on the question trying to solve their own problem to know that my solution really was the answer. Is asking the OP to accept your answer when they've said that it solved their problem a reasonable thing to do or does that feel like nagging for reputation?


In  I learned about this URL  which provides the full reputation history on Stack Overflow.  Is there an equivalent URL for specific sites in the Stack Exchange family? If there is not such an equivalent URL, what is the simplest way I can obtain this information for myself, given that I have less than <10k reputation events? In particular, I would like to obtain a precise histogram of my reputation per day on a specific site.

If I am concerned that my reputation score is incorrect, how can I audit it, or get a report of a detailed breakdown of my reputation?


by using netstat -n -o -a i see that process id 4 listening to that port.  TCP    0.0.0.0:3000           0.0.0.0:0              LISTENING       4  By using task manager i found that process id 4 is NT Kernel & System     hence  Since i need that port for other service, i am wondering, why the kernel needs to hold that port?   can i release it?   how can i find the specific feature that use that port?

How to know who is listening to port 80 on Windows?  Don't suggest to use   netstat -aon | findstr :80   because it is reporting PID of NT Kernel & System which is useless information.  I need to know exact name of component in order to control it.


I have just encountered this exercise which has me stumped:     We are asked to prove that if $ f $ is holomorphic on the unit disk $ D $ and if $ f(z) \neq 0 $ on $ D $, that there is a holomorphic function $ g(z) $ on $ D $ such that $ f(z) = e^{g(z)} $. We are also asked to show that if $ D $ is replaced by an arbitrary connected open set, the result may not hold.   In fact, I have no idea where to start. Should I take a complex logarithm and show that it works, is there a straightforward solution here? I see that $ f(z) \neq 0 $ makes a lot of sense as an exponent can never be zero, but other than that I cannot show such a function exists and I also don't see why the unit disk is special as a domain. Any help would be appreciated.

We want to prove the following:     If $f$ is a holomorphic function on the unit disc $\mathbb{D}$ s.t. $f(z) \neq 0$ for $z \in \mathbb{D}$, then there is a holomorphic function $g$ on $\mathbb{D}$ such that $f(z)=e^{g(z)}$ for all $z \in \mathbb{D}$.   For such a $g$, we have that $\frac{f'(z)}{f(z)}=g'(z)$ on $\mathbb{D}$ since $f$ has non-zero derivative.   Perhaps then we define $g(z)=\int_\gamma \frac{f'(z)}{f(z)}dz$ where $\gamma$ is a path in $\mathbb{D}$ from $0$ to $z$.  Does this work?


I've had strange output on answer submit :)  The message was :     Oh tin of pink meat / I ponder what you may be / Snout or ear or feet?   Screenshot:        Funny :)  Why?

When for the first time A new question I answer This haiku appears:     Little slab of meat   In a wash of clear jelly   Now I heat the pan   Such a message is Very strange; is anyone Seeing the same thing?  Have not seen again. Came and went like the wind does! Why I am so blessed?


I encountered large performance differences for spatial intersections in PostGIS depending on the operator I'm using and I can't figure out what's causing them.  Background:  I have a large set of points and I'm usually selecting a subset of them based on a polygon outline. Something like st_intersects (polygon, points) works for this, but there is also the && operator. Looking at the  and  documentation, they seem to do, at least in the case of points and polygons, the same thing. I would even have imagined && to be a bit slower, since it constructs bounding boxes around the geometries to compare.  However, when optimizing my query, I used EXPlAIN to estimate the costs of different approaches and discovered that && tends to be much cheaper (factor ~10). Can someone please explain to me what I'm missing here?  I made two small examples in PostGIS 2.5.0 to try it out. Note that they only differ in the one line where the comparison takes place. The rest is just random point generation.   EXPLAIN  WITH x AS     (select generate_series (1,1000),      st_setSRID(st_makepoint(         (random()*360)::float - 180,         (random()*180)::float - 90),      4326) geom)  SELECT * FROM x WHERE st_intersects (geom, st_setSRID(st_geometryfromtext('POLYGON((-74.1 83.8, -13.0 83.8, -13.0 59.6, -74.1 59.6, -74.1 83.8))'), 4326));      CTE Scan on x  (cost=5.04..277.54 rows=67 width=36)   EXPLAIN  WITH x AS     (select generate_series (1,1000),      st_setSRID(st_makepoint(         (random()*360)::float - 180,         (random()*180)::float - 90),      4326) geom)  SELECT * FROM x WHERE (geom && st_setSRID(st_geometryfromtext('POLYGON((-74.1 83.8, -13.0 83.8, -13.0 59.6, -74.1 59.6, -74.1 83.8))'), 4326));      CTE Scan on x  (cost=5.04..27.54 rows=200 width=36)

CartoDb Recommend  that the following query is faster than an St_intersects Query  SELECT * FROM {table_name} WHERE the_geom && ST_SetSRID(ST_MakeBox2D(ST_Point(-73.9980, 40.726), ST_Point(-73.995, 40.723)), 4326)   I have the following Query that works just fine and returns GeoJson as needed,   WITH c AS (SELECT -73.976440429688, 40.743095232182, -73.970947265625, 40.738933241136, 4326 As srid)  , bbox AS (SELECT ST_Transform ( ST_MakeEnvelope( -73.976440429688, 40.743095232182 ,-73.970947265625 , 40.738933241136 , 4326) , 900913 ) As geom FROM c ) SELECT row_to_json(fc)     FROM ( SELECT 'FeatureCollection' As type, array_to_json(array_agg(f)) As features     FROM (SELECT 'Feature' As type, osm_id As id,         ( SELECT row_to_json(t)           FROM (SELECT osm_id, "name" ) t )As properties,          ST_AsGeoJSON(ST_Transform (lg.way ,4326 ) )::json As geometry      FROM planet_osm_polygon As lg, bbox         WHERE ( building is NOT NULL) AND ST_Intersects(lg.way, bbox.geom)             ) As f ) fc;                   I have been trying to create the same JSon result using ST_MakeBox2D in a similar fasion to the CartoDb example and failing miserably.  My objective is to have the fastest possible query for any geometry that any part of itself WITHIN the bounding box.  My Questions are:   Which method will return the fastest possible result, assuming that the Columns in the WHERE clause are indexed properly? How do I change my query to use St_makeBox2D with the geom && syntax as per the CartoDb Example?


I feel that there is a little inconsistency between the canonical momentum of a  classical charged particle in an electromagnetic field and the momentum operator associated to the equivalent quantum system.  Explicitly, let $\vec{A}$, $\varphi$ be potentials for electric and magnetic fields $\vec{E}$, $\vec{B}$. The Lagrangian that describes the motion of a charged particle (of charge $e$) under these fields is  \begin{equation} L(x,\dot{x},t) = \frac{1}{2}m\dot{x}^2 -e\varphi + \frac{e}{c}\dot{x}\cdot\vec{A}. \end{equation}  The canonical momenta associated to $x$ are given by \begin{equation} p_i = \frac{\partial L}{\partial{\dot{x}^i}} = m\dot{x}^i +  \frac{e}{c}\vec{A}. \end{equation}  If we perform a gauge transformation \begin{align*} \vec{A}' &= \vec{A} + \nabla\Lambda\\ \varphi' &= \varphi -\frac{1}{c}\frac{\partial\Lambda}{\partial t},  \end{align*} then the canonical momentum transforms as   \begin{equation} p \mapsto p'= p +\frac{e}{c}\nabla\Lambda. \end{equation}  However, in the quantum case, the gauge transformation transforms operators by conjugation with the unitary operator $U(\Lambda) = \exp(\frac{ie}{\hslash c} \Lambda)$. Namely, for the momentum operator, we have \begin{equation} p \mapsto UpU^{-1} = p + [U,p]U^{-1} = p - \frac{e}{c}\nabla\Lambda. \end{equation} Here I used the fact that $[f(x),p]=i\hslash\nabla f$.  Where does this inconsistency come from? I suspect that it has to do with something fundamental about the momentum operator, and how it differs from the classical momentum. Indeed, the canonical momentum depends explicitly on the Lagrangian, so it depends on the dynamics of the problem, but in the quantum case, the momentum operator is just an operator defined on a Hilbert space.  What is the meaning of $p$ and $p'$ in the classical case, and how does it differ from the quantum case?

The  is always used to add an EM field to the Schrödinger/Pauli/Dirac equations. Why does one not use the ? As far as I can see, the difference is a factor i in front of the vector potential. I know I'm combining two seemingly unrelated things, but they seem very similar, an the covariant form seems much "better" with respect to the inherent gauge freedom in the EM field. I can also see that with the canonical momentum form, the equations remain unchanged after an EM and a QM (phase) gauge transformation. Suffice to say my field theory knowledge is not that impressive.


How to visualise solenoidal vector field;I am thinking it as a solenoid going  in a circular fashion with propagation in the z direction.  I was solving a problem to check that field is solenoidal or not ?

Let $V$ be a vector point function. $V$ is solenoid if $\operatorname{div} V =0$ and irrotational if $\operatorname{curl} V =0$.  How can one visualize examples of solenoid or irrotational functions? Are there any functions such that they are both irrotational and solenoid? (Except constant functions)


We are having an issue at trying to restore a database:     System.Data.SqlClient.SqlError: The database was backed up on a server   running version 13.00.4001. That version is incompatible with this   server, which is running version 12.00.2269. Either restore the   database on a server that supports the backup, or use a backup that is   compatible with this server.

When trying to restore a backup to a SQL Server Express 2008 database I got the following error:  Restore failed for Server '...\SQLEXPRESS'.  (Microsoft.SqlServer.SmoExtended) System.Data.SqlClient.SqlError: The database was backed up on a server running version 10.50.1600.  That version is incompatible with this server, which is running version 10.00.2531.  Either restore the database on a server that supports the backup, or use a backup  that is compatible with this server. (Microsoft.SqlServer.Smo)   Is there a way to get a backup which is compatible with the older (in my case 10.00.2531) version from the newer (in my case 10.50.1600) version of SQL Server Express?


Does there exist a prime number $p$ such that there exist no prime numbers between $p$ and $p^n$, $n\geq2$, $n\in N$? If yes, what is the smallest such prime number?

Consider the following statement:     For any integer $n>1$ there is a prime number strictly between $n$ and $n^2$.   This problem was given as an (extra) qualification problem for certain workshops (which I unfortunately couldn't attend). There was a requirement to not use Bertrand's postulate (with which the problem is nearly trivial), and I was told that there does exist a moderately short proof of this statement not using Bertrand. This is my question:     How can one prove the above statement without Bertrand postulate or any strong theorems?   Although I can only accept one answer, I would love to see any argument you can come up with.  I would also want to exclude arguments using a proof of Bertrand's postulate, unless it can be significantly simplified to prove weaker statement.  Thank you in advance.


Note this question is not a duplicate of  because that question does not address the use of "far more".  It sounds strange to me but it's probably perfectly fine.  "Many more" or "far more people" sounds better. The example sentence:  Much more people came to the party last time.

This year there were:   many more people much more people   Alternatively:   many fewer people much fewer people   Which is considered better English?


as I wanted to increase the space surrounding the = sign in my equations, I changed the thickmuskip length in the preamble  \setlength{\thickmuskip}{14mu}   It works fine, and I like the result in display-style equations. The problem is that it also affects equations written in text-style (ie those with $$) and there it does not look good. How can I get a different spacing around = in display and text mode?  Thanks

I'd like to change spacing around binary operators and this issue is discussed there:   Is there way how to change spacing in math and displaymath separately?


A line is drawn through the point $A=(1,2)$ to cut the line $2y = 3x-5$ in $P$ and the line $x+y = 12$ in $Q$.  If $AQ$ = $2AP$, find the coordinates of $P$ and $Q$.

A line is drawn through the point $A(1,2)$ to cut the line $2y=3x-5$ in $P$ and the line $x+y=12$ in $Q$. If $AQ=2AP$, find the coordinates of $P$ and $Q$.  I found the lengths of the lines $AQ$ and $AP$ in terms of $x$ and $y$ and used $AQ=2AP$ to get this equation $11x^2-40x-16=0$  Working: $AP=\sqrt{(x-1)^2+(\frac{3}{2}x-\frac{9}{2})^2}=\sqrt{\frac{1}{4}(13x^2-62x+85)}$  $AQ=\sqrt{(x-1)^2+(-x+10)^2}=\sqrt{2x^2-22x+101}$  $AQ=2AP\Rightarrow \sqrt{2x^2-22x+101}=2\sqrt{\frac{1}{4}(13x^2-62x+85)}$  $\Rightarrow 2x^2-22x+101=13x^2-62x+85\Rightarrow 11x^2-40x-16=0$  Using the quadratic formula I found $x=4,x=-\frac{4}{11}$  I then substituted these values into the two equations in the question to get the coordinates $(4,\frac{7}{2}),(-\frac{4}{11},-\frac{15}{11})$ or $(4,8),(-\frac{4}{11},\frac{136}{11})$  But the answers in the book are $(4,\frac{7}{2}),(7,5)$ or $(\frac{2}{5},-\frac{19}{10}),(\frac{11}{5},\frac{49}{5})$  I don't know where I went wrong in my method.  Edit: Found some errors in my method and calculation.  Using $x=4$ in $2y=3x-5$ gives $P(4,\frac{7}{2})$  Line with points $AP$ has equation $y-2=\frac{\frac{7}{2}-2}{3}(x-1)\Rightarrow y=\frac{1}{2}x+\frac{3}{2}$  $Q$ lies on the same line. Therefore, the intersection between $y=\frac{1}{2}x+\frac{3}{2}$ and $y+x=12$ is the point $Q$. Working: $\frac{1}{2}x+\frac{3}{2}=-x+12\Rightarrow x=7$ Therefore, $y=-7+12=5$. Point Q has coordinates $(7,5)$.  But $x=-\frac{4}{11}$ is not the other $x$ coordinate of $P$ according to the answers in the book. I have no idea where I went wrong at this point.


I have been doing an exam review and this is one of the problems I could not solve.  Let $X_1, X_2, ..., X_n$ be a sequence of mutually independent random variables. For each $i$ with $1 \leq i \leq n$,   the variable $X$, is equal to either $0$ or $n+1$ $E(X_i) = 1$   Determine $Pr(X_1+ X_2 + ... + X_n  \leq n)$

Given that $X_1, X_2...$ are mutually independent random variables. For each $i$ with $1\le i \le n$   the variable $X_i$ is equal to either $0$ or $n+1$ $E(X_i)$ = $1$   also.. if $X_i$ is equal to either $0$ or $n+1$, doesn't that mean that all $X_i$ need to be $0$?  Thanks


There are a lot of questions which have (often enough) complex and good answers in comments, which should really be posted as answers.  A good example is here: . Virtually all of the questions in "assembly" listed when using "unanswered" have answers provided via comments.  Now I was reading  and notice this comment:     More than that... in case you ask them to post as answer and they don't do that within a day or so, just post your own answer and mark accepted. Case solved. :) –  Sha Wiz Dow Ard   And I'm unsure if this was just a joke or meant seriously.  On the one hand, SO should provide answers, and it would be helpful, if the answer is provided in comments, if it were summarized in a real answer. On the other hand, I would feel a bit like a rip off (is this the proper term?) if I would do this from somebody else's comments and possibly even get the rep for it.

I'm trying to go through and provide answers to every unanswered question (search "closed:0 answers:0"), somewhat following the spirit that was blogged about at  .  However, I'm finding this much more difficult than it needs to be, as many of the questions have already been answered without the use of an "answer" - but instead, in the form of a comment by either the OP or another poster. I wouldn't mind reading through and skipping these, as long as there was some appropriate action I could take to at least assist with preventing these questions from being seen again from the same query - either by myself or another SO member.  Is there such an appropriate action?  Should we vote to close?  If so, using what reason? Even if I vote to close, what are the chances that 4 other users will also view the question and also vote to close?  (i.e., will my individual vote even do any good?  Is there any report to show recent close votes, so that others may also review and contribute supporting close votes?) Should we post some sort of an answer - even just something to the effect of "this was already answered by the OP's own comment to his answer (above)"? Would something like this be appropriate to flag for moderator attention, and let the moderators deal with it?  (Or would this be considered too trivial?) Should we rename the question title to something standard that can be used in a search exclusion?  (Maybe "SOLVED:"?)  Basically, how can I help to denote questions as "This question is no longer in active search of an answer - though better answers may still be appreciated."? I've already reviewed , which was closed as a duplicate of  - but this requires effort on part of a user who may very likely no longer be active. Otherwise, is there something I should be doing to improve my search to filter out these types of questions? I've run across this many times, so I don't consider it to be a rare issue.  However, the last question like this I just ran across, prompting this question, was .  In this case, the question was self-answered by the OP in the form of a comment, this question is the OP's only question, the OP has no other visible activity on SO, and the OP hasn't been seen on SO since he registered and posted the question 5 months ago. Another one I just ran across is .  However, here the "answer" comment was posted by a reputable and recently active SO member.  Should I leave a comment directed at him, asking him to re-post his comment as an answer, or should I post my own answer echoing his comment?  (Or something else?) Yet another is .  Interestingly, the OP actually self-edited the question to include the "SOLVED:" prefix on to the question, instead of posting his resolving comment as an answer (and ideally accepting it) as he was asked to do by another comment.  This brings up another good idea - is there a "standard" we should use to rename the titles on these "resolved but unanswered" posts that could be used as a search exclusion?  (Also added to the above list.)


I want to do an jQuery fade in and fade out in a loop such as   But I want to maintain different css positioning for each of the .trip elements, ie, the elements fading in and out.  For example with the element
Item3
 , I want to add positioning so that it displays left 200px when it fades in, such as in this css:  #3{position:absolute; left:200px;}   AND for another element  #2{position:absolute; left:100px;top:100px;}   With the current code in the jsfiddle, the elements are loaded in the same spot on the page.  I tried adding css to the different elements as I did above, but it still loads in the same place as in the jsfiddle.  How do I fix this?

When creating the id attributes for HTML elements, what rules are there for the value?


I'm trying to make automatic generation of a value in a class in C++.  This is Shape.h  #pragma once class Shape { public:     Shape();     ~Shape();     // Return ID of the Shape     virtual int getId();     // Return area of the Shape     virtual double getArea(); protected:     static int _id;     double _area;     // Compute the area of the shape     virtual void compArea() = 0; };   And this is Shape.cpp  #include <iostream> #include "Shape.h"   Shape::Shape() { _id++;     //ID is incremented in every instance _area = 0.0; }   Shape::~Shape() {     std::cout << "Distruttore Shape" << std::endl; }   // Return ID of the Shape int Shape::getId() {     return _id; }   // Return area of the Shape double Shape::getArea() {     return _area; }   And when I compile I receive:  error LNK2001: external symbol "public: static int Shape::_id" (?_id@Shape@@2HA) unresolved  What am I doing wrong?  Thanks for help :)

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


This is a hypothetical question.  An Alcubierre Warp Drive can theoretically go any speed because space is moving and the ship is not.  Could a ship equipped with this drive escape from inside an event horizon?  As I understand it, the space is not complete curved just inside the event horizon.  Is there anything that would keep said drive from functioning inside an event horizon?

Could a ship equipped with Alcubierre drive theoretically escape from a black hole?  Also, could it reach parts of the universe that are receding faster than the speed of light from us?


I'm designing a program in Python to handle the calculation of key performance indicators (KPIs) for an industrial application. The results are calculated from raw process data, which in the program is stored in a NumPy matrix.  I wanted to keep the actual calculation procedures separate from the main program, which handles the other heavy lifting, like fetching the relevant raw data. There are multiple real-life "units" for which the KPIs can be calculated, so each of them has their own Python file containing the specific implementations of the KPIs. A for-loop in the main program module calculates all the KPIs for all the units in succession.  So what I do is as follows:  1) Import the calculation file for the unit under calculation this round:  print("Importing calculation module '{}.py'...".format(file_name)) try:     module = __import__(file_name) except ImportError:     status = "Error: no plant file defined." else:     print("Done.")   2) Pass the imported module to a function, which determines, which KPI function to call in the module:  def CalculateKPI(KPIToCalculate, raw_data, kpi_module):      status = ""     kpi_result = []      not_defined = "Error: Calculation method not defined for this KPI."      print("Calculating KPI values... ")      if(KPIToCalculate == "SupportFuelUsage"):         try:             kpi_result, status = kpi_module.SupportFuelUsage(raw_data)         except AttributeError:             status = not_defined     elif(KPIToCalculate == "Lambda"):         try:             kpi_result, status = kpi_module.Lambda(raw_data)         except AttributeError:             status = not_defined     elif(KPIToCalculate == "PrimaryAirRatio"):         try:             kpi_result, status = kpi_module.PrimaryAirRatio(raw_data)         except AttributeError:             status = not_defined      ... As many ELIF forks as there are possible KPIs, close to 200      else:         status = "Error: Function CalculateKPI does not contain if-statement for this KPI."         return kpi_result, status      print("Done.")      return kpi_result, status   It does work. However, this seems like a very bulky and crude way of doing this, and in the long term will likely be a nightmare to manage.  So basically, what I'm asking is: is there any way of determining the function to call in the module based on the variable "KPIToCalculate" alone, and not have to list each possible function separately?

What is the best way to go about calling a function given a string with the function's name in a Python program.  For example, let's say that I have a module foo, and I have a string whose content is "bar". What is the best way to call foo.bar()?  I need to get the return value of the function, which is why I don't just use eval. I figured out how to do it by using eval to define a temp function that returns the result of that function call, but I'm hoping that there is a more elegant way to do this.


Background: I did an "A" level in electronics 25 years ago; now been a professional programmer for nearly 20 years. I want to build some very basic circuits to interact with an Arduino but I've forgotten a lot, apparently :)  Question: I am playing around with the below circuit, and it is confusing me. The values below are taken from a website, and they work fine and as expected. However, they clip the bottom half of the waveform.  Reading that the gain is only set by RL and RE, naively, I though that biasing the transistor to half the supply would move the waveform up so that it would be amplified the same in both directions, so I altered R1 to 11k.  However, this seems to completely stop the circuit amplifying at all; in fact the gain is now ~-0.5. Now, I'm willing to accept that my change didn't do what I wanted, but if the load is only set by RL and RE, why did this have such a dramatic effect?  NOTE: I have read all the many Common Emitter questions on the site and I'm afraid the answers are a bit over my head, so if you could aim your responses at my beginner 17yo self, that'd be good :)  NOTE TWO: RE should be 470R, not 5R. Screenshot is wrong.  (Also I cannot get it to run in Circuit Lab for some reason, so here it is in PartSim - )

What is the significance of a coupling capacitor in a common-emitter amplifier? What would happen if it is removed? What will be  the effect on AC amplifier gain on removing it?


Consider a system on the level ground (let this be the datum line). Only gravitational force(force 1) and a vertically upward force(force 2) are acting on it and there is no heat transfer. When the upward force, force 2, is greater than gravitational force, force 1, there is a net-upward force which causes the system to accelerate up. After a certain distance, force 1 and force 2 become equal and the system starts moving at a constant velocity. The net-upward force multiplied by the distance traveled gives the work done on the system by the net-force which is equal to the increase in kinetic and potential energy of the system during acceleration.   Now, when it is moving at a constant velocity, as there is no net force acting on the system, the net-work would be zero. But still, the potential energy is increasing with the kinetic energy remaining constant. How is the energy in the system increasing without any work being done on it?

I'm little confused here.  done on the body when we lift it and put it on the table is zero, because according to work energy theorem, change in kinetic energy of the body is zero. So, the net work done is zero.   Fine, but now the object has $mgh$ (where $m=$mass of body; $h=$height of body) amount of potential energy stored in it. If the net work done is zero then who has increased its energy?  I'm confused and unable to think it through kindly help.


My windows 7 boot very slow (stage when windows desktop appear), it need something about 10 minutes, to start working normal. Do you know any software to profile/analyze windows booting time ? I want to check which applications/services takes the most booting time and why.

It's taking some minutes until my windows 7 load. Then it asks for my password. After I enter the password it takes 1 minute or more to load the basic and some more minutes to start everything.  This is my Startup Services and Programs    Is there something wrong with it? It wasn't so slow a while ago.  I have run some cleans on registry and files with CCleaner.  Is my profile corrupted or something like it? What should I do?  My config: Quad Core 2.0 GHz, 6 GB RAM, 3 GB Video


When i install 32-bit libraries through command   sudo apt-get install 32-bit    libraries.Error occurred unable to locate package.  Please give me solution of this error.

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


Let $A \subseteq \mathbb{R}$ and $|A|=\omega$, prove $|\mathbb{R}\setminus A| = 2^\omega$. Hint: $\mathbb{R}\sim \{0,1\}^\mathbb{N}$  I'm somewhat stuck trying to prove this, could someone give some hints (no full answers please) I know $|A| = \omega < |\mathcal{P}(A)|=2^{\omega}$ (Cantor). I guess I should look for some bijective function between $\mathbb{R}\setminus A$ and $\mathbb{R}$ or $\mathcal{P}(A)$. I also don't see how I can use the hint... Should I look for a bijection between $\mathbb{R}\setminus A$ and $\{0,1\}^\mathbb{N}$? I was given another hint to use a diagonalization argument, but isn't that just usefull to prove strict equalities like $|A| < |\mathcal{P}(A)|$?

I'm currently reading a little deeper into the Axiom of Choice, and I'm pleasantly surprised to find it makes the arithmetic of infinite cardinals seem easy. With AC follows the Absorption Law of Cardinal Arithmetic, which states that for $\kappa$ and $\lambda$ cardinal numbers, the larger infinite and the smaller nonzero, then $\kappa+\lambda=\kappa\cdot\lambda=\max(\kappa,\lambda)$.  I was playing around with the equation $k+\aleph_0=\mathfrak{c}$ for some cardinal $k$. From the above, it follows that $\mathfrak{c}=k+\aleph_0=\max(k,\aleph_0)$, which implies $k=\mathfrak{c}$.  I'm curious, can we still show $k=\mathfrak{c}$ without the Axiom of Choice? Is it maybe possible to bound $\mathfrak{c}-\aleph_0$ above and below by $\mathfrak{c}$? But then I'm not quite sure such algebraic manipulations even mean anything, or work like that here. Certainly normal arithmetic does not! Thanks.


In C, when I am reading a file, or some other input, all at once with fread how would I know what size to declare the buffer with?  char buffer[1024]; fp = popen("ls /", "r"); fread(buffer, 1, sizeof(buffer), fp);   The input data could have 1000 lines or 1 line, or even 100000 lines or more.  Is there any general rule for it?

How can I figure out the size of a file, in bytes?  #include <stdio.h>  unsigned int fsize(char* file){   //what goes here? }


Let $x \in \mathbb{N}$ and let $p$ be a prime divisor of $x^4+x^3+x^2+x+1$, prove that $p = 5$ or $p \equiv 1 \mod{5}$   Note that $(x^4+x^3+x^2+x+1)(x-1) = x^5 - 1$.  I tried reducing the equation $\mod{5}$, which gave me some information on $x$, but I was not able to utilize this information.

We can write the "polynomial" as follows: $$x^4+x^3+x^2+x+1=\frac{x^5-1}{x-1}.$$ For even $x=2y$, we have that $x^5-1=(2y)^5-1=32y^5-1\equiv1$ mod $5$.  For odd $x=2y+1$, we have that $(2y+1)^5-1\equiv_532y^5\equiv2$ mod $5$.  I find it hard to believe my computations above. I guess this makes me rather clueless. I was hoping there was some way out with Legendre symbols. Any help is appreciated.


I've got a samba share hosted on a Windows 10 PC and I have mounted it via a script that is set to automatically run on startup (my fstab wasn't working right) and the script looks like this:  sudo mount -t cifs //ipaddress/sharedfoldername /mount/location --verbose -o credentials=/credentials/file/location   When I access the mount location folder before the mount, I have full write access as a standard user. However, after mounting, root becomes user and I have no write access. I have tried multiple commands including all on this . I have also tried logging in as root and changing file and folder permissions through my file browser (Caja). I am running CentOS7 and need a simple set of commands to use to set write access to all standard users on either all mounts or specific mounts that can be chosen. I have also set the share to allow 'Everyone' to access when sharing on the Windows PC. So when the share is mounted, the standard user can view and open files, just not create, delete, edit and save files.  Does anybody have any ideas?

Not sure how mount works with CentOS, but I have a drive accessed through my CentOS file explorer at the path:   smb://ipaddress/sharedfoldername   And want to permanently mount it to my PC at /mnt/ or at /home/user/desktop but the following commands are probably wrong but could someone tell me how to get the machine to connect to the address and mount it to the place I want it on startup/login?  These commands are probably wrong but it's just what I assumed would do the trick:  sudo mount smb:/ipaddress/sharedfoldername /mnt/   Obviously replacing ipaddress with my actual IP ADDRESS and replacing sharedfoldername with my real shared drive name. - But.... it doesn't work - it tells me that smb doesn't work...?... and also says I may have got the mount command wrong too because it brings up mount help...?  It is accessable from CentOS if I access the path smb://ipaddress/sharedfoldername but I would like it mounted to a specific folder...  Any help would be greatly appreciated. Thanks.    SUBQUESTION  Why is _netfs not recognised if you look at the command for fstab in @jsbillings comment?


I have been trying to look for a file in all the possible directories inside "My Documents", but it's throwing the "System.UnauthorizedAccessException" exception because of the "My music" folder.  I thought maybe listing all the folders within "My documents", then getting the path of "My music" and excluding it from being searched would solve the problem, but it failed...   So now I have no idea how to find a specific ".ini" file within all the folders inside "My documents" without getting that exception, can anyone help me please? :)   The code I used:  DirectoryInfo dir = new DirectoryInfo(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)); foreach(FileInfo file in dir.GetFiles("*.ini", SearchOption.AllDirectories)) {     listBox1.Items.Add(file.Name); }

I am trying to display a list of all files found in the selected directory (and optionally any subdirectories). The problem I am having is that when the GetFiles() method comes across a folder that it cannot access, it throws an exception and the process stops.  How do I ignore this exception (and ignore the protected folder/file) and continue adding accessible files to the list?  try {     if (cbSubFolders.Checked == false)     {         string[] files = Directory.GetFiles(folderBrowserDialog1.SelectedPath);         foreach (string fileName in files)             ProcessFile(fileName);     }     else     {         string[] files = Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.*", SearchOption.AllDirectories);         foreach (string fileName in files)             ProcessFile(fileName);     }     lblNumberOfFilesDisplay.Enabled = true; } catch (UnauthorizedAccessException) { } finally {}


Hi everybody, is there anybody who can answer the following problem? I dont know how to start solving it, thank you very much.![the question is in the picture below][2]

I appreciate anyone who answer this question and I anyone who design appropriate graph.


I have been using Win7 ubuntu 12.04 dual boot laptop and one day I got Disk failure imminent message in ubuntu.I have been using Win 7 since then for about 2 months now and havent experienced anything problematic but it is not letting me boot in Ubuntu.What should I do?

I want to run the check file system tool, but for that I need to unmount the volume, I have just one partition, should I go ahead with unmount and repair. I am new to Ubuntu, so please help.(Image)


This problem was inspired by this question.  $\sqrt [ 3 ]{ a(\frac { a+b }{ 2 } )(\frac { a+b+c }{ 3 } ) } \ge \frac { a+\sqrt { ab } +\sqrt [ 3 ]{ abc }  }{ 3 } $  The above can be proved using Hölder's inequality.   $\sqrt [ 3 ]{ a(\frac { a+b }{ 2 } )(\frac { a+b+c }{ 3 } ) } =\sqrt [ 3 ]{ (\frac { a }{ 3 } +\frac { a }{ 3 } +\frac { a }{ 3 } )(\frac { a }{ 3 } +\frac { a+b }{ 6 } +\frac { b }{ 3 } )(\frac { a+b+c }{ 3 } ) } \ge \sqrt [ 3 ]{ (\frac { a }{ 3 } +\frac { a }{ 3 } +\frac { a }{ 3 } )(\frac { a }{ 3 } +\frac { \sqrt { ab }  }{ 3 } +\frac { b }{ 3 } )(\frac { a }{ 3 } +\frac { b }{ 3 } +\frac { c }{ 3 } ) } (\because \text{AM-GM})\\ \ge \frac { a+\sqrt { ab } +\sqrt [ 3 ]{ abc }  }{ 3 } (\because \text{Holder's inequality)}$  However, I had trouble generalizing this inequality to   $\sqrt [ n ]{ \prod _{ i=1 }^{ n }{ { A }_{ i } }  } \ge \frac { \sum _{ i=1 }^{ n }{ { G }_{ i } }  }{ n } $  when ${ A }_{ i }=\frac { \sum _{ j=1 }^{ i }{ { a }_{ i } }  }{ i } $  and ${ G }_{ i }=\sqrt [ i ]{ \prod _{ j=1 }^{ i }{ { a }_{ i } }  } $ as I could not split the fractions as I did above.

For positive real numbers $x_1,x_2,\ldots,x_n$ and any $1\leq r\leq n$ let $A_r$ and $G_r$ be , respectively, the arithmetic mean and geometric mean of $x_1,x_2,\ldots,x_r$.  Is it true that the arithmetic mean of $G_1,G_2,\ldots,G_n$ is never greater then the geometric mean of $A_1,A_2,\ldots,A_n$ ?  It is obvious for $n=2$, and i have a (rather cumbersome) proof for $n=3$.


I was playing an  when I came across the following question:     You and your friend are reading. It's getting dark and you decide to turn on the light. You stand up and walk towards the light switch.      A: What are you doing?   B: __________________              I'll turn on the light.    I'm going to turn on the light.     I'm turning on the light.          According to  we use will when we make rapid decisions. Isn't this the case in the game? I am asking, because the right answer turned out to be "going to turn on the light" - am I missing anything obvious here or is it a mistake in the game?

I know several questions were asked about the difference between "going to" and "will". Based on several answers (see, for instance, ,  and ), I understood that "will" is more spontaneous and "going to" is used with more planned actions.  So, it seems that everything is pretty fine. However, in , Kosmonaut has an answer in which he states: "Let's say that tomorrow you will walk your dog from 7 - 8 AM".  On the one hand, you probably planned to walk your dog long before and thus I should use "Let's say that tomorrow you're going to walk your dog from 7 - 8 am".   On the other hand, since I'm saying "let's say...", I'm deciding right now (thus, unplanned) that you will walk your dog. So, even though in this hypothetical situation you made a plan, I'm in a more spontaneous mood deciding right now that that's what you will do tomorrow, and, thus, I should use "will".  Which one (if any) of the above explanations is right?


Can attachments be sent in vacation auto-responder in Gmail? I have set up the vacation responder and want to send along an attachment with it to every one who mails me from my contacts only.

I would like to setup an auto-responder in Gmail that includes an attachment. I can setup the auto-responder without issue but how do I add an attachment to an auto-responder in Gmail?


I'd like to split the apex in two lines. I'm commenting a part of an equation with \overbrace and I need to split the comment in two line because it is too long.  $$ x = \overbrace{y}^{very big comment} $$

Here is a little snippet of my code:  \begin{center} $\small \displaystyle \underbrace{(- \frac{1}{2})^0}_{\text{1st term, j = 0}} + \underbrace{(- \frac{1}{2})^1}_{\text{2nd term, j = 1}} + \underbrace{(- \frac{1}{2})^2}_ {\text{3rd term, j = 2}} + ~...+ \underbrace{(- \frac{1}{2})^k}_{\text{kth term, 2nd to \linebreak last term, j = k}} + \underbrace{(- \frac{1}{2})^{k+1}}_{\text{(k+1)th term,  last in the sum}}$   \end{center}   and this is the output    I would like this to be on one line, but have the notes underneath the last two terms split into two. How might I do this?


Recently I was using a VPN (provided by Avast) to secure my connection whilst traveling.   Right now I am not using it as I am back in my office.   But using it seems to have caused an issue with the auto time clock on my computer (see attached screenshot) any ideas how to resolve this?

Although I keep my system time & date in check using time.asia.apple.com, I can't "Set time zone automatically using current location". I get the error message, "Unable to determine current location at this time" every time I try this.    Does anyone know why this is happening?  Thanks.


I have installed Ubuntu as a guest OS on Windows. Well I am getting this error when I try to install GCC:

I get this error when trying to use apt-get:  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?     How can I fix this?


I have created a schedule class with AllowCallouts interface used and invoking my batch Apex from It and also my Batch Apex has allowcallouts interface used. But still i am getting CalloutException. i am doing a callout in start method of batch apex and execution methods from re usable BAL helper class     Scheduler   global class KanbanizeCardActivitySchedule implements Schedulable, Database.AllowsCallouts {   global void execute(SchedulableContext sc) {  //small code blocks of getting  //username,pswd,others from custom setting  //Inovoke of batch apex         if(string.isNotBlank(userName) && string.isNotBlank(paswd) ){             ID jobID = database.executeBatch(new KanabanizeCardActivityBatch(fieldsSet, wherClause, userName, paswd ), 200);             system.debug('--jobID for Kanabanize Data Check--'+jobID);                   } }      Batch Apex   global class KanabanizeCardActivityBatch implements Database.Batchable<sobject>, Database.AllowsCallouts {       global KanabanizeCardActivityBatch(set<String> qFields, String whClause, string kanbanUserName, string kanbanPswd){        KanabanizeService_BAL.doLoginKanbanize(kanbanUserName, kanbanPswd);         if(KanabanizeService_BAL.isStatusOkForLogin()){          //setting some final variables here, based on response        }     }   global Database.QueryLocator start(Database.BatchableContext BC){       return Database.getQueryLocator(queryString);    }     global void execute(Database.BatchableContext BC, List<sObject> scope){     //making a callout in execute method, some heavy lines cant share here    }    global void finish(){}   however when i call my batch apex outside scheduler pulling everything perfectly. Not sure this behaviour even after using allowcallouts interface. As per sf documentation we can call batch apex with allow callouts implemented.

i have created a schedulable class which has to trigger a batch job. The run method for the batch class will get list of data to process from a webservice callout. Now, i got the exception below. Any suggestions please.     System.CalloutException: Callout from scheduled Apex not supported.   global class scheduledDeltaBatchable implements Schedulable {    global void execute(SchedulableContext sc) {     ID batchprocessid = BatchUpsertSAPCustomerMasterBPSync.run(SAPServices.GetSAPCustomerMasterBPSync('Delta'));    } }


This is not a case of me not being able to hear the sounds, but rather my computer seems incapable of playing them in the first place. For example, Youtube videos cannot play, and the Videos app will not even start an MP3. If I turn off the bluetooth speaker, everything works fine.  This is a Photive speaker and I have configured it via Ubuntu "Sounds" app as well as "Pulse Audio Control" to use the High Fidelity Playback (A2DP Sink) option. I've also tried using the "Bluetooth Manager" app (blueman) as well as restarting the devices, and some other questions on AskUbuntu / StackExchange. I would gratefully appreciate any help.

I have an bluetooth headset connected to my computer, the buttons play/pause/volume are working fine, but I have no sound in the headset, but in the speaker of the computer.   In fact, I played with the sound settings of my headset in the sound settings of Ubuntu, and after choosing "switch off", the headset did "disappear" from the settings.   My question is: how can I make it appear there again, to be able to hear the sound via the headset? Thank you all for your help!


The problem is:  "Find all $2\times 2$ matrices A that have the property that for any $2\times 2$ matrix  B, AB = BA."  Given hint: "The given equation must hold for all B. Try matrices B that have lots of zero entries."  I tried bashing by letting $A=\begin{pmatrix}a & b\\c & d\end{pmatrix}$ and $B=\begin{pmatrix}w & x\\y & z\end{pmatrix}$, but as you can tell, this got messy quickly. Any help would be appreciated, thank you.

Assume M is a $2 \times 2$ real matrix such that $MX = XM$ for all real $2\times2$   matrices $X$. Show that $M$ must be some real multiple $q$ of $I$.   I can see that this is logical and have tried a few examples where I have multiplied $qI$ by some random $2\times2$ matrix from both sides and get the same matrix in both cases. How would I go about showing this though? Surely a few examples aren't actually showing anything for the general case, right?  Also, does the property shown in the question hold for all square matrices, or just $2\times2$ ones?


Sometimes i try to add a new edge loop but than it doesn't go all the way around. Does anybody know what I am doing wrong? I am using a Mirror modifier. And sometimes i like to delete a line by using x and than disolve edge. Or is this the problem? Picture:   Thanks for helping in advanced.

I can still cut it entirely with the Loop cut.    Thing is, I want to get rid of that edge, I do that by dissolving it:    Now here's the problem, after that, I can't cut it entirely. I've also tried dissolving the remaining vertices but it didn't work.    So what I want to do is to cut it entirely after dissolving the edge, instead of doing it separately as you can see in the pic. Is there a way to achieve that? Did I make a wrong move?


Trying to render the default scene.  Have set my user preferences to have Render Output go to F:\Blender\BStills\ - and this is what's listed in Properties panel as well.  If I try to render an animation, things work fine. If I try to render a single, still image, I'm not getting any output (even though the render looks like it runs fine within blender).  Also, is there a simple way to attach .blend files so people can look at those directly to help with troubleshooting?    Thanks for any help.

I usually am able to render successfully to the c:\tmp folder, but when I came into work today, I rendered out the image on my work laptop, and everything seems to work, but I'm not getting an output to the tmp directory.  Does anyone know how to make this work?


Solve the equation $(z+1)^5=z^5$ Since we are dealing with complex numbers I don't think we can take the fifth root of both sides. I can change the right side of the equation to $r^5e^{5i\theta}$, but I don't know what to do with the left side. I don't think substituting $z$ with $x+yi$ would help me, besides foiling out the left side I don't know what to do. Any ideas?

The question says to solve this equation: $(z+1)^5 = z^5$  I did. Just want to find out if I did it properly and if my run-around logic makes sense.  First I begin my writing the equations as:  $$ (z+1)^5 = z^5$$ $$ \mathbf{e}^{5 \mathbf{Log}(z+1)} = \mathbf{e}^{5 \mathbf{Log}(z)} $$ So $$  \mathbf{Log}(z+1) = \ln|z+1| + \mathbf{Arg}(z+1)i $$   $$  \mathbf{Log}(z) = \ln|z| + \mathbf{Arg}(z)i $$   Now, because the natural logarithm is one-to-one, I write:  $$ \ln |z| = \ln |z+1| \Rightarrow |z| = |z+1|$$   So assign $ z = a +bi$   So that $|z| = \sqrt{a^2 +b^2} = |z+1| = \sqrt{(a+1)^2 +b^2} \Rightarrow a^2 +b^2 = (a+1)^2 +b^2 \Rightarrow a^2 = (a+1)^2 \Rightarrow a = -\frac12 $  So, $z = -\frac12 + bi$ and $z+1 = \frac12 + bi$ for some $b \in \mathbb R$  Now to find $b$  $$ \mathbf{Arg}(z+1) = \mathbf{Arg}(z)$$ $$ \tan^{-1} \frac{b}{\frac12} = \pi - \tan^{-1}\frac{b}{-\frac12}$$  I have a feeling this last part isn't quite right, so I just want to find out if I'm approaching this question properly?  Ultimately, I get $ z = -\frac12$ which upon inspection...is wrong...


When creating a LinkedList with this statement in Java  LinkedList<Integer> adj[] = new LinkedList[numPlaces()];  I get two warnings saying   RoadMap.java:247: warning: [rawtypes] found raw type: LinkedList                         LinkedList<Integer> adj[] = new LinkedList[numPlaces()];                                                         ^   missing type arguments for generic class LinkedList<E>   where E is a type-variable:     E extends Object declared in class LinkedList RoadMap.java:247: warning: [unchecked] unchecked conversion                         LinkedList<Integer> adj[] = new LinkedList[numPlaces()];                                                     ^   required: LinkedList<Integer>[]   found:    LinkedList[] 2 warnings   The code runs the way it is inteded to but what do I need to change to solve them?

Due to the implementation of Java generics, you can't have code like this:   public class GenSet<E> {     private E a[];      public GenSet() {         a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation     } }   How can I implement this while maintaining type safety?  I saw a solution on the Java forums that goes like this:  import java.lang.reflect.Array;  class Stack<T> {     public Stack(Class<T> clazz, int capacity) {         array = (T[])Array.newInstance(clazz, capacity);     }      private final T[] array; }   But I really don't get what's going on.


Just like the title said, I have a char (e.g. 00101011), how can I know the position of first   '1' bit in it? (in this case, it is 6, or 5 if we consider the rightmost position is 0). I know a for-loop shift would be helpful, but is there a more efficient way?

If I have some integer n, and I want to know the position of the most significant bit (that is, if the least significant bit is on the right, I want to know the position of the furthest left bit that is a 1), what is the quickest/most efficient method of finding out?  I know that POSIX supports a ffs() method in strings.h to find the first set bit, but there doesn't seem to be a corresponding fls() method.  Is there some really obvious way of doing this that I'm missing?  What about in cases where you can't use POSIX functions for portability?  Edit: What about a solution that works on both 32 and 64 bit architectures (many of the code listings seem like they'd only work on 32 bit ints).


Every now and then, various programs create conhost.exe processes on my (Windows 7 x64) computer. I know they are console windows, except the windows themselves are hidden.  I don't suspect any malware, but being a curious person, I'd still like to know what they are doing.  Specifically, I'd like some way to view or dump STDIN and STDOUT of [conhost processes that I didn't create myself]. Does anyone know how to do that?  Edit: This got marked as a duplicate of another question. Perhaps I was unclear. I know exactly what conhost.exe is. What I'm asking for is different.  I know how to capture stdin, stdout and stderr of child processes. However, here I'd like to capture those streams of processes I did not create myself. Given the lack of information I can find, I'm beginning to suspect it is impossible, but perhaps someone knows some arcane magic that would be of use.

The process conhost.exe started showing up on Windows 7, and searching Google doesn't reveal an explanation of what this process is and why it shows up.  What is the conhost.exe process?


When searching for QFT's applications, most articles and answers tend to mention how it is used to expand our understanding of physics, e.g. with the LHC.   So I'm wondering if you know of any examples (outside of particle/theoretical physics) where QFT has been used to develop new forms of technology, products, new processes, etc.  Thank you for any replies

Are there nowadays any actual devices or experimental applications which are based on the quantum field theory and if so, how are they related to QFT?  I could not find any similar question besides  one.


I have a server with debian 7.4 and apache2 installed. I have setup virtual hosts and all works well. Now instead of pointing the virtual host to a documentroot I need it to point to a port on the same server. "Java app running a jetty server"   --- EDIT --- Down votes... I have been an iis user for years and only this week started using linux  My current virtualhost file is as follows  <VirtualHost *:80>      ServerAdmin ******@****.**      ServerName ****.***      ServerAlias ***.*******.***       ProxyPass / http://localhost:8080/  </VirtualHost>   proxy.conf  <IfModule mod_proxy.c>     ProxyRequests On     <Proxy *>         AddDefaultCharset off         Order deny,allow         Deny from all         Allow from 127.0.0.1     </Proxy>     ProxyVia On </IfModule>   ---Another EDIT--- Getting internal server error with the following conf I did see those post mentioned in the comment yet still cnt get this going.....  <VirtualHost *:80>     ProxyPreserveHost Off     ProxyRequests On     ServerAdmin webmaster@+++.***     ServerName ***.***     ServerAlias www.***.***     ProxyPass / http://localhost:6666/     ProxyPassReverse / http://localhost:6666/ </VirtualHost>   ---AND THE FIX---- I fixed the problem by enabling proxy_http aswel... a2enmod proxy_http service apache2 restart

I have some subdomains I want to redirect to specific ports on the same server. Say I have  dev.mydomain.com    I want dev.mydomain.com to transparently redirect to mydomain.com:8080 and I want to preserve the original sub-domain name the url of the browser.  How do I do this with Apache 2.2? I have Apache 2.2 running on default port 80. I can't figure out the write configuration to get this to happen.  I have already set up dev.mydomain.com to resolve in DNS to mydomain.com.     This is for an intranet development server that has a non-routable ip   address so I am not so concerned about exploits and security that   would compromise a publicly facing server.


I was thinking it would be a good idea to run administrative functions in a browser that isn't in the same firefox profile as the one I use for regular browsing.  Is it possible to run more than one firefox profile at the same time on Windows?  When I run firefox -P while firefox is running I just end up with a new window.  Is firefox a singleton on windows?

Firefox can run in different profiles, that can be setup using different plugins, for different purposes such as basic web browsing, web development, trading on ebay etc...  Is it possible to run more than one of these at a time, or does Firefox always run as a singleton?


With android and Google Play becoming so popular, it would be great to have Ubuntu on mobile devices again.  Some archaic references:

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


When "of course" is at the end of a sentence, should a comma precede it?

When an adverb is the last word in a sentence, is it preferable to insert a comma before that word or to leave it as is (with no comma)? For example:  How many employees, roughly? or How many employees roughly? How long was the driveway, approximately? or How long was the driveway approximately?


I tried: echo "libgtk-3-0 hold" | sudo dpkg --set-selections  I got the answer from this thread:  It didn't help. Do I need to install an older version? This the response when I try to: sudo apt-get install mate-desktop-environment Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libgail-3-0 : Depends: libgtk-3-0 (= 3.24.25-1ubuntu4.1) but 3.24.25-1ubuntu4 is to be installed E: Unable to correct problems, you have held broken packages.  I am using Ubuntu 21.04 Linux 5.11.0-17-generic on x86_64 Output from "apt policy libgail-3-0" is: The operation couldn’t be completed. Unable to locate a Java Runtime. Please visit http://www.java.com for information on installing Java.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


If I have for instance, the list: ['a', 'b', 'c', 'd', 'e']  and I want each letter by index to be equal to the ints by index in this list:  [1, 1, 2, 1, 1]  so that 'a' == 1, 'b' == 1, 'c' == 2, etc.  Is there a simple way of doing this that I'm missing?

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


If I press CRTL+Down I move to the cell before the empty cell.    If I press CTRL+SHIFT+End I end up selecting everything between the active cell and the next empty cell.    Now if I want to auto fill the same range of cells, what is the keyboard shortcut for that? (Autofill; also known as clicking the handle in the lower right hand corner of the cell and dragging)

So when I want to extend a series or something along those lines, I can highlight a group of cells, then click on the bottom right corner of the highlighting box and drag down.  Excel will then attempt to automatically extend the contents as well as it can.  Is there a keyboard function that will allow me to do this?  I like to use the keyboard to avoid repetitive mouse motions.  I can use the shift key and arrow keys to make a selection, but I don't know what (if any) key can trigger this function.  I also don't really know what this function is actually called.


Earlier I was using Windows 7. It was having IDM (Internet download Manager) from which I was able to download almost all the types of files from the internet. I was also able to download online streaming videos by the help of IDM. It was really helpful for me regarding the downloading. I was also able to resume my downloads which were paused or stopped due to some reason.  So, I would like to ask that whether there is any software in Ubuntu form which I could get these functions and if there is any software, then how to download it.  I am a new user in Ubuntu. I am using Kubuntu 13.04.

This question exists as it fills a specific criterion.  While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will likely be closed per the . More information on the .   What download managers are available for Ubuntu? Can you provide the link as well?


When I hit the play button, the Exe file just closes and opens again. It only does this after I have installed a mod. The regular one works fine.

I have tried many tutorials but none of them are clear enough. I have also tried installing it using Wine but it won't update and Wine goes gray and stops working.  Does anybody know an easy way to install Minecraft though the Java file without using Wine?


Before everyone starts explosively typing essays about why a stock's price is virtually impossible to predict, I want to iterate that I am not asking how to know what a stock's price will be. I am asking what mechanism is actually responsible for changing the stock's price. Not the multitude of factors that influence it, but literally what is changing the number. Why is a stock's price $43.56 one second, and then $43.57 the next? What changed the number? A computer program? If the answer is something like 'an algorithm changes the number based on what people are willing to pay for it', what does that even mean? What number would anybody be paying for the stock other than its instantaneous price? Does more and more people purchasing at $43.56 tell the algorithm 'lets move it to $43.57 and see if people continue to buy at the same/increased rate'?

Is stock price determined only by the last trade that takes place?  For example, if a stock I own is trading at $3.42, and I place a Sell Limit order for $0.00, will the stock price temporarily dip to $0.00?  Likewise, if I place a Buy Limit order for $100.00 for a stock that is trading at $1.23, will the price spike to $100.00?  Is there some sort of "average price" that is reported on the stock ticker?  Thanks for your help in understanding this!


How does Dirichlet regularization assign value $-1/12$ to $\sum_{k=1}^{\infty} k$?  Yes, I know that $\zeta(-1) = - 1/12$, a result that follows from the Riemann functional equation $\zeta(s) = 2^s \pi^{s-1} \sin(\pi s/2)\, \Gamma(1 - s)\, \zeta(1-s)$.

$\displaystyle\sum_{n=1}^\infty \frac{1}{n^s}$ only converges to $\zeta(s)$ if $\text{Re}(s) > 1$.  Why should analytically continuing to $\zeta(-1)$ give the right answer?


I am looking for a way to smooth/blur the edges of a crunched procedural texture using nodes. (for example a noise texture) The way I want to do this is by placing 'the solution node setup' between nodes for full control. Also, is it possible to have the scaling of the blur always match the input size? (so that the image won't get blurred more or less when aplied to a different model.)  I want to achieve a result like the image shown below:  PS: feel free to edit the question if my english confuses you :)

For a Cycles material I need to blur a texture. If the texture where a Texture Image node, I can blur the image before adding it but in my case I need to blur a Voronoi Texture and so I can't do it.  I have searched but I didn't find a blur node. Can this be achieved?


I was on Music, and I saw this question title:    I found a question it is apparently a duplicate of with this title:    If I were to ask a question called "What is concert pitch?" the system would stop me, as it would have the same title as another—I assume to avoid some obvious duplicates. However, apparently because of the lack of a question mark (), the newer question was able to be titled that.  If a question has a question mark or other punctuation as the only difference between its title and another, it should be treated as the same question title and not be allowed. This could stop things like if I tried to ask a question called "How do you conjugate the first-person imperative?" on Spanish and then change it to "How do you conjugate the first person imperative" (which ) to get it through, making an dupe and filling the review queues.

I recently saw a question titled "" (10k+ users only). I thought, "surely someone has asked this question before", and began looking for a duplicate.  is a question with the exact same title, just with a little different punctuation and casing. It was "Jquery vs Javascript" and "jQuery vs. Javascript?". The only difference being the ., ?, and the casing.  Since we now , I propose that when checking for questions with duplicate names, certain punctuation be striped out to prevent the duplicate from occurring in the first place.  As pointed out in the comments, if isn't already, white-space and non-printable characters may want to be removed for duplicate detection as well.


I know I can use the listings package to include specific lines of a source file in my document, but is there any option or package that would allow me to specify a particular function to include instead?

Is there a way to input particular sections of source code using \lstinputlisting (from the listings package) in a flexible way?  It's possible to use the firstline and lastline options to input particular line ranges, but this isn't robust to changes to the source file.  For example, suppose that the input source file is:  int square(int x) {   return x * x; }  int cube(int x) {   return x * x * x; }   In my LaTeX document, I can include the cube procedure using the command \lstinputlisting[firstline=5,lastline=7]{source.c}.  But suppose I later decide to rewrite the cube procedure.  The input source file becomes:  int square(int x) {   return x * x; }  int cube(int x) {   int x2;   x2 = square(x);   return x * x2; }   Now my LaTeX document will not show the final two lines of cube because the listing uses only lines 5-7.  I could manually update the line range, but this is tedious and error-prone.  Is there a way to mark sections of source code with some kind of label so that the listing will be robust to these sorts of changes?  For instance, perhaps the input source file would be something like  int square(int x) {   return x * x; }  /**\beginlabel{lst:cube} **/ int cube(int x) {   int x2;   x2 = square(x);   return x * x2; } /**\endlabel{lst:cube} **/   so that I could use something like \lstinputlisting[lines=lst:cube]{source.c} to include the section that I want and remain robust to changes.  I am open to using other packages for source code listings (e.g., minted) if helpful.


I want to do the opposite of what grep does. I want to excludes the output lines with a certain pattern.  What I wish to have is a command "ngrep":  $ output hi how are you? hi hi haw are you? hu hi how are you? haw haw haw are you?  $ output | ngrep 'haw' : hi how are you? hu hi how are you?

Say I'm printing out a long series of strings, and instead of only showing lines containing a certain pattern (which one uses "grep" to do), how do I filter out certain patterns?


Recently I was told that scientific papers in English use - log_e while French papers use - ln to denote natural logarithms.  The two notations do mean the same. But I was informed that using the notation ln for natural logarithms in scientific papers in English language is inappropriate and I should use only log_e. But I have always been using log for log-base-10 and ln for natural logarithms. (At least this was what I was taught in school)  Do such notations vary from language to language?  I am referring to the publications specific to IEEE, Elsevier etc. related to the Electrical and Electronics field.

I'm studying statistics and often come across formulae containing the log and I'm always confused if I should interpret that as the standard meaning of log, i.e. base 10, or if in statistics the symbol log  is generally assumed to be the natural log ln.  In particular I'm studying the  as an example, but my question is more of general one.


I was told that the first line shebang (#!/bin/bash) is necessary in the shell script file, and the file won't run accurately without this line. But I tested some scripts. They work just fine without that line.  Is that line simply a comment? Does bash omit this line, as it does with other comments? Or does bash interpret it?  Is that line forced in that format? Or just a helpful readable note? What if I put it in other way, say, without the !?

I am new to shell scripts and many books have written that use #!(sha-bang) line in starting of the script to invoke the interpreter .And this will invoke a new shell for script and do the interpretation line by line.But one of my basic script is still running without the magic line.  so my questions are:   from where did my basic script get the interpreter. how did the script manages to locate the interpreter.   now let me tell you about my basic script it just contains the following line:  echo "basic script without the magic lines"


I can't seem to find the answer to my problem so here I am. I have a tree that has been filled in with strings from a file and need to count how many times a string is seen. So everything works fine except me counting the strings right. So here is the code where I attempt to count the occurrences of each string.  /* Function for postorder traversal */ public void postorder(Scanner file) {     postorder(root,file); }  private void postorder(BSTNode r,Scanner file) {     int counter = 0;     String key;     if (r != null)     {         key = file.next();         postorder(r.getLeft(),file);         postorder(r.getRight(),file);         if(key.compareTo(r.getData()) == 0)         {             counter++;         }     System.out.println(r.getData() +", " + counter);      } }   If it'll help this is the output to the console I'm getting:  McGurkus, 0  Kircus, 0 call, 0 I'll, 0 I, 0 circus, 0 it, 0 my, 0 for, 0 put, 0 tents, 0 think, 0 the, 0 up, 0 to, 0 ready, 1 All, 1   Everything is supposed to be 1. Any help or guidance to where I can derive the solution will be greatly appreciated.

First of all, I swear this is not homework, it's a question I was asked in an interview. I think I made a mess of it (though I did realise the solution requires recursion). Here is the question:  Implement the count() method which returns the number of nodes in a tree. If a node doesn't have either a left or right child, the relevant getXXChild() method will return null  class Tree {    Tree getRightChild() {     // Assume this is already implemented   }    Tree getLeftChild() {     // Assume this is already implemented   }    int count() {     // Implement me   } }   My reason for asking the question is simply curious to see the correct solution, and thereby measure how bad mine was.  Cheers, Tony


I've found a very strange behavior in UNIONed select statements with same values.  tried to find something on the web for whats happening, but didn't know how to phrase the search for this issue, it needs explanation, and it is as follows:  Test 1:  SELECT          ID, SUM(AMT) AS AMT     FROM     (         SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION         SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION         SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION         SELECT 1 AS ID, 100 AS AMT FROM DUAL     )     GROUP BY ID;    Test 2:  SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION SELECT 1 AS ID, 100 AS AMT FROM DUAL UNION SELECT 1 AS ID, 100 AS AMT FROM DUAL;   All these select statements are giving the same result:    So, supposing I'm writing a dynamic code to be generated and executed at run time in one of my apps, and it happens that the code turned up to be as above! how to make this select statement work ?

What is the difference between UNION and UNION ALL?


While I am browsing through few Stack Exchange sites from official Android application, I can't find a way to raise flags on invalid posts. How can I do that?

Are moderator tools, specifically flagging or voting to close going to be implemented in the Android app? If we have a dispute, we should at least have the flag option.  What about share option? If we would like to share a question, we could long press on the question title, and the question title, excerpt, and short URL copied to clipboard.


I am trying to clip a raster using a virtual raster as mask layer in QGIS. It doesn't create a file. Could anyone explain how I should proceed to do that?

Given two input layers  The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) The mask layer - a paletted raster in which every pixel is either NO DATA or a single "color" value, same for every pixel.  I want to create an output raster whose overall extent matches the extent of the mask layer and each pixel is either NO DATA if the corresponding pixel of the mask layer is NO DATA or the value of the corresponding pixel from the clip layer if the corresponding pixel of the mask layer is not NO DATA. I know I can mask the clip layer with a polygon, but the mask layer is a raster. Polygonizing the raster layer is possible in principle, but would result in a polygon with a lot of very short edges. Is there a direct way to do this in QGIS? I suppose there's probably a path that involves creating a new layer and using the raster calculator, but I'm hoping there's something more direct. Further complicating the matter is that the two rasters might not have the same resolution and origin. I believe this is equivalent to  in ArcMap.


The acceleration in a circular motion is directed towards the centre and is directly proportional to the radius of circle if it has uniform angular velocity. Is circular motion with uniform angular velocity simple harmonic motion?

I know the projection along a diameter is an SHM but is circular motion itself an SHM? If we consider the mean position to be the center of the circle then the centripetal acceleration is proportional to the distance and in opposite direction of the position of the particle. So shouldn't it be an SHM?


For a photon or anything that travels at the speed of light, time is dilated infinitely, meaning there is no time. Also, length along the direction of motion is dilated infinitely, meaning the length of the universe along that direction becomes zero. Is this interpretation correct? How do you make sense of this? Does it mean that the photon is omni-present at all times and places? Does this imply some kinds of connection with field theory, where it becomes a field that is just present everywhere?

To an an external observer it appears that time has stopped for photon. But this relation is reflexive, so for an observer travelling with the photon it appears the universe has stopped everywhere.  Is this right?  Space also gets distorted parallel to the direction of motion, but not perpendicular to it.   Does this mean that for an observer travelling with a photon sees spacetime as a flat plane?  Note 1: I'm using language vividly not literally when I say a photon experiences space and time. Not that I'm against idealist or panpyschist interpretations of matter or energy come to that.  Note 2: Since it's been pointed out that an inertial frame can't be boosted into the frame of a photon and moreover there is no limiting behaviour here - no matter what frame you are boosted into, light will always appear to travel at c. Nevertheless, when an external observer watches a train chasing a photon by gradually increasing its speed, he will note that the train speed is approaching the speed of the photon (but will never match it) and when he looks at the clock inside the train he will not too that it is gradually slowing down (but never actually stops). Using this picture, we can attempt the thought experiment - if not one that can be carried out - of what a world looks like to a photon.


I hope I will get your precious help for my R problem.  I want to study the classroom, the teacher and the school effect/result on the pupil's success (or not) at school. I also want to know the effect of the age, the gender and if the pupils have or not repeated 1 year school on the pupil's success (or not).  The pupil's variables are (fixed effects levels) : the age (11 or 12), the gender (M or F), if they have repeated one year (yes or not), the success (yes or not). The other variables are (random effects levels) : the classroom they belong to (A and B), the teacher they have (K; L; M and N) and the school they belong to (C and D).  Firstly I am looking for the effect of the classroom, the effect of the teacher and the effect of the school on the pupil's success and secondly I want to know the effect of the age, the gender and if the pupils have (or not) repeated one year on the pupil's success.  How can I do my GLMM (hierarchical multilevel model) with R ?  Best,

I want to study the classroom and the school effect/result on the pupil's success (or not) at school. I also want to know the effect of the age, the gender (of the pupils) and if the pupils have or not repeated 1 year school on the pupil's success (or not).  The pupil's variables are :  - the age, (11 or 12) - the gender, (male or female) - if they have repeated one year, (yes or not) - the success, (yes or not)  The other variables are :  - the classroom they belong to, (A or B) - the school they belong to, (C or D)  I would like to proceed by GLMM, more precisely a multilevel (hierarchical) model using R on my dataset knowing that firstly I am looking for the effect of the classroom and the effect of the school on the pupil's success (or not) and secondly I want to know the effect of the age, the gender and if the pupils have (or not) repeated one year ?  Many thanks for your help !


I am going to apply for a uk visit visa to visit my Aunt and for tourism. My Aunt will be my sponsor, and on my application I have to show the visa officer that my Aunt and I have a strong close relationship.     Would you help me with what I should show the visa officer to prove that my Aunt and I are closely related?

In the UK immigration rules for visitor visa  it states if;      Funds, maintenance and accommodation provided by a third party      V 4.3 A visitor’s travel, maintenance and accommodation may be   provided by a third party where the decision maker is satisfied that   they:      (a) have a genuine professional or personal relationship with the   visitor;and      (b) are not, or will not be, in breach of UK immigration laws at the   time of decision or the visitor’s entry to the UK; and      (c) can and will provide support to the visitor for the intended   duration of their stay.   I'm a UK  citizen. I'm planning to invite my brother-in-law and another close friend to the UK. In my invitation letter, I have clearly mentioned that I'm going to provide them accommodation only. They have prove sufficient funds to support themselves. I have sent them an invitation letter along with a copy of my passport and tenant agreement.   What other documents do I need to provide to indicate that it is a genuine professional or personal relationship with the visitor?


I have read this question where anna v says:  The photon is an elementary particle in the standard model of particle physics. It does not have a wavelength.   And this one where Emilio Pisanty says:  Photon frequency and wavelength are the same as the corresponding classical mode. If the state of the field is such that there is, whenever you look, only one excitation present, then we say the field is in a single-mode, single photon state. This photon then has a well-defined frequency (ν=ω/2π) and wavelength (λ=2π/k).   And if you look on this site, you find numerous occasions where people talk about the wavelength of a single photon.   Naively, I would think that a photon does have energy, and frequency associated with it, and since frequency and wavelength are inversely related (in vacuum), even a single photon could have a wavelength too. But if I interpret it as a point particle defined in the standard model, then the meaning of wavelength is not so obvious. Question:  Does a single photon have a wavelength or not?

I've been thinking about this for quite some time, and from looking online I haven't found a satisfying answer.  Lots of photons, such as visible-light photons have very small wavelength (which from my understanding of basic physics is the distance between two crests/troughs), but I also know that some EM waves have wavelengths a few metres or even kilometres long e.g radio waves.   What keeps me up at night is the question "How can a photon have a wavelength of a few kilometres and yet still be thought of as a particle?"  Does this mean that one individual photon is several kilometres long? If so, wouldn't it be subject to so many variations between the beginning of the wave and its end?  I realise that matter is also wave-like, where it's uncertainty in position is given by its De Broglie wavelength. Does this apply to the photon?  In other words, is the wavelength of a photon simply the uncertainty in its position?


I am having issues trying to run Virtual Box; which are the "appropiate headers"??  WARNING: The character device /dev/vboxdrv does not exist.      Please install the virtualbox-dkms package and the appropriate      headers, most likely linux-headers-generic.       You will not be able to start VMs until this problem is fixed.   I have installed virtualbox-dkms package, but I have no idea about the headers.  Also when trying to run a VM     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please install virtualbox-dkms package and load the kernel module by executing  'modprobe vboxdrv'       as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.      where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On Linux, open returned ENOENT.    I cannot run modprobe vboxdrv (yes, I run it with sudo)  modprobe: ERROR: could not insert 'vboxdrv': Operation not permitted   I think this is a common question but cannot find answers for Ubuntu 16.04, just outdated ones.  UPDATE  linux-headers-generic is installed but it still doesn't work.

I upgrade from Ubuntu 15.10 to 16.04 and since then VirtualBox 5.0.18 isn't starting my VMs anymore. It complains that 'vboxdrv' isn't loaded. So I try to load it and get the following error:  $ sudo modprobe vboxdrv modprobe: ERROR: could not insert 'vboxdrv': Required key not available   I believe it is related to secure boot which I use and which I want to continue using. Actually with Ubuntu 15.10 secure boot and VirtualBox were working just fine.  Also I tried $ sudo apt-get --reinstall install virtualbox-dkms which built the kernel module successfully but didn't solve this issue.  Any idea how to get vboxdrv loaded while keeping secure boot enabled?  Update 2: Also I tried executing sudo mokutil --disable-validation. When executing this command, during the next boot I get prompted to disable secure boot, add a key or hash from disk. Since I don't want to disable secure boot, it seems that this doesn't solve my issue either. Also I want to keep UEFI activated for a parallel Windows installation.  Note: If you don't mind disabling secure boot, see  instead.


Duplicated: Please see   Using CI for deploying /processes to the same environment results in error if existing version has been already activated:  flows/YYYY-1.flow -- Error: The version of the flow you're updating is active and can't be overwritten.   What is the best practice to use CI for flows deployment?

I've started using Processes and Flows and am really excited about these features -- but am still wrapping my mind about how to manage them in Version Control (which I use) and Continuous Integration (which I don't yet... but am trying to work in that direction). The underlying challenge is that each time a process or flow is edited, the metadata file is renamed to reflect its update version, e.g. MyFlow-1.flow, MyFlow-2.flow, etc. The Challenge for Version Control If each version of the flow has its own file name, this makes it more complicated to track changes to flows.  It seems like there could be two strategies here:  Rename the files to remove the version number.  I'd need a script to run through my src folder pre-commit, and remove the number so that my file name is always MyFlow.flow.  This is an annoying extra step, but makes version control simpler.  On the other hand, it probably makes deployment much harder.  Track each file in version control with its original name.  We'd need to be diligent about deleting MyFlow-1 in the commit where we add MyFlow-2 so that git would recognize this as a rename/move and show helpful diffs.  Otherwise, the whole file appears to change with every change, which makes version control rather less useful.   The Challenge for Deployment/Continuous Integration From my experiments so far, once a flow has been activated in a given environment, the metadata file can't be deployed again (either it is currently active, or has been active in the past and superseded). That means that I need to prevent my previous flow versions from being included in a deployment package (either by not tracking them at all, or by using a script to delete earlier versions).  I also need some way to determine whether the current version (in my repo) should be included in the deployment payload for a given environment or not. I could imagine a script that (1) downloads flows from the target environment, and removes *.flow files from the payload if they already exist in the target environment, but that feels complicated.  And it's even harder if I've removed the version numbers from my flow files. Are you using flows in VS or CI?  How are you managing these issues? Note:  I'm not sure whether VC and CI should be one question or two - depends on how integrated the strategy for dealing with these two challenges.  If you think these should be separate questions, comment and I'll re-post.


How can I bulk replace the suffix for many files?  I have a lot of files like   NameSomthing-min.png NameSomthing1-min.png NameSomthing2-min.png   I would like to change all them to   NameSomthing.png NameSomthing1.png NameSomthing2.png   i.e., remove the characters -min from the name.  How would I do this?

I'm using this command to rename files:  for fname in *; do     mv "$fname" $(echo "$fname" | sha1sum | cut -f1 -d' ') done   But it only renames in the current directory. Let's say I have many directories, and each directory contains some other directories, and last directory tree contains files. I want to rename them with random characters.  I think find . -type f should work, and have tried it, but still did not get any working command.


I am using Ubuntu 12.04 with Unity. I just found that there is no Trash directory at: ~/.local/share/Trash like  here.  Where is the Trash dir?

Using Ubuntu 11.10, I accidentally deleted a file that was approximately 700 MB. I tried to find it in the in following locations, but couldn't:  /home/user/.local/share /home/user/ <-- there was no folder .Trash /home/user/Desktop/ <-- there was no folder .Trash   So where did .Trash go in Ubuntu 11.10 onward? I use the Gnome environment.


I'm very new to linux and have Jaunty 9.04 installed on my computer.   What are the steps should I take to upgrade it to 12.04?   When I use Upgrade manager, it tells me "upgrade from jaunty to lucid is not supported with this tool".   Thank you

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


How do you breed horses in Minecraft?  Do you just spawn one in creative mode right on top of another one or something like that?

In Minecraft, I know you can breed animals. In fact, in recent updates it's required for the player who just can't start their mornings without bacon and eggs!  I've tried pulling two pigs together in a single pen, but all they do is snort at me. And the chickens? Well, there's plenty of eggs, but no hatching.  How do I get them to make more bacon and eggs?


How can we prove that the limit $\lim_{(x,y)\rightarrow (0,0)} \dfrac{x^2y^2}{x^3+y^3}$ doesn't exist?  I have tried a lot of different paths and all of them lead to zero. I have only tried paths belonging to the domain and so I thank you for the lights that you've thrown here for me. When I've plotted the graphic of the function, it was clear that this limit doesn't exist, but could not prove it. For instance, this is an exercise of the book of Louis Leithold.

I want to know whether $\lim_{(x,y)\to (0,0)}\dfrac{x^2y^2}{x^3+y^3}$ exists or not. I tried to approximate to (0,0) from different "paths" and the result was always 0. For example,  $f(x,mx^2) = \dfrac{m^2x^3}{1+m^3x^3}$  But that doesn't show that the limit is 0.


I have this stuct declared in C. When I call sizeof(struct pixel), I am told that the size of this struct is 12 Bytes when I expect it to be 7 Bytes (1 for chars and 4 for the int). Why does this happen?  Struct:     struct pixel {         unsigned char red;         unsigned char green;         unsigned int alpha;         unsigned char blue;     };

Why does the sizeof operator return a size larger for a structure than the total sizes of the structure's members?


I have forgotten my Apple iCloud username and password. I can't remember the email address I used to sign up for the account. I need to turn off Find My iPhone before sending my iPhone in for servicing. My screen won't turn on at all so I don't know what else to do. I am being told that if I don't turn Find My iPhone off I can't get my phone fixed.  Is there any way I can recover my account information and turn off Find My iPhone in this situation?

I bought a used iPhone 4.  The previous owner re-set the phone, but did not remove the device from their iCloud.  It is asking me for their iCloud information when I try to set-up the phone.  I don't have contact with the previous owner anymore.  Is there a way to remove the device from their iCloud so I can use a new one?


Prove $\sum_{p=0}^k {n \choose p}(-1)^p=(-1)^k{n-1 \choose k}$ I tried use the expansion $(1-1)^n=0$ , but I can't find a simetry or binominal relactions.

QUESTION:   Prove that for all positive integers  $k\leq n$:  $\sum_{i=0}^{k}{n \choose i} (-1)^i = {n-1 \choose k}(-1)^k$  MY THOUGHTS:  INDUCTION : (assuming k even) - We assume:  ${n \choose 0} - {n \choose 1} + ... + {n \choose k-2} - {n \choose k-1} = {n-1 \choose k-1}$  We need to show:  ${n \choose 0} - {n \choose 1} + ...-{n \choose k-1} + {n \choose k} = {n-1 \choose k-1}$  My issue here is that we can say LHS equals ${n-1 \choose k-1} + {n \choose k}$, which is close, but not quite Pascal's Rule.   Another way: I thought looking to find some bijection that can be applied.   Let's assume n is even. Writing out the left and sum and moving all the odd (negative) terms to the RHS gives (note that the last term on the RHS is simply the original RHS:  ${n \choose 0} + {n \choose 2} + ... + {n \choose k} = {n \choose 1} + {n \choose 3} + ... + {n \choose k-1} + {n-1 \choose k}$    I am stuck here, but how I worked out in my mind was that:  $\bigg\{$set of even sized groups of  $\leq$ n people$\bigg\}$ -->  $\bigg\{$set of odd sized groups of  $\leq$ n-1 people$\bigg\}$ + ${n-1 \choose k}$  Then possibly, it would have something to do with adding or removing person n. Let me know your thoughts or suggestions.


I have an Integrated Intel graphics and AMD Radeon R5 M230 graphics card. and I want to switch to AMD whenever I want to.    I ran the lspci command for you to see.  00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 0b) 00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) 00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 0b) 00:14.0 USB controller: Intel Corporation 8 Series USB xHCI HC (rev 04) 00:1b.0 Audio device: Intel Corporation 8 Series HD Audio Controller (rev 04) 00:1c.0 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 3 (rev e4) 00:1c.3 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 4 (rev e4) 00:1c.4 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 5 (rev e4) 00:1d.0 USB controller: Intel Corporation 8 Series USB EHCI #1 (rev 04) 00:1f.0 ISA bridge: Intel Corporation 8 Series LPC Controller (rev 04) 00:1f.2 SATA controller: Intel Corporation 8 Series SATA Controller 1 [AHCI mode] (rev 04) 00:1f.3 SMBus: Intel Corporation 8 Series SMBus Controller (rev 04) 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 10) 02:00.0 Network controller: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter (rev 01) 03:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun LE [Radeon HD 8550M / R5 M230]

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


I need to generate ALL possible combinations of EACH element in each list of strings  list1 = ['The girl', 'The boy'] list2 = ['wears', 'touches', 'tries'] list3 = ['a red sweater', 'a blue sweater', 'a yellow sweater', 'a white sweater']   So the result is a list of a string combining each element combines with each other element:  The girl wears a red sweater The boy wears a red sweater The girl touches a red sweater The boy touches a red sweater The girl wears a blue sweater The boy wears a yellow sweater (ETC...)   I don't particularly care about the order of the output as long as ALL combinations are obtained.  From my research I guess "permutation" would be a solution but I only found several answers regarding permutations of lists of numbers, or combinations of each letter in a string. None of those things is what I need. I need to combine blocks of text arranged in lists.  How can I create a long list of sentences containing all of the combinations of the different elements in each one of the lists of strings?   Thank you

I have a list with 15 numbers in, and I need to write some code that produces all 32,768 combinations of those numbers.   I've found  (by Googling) that apparently does what I'm looking for, but I found the code fairly opaque and am wary of using it. Plus I have a feeling there must be a more elegant solution.  The only thing that occurs to me would be to just loop through the decimal integers 1–32768 and convert those to binary, and use the binary representation as a filter to pick out the appropriate numbers.   Does anyone know of a better way? Using map(), maybe?


How can I get rid of those little white dots? I am using Blender 2.70a.

I often use Cycles' built in Glass BSDF shader to achieve realistic refraction effects, but in many cases, it seems that Cycles' glass caustics creates an unfortunately large number of fireflies (pixels that are abnormally bright relative to their surroundings). In some models of mine, even when I render for 3000 or more samples/pixel, my final image is still covered in fireflies. While I can improve this in many cases by increasing the total amount of light available in the scene, this loses a lot of the potency of the refractive effects I'm looking for, especially in scenes with low light levels.  So my question is, how can I reduce the amount of fireflies while using Cycles' caustics without sacrificing the quality of the refractive effects?  Note: I am aware that Cycles' caustics will perform much better once Cycles has full support for bidirectional path-tracing, but it looks unlikely that that will become , unfortunately.


I installed VNC Viewer on my Ubuntu from . Then, I could connect to my Raspberry PI by both hostname and IP address. However, I can't do the same from my Samsung Note 8 I can't connect by hostname - I'm getting something like "Cannot resolve hostname". If I use the IP address then I don't have any problem.   Ubuntu PC, Samsung Note 8 and Raspberry PI3 are all connected to the same WIFI network.  Can someone explain what is wrong here?

I have a very strange behavior on an Android device (Nexus 7) when trying to access local network applications. Instead of getting the actual IP of the machine on LAN, the Android device gets the public IP, which means that Chrome, Firefox or any other browser simply shows the web page of the router.  I have an internal DNS server which handles the local networks. Doing ping from a PC works correctly:  $ ping s.pelicandd.com  PING pelicandd.com (192.168.1.15) 56(84) bytes of data. 64 bytes from front.pelicandd.com (192.168.1.15): icmp_seq=1 ttl=64 time=0.524 ms 64 bytes from front.pelicandd.com (192.168.1.15): icmp_seq=2 ttl=64 time=0.578 ms ^C   On an HTC One device (accessed with adb shell), it works well too:  shell@m7:/ $ ping s.pelicandd.com  PING pelicandd.com (192.168.1.15) 56(84) bytes of data. 64 bytes from front.pelicandd.com (192.168.1.15): icmp_seq=1 ttl=64 time=2.56 ms 64 bytes from front.pelicandd.com (192.168.1.15): icmp_seq=2 ttl=64 time=27.8 ms ^C   However, this is what I get when doing the same ping from Nexus 7:  shell@flo:/ $ ping s.pelicandd.com  PING pelicandd.com (90.78.26.42) 56(84) bytes of data. 64 bytes from LFbn-1-2441-42.w90-78.abo.wanadoo.fr (90.78.26.42): icmp_seq=1 ttl=64 time=2.56 ms 64 bytes from LFbn-1-2441-42.w90-78.abo.wanadoo.fr (90.78.26.42): icmp_seq=2 ttl=64 time=8.63 ms ^C   Instead of resolving to the internal IP, it resolves to the public one.  The network configuration is—except the IP address of the device—exactly the same on both devices: IP settings are set to Static, and DNS servers are the internal ones. Both Android devices are connected through Wi-Fi (unlike the PC). A major difference, however, is that Nexus 7 is using Android 6.0.1, while HTC One uses Android 5.0.2.  There is no nm-tool, dig or nslookup on Nexus 7. The device is not rooted.  The problem existed since I bought the device a few weeks ago, so it could hardly be the issue with DNS cache.  What can I do to further inspect this issue?


Is it possible from the command line to identify whether the current Wi-Fi connection, or a detected SSID, is an iOS personal/instant hotspot?   I know OS X can detect this, as it shows a specific "hotspot" icon in the topbar when scanning the list of SSIDs or when being connected to an iPhone (see screenshot)   I tried using /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I and ifconfig but I'm not able to find information that helps me identify an iOS hotspot.

When there is a Personal Hotspot network available, it displays a chain link icon instead of the usual lock icon in the list of available networks on iOS and OS X.    My question is, how does OS X distinguish these networks? Is it specified in 802.11 how hotspots broadcast their SSID's differently?