Can we (please) have the ability to comment while reviewing restored?

Related:   In the question linked to above, Affable Geek asked : Why was this changed and was it intentional. I don't know if what I'm asking here is implied on those questions, but just to be sure, I'd like to officially put in a feature request to have this ability restored. I spend most of my time on various S.E. sites reviewing instead of asking and answering.  I'm not sure what was behind the decision to remove this functionality, but as someone who spends most of my time trying to help new users, offer constructive guidance, and , the inability to leave comments seems extremely counter-productive. For new users, the most helpful thing we can do to help them improve their posts is to provide polite, helpful, constructive comments in the spirit of the .  (Which, IMO is or should be an endless summer...)  The inability do do this gains us nothing, and severely hampers our ability to help. This new restriction also seems a bit odd to me in light of all the Meta posts asking about how we can encourage (or force)people to comment when down-voting.  I realize it's a bad idea to force people to comment when down-voting, and I wouldn't suggest that, but the point is, all of these people recognize that simply voting down a question without leaving a constructive comment does absolutely nothing to help the person whose post is being down-voted.  I may be wrong, but I thought that the purpose for having the community moderate is to  Help your fellow members learn to use the site and raise the quality of Q&A by:  Evaluating new posts Voting to close or reopen questions Reviewing suggested edits   It's awful hard to be helpful when you have to . I ask the StackExchange team to please consider restoring our ability to comment while reviewing.


Chapter with specific number (1, 1b, 2, 2b, 3, 4)

Currently I use a manually declared version of the chapter title. But the idea is to extend it to use specific and manually chosen number of the chapters.  I try to obtain numbers like this 1, 1b, 2, 2b, 3, 4. But for obtaining b, I want to specify it manually with for example an option in the \chapter command (something like this \chapter{...} for obtaining 1 then \chapter[b]{...} for obtaining 1b.   Do you have any ideas for obtaining this result?


I just got to chapter 4 where       the gang moves to the swamp   and I bought the gold horse from the stable for $950. I only bought the horse because it was a war/racing horse breed. I did a couple of missions       in Saint Denis   and then I returned to camp to do a Strauss mission when you go and collect debts from people who owe the gang. On the way to a "Catfish Jackson" house I was met with 10+ bandits that in the end they ended up killing me. After I died it put me back in the game but it gave me a Tennessee Walker horse as my main horse. I have died by bandits before and I have always responded back with the horse that I died with and this just confused me. I wasn't too mad because I still have about $7000 but I am just curious of what happened. If you have any idea please respond.


From Lagrangian of Electromagnetic field to the Lorentz force?

The dynamics of a charged particle with velocity $\textbf{v}$ in electromagnetic field is dominated by the Lorentz force   $$\textbf{F} = q(\textbf{E}+{\textbf{v} \times \textbf{B}}), \tag{1}$$  and the corresponding Lagrangian is  $$L = \dfrac{1}{2}mv^2 - q\phi(\textbf{r},t)+q\textbf{v} \cdot \textbf{A}. \tag{2}$$      My question is: How to derive the equation $(1)$ just from $(2)$ ?


remove _ as prefix from the multiple files in a directory in Soalris

I have to remove _ which is as prefix for a file. I used:  for i in _*.txt; do mv ${i} ${i/#_/''}; done   but it does not change the names of the files which has space in between as _abc xyz-abc.txt  I want _ as prefix to be removed from all the files in a directory irrespective of space.


Deleting files on my macbook is not affecting the storage space?

How do I solve this problem? The storage space does not increase when I delete files. Yesterday, I deleted 250MB of files but made zero change to storage space. I have emptied the trash. I don't use Time Machine


Why does sound stop and how can I prevent it from stopping?

I have a Focusrite Scarlett 2i2 second generation USB card. The manufacturer doesn't supply a Linux driver. It works well right out of the box with Ubuntu Gnome 17.04, but stops after few minutes of playing sound. The card is ok, works well under Windows.  I checked out this article:   But I don't hear any difference after using Jack. Sound comes back in two cases, when I reboot the OS or when I unplug and plug the card again. It seems to me like the OS is disabling this device after a while convinced that it's not in use or was unplugged.   It's not power related. USB is still working. I see glowing diode on card's front pannel.  Can anyone help me with this issue?  Edit:  :~$ lspci -nnk | grep -A2 Audio   00:1b.0 Audio device [0403]: Intel Corporation 5 Series/3400 Series    Chipset High Definition Audio [8086:3b56] (rev 06)       DeviceName:  Onboard Audio       Subsystem: Samsung Electronics Co Ltd R730 Laptop [144d:c06a]   Kernel driver in use: snd_hda_intel  --   01:00.1 Audio device [0403]: NVIDIA Corporation GT216 HDMI Audio   Controller [10de:0be2] (rev a1)       Subsystem: Samsung Electronics Co Ltd GT216 HDMI Audio Controller [144d:c06a]       Kernel driver in use: snd_hda_intel       Kernel modules: snd_hda_intel    $ aplay -l   **** Lista PLAYBACK urządzeń ****   karta 0: MID [HDA Intel MID], urządzenie 0: ALC269 Analog [ALC269 Analog]   Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0   karta 1: NVidia [HDA NVidia], urządzenie 3: HDMI 0 [HDMI 0]     Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0   karta 1: NVidia [HDA NVidia], urządzenie 7: HDMI 0 [HDMI 0]     Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0   karta 1: NVidia [HDA NVidia], urządzenie 8: HDMI 0 [HDMI 0]     Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0   karta 1: NVidia [HDA NVidia], urządzenie 9: HDMI 0 [HDMI 0]     Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0   karta 2: USB [Scarlett 2i2 USB], urządzenie 0: USB Audio [USB Audio]     Urządzenia podrzędne: 1/1     Urządzenie podrzędne #0: subdevice #0    $ pactl list short sinks   0   alsa_output.pci-0000_00_1b.0.analog-stereo  module-alsa-card.c  s16le 2 k 44100 Hz  SUSPENDED   1   alsa_output.usb-Focusrite_Scarlett_2i2_USB-00.analog-stereo module-alsa-card.c  s32le 2 k 48000 Hz  SUSPENDED     And yes, card is selected, is not muted, sound is being produced for a minute or so while playing from youtube or spotify. Then stops.


I've been trying to generalize the solution to this question: , so that it can work on an arbitrarily long bezier curve, but I can't seem to get the hook_assign() function to work right. (See also )  When I print the state of .select_control_point for each point on the curve before (or after) I call the hook_assign function, the console output looks right except the function still returns Warning: Requires selected vertices or active vertex group.   Below the code is some sample console feedback.  noodcurv = bpy.data.curves.new('noodcurve', type='CURVE')       #create a new curve noodcurv.dimensions = '3D'                                      #set some settings noodcurv.resolution_u = 2 noodcurv.bevel_object = bevob noodcurv.use_fill_caps = True  bez = noodcurv.splines.new('BEZIER')                            #create a new spline bez.bezier_points.add(len(coords)-1)                            #add points for k, coord in enumerate(coords):                              #set coordinates & handles     p = bez.bezier_points[k]     p.co = coord     p.handle_right_type = 'VECTOR'                              #or 'AUTOMATIC', 'ALIGNED', 'FREE_ALIGN'     p.handle_left_type = 'VECTOR'  noodcurvobj = bpy.data.objects.new('noodcurve', noodcurv)       #create object modnames = ['hook.'+str(k).zfill(3) for k in range(len(coords))] #create modifier names  for k, coord in enumerate(coords):                              #create modifiers & set Parent Object     noodcurvobj.modifiers.new(modnames[k], type='HOOK')              noodcurvobj.modifiers[modnames[k]].object = bpy.context.scene.objects['link'+modnames[k][4:]]  scn = bpy.context.scene                                         #scene variable scn.objects.link(noodcurvobj)                                   #link to scene & activate scn.objects.active = noodcurvobj  bez.bezier_points[0].select_control_point = True                #this fixes the warning!?  bpy.ops.object.mode_set(mode='EDIT')                            #change context for k, coord in enumerate(coords):                              #assign points to modifiers     p = bez.bezier_points[k]                                    #assign points to variables     p.select_control_point = True     for q,t in enumerate(bez.bezier_points):                    #debugging check         print('control point: ', q, ' is', t.select_control_point)     bpy.ops.object.hook_assign(modifier=modnames[k])            #assign vextex to modifier     p.select_control_point = False  bpy.ops.object.mode_set(mode='OBJECT')   Some of the console output:  control point:  0  is True control point:  1  is False control point:  2  is False control point:  3  is False control point:  4  is False Warning: Requires selected vertices or active vertex group  control point:  0  is False control point:  1  is True control point:  2  is False control point:  3  is False control point:  4  is False Warning: Requires selected vertices or active vertex group  control point:  0  is False control point:  1  is False control point:  2  is True control point:  3  is False control point:  4  is False Warning: Requires selected vertices or active vertex group ...   (I know it'd be better if I could use one loop instead of three, but as I ran into problems I kept rearranging stuff to more closely mimic the original answer, and at this point I'm out of ideas!)  I also noticed that if I set .select_control_point = True for one or more points before I enter the third loop, the warnings go away and the modifiers are all assigned to whatever control point(s) I selected before the loop (even though the console output will indicate I'm still stepping through the selected points correctly).  So what am I missing?


Short story about survivors on Earth after the atmosphere has frozen

This is a short story I read maybe in the '80s.  Earth has been thrown away from the Sun, probably due to a very large object passing through the Solar System, and the atmosphere has frozen in layers. There is a small family - father, mother, two children, who live in a room they have made airtight by hanging many layers of material to slow the loss of air. They keep warm with a 'camp-fire'. The father goes out every day in a suit of some sort to find food and mine frozen oxygen. It ends when they are found by another, larger group of survivors.  Does anybody know the title and author?


Which is correct: me and my wife or my wife and me?  The sentence in which this is used is       Ms. Smith informed me and my wife that she was afraid of being accosted.


can you release a game made by unity free on google play store

do i need to pay for anything in this situation : i m making mini games to raise money and cant afford unity pro or plus(don't think its worth it)for my original idea/game.i am also thinking about using unity ads(is that free to use as well).


The Proper use of Stations in Ticket to Ride Europe

I played a game of Ticket to Ride Europe recently, I don't own it but am vaguely familiar with the rules. When we started playing however there was some confusion about the placement of stations and I was out-voted 3:1. What the rules specifically say:     A Train Station allows its owner to use one, and only one, of the routes belonging   to another player, into (or out of) that city to help him connect the cities on his   Destination Tickets.    My interpretation is that this allows you to do what it says, use a single route owned by another player. The next bit toward the end of the section however states:     If a player uses the same Station to help connect cities on several   different Tickets, he must use the same route into the city with the   Station for all of those Tickets. The Train Station owner does not   need to decide which route he will use until the end of the game.   At this point the same route into the city statement was picked up really strongly. The group believed that this means several routes going out of a city could be used, as long as the same route into the city was used. In the end this meant that during the scoring they believed in the following diagram (red routes):   A continuous path from Frankfurt->Madrid exists. No continuous path from Brest->Madrid exists because it didn't use the same route into Paris as the Frankfurt route, and therefore couldn't share the blue link.     Can someone confirm if I'm correct, in that you can only use 1 link, and in this scenario both destination tickets are completed at the end of the game. If so can you think of any convincing arguments I can put forward to the group?


Is it possible to adjust your walk speed?

When I'm sneaking around, I can move more slowly and quietly by holding shift.   But walking this way is really slow. I would like to move a little bit faster, but not full speed.    On a console I imagine you have much finer control over how fast you move with the joysticks. Is there any way to accomplish this on the PC (without an external joystick)?  Perhaps there is a console command or config file setting that will change the % speed modifier that holding down shift uses?


Was this Apache v2.4 configuration correct?

I am using a VPS Server running on CentOS, Linux Platform. Recently some two to three before the VPS server starts behaving strangely.  I am using Google Analytics to track down the visitors. Take one hour time as an example. The live visitors to the site was about 50+ and everything seems fine, suddenly for no reason, the live visitors starts falling to less than 15. After 2 - 5 minutes, it starts to rise again to 40+, sometimes goes above 50. Then, again the traffic starts falling.   This cycle repeats 5 - 6 times every hour which causes a huge fall in the 24hr traffic. I asked the hosting team and they said the server is fine with enough resources to handle even more traffic.  Here are the following specs for Apache.  Start Servers: 8 Minimum Spare Servers: 8 Maximum Spare Servers: 16 Server Limit: 256 Max Request Workers: 250 Max Connections Per Child: 2500 Keep-Alive Timeout: 10 Max Keep-Alive Requests: 300 Timeout: 60   One Wordpress site is hosted which is getting 5000 unique visitors every day. But the Apache server struggling to serve more than 25 visitors constantly. There are heavy fluctuations occurring every hour, sometimes the live visitors grow more than 50+ and fall after 2 - 3 minutes to less than 20. After 10 minutes, the cycle repeats.  I tested average server load which is very normal, 98% CPU is idle always. How to tune Apache to serve requests constantly 40+(Approx)?


How do I start investing stocks?  I have around 50 bucks I want to start buying stocks the problem I don't want pay a commission fee and the second problem is I live in Europe which means I don't have access to apps like Robinhood  so if you guys know any alternatives it would be really helpful!


What happens to atoms inside a black hole?

Black holes have very high gravitational force that tends to crush everything. So as we know atoms in a molecule have inter-atomic spacing between them and further electrons also revolve at a certain distance to the nucleus and inside the nucleus there is also some empty space. So does the strong force of a black hole crush them all the way, leaving no space in between them? And, if that happens, then it should give rise to a completely new species of atoms and molecules, right?


How do you get a value between "," in JS (comma)

I'm trying to get a value that's between, next or before of a comma.  For example, my string is: "value1,value2,value3,value4", sent to JS through PHP (ajax)  How do I just get value2 and value4 inside the .js file?


Let $\; p,d \,$ be prime numbers I wanna proof that $\; M:=\{a_o+a_1\sqrt p +a_2\sqrt d +a_3\sqrt {pd}:a_o,a_1,a_2,a_3 \in \mathbb Q  \}\;$ is a field. The only thing I am having trouble with is finding the inverse of $p \in M$. Is it true that $\;M\;$ is a field and if so how would one find the inverse of an element. Give me a little hint.


Does there exist a positive integer $n$ such that $4^n - 1$ is not divisble by $3$?

Does there exist a positive integer $n$ such that $4^n - 1$ is not divisible by $3$? If so, what is it, and if not, prove it. This is just a recreational problem that seemed simple at first but I couldn't figure it out.


Is there any way to upgrade my distro from 14.04 to the development version of 16.04.  Using  update-manager -d   tells me about 14.10, which is weird since this version is not suppported anymore.


Is Thanos the only survivor of his planet?

When Thanos described his planet, he mentioned that they were on the brink of collapse as a civilization. But I haven't seen anyone from his species in the movies.   Is he the only survivor? I guess many did have escaped Titan before their impending doom. Or nobody make it except Thanos?


The effect of gravitational & Coulomb forces on free electrons in a conductor

In a metal, why don’t the free electrons fall to the bottom of the metal due to gravity?  Also, charges in a conductor are supposed to reside on the surface so why don’t the free electrons all go to the surface?   Regarding the first question, my hunch is that it is due to the electric force which is greater than the gravitational force and electric force act along the length of the conductor.  I don't have any intuition for the second.


How to get text messages off phone with broken screen

I would like to access and transfer text messages from an Xperia E to a new phone. I've found several applications that appear to let me do so, but all of them require USB Debugging to be on. Since the screen is broken (but I do still have touch functionality as far as I can tell) I have no idea how to turn this feature on.   All questions about the USB debugging issue get closed and redirected to an existing question that doesn't help me, so I'm hoping that there is some way to get the texts without the need for USB debugging.


Remove Duplicate Values from stored procedure object

I have a stored procedure which will grab team names along with the admin users of the team, or if the team does not have an admin, replace the user with N/A. The following is the stored procedure: BEGIN     SELECT teams.name,             IFNULL(users.email,'N/A') as email,             IFNULL(users.name,'N/A') as user_name,             IFNULL(team_user.role,'N/A') as role     FROM teams         LEFT JOIN team_user ON teams.id=team_user.team_id         LEFT JOIN users ON team_user.user_id=users.id     WHERE role is NULL     OR role='admin'; END  I would like to display the result of the stored procedure in a table. The following is an example of the table that it displays:     Team Name User Name     Team1 AdminUser1ForTeam1   Team1 AdminUser2ForTeam1   Team 2 AdminUser1ForTeam1   Team3 AdminUser1ForTeam3   Team3 AdminUser2ForTeam3     The problem with this table is that if a team has more than 1 admin, the team name will be repeated in two separate rows. The following is the result I want to achieve:     Team Name User Name     Team1 AdminUser1ForTeam1, AdminUser2ForTeam1   Team 2 AdminUser1ForTeam1   Team3 AdminUser1ForTeam3, AdminUser2ForTeam3     Here is the html/php code to draw the table

         @foreach($tester as $test)
             {{$test->name}}	             {{$test->user_name}}	             {{$test->email}}
         @endforeach

      With $tester being the variable returned from the stored procedure. Any ideas on how I can achieve the second table, any help is greatly appreciated!


Showing a commutative ring with field subring has a unique ring homomorphism on polynomials

Consider the following problem, given without solution in a german abstract algebra text book:     Let $R$ be a commutative ring with $1$ and $K \subseteq R$ a subring,   such that $1 \in K$ and $K$ is a field.      Show that for each $r\in R$ there exists a unique ring homomorphism   $\varphi: K \left[X\right] \rightarrow R$, such that $\varphi(a) = a$   for $a \in K$ and $\varphi(X) = r$.       $K\left[X\right]$ is the ring of all polynomials over $K$ with variable $X$.   I do not know at all about how to approach this. This is the beginning of a very introductory course on abstract algebra, and I feel like I'm missing the required tools here. How can this be proven?


How can I save file’s to the user’s computer via JavaScript in Firefox and IE?

I need to create a persistent file and save about 50mb of data in it.  . Is there another way to create local files that works in latest versions of Firefox and IE?


Capacitor with different charges on each plate

I am confused as to whether/how capacitance changes when each plate has a different charge.  For example, consider a coaxial cable and put $20Q$ on the outer cable, and $-Q$ on the inner. Or how about concentric spheres, grounding either the inner or the outer?


What are the differences between class, set, family, and collection?

In school, I have always seen sets. I was watching a video the other day about functors, and they started talking about a set being a collection, but not vice-versa. I also heard people talking about classes. What is their relation? Some background would be nice.   It has to do with something called Russell's paradox, but I don't know what that is.   I think that the difference between a family and a set is that the former is a function and the latter is a set. Is this right?


I don't know a thing about LaTex, but I grab this bash script from the internet to convert .c and .h file to PDF.  I would like to change the font, or at least make it bigger.   Here's the code :   #!/usr/bin/env bash  tex_file=$(mktemp) ## Random temp file name  cat<<EOF >$tex_file   ## Print the tex file header \documentclass{article} \usepackage{listings} \usepackage[usenames,dvipsnames]{color}  %% Allow color names \usepackage{courier} \lstdefinestyle{customasm}{   belowcaptionskip=1\baselineskip,   xleftmargin=\parindent,   language=C,   %% Change this to whatever you write in   breaklines=true, %% Wrap long lines   basicstyle=\footnotesize\ttfamily,   commentstyle=\itshape\color{Gray},   stringstyle=\color{Black},   keywordstyle=\bfseries\color{OliveGreen},   identifierstyle=\color{blue},   numbersep=100pt,   showspaces=false,   showstringspaces=false,   xleftmargin=-8em, } \lstset{    basicstyle=\fontsize{25}{13}\selectfont\ttfamily }  \usepackage[colorlinks=true,linkcolor=blue]{hyperref} \begin{document} \tableofcontents  EOF  find . -name "*\.c" -o -name "\.h" | sed 's/^\..//' | sed 's/^\..//' |                 ## Change ./foo/bar.src to foo/bar.src  while read  i; do                ## Loop through each file    echo "\newpage" >> $tex_file   ## start each section on a new page   echo "\section{$i}" >> $tex_file  ## Create a section for each file    ## This command will include the file in the PDF   echo "\lstinputlisting[style=customasm]{$i}" >>$tex_file done && echo "\end{document}" >> $tex_file && pdflatex $tex_file -output-directory . && pdflatex $tex_file -output-directory .  ## This needs to be run twice                                            ## for the TOC to be generated   I've tried to add the line   \lstset{    basicstyle=\fontsize{25}{13}\selectfont\ttfamily }   and add :   numbersep=100pt,   to change the font size, but nothing happened. Any help would be greatly appreciated!


Maximum number of monitors Win 7 Supports

In a post sometime last year you wrote;  "... The maximum continuous windows desktop available is up to 32k horizontal pixels by up to 32k vertical pixels with an overall pixel limit of 128 million pixels..."  Is this based on some Microsoft/other reference doc or your practical experience perhaps? Looking for a definitive answer here - thx.


How much did the Trade Federation know about their 'lord' at time of blockade?

Once it became clear who Palpatine/Sidious was, I got to questioning just how much the Trade Federation knew about the mysterious hooded figure who was ordering them around. At one point we have the exchange about landing troops on Naboo:     Nute Gunray: My lord, is that legal?   Palpatine: I will make it legal!                                    It must have seemed strange to them that the senator (at that stage at least) wanted them to first blockade his own planet, then invade it.  It is implied they knew something about him in that they accepted his assurance that he would make it legal. Unless he was the chancellor, or a very highly regarded or skillful senator, the claims of 'making it legal' would not have had much chance of convincing fearful underlings.   I figure that the group powerful enough to realize those claims must have consisted of less than 50 individuals in the entire senate. Probably half of those had Jabba the Hutt bodies or eye stalks, meaning they would not look close enough to humanoid and could be immediately discounted - so that leaves only around 25 individuals it might have been. Remove the female senators, and the men whose voices were completely different to that of their lord and you might have 3-4 left.  On the other hand, if they did not know who he was, why were they following his instructions?


Volume of revolution by the region bounded by the parabolas $y^2=x, y^2=8x, x^2=y, x^2=8y$ about the $x$ axis is $\frac{279\pi}{2}$.

Show that the volume generated by revolving the region in the first quadrant bounded by the parabolas $y^2=x, y^2=8x, x^2=y, x^2=8y$ about the $x$ axis is $\frac{279\pi}{2}$.  I've used the substitution $y^2=ux, x^2=vy$. The domain I'm supposed to integrate over is something like this leaf shaped region with another leaf cut out from it.  So I've computed the inverse Jacobian to be $\frac{\partial u}{\partial x}\frac{\partial v}{\partial y}-\frac{\partial u}{\partial y}\frac{\partial v}{\partial x}$ = $-\frac{y^2}{x^2}(-\frac{x^2}{y^2})-\frac{2x}{y}\frac{2y}{x}$=$1-4$= $-3$  So we get the Jacobian of this transformation to be $\frac{-1}{3}$.  The problem is that I don't know what to plug into my limits of integration and the function I have to integrate over. I have the general sense of where I'm supposed to go from here. For instance, I can visualise values of $u$ taking on a family of curves 'fitted' in between $x=y^2$ to $x=8y^2$ and likewise for values of $v$. Increasing values of $u$ and $v$, intutively seems like going along these family of curves until you get to u=8 and v=8 respectively.  But I have no idea how to translate what I know about calculating the volume of a region rotated into this kind of $u$-$v$ 'coordinate system', if that's even a possible way of putting it.  Intutively, it seems like $\int^8_1 \int^8_1 u^2-v^2 (-\frac{1}{3}) du dv$ would work, but it doesn't. Can someone help me from here? Also, the negative value of the Jacobian seems a little fishy to me. I'd be grateful if someone could help me clarify any mistakes/misconceptions.


What triggers the benefit of the bard's "Song of Rest" feature?

In D&D 5e, the benefit of the Bard's "Song of Rest" feature triggers "if you or any friendly creatures who can hear your performance regain hit points at the end of the the short rest."  Does Song of Rest's benefit apply just when spending hit dice to regain hit points? Or does it apply to any other way that a player might regain hit points at the end of a short rest (e.g. by casting a spell, using a Second Wind, eating a Goodberry, etc.)?


what does frozen and unfrozen discard pile mean? I've been playing for a while and never heard that term?

What makes the discard pile locked or frozen? I've never heard of this term.


So, i have a function in my template file functions.php which cache a search form that contain a custom taxonomie terms. I want to flush cache (or delete one cache group) when I add/delete/edit terms of a specific taxonomie.  Is it possible? maybe with do_action, but for which hook? thx


Which registry key holds the license type in ArcGIS 10.x?

I'm unable to change my license type (ArcView, ArcEditor or ArcInfo) in ArcGIS 10.0 using the Desktop Administrator due to permissions restrictions.  I'm trying to use the back-door method of changing the registry key in Regedit. In older versions of ArcGIS this was found under > HKEY_LOCAL_MACHINE > Software > ESRI > License but I'm not seeing this in ArcGIS 10.0  The post  mentions a similar problem on Citrix, however I'm unable to set a system variable due to the same permissions issues.  Which registry key holds the license type in ArcGIS 10.0, and is it still possible to change the license type using this method?


Show that a star convex set $X \subset \mathbb{R^n}$ is simply connected.

Show that a  set $X \subset \mathbb{R^n}$ is simply connected.  I have the idea of the proof : There is a natural  of $X$ onto the set  $\{x_0\}$, because every other point $x \in X$ can be continuously mapped  by $f:X \to \{x_0\}$ to $x_0$.  ( I am sure that I need to say : along the segment joining them, but seemingly I can write a retraction without specifying how to map $X$ onto $\{x_0\}$, it is strange !!! ).   the only open sets in $\{x_0\}$ are the empty set $\emptyset$ and the whole space $\{x_0\}$, preimage of both under $f$ is open in $X$. And since, obviously !, $f(x_0)=x_0$, $f$ is a retraction of $X$ onto $\{x_0\}$.  Since $\pi_1(\{x_0\})$ is trivial, the theorem implies that $X$ is simply connected.  My proof can not be correct, since I can find :D a retraction from a subset of $\mathbb{R^n}$ which is not star convex onto a point $x_0$ , and finally claim that $X$ is simply connected.  Any help is appreciated, Thanks !


Template meta programming : print type list

How can I print a type list ??  here is what I tried + my type list :  template<typename ...T> struct typeList; template<typename H, typename ...T> struct typeList<H, T...> {     using head = H;     using tail = typeList<T...>; public:     static inline void print(){         std::cout << H::name << " "; // How can I get the name of H ???         typeList<T...>::print();     } };  template<> struct typeList<>{    static inline void print(){        std::cout << endl;    } };   so that typeList<A,B,C,int>::print() would give A b C int ,   A B and C are some user defined structs  Can I do this without adding a static function called name in every struct??  There is no compile time function that returns the type name ?  EDIT :  This is not a duplicate of , where did I mention variables ??


What's the subject of 'mind not so much to know' ? (1670 UK, Isaac Penington)

Para 5, , by      The Lord so guide thee, manifest himself to thee, help thee, and lead   thee by his Holy Spirit and power, as that thou mayst come undeniably   to experience, and to be satisfied by him about these things. And mind   not so much to know, as to be obedient <445> [sic] and subjected to the   Lord, both in thy heart and in thy conversation also, in the least thing that he makes manifest.    1. What's the subject of the verb mind? How do you determine/deduce this?  2. Does this para reveal what is the least > thing that he makes manifest?


Ctrl+Alt registering as AltGr for US International Alternate, any way to disable?

I am using the US International Alternate keyboard layout on Windows. Google Docs has Ctrl+Alt+M to enter a comment, but with this keyboard layout that registers as AltGr+M, which produces µ. Is there any way to prevent Ctrl+Alt from registering as AltGr?


I was asked on the best and worst case scenario for this function:  def is_palindromic(the_list):      result = True      the_stack=Stack()     for item in the_list:         the_stack.push(item)     for item in the_list:         item_stack=the_stack.pop()         if item != item_stack:             result = False     return result   This function determines if a list is the same as its reverse using a stack. I thought the time complexity was the same for every case but when I tested, it took longer to run if the list was indeed the same as its reverse. Can anyone explain why? I am a bit confused.


Pointers are the core to programming languages like C and C++. This at the same time leads to many errors and memory leaks. What are some precautions that must be taken while using pointers in C and C++?


Difficulty in understanding a part in a proof from Stein and Shakarchi Fourier Analysis book.

Theorem 2.1 : Suppose that $f$ is an integrable function on the circle with $\hat f(n)=0$ for all $n \in \Bbb Z$. Then $f(\theta_0)=0$ whenever $f$ is continuous at the point $\theta_0$.      Proof : We suppose first that $f$ is real-valued, and argue by contradiction. Assume, without loss of generality, that $f$ is defined on $[-\pi,\pi]$, that $\theta_0=0$, and $f(0) \gt 0$.      Since $f$ is continuous at $0$, we can choose $ 0\lt \delta \le \frac \pi2$, so that $f(\theta) \gt \frac {f(0)}2$ whenever $|\theta| \lt \delta$. Let $$p(\theta)=\epsilon + \cos\theta,$$   Where $\epsilon \gt 0$ is chosen so small that $|p(\theta)| \lt 1 - \frac \epsilon2$, whenever $\delta \le |\theta| \le \pi$. Then, choose a positive $\eta$ with $\eta \lt \delta$, so that $p(\theta) \ge 1 + \frac \epsilon2$, for $|\theta| \lt \eta$. Finally, let $p_k(\theta)=|p(\theta)|^k$, and select $B$ so that $|f(\theta)| \le B$ for all $\theta$. This is possible since $f$ is integrable, hence bounded.      By construction, each $p_k$ is a trigonometric polynomial, and since $\hat f(n)=$ for all $n$, we must have $\int_{-\pi}^{\pi} f(\theta)p_k(\theta)\,d\theta=0$ for all $k$.   I understood the first paragraph clearly. But the rest is not making it's way into my head.   In the beginning of second paragraph, how does the given range works for choosing $\delta$? If the continuity is used to get the range, then how? How can we choose $\epsilon$ so small such that, $|p(\theta)| \lt 1 - \frac \epsilon2$, whenever $\delta \le |\theta| \le \pi$? How can we choose positive $\eta$ with $\eta \lt \delta$, so that $p(\theta) \ge 1+ \frac \epsilon2$, for $|\theta| \lt \eta$. Why do we must have $\int_{-\pi}^{\pi}f(\theta)p_k(\theta)\,d\theta=0$ for all $k$?


I've made  about this, but I think it deserves a feature-request now - we've been getting a lot of use of the spoiler syntax on gaming. The spoiler box is great but it could really use some sort of message telling viewers it's a spoiler, otherwise it looks like a badly-formatted answer on first glance - especially for users unfamiliar with SE sites, the kind of users we also cater for and try to draw. I think having some sort of "SPOILER - hover over this to reveal text" message is important. If this is technically too difficult, maybe just add it as a small-font red message just above the block. Mockup time!


Ubuntu won't update apps or main OS - how can I go back to Windows?

Nothing happens when I select update, the update just hangs Both for apps and main OS updates.  I've tried opening terminal and typing   sudo apt-get update    and   sudo apt-get upgrade   But i get an error:  E: Unable to lock directory /var/lib/apt/lists/   I have this system dual booting with Windows 10, I wish I'd never put it in now.  People keep telling me it runs better, but it wont even update.  Now I am stuck with it anyway, so I try to use it sometimes, but usually have little success.  Any ideas?


Why falling camera/objects rotate and then stabilize?

I was going to ask something very similar to  (which hasn't been answered). Basically a camera fell from an airplane and it began to rotate (maybe because initially it was put in rotation by the hand from which it fell) but then it stabilized! I saw the same phenomena with Felix (the guy from red bull Stratos), though I think the stabilization occurred because of the little-mini-parachute that skydivers use to stabilize their descent.  My question is, does terminal velocity have something to do with this stabilization? GoPro cameras are like a cube, so intuitively, when the cube reaches terminal velocity it will receive the same force throughout the surface that points downwards, if it's not rotating, it will remain stable, if it is rotating how does this "uniform" force over the rigid body stabilize it?  I appreciate your thoughts on the problem.


On the proof that every positive continuous random variable with the memoryless property is exponentially distributed

The theorem to prove is: $X$ is a positive continuous random variable with the memoryless property, then $X \sim Expo(\lambda)$ for some $\lambda$. The proof is explained in this , but I will type it out here as well. I would like to get some clarification on certain parts of this proof.  Proof Let $F$ be the CDF of $X$, and let $G(x)=P(X>x)=1-F(x)$. The memoryless property says $G(s+t)=G(s)G(t)$, we want to show that only the exponential will satisfy this. Try $s=t$, this gives us $G(2t)=G(t)^2,G(3t)=G(t)^3,...,G(kt)=G(t)^k$. Similarly, from the above we see that $G(\frac{t}{2})=G(t)^\frac{t}{2},...,G(\frac{t}{k})=G(t)^{\frac{1}{k}}$. Combining the two, we get $G(\frac{m}{n}t)=G(t)^\frac{m}{n}$ where $\frac{m}{n}$ is a rational number. Now, if we take the limit of rational numbers, we get real numbers. Thus, $G(xt)=G(t)^x$ for all real $x>0$. If we let $t=1$, we see that $G(x)=G(1)^x$ and this looks like the exponential. Thus, $G(1)^x=e^{xlnG(1)}$, and since $0 <G(1) \leq  1$, we can let $lnG(1)=-\lambda$. Therefore $e^{xlnG(1)}=e^{-\lambda x}$ and only exponential can be memoryless.  So there are several parts that I am confused about:  Why do we use $G(x)=1-F(x)$ instead of just $F(x)$? What does the professor mean when he says that you can get real numbers by taking the limit of rational numbers. That is, how did he get from the rational numbers $\frac{m}{n}$ to the real numbers $x$? In the video, he just says that $G(x)=G(1)^x$ looks like an exponential and thus, $G(x)=G(1)^x=e^{xlnG(1)}$. How did he know that this is an exponential?


I am new to Salesforce development. I made a trigger that creates a new asset record and autofills some of the fields on said record. What I want ultimately would be a button that I can put on the "Products" related list on the opportunity page that does what my trigger does. From what I understand, I can't just call my trigger on the button click, and I have to create a VF page or an Apex class that uses the trigger's logic. Does anyone know how I would go about doing this? Here's my code:  trigger ConvertOpportunitiesToAssets on Opportunity (after update) {      List<Asset> a = new List<Asset>();     OpportunityLineItem oli = new OpportunityLineItem();      for(Opportunity o: Trigger.new)     {                   a.add( new Asset(             PSI_Supplier__c = o.Supplier__c,             PSI_Opportunity__c = oli.Product2Id,             AccountId = o.Accountid,             Name = oli.Product2Id,             Product2Id = oli.Product2Id,             Product_Name__c = oli.Product_Name__c             ));            }     insert a; }   Thanks in advance!  UPDATE So I tried making the trigger into a class and button (thanks sfdcfox!), but now it won't work. Here's what I've got:      global class OpportunityWS{     webservice static void createAsset(Id opportunityId)     {         List<Asset> a = new List<Asset>();         Opportunity o = new Opportunity();         OpportunityLineItem oli = new OpportunityLineItem();          a.add( new Asset(             PSI_Supplier__c = o.Supplier__c,             PSI_Opportunity__c = oli.Product2Id,             AccountId = o.Accountid,             Name = oli.Product2Id,             Product2Id = oli.Product2Id,             Product_Name__c = oli.Product_Name__c             ));                 insert a;      } }  {!RequireScript("/soap/ajax/34.0/connection.js")} {!RequireScript("/soap/ajax/34.0/apex.js")} function success() { var alertString="Success!";  alert(alertString);  } function error() { var alertString="Error!";  alert(alertString);  } sforce.connection.sessionId = "{!$Api.Session_ID}"; sforce.apex.execute("OpportunityWS", "createAsset", { opportunityId: "{!Opportunity.Id}" }, { onSuccess: success, onFailure: error });   I can't tell if it's something wrong with the class or the button. I think it must be the class.  UPDATE(AGAIN) Alright so I followed Doug's advice and tried to use the opportunityId to query the opportunity and opportunityLineItem sobjects, was able to compile without errors. But now I'm getting the error message that I made in the button thrown and the asset isn't being created. Unfortunately, I haven't been able to track down the issue. Here's the OpportunityWS apex class that I've updated since last edit:  global class OpportunityWS{ webservice static void createAsset(Id opportunityId) {     List<Asset> a = new List<Asset>();     List<Opportunity> o = [SELECT Supplier__c, Accountid FROM Opportunity WHERE Id = :opportunityId];     List<OpportunityLineItem> oli = [SELECT Product2Id, Product_Name__c FROM OpportunityLineItem WHERE Id = :opportunityId];      a.add( new Asset(         PSI_Supplier__c = o[0].Supplier__c,         PSI_Opportunity__c = oli[0].Product2Id,         AccountId = o[1].Accountid,         Name = oli[0].Product2Id,         Product2Id = oli[0].Product2Id,         Product_Name__c = oli[1].Product_Name__c         ));             insert a; }   }


I have two hard drives (one internal, one usb, both connected to the same PC), each has a 'movies' folder. Can I somehow view both 'movies' folders in one folder as though all files resided together?


I vaguely remember seeing this theorem somewhere but am having trouble finding a proof. It is difficult to search for a proof because it is difficult in general for symbolic identities and terms like "inverse", "multiplication", "ring", and "distributive" are quite general in ring theory.  I have gotten this far:  $1=\left(ab\right)^{-1}\left(ab\right)\quad1=bb^{-1}a^{-1}a$  $\left(ab\right)^{-1}\left(ab\right)=bb^{-1}a^{-1}a$  $\left(ab\right)^{-1}\left(ab\right)a^{-1}=bb^{-1}a^{-1}aa^{-1}$  $\left(ab\right)^{-1}\left(ab\right)a^{-1}=bb^{-1}a^{-1}$  $b^{-1}\left(ab\right)^{-1}\left(ab\right)a^{-1}=b^{-1}bb^{-1}a^{-1}$  $b^{-1}\left(ab\right)^{-1}\left(ab\right)a^{-1}=b^{-1}a^{-1}$  Without commutativity, I cannot simply rearrange the $\mathrm{LHS}$ to an expression where I can eliminate $(ab)$.  I may be taking the wrong approach, so any help (including starting over from the beginning) is welcome.


When asking from Android app, showing new question fails

I've only used the app to post a few times, but when I do this always happens: I submit the question, the app seems to try to take me to my new question, and I get a failure message with a "retry" button, which doesn't change anything. However, my question really was posted, as confirmed in a browser on a computer.  Is this normal? (Maybe my connection is dicey and the timing is unforgiving?) The first time it happened I was alarmed because I thought I'd lost my work.


Which one is more common? Example sentence:  The firework festival was held at/by the river.  Or are they equally correct?


How to do a Point to Polygon analysis with multiple variables in QGIS?

I have a database of almost 10k crimes, which are divided in to 10 categories and plotted on a map  I also have a database of 12k addresses, which are also plotted on the map.   I aim to perform a multiple regression to determine whether there are correlations between types of crime and house price.  I have created a buffer of 250 meters around each of the addresses, and would like to list a count of each of the crimes which are located within this buffered zone for each of the addresses, however, I can only get QGIS to give me a count of all types of crime, rather than the specifics.   Does anyone know how to do a point to polygon analysis of this type? I am in the middle of breaking the crime databases to analyse each one separately, which is a bit difficult!


I will be staying in Krabi on 29 October 2017. My flight from Krabi airport is at 8.00 am on 30 October 2017. I have to be at the airport at least by 7.00 am. Please advise me the cheapest and most efficient transport to the airport. (I will be only carrying a backpack).


Is there a way to declare first and then initialize an array in C?  So far I have been initializing an array like this:  int myArray[SIZE] = {1,2,3,4....};   But I need to do something like this  int myArray[SIZE];  myArray = {1,2,3,4....};


Use LightningStylesheets=true on Lightning Community

We are developing a new Lightning Community to replace our Partner Community. However, when we use our visualforce pages with LightningStylesheets=true on the Lightning Community, the Lightning styling is not applied.  I understand that this is the case because Lightning Communities are not Lightning Experience.  Is there a way to force LightningStylesheets anyway? I am trying to stay away from having to rebuild/restyle all our legacy visualforce pages.


One prepaid SIM for 4 weeks of travel in both the US and Canada?

I'm planning to visit the US and Canada in summer (4 weeks, road trip along the east coast), and I'd like to have mobile internet while being there.  Are there any reasonably priced prepaid SIM options that cover both countries?


Linux, find all files matching pattern and delete

Looking to find all files (recursively) which have an underscore in their file name and then delete them via command line.


I am having problems with Adobe Flash in Ubuntu, what are my options?


I have a very stupid question. I developed a website that has only one page at the public html directory(index.php).  all content are dynamically loaded as different pages.   How can i SEO my pages for google?  i mean like the what we type in this site are .............i believe stored in database and search engine find these pages like any static pages...  Just a little tip would be appreciable.......!


How to replace the search submit button with a Font Awesome character?

I would like to replace the search submit button with a Font Awesome character like the Magnifier (Search Icon) character, and put Search the site inside the search box.  How can I achieve something like this?


How many solutions has the equation $x_1+x_2+\cdots+x_k=n$ in non-negative integers?


What kind of special character is this: 𝓱𝒆𝓪𝓿𝒆𝓷𝓼 𝓰𝓪𝓽𝒆?

I see someone wrote this comment in a Facebook post:     𝓱𝒆𝓪𝓿𝒆𝓷𝓼 𝓰𝓪𝓽𝒆     ...and I'm quickly interested in finding what kind of character is that, so I googled it, but the search results return the ordinary text as "heavens gate", not the stylized one.  What kind of special character is that? How to write that character and what is the unicode number range for that stylized character from A to Z (and for number too, if exist)?


Project Honeypot says my mail server has become a spammer

I need help diagnosing this:  It says my server has been sending spam for 4 months!  I try to be a responsible mail server admin, I hate spam, I do everything I am capable of to prevent it from happening. I need to figure out what is going on and where it is coming from so I can stop this.  I have watched the logs and tcpdumped traffic and I cannot find anything out of the ordinary. Everything going out is legitimate emails from users. There is no sign of spam, and no sign of increased traffic.  Network is locked down by a firewall/gateway server running shorewall. The 66.18.204.186 IP address is one of several static IP addresses I have, but it is the ONLY IP address I use for mail and it is dedicated to only that purpose. It is 1:1 NAT translated to an internal server at 192.168.50.9 (bismark - my mail server) The firewall is configured to allow traffic in/out on port 25 ONLY from this server, and ONLY mapped to that outbound IP. This works, I've tested it, there's no way in or out on port 25 from any other computer on the network.  This leaves me with the conclusion that any spam originating from that IP address must indeed be coming from my mail server but I have no idea how. My only guess is a compromised user account password (it does allow external SMTP auth, defended against brute force by fail2ban)  I can't see any spam going out at the moment. How do I monitor for it? How will I know if it starts again? More importantly, how do I make sure it will never start again? Help! I don't want to be one of the bad guys!


I was hoping to left align the 'Reason not found' text so that it is in line with the other rows. \begin{table}%[htb!]     \caption{Reasons}     \centering     \begin{tabular}{|p{2cm}|l|l|l|l|}         \hline         \textbf{Scheme} & \textbf{R } & \textbf{Type} & \textbf{State} & \textbf{P} \\ \hline         \multirow{2}{*}{V (3)}          & M (2) & \multirow{4}{*}{S } & Accepted & 2 \\ \cline{2-2} \cline{4-5}          & No M. (1) &  & Rejected & 1 \\ \cline{1-2} \cline{4-5}                   \multirow{2}{*}{P (2)} & M (1) &  & Accepted & 1 \\ \cline{2-2} \cline{4-5}          & No M (1) &  & Rejected & 1 \\ \hline                  \multirow{5}{*}{                           \begin{tabular}{l}Reason\\not found\\(38) \end{tabular}         } & & \multirow{2}{*}{S} & Accepted & 32 \\ \cline{4-5}          &  &  & Rejected & 3 \\ \cline{3-5}          &  & P & Accepted & 2 \\ \cline{3-5}          &  & I & Accepted & 1 \\   \hline  % \cline{2-5}               \end{tabular} \end{table}


passwordless ssh setup without user directory

Password less SSH without user directory?  The folder .ssh should be stored in a user directory as far as I understood.  ServerA: Linux without /home/users ServerB: Linux with /home/users client:  Linux/mac etc...   Cases:   client password-less ssh to ServerB, no problem client password-less ssh to ServerA, no problem SeverA password-less ssh to ServerB, problem!   If there is no actual user directories in ServerA how public key for each user without user directory existing?  Or is there other ways to safely ssh to ServerB from ServerA?


How to check the value of a dictionary key is string or integer

seatList1 = {'seat1': 1, 'seat2': 2, 'seat3': 3, 'seat4': 4, 'seat5': 5, 'seat6': 6, 'seat7': 7, 'seat8': 8, 'seat9': 9, 'seat10': 10 }      We were asking to make a ticket selling system, there are ten seats in total. I am planning to check they are ordered or not by data types. Once user typed their details in and choose an empty seat, the value of seat they choose will become to their first name. So that, to check a seat is ordered or not, the only thing I need to do is check those value of keys are integer or string  For example: user typed his details first, and then choose seat1, after that the value of 'seat1' key will be his name, instead of   'seat1': 1   But  'seat1': 'Tom'   If the value is a String instead of a number, there's no doubt that this seat has been ordered. But I don't know how to do that. I can use "if" to solve this problem, but that is too inefficient. Is there a better way to solve it? Thank you very much!


I have several equations where some text repeats, so I want to match each following word with a "»" in next equations. Important that "»" should be in the middle of the word above.  Here is the demo example I made in an image editor.


Can you change the location where windows stores its updates?

On my personal home PC I want to change where windows downloads it updates to: C:\ProgramData\Package Cache(in folders with long ID numbers).  When installing Python I found that it needs an update (). The Python installer goes ahead and tries to run the update but can fail with security errors unless run as admin - I don't want to have to run as admin, especially since I am installing to a non-system access area on D:\  So my question is, can I get windows to use a different folder so that I don't need to run with full admin rights?   for example: D:\myWindowsUpdates


$A$ and $B$ are finite sets. Proof $\#A+\#B=\#A\cup B +\#A\cap B$ (solved)

The title it's self explanatory. I've tried a few things but I don't know where to start. I think that with a hint I can proof this and a written formal proof to compare my answer would be nice too.  obs: $\#$ means cardinality of a set.  Edit: Solved just now.  Solution: Since $A\cup B=(A-B)\cup( B-A) \cup( A \cap B )$ and the intersection of this three sets it's empty, so $\#A\cup B=\#A-B+ \#B-A + \# A \cap B $. Since $A=(A-B) \cup (A\cap B) $ and $B=(B-A) \cup (A\cap B) $, we have $\#A+\#B=\#(A-B)+\#(B-A)+2\#(A \cap B) $. The conclusion is trivial.


Prove that $\int f\ d\lambda = \int_{a}^{b} f(x)\ dx,$ for any $f \in \mathcal R[a,b].$

Theorem $:$ Let $f : [a,b] \longrightarrow \Bbb R$ be a Riemann integrable function. Then $f \in L_1[a,b]$ and $$\int f\ d\lambda = \int_{a}^{b} f(x)\ dx.$$  The proof given in my book is as follows $:$     At the fag end of the proof $f$ has been proved to be measurable which uses the completeness of the measure space $\left ([a,b], \mathcal L \cap [a,b], \lambda |_{[a,b]} \right ).$ Then it has been stated that $f \leq \Phi_n,$ $\forall$ $n$ and hence $f \in L_1[a,b]$ since $\Phi_n \in L_1[a,b]$ by the proposition $5.4.3 \ $(i) which states the following $:$  Let $f \in \Bbb L$ and $g \in L_1[a,b].$ If $|f(x)| \leq g(x)$ for a.e. $x(\mu).$ Then $f \in L_1[a,b].$  I don't know how to use this proposition to claim that $f \in L_1[a,b].$ Also I don't understand the way dominated convergence theorem used here. What I know about dominated convergence theorem is as follows $:$  Let $(X, \mathcal S, \mu)$ be a complete measure space. Let $g \in L_1(X)$ and $\{f_n \}_{n \geq 1}$ be a sequence in $\Bbb L$ such that $|f_n(x)| \leq g(x)$ a.e. $x(\mu).$ Let $f_n(x) \to f(x)$ as $n \to \infty$ a.e. $x (\mu).$ Then $f \in L_1(X)$ and $$\int f\ d\mu = \lim\limits_{n \to \infty} \int f_n\ d\mu.$$  From here how to conclude that $$\Psi_n\ \bigg\uparrow\ f \implies \int f\ d\lambda = \lim\limits_{n \to \infty} \int \Psi_n\ d\lambda.$$ Please help me in this regard. Thanks in advance.


How to calculate distribution of Y|X from distributions of X|Y and Y

I'm trying to solve the following homework problem:     Let $X$ given $Y=y$ have a normal distribution with mean $y$ and variance one, and let the marginal distribution of $Y$ be normal with mean $\mu_{Y}$ and variance $\sigma_{Y}^{2}$. What is the distribution of $Y$ given $X=x$?   I know that     Definition Given two continuous random variables $X$ and $Y$ with joint probability density function $f_{XY}(x,y)$, the conditional probability density function for $X$ given $Y=y$ is           $f_{X|Y}(x|y)=\dfrac{f_{XY}(x,y)}{f_{Y}(y)}$      My thoughts so far:  We want to calculate $f(y|x)=\dfrac{f(x,y)}{f(x)}$. So we need to work out $f(x,y)$ and $f(x)$.  But $f(x,y)=f(x|y)f(y)$, and we know $f(x|y)=\dfrac{1}{\sqrt{2\pi}}\exp{-\dfrac{(x-y)^2}{2}}$ and $f(y)=\dfrac{1}{\sigma_Y^2\sqrt{2\pi}}\exp{-\dfrac{(y-\mu_Y)^2}{2\sigma_Y^2}}$.  Moreover, $f(x)=\int_{-\infty}^{\infty}f(x,y)dy$.  So we have  $f(y|x)=\dfrac{\dfrac{1}{\sqrt{2\pi}}\exp{-\dfrac{(x-y)^2}{2}}\cdot\dfrac{1}{\sigma_Y^2\sqrt{2\pi}}\exp{-\dfrac{(y-\mu_Y)^2}{2\sigma_Y^2}}}{\int_{-\infty}^{\infty}[\dfrac{1}{\sqrt{2\pi}}\exp{-\dfrac{(x-y)^2}{2}}\cdot\dfrac{1}{\sigma_Y^2\sqrt{2\pi}}\exp{-\dfrac{(y-\mu_Y)^2}{2\sigma_Y^2}}]dy}$  Is this correct? If so, is there any way to simplify this expression?  Many thanks in advance for any pointers.


Just ruined /etc/passwd is there anyway to fix

I'm a noob. I'm messing around on a raspberry pi trying to get the hang of things. I'm having a jolly time.  I don't now how to use vim. I know that you need to hit i to insert text, but I know very little about the commands to get things done.  Raspberry pis start you with a user named pi. There is also the root user. I was trying to update the password for the root user so that I could log into it instead of pi.  Because I don't know how to use vim I accidentally overwrote one of the colons separating data for the root user with an 8 or something. I was all like, I need to get out of here! :wq "Wait... No! That must mean write and quit!"  Is there any way that I can fix this. I will just reinstall the OS otherwise.  I'm nearly certain using root like this is a terrible idea, but whatever. I wouldn't do this for anything important. I'm literally just farting around and learning lessons. I was going to see if it allowed me to add another user, because I keep getting a limit message with 'pi'.


Unable to echo "à" instead php prints "Ã"

I am trying to translate date/time into french. below is my code but i have a problem when getting the character "à", what php gives me is "Ã" character.  setlocale(LC_TIME, "");  setlocale(LC_TIME, 'french'); echo 'locale - ' . setlocale(LC_TIME, '0'); echo ' : month - ' . strftime('Le %d %B %Y') . 'à'; //Le 07 Octobre 2014 à


Do i need a transit visa for Paris if i have a Schengen visa issued by Portugal?

I am a Indian citizen going to Portugal from India with a Schengen visa issued by Portugal. I am travelling on the sponsorship of my friend in Portugal and have to change flight at Paris with a layover time of 13 hours. Do i need any transit visa for the Paris transit city tour at CDG airport? Also i want to take another tour of Paris while returning to India from Portugal. I will be having a layover time of 13 hours at Paris while returning also.


This is my Main Class  package application;  import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.stage.Stage; import javafx.scene.Parent; import javafx.scene.Scene;  public class Main extends Application {      @Override     public void start(Stage primaryStage) {         try {             Parent root = FXMLLoader.load(getClass().getResource("application/anwendung.fxml"));             primaryStage.setTitle("Benutzerverwaltung");             root.getStylesheets().add(getClass().getResource("application.css").toExternalForm());             primaryStage.setScene(new Scene(root));             primaryStage.show();         } catch(Exception e) {             e.printStackTrace();         }     }      public static void main(String[] args) {         launch(args);     } }   This is my Controller class  package application;  import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.scene.Node; import javafx.scene.control.Button; import javafx.scene.input.InputEvent; import javafx.stage.Stage;  class AnwendungsController {      @FXML     public Button closeButton;       @FXML     public void handleCloseButtonAction(ActionEvent event) {         Stage stage = (Stage) closeButton.getScene().getWindow();         stage.close();     } }   And this is my fxml file  <?xml version="1.0" encoding="UTF-8"?>  <?import javafx.scene.control.Button?> <?import javafx.scene.control.Label?> <?import javafx.scene.layout.AnchorPane?> <?import javafx.scene.text.Font?>  <AnchorPane prefHeight="140.0" prefWidth="350.0"     xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1"     fx:controller="application.AnwendungsController">   <children>    <Button fx:id="closeButton" layoutX="18.0" layoutY="100.0" mnemonicParsing="false" onAction="#handleCloseButtonAction" onMouseClicked="#onMouseClickedCancelBtn" prefHeight="26.0" prefWidth="77.0"  text="Abbrechen" />    <Label layoutX="10.0" layoutY="27.0" prefHeight="27.0" prefWidth="342.0" text="Sie können das System nun verwenden" textAlignment="CENTER" textOverrun="CLIP">      <font>         <Font name="System Bold" size="18.0" />      </font>   </Label>    </children>   </AnchorPane>   How can I fix it? I try everything from here   UPDATE:   java.lang.NullPointerException: Location is required. at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3207) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104) at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097) at application.Main.start(Main.java:20) at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863) at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326) at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295) at java.security.AccessController.doPrivileged(Native Method) at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294) at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95) at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) at java.lang.Thread.run(Unknown Source)


How to properly remove mold from camera body?

Long story short, I'm living in Vietnam which has a pretty hectic rainy season. Thankfully it's almost over. My room unfortunately got a fair amount of mold that seeped through the concrete walls. After advising my landlord to not just paint over the walls he came in and did it anyways releasing spores all over my apartment. 2 days after the painting I came home to find a ton of mold growing on the body of my camera that was sitting out in the room as well as other various items around my home. I only found mold on items that were sitting out. Not in any cabinets. I wiped the body off and after two days of not seeing any mold come back i'm hoping that I'm in the clear. As it is still quite humid i'm leaving my camera where it gets a fair amount of sunlight while also turning the AC on to hopefully dry out the room a bit. My lens that was attached looks to have a small speck of fungus forming within the front. I've been on a pretty steady mission of wiping down my entire apartment with a vinegar and water solution, but mold continues to show up in random places on an almost daily basis. I've not used the vinegar on my sony A7. Not sure if I should do that. Does anyone have any advice on how to keep the mold under control or keep it from coming back, or been in a similar situation? I've heard about lens fungus, but have never dealt with it growing on the actual body of the camera. Thanks in advance for your help. I don't have access to any sort of dry box either..


In DS9 'Dax' they cannot find the location of the kidnappers of Dax. However, during the episode 'The Nagus', Sisko requests Jake's location from the computer, and it's given.  In previous episodes, they cannot locate people after they removed their combadges. So, surely the computer looks for the combadge, and if it has been removed, then locates using sensors.  So why didn't they do this in episodes which they were trying to find people who had removed their combadges?


What would you call a person from India?

My guess would be Indian, but that sounds like a guy with a feather on his head who hunts buffalo.  Is there a better name?


Exception in thread 'main' java.lang.NullPointerException

Hi I'm very new to Java and have this HW problem, we are asked to build a Class RandomBag -- a generic bag container which allows 'RandomPick' of an element. I keep getting this error I have little idea to fix, any help is greatly appreciated!     public RandomBag() {       ArrayList<E> Bag=new ArrayList<E>();       Random Rand =new Random();   }   public RandomBag(int seed) {        ArrayList<E> Bag=new ArrayList<E>();       Random Rand =new Random(seed);


Air France cancellation policy seems to violate EU261

Air France states that for COVID-19 related cancellations:     "... or complete the online form below to obtain a travel voucher. This voucher is valid for 1 year on all Air France, KLM, Delta Air Lines and Virgin Atlantic flights. This voucher will be refundable after one year if it is not used."     That seems like a ploy to circumvent EU261 regulations which I believe require a full refund in cases of cancellations. Air France is offering sort of a refund but with one year delay built in.   Background: we have an US<->India ticket booked on Expedia with an Air France ticket. We obviously can't fly this and some legs have already been cancelled anyway. We like a full refund, not airline credit.  Question: What's the best strategy to approach this? We shouldn't really call Expedia until 72-hours before departure, Air France says "call your travel agent" and I'm worried that Expedia will simply say "airline is offering credit: take it or leave it. EU261 is not our problem". Does anyone have some experience with Air France cancellations recently?


This is exercise $10.E.4$ from Pinter:     Let $a$ and $b$ be elements of a group $G$.      Let ord($a$) = $m$ and ord($b$) = $n$.      Prove:      Let $a$ and $b$ commute.      If $m$ and $n$ are relatively prime, then ord($ab$) = $mn$.      (HINT: Use $10.E.2$.)   Here is $10.E.2$, which Pinter suggests that we use:     If $m$ and $n$ are relatively prime, then no power of $a$ can be equal to any power of $b$ (except for $e$).   I'm also going to use $10.E.1$:     If $a$ and $b$ commute, then ord($ab$) is a divisor of lcm($m$,$n$).   As well as $B.T6.i$ (Theorem $6.i$ from Appendix $B$. A fact from basic number theory.):     If   gcd($m$,$n$) = 1   then   lcm($m$,$n$) = $mn$   Let's begin.  We are given that $m$ and $n$ are relatively prime which means that:  $$\text{gcd}(m,n) = 1$$  By $B.T6.i$:  $$  \text{lcm}(m,n) = mn \tag{1}  $$  By $10.E.1$:  $$ \text{ord}(ab)\ |\ \text{lcm}(m,n) $$  Substituting $(1)$:  $$ \text{ord}(ab)\ |\ mn $$  Which means that there is an integer $x$ such that:  $$ \text{ord}(ab) x = mn $$  This is so close! For the theorem to be true, we'd have to show that $x = 1$.  However, the original exercise statement says to use $10.E.2$.   Is that helpful in showing that $x = 1$? Or is there some other completely different approach whereby $10.E.2$ is used?     UPDATE: Some comments regarding the  below.  The proof uses the following fact:     If $a|c$ and $b|c$ then $lcm(a,b)|c$.   For this exercise, I wanted to only use theorems that had been presented in the book up to that point. And, I didn't seem to recall seeing this theorem. (If anyone spots this in Pinter, please comment below with the location.)  However, I did notice that the following similar fact is in Appendix B (REVIEW OF THE INTEGERS) as exercise B.9:     If $a|c$ and $b|c$ and $gcd(a,b) = 1$ then $ab|c$.   So yeah, it looks like the approach shown below is definitely a valid way to go if you want to stick to what's presented in the book.


Using of word "just" with present perfect- "your friends have arrived" Vs "you friends have just arrived."

Could any one please explain the use of word " just " with present perfect ? I know that it's used to say that an action happened very recently, but I want to know what is the difference between placing and removing just from the sentence?  I think if want to remove it,  there must be a clear present relevance is that right ?  For example:     your friends have arrived.   or     you friends have just arrived.


Calculating certain functions if only certain buttons on a calculator are permitted

A calculator is broken. The only keys that work are  $\sin, \cos, \tan, \cot, \arcsin, \arccos$, and $\arctan$ buttons. The original display is $0$. In this problem, we will prove that given any positive rational number $q$, show that pressing some finite sequence of buttons will yield $q$. Functions are always in radian form. (a) Find and prove that there exists a  sequence of buttons that will turn  $\sqrt x$ into $\sqrt{x+1}$.  For this, I got lucky and tried out $\sec (\arctan(x))$ on my calculator and got $\sqrt{x^2+1}$, so I just used the reciprocal and got $\cos (\arctan (x)) = \frac{1}{\sqrt{x^2+1}}$. However, how I can actually prove this?  (b) Prove that there exists a sequence of buttons that will yield $\frac{3}{\sqrt{5}}$.  I know that to go from $x$ to $\frac{1}{x}$ it is $\cot (\arctan (x))$, and I will have to use part a) to get to part b). How do I utilize this? I also know that $\sqrt{\frac{9}{5}}$ = $\frac{3}{\sqrt{5}}$, but after that, I'm stuck. Any hints?


Aviation icon showing for non-aviation change in points

This may be a larger issue, as I faced the same thing on travel.se; and reported it to the .    I'm not sure if this is a design issue or a caching problem, but today I received a notification for a rep change on stackoverflow, but with the icon for aviation:


Resolving a relative url path to its absolute path

Is there a library in python that works like this?  >>> resolvePath("http://www.asite.com/folder/currentpage.html", "anotherpage.html") 'http://www.asite.com/folder/anotherpage.html' >>> resolvePath("http://www.asite.com/folder/currentpage.html", "folder2/anotherpage.html") 'http://www.asite.com/folder/folder2/anotherpage.html' >>> resolvePath("http://www.asite.com/folder/currentpage.html", "/folder3/anotherpage.html") 'http://www.asite.com/folder3/anotherpage.html' >>> resolvePath("http://www.asite.com/folder/currentpage.html", "../finalpage.html") 'http://www.asite.com/finalpage.html'


How many idempotent elements does the ring ${\bf Z}_n$ contain?

Let $R$ be a ring. An element $x$ in $R$ is said to be idempotent if $x^2=x$. For a specific $n\in{\bf Z}_+$ which is not very large, say, $n=20$, one can calculate one by one to find that there are four idempotent elements: $x=0,1,5,16$. So here is my question:     Is there a general result which tells the number of the idempotent elements of ${\bf Z}_n$?


Number of Solutions in this Number Puzzle

Today in math class, a number puzzle arose where you would have to find a 10 digit number, where each digit describes the number of other digits in the number, for example: $$\text{0 1 2 3 4 5 6 7 8 9}$$ $$\text{6 2 1 0 0 0 1 0 0 0}$$  $\textit{The top row being digit number $n$, and the bottom row being the $10$ digit number.}$    You can see that since there are six zeros in the $10$ digit number, there is a $6$ in the $0$'s column. And since there are two $1$'s, there is a $2$ in the $1$'s column and so on.  So, my question would be: Are there any more solutions to this puzzle? And if not, how could you prove this?


Where in the Dragon Ball timeline is the Super series?

At the end of the Dragon Ball series we can see . There had been years of peace so we see Goten and Trunks all grown to teenagers, yet in the Super series they are still young. So it seems that Uub does not exist yet and the Super series does not follow directly after the Dragon Ball series, the same way the GT series did. So where does it fit in? When does the Super series take place?


Since Spellforge is gone, what Spellbook management software is available?

I want to be able to manage my Sorceror's "spellbook" on my computer and print a nice list of spells, and ideally descriptions. We level up very frequently compared to normal (accelerated campaign), so I don't want to do it by hand.  Older forum posts all seem to reference Spellforge, and I use Heroforge for my character sheet, but the developer seems to have fallen ill and abandoned the project and server.


Does the series $\sum_{n=1}^{\infty}a_n=\frac{1}{n^\frac{1}{n}n}$ converge? I know that I can apply comparison test because this series contains nonnegative members.


Invisible faces problem in Game Blender Engine

How to fix the error shown on screeshots ? Thank you for your answers.


The vertical line at the end of the cell where i used cell merge is missing.


How can I know which formula create this file

$ brew link binutils  Linking /usr/local/Cellar/binutils/2.24... Warning: Could not link binutils. Unlinking...  Error: Could not symlink file: /usr/local/Cellar/binutils/2.24/share/info/configure.info Target /usr/local/share/info/configure.info already exists. You may need to delete it. To force the link and overwrite all other conflicting files, do:   brew link --overwrite formula_name   As I see I can not link binutils because there is configure.info file in my filesystem.  I am just wondering if there is any way to know which of installed home-brew formulas had installed this file ?


How to find $A^{100}$ where $A$ is a matrix with trigonometric entries?

How to find $A^{100}$ where $A=\left(\begin{matrix}\cos \theta &  -\sin \theta\\  \sin \theta & \cos \theta\end{matrix}\right)$. ? (Given$\theta=\frac{2\pi}{7}$)   I am a highschool student and new in linear algebra and seeking for only problem solving strategies. I found somewhere the trick to solve this kind of problem is find characteristic equation and then for some of the cases it is possible to find any power of matrix just by exponentiation of both sides. But here this is not applicable. The characteristics equation found to be $\lambda^2-2\lambda \cos \theta+1=0$ I  how to proceed now ?


Using regular expressions to parse HTML: why not?

It seems like every question on stackoverflow where the asker is using regex to grab some information from HTML will inevitably have an "answer" that says not to use regex to parse HTML.  Why not? I'm aware that there are quote-unquote "real" HTML parsers out there like , and I'm sure they're powerful and useful, but if you're just doing something simple, quick, or dirty, then why bother using something so complicated when a few regex statements will work just fine?  Moreover, is there just something fundamental that I don't understand about regex that makes them a bad choice for parsing in general?


By default, man uses less to output text. How can I tell it to just output to stdout? My terminal emulator has a scroll bar and search function and I want to use those instead of the arrow keys.


Let $a,b,n$ be any integers greater than $1$ and $b >\phi(n),$ where $\phi$ is Euler's totient function; is the below equation is true or not? $$ a^b \equiv_n a^{\phi(n) + (b \mod \phi(n))}$$


How do I merge array values fo a multidimensional array

I want to merge the values of a multidimensional array that was returned by a function. It contains duplicated values and I want to get rid of the duplicates. I only know that of arrays saved in different variables. This is the array:  Array (     [0] => Array         (             [content] => Array                 (                 [0] => 0                 [2] => 2             )          )      [1] => Array         (             [content] => Array                 (                     [1] => 1                 )          )      [2] => Array         (             [content] => Array                 (                     [0] => 0                     [2] => 2                 )          )  )


Calling virtual method in base class constructor

I know that calling a virtual method from a base class constructor can be dangerous since the child class might not be in a valid state. (at least in C#)  My question is what if the virtual method is the one who initializes the state of the object ? Is it good practice or should it be a two step process, first to create the object and then to load the state ?  First option: (using the constructor to initialize the state)  public class BaseObject {     public BaseObject(XElement definition) {         this.LoadState(definition);     }      protected abstract LoadState(XElement definition); }   Second option: (using a two step process)  public class BaseObject {     public void LoadState(XElement definition) {         this.LoadStateCore(definition);     }      protected abstract LoadStateCore(XElement definition); }   In the first method the consumer of the code can create and initialize the object with one statement:  // The base class will call the virtual method to load the state. ChildObject o = new ChildObject(definition)   In the second method the consumer will have to create the object and then load the state:  ChildObject o = new ChildObject(); o.LoadState(definition);


7 days block for not passing controversial audit - why my passed audits are completely ignored?

I was a few times blocked from reviewing for not passing audits (rather controversial ones). Since the last block I can't remember any failed audits, but I've passed a couple of them. Now I've failed that audit on that question:  and boom     You have failed too many recent review audits – looks like you might need a break. Come back in 7 days to continue reviewing.(more)     Why have I voted to close the linked question? Because it provides no code example, only a link to the site and "please diagnose my problem with that site". I don't think such questions are good. After a year the site will be either fixed or no longer operated, and the question will be probably useless.  What is the issue? The issue is, no matter how many audits I will pass, I will be blocked for failing single one, and with current system failing an audit is the question of time, until you install browser extension checking if it's an audit.   How to fix it?    never block for failing single audit count passed audits since last review block, not only the failed ones don't count failed audits forever, use some time window remove failed audits from the history, if the audit was disputed (the action contradicting the audit was taken, for example the question in leave-open audit was actually closed)   The last point is the most important one, because current mechanism of choosing audits is overly flawed. Meeting bad audits is as sure as death and taxes.  A positive aspect of current system: I don't care for the size of the close queue anymore. At least not in the next 7 days.


Find a minimal sufficient statistic for logistic distribution

Let $X_1,...,X_n$ be a random sample. Find a minimal sufficient statistic for $\theta$. $$f(x|\theta)=\frac{e^{-(x-\theta)}}{(1+e^{-(x-\theta)})^2}$$, $-\infty <x<\infty, -\infty <\theta<\infty$ The answer is the order statistics. I am not sure what the meaning of x and y have the same order statistics is.


Headline format differs in preview from published

On SO I was just editing an answer when I noticed this. In the preview the headline appears large & bold:  but in the published version it is just followed by an HR:  I was editing  if it matters.


Given that $k_1,...,k_n$ are algebraic integers and the complex number $c$ is a root of the polynomial $X^n+k_1X^{n-1}+..+k_n$ it is an exercise to prove that $c$ is also an algebraic integer. I know that, by definition, an algebraic integer is a complex number that is a root of some monic polynomial with integer coefficients. My question then is I don't quite get what is there exactly to be proved here. Am I missing something?   Edit: So, can I say for any polynomial $f$ with algebraic coefficients and root $c$, there is a polynomial $g$ with integer coefficients and with same root $c$. Then perhaps multiplying some polynomials with some roots will give a polynomial with integer coefficients? But I am not sure of the details~


What was the historical pronunciation of the digraph  like?

What was the historical pronunciation of the digraph <gh>, as in height, thought, thorough, laugh, enough, Edinburgh like?


Improper rational/trig integral comes out to $\pi/e$

During my studying to integration I find this integration.  So I tried to prove but I got stuk.  So I need help in this integration.  $$\displaystyle\int_{-\infty}^{\infty} \frac{x \sin (x)}{1+x^2}  dx = \frac {\pi}{e} $$


I want to sort the labels in my own order instead of the default abc order, so that, for example, the label named bills should come up first.  Any way to do that?


How to disconnect pptp client connected to Cent OS 6.2 server from the server side ? ifdown ppp0 doesn't work.


What are the floating translucent little objects called in the field of view?

Sometimes we see these small translucent shapes moving by when the eyes are open. When the eyes are moved they seem to follow that movement, but with a certain delay, as if they are floating in a thick viscous liquid. What is this phenomenon called?


I have a question which derived from a comment I got to another question. I know that LTS Ubuntu versions have support for 5 years so that means that Ubuntu 16.04 is supported up to 04/20.  If I replace the GUI of Ubuntu with another not supported version like mate (which I have done) without formatting is this considered an action that breaks the system and, thus, it is now considered Ubuntu mate instead of Ubuntu or not?


I need to compare the content of files on 2 different machines. There are around 50 files in the folder on each PC. So far I have done this:  compare (gc \\PC1\d$\Data\Config\*) (gc \\PC2\d$\Data\Config\*) | Out-GridView   and it works fine, but in that way I can't see in which file the difference exist. So I need the filename in the result.


Question: Prove or disprove that $\lim_{n \to \infty} {n \choose k} / a^n = 0$ for all $k \in \mathbb{Z_+}, a \in \mathbb{R}: a> 1$.  Comment: When I was falling asleep last night I was thinking about increasing integer sequences like triangle numbers $(0,1,3,6,10,15,\cdots)$ and  $(0,1,4,10,20,35,\cdots)$ or in short any integer sequences of the type $\left({0 \choose k}, {1 \choose k}, {2 \choose k}, \cdots\right)$ for some integer $k$ and I was wondering if for some $k$ that there is exponential growth at the limit, hence my question. I suppose not, but I could not prove it directly.   What if the $k$ constant increases as a function of $n$, for example if $k = \lceil n/2 \rceil$ (giving the sequence $\left({0 \choose 0}, {1 \choose 1}, {2 \choose 1}, {3 \choose 2}, \cdots\right)$)?


How to integrate $ \int_0^\infty \sin x \cdot x ^{-1/3} dx$ (using Gamma function)

How can I calculate the following integral:   $$\int_0^\infty x ^{-\frac{1}{3}}\sin x \, dx$$   WolframAlpha gives me $$ \frac{\pi}{\Gamma\Big(\frac{1}{3}\Big)}$$  How does WolframAlpha get this?  I don't understand how we can rearrange the formula in order to apply the gamma-function here. Any helpful and detailed hint/answer is appreciated.


What should an entry for arXiv entries look like for biblatex?

The tool I'm using to manage references ( for OS X) doesn't seem to be capable of properly exporting  entries for use with biblatex. What is the correct biblatex format for an arXiv entry?  For example, Papers generates items like   @article{Altshuler2002,     author = {Altshuler, B},     title = {{Calculation of the observationally small cosmological constant in the model of six-dimensional}},     journal = {Arxiv preprint hep-th},     year = {2002},     url = {http://arxiv.org/pdf/hep-th/0206225}}  @article{Acemoglu2010,     author = {Acemoglu, Daron and Como, Giacomo and Fagnani, Fabio and Ozdaglar, Asuman},     title = {{Opinion fluctuations and disagreement in social networks}},     journal = {arXiv.org},     year = {2010},     volume = {cs.SI},     month = sep,     rating = {0},     url = {http://arxiv.org/abs/1009.2653v1}}   which, , should actually look like  @eprint{Altshuler2002,     eprinttype={arxiv},      eprint = "hep-th/0206225"     author = {Altshuler, B},     title = {{Calculation of the observationally small cosmological constant in the model of six-dimensional}},     year = {2002},     url = {http://arxiv.org/abs/hep-th/0206225}}  @eprint{Acemoglu2010,     eprinttype={arxiv},      eprint = "1009.2653v1",     primaryClass = "cs.SI",     archivePrefix = "arXiv",     author = {Acemoglu, Daron and Como, Giacomo and Fagnani, Fabio and Ozdaglar, Asuman},     title = {{Opinion fluctuations and disagreement in social networks}},     year = {2010},     month = sep,     url = {http://arxiv.org/abs/1009.2653v1}}   in order to take full advantage of biblatex.   Are these the correct BibLaTeX forms for arXiv entries? I'm having trouble reconciling  I find here, the output from  for generating BibTeX, and the —not to mention the seemingly arXiv-unaware output (above) that I get from Papers (or, for that matter, JabRef or Zotero).


Need help understanding C# float string formatting

In a nutshell, I'm wondering why the ToString() lines below don't match my expectations.   float actual = 111253.469F; double rounded = Math.Round(actual, 2); //  111253.47 (expected) string stringified = actual.ToString(); //  111253.50 (expected 111253.469) string currency = actual.ToString("C"); // $111253.50 (expected 111253.47 or possibly .46)   Can someone explain what is going on?   Note: I don't expect the floating point value to be exact, per the other questions on floating point numbers. However I do expect the string output to reflect the string value of the floating point number in question.  In this case, if I set a break point and look at the value of 'actual' in a quick watch, it doesn't display '111253.5', it displays '111253.469'. I don't understand why that wouldn't be the case when printing as well. And especially in the currency case, I would expect it to round to the appropriate decimal point and then display, rather than picking some other literal value. This isn't a math question, it is a ToString() behavior question.  Edit: Per Quantic's comment below, it appears the ToString is using the G format by default which limits the number to 7 significant digits, resulting in the number being seen here.


What am I trying to mine, but can't, in Pre-Hardmode?

I'm Pre-Hardmode, Expert Large World, with an Iron Pickaxe, and Underground.  I spotted some sort of shiny rock in the dark, dug my way to it, and found that I can't seem to break it.  I hit it, and its image changes, but no breaking.  I looked up what materials need high levels of pickaxes to break them, but it doesn't seem to fit any of them, since it seems none of them should be Underground, Pre-Hardmode?  I haven't seen any lava yet, either.  No Screenshot, right now.


I am in the process of resurrecting an ancient desktop PC.  Managed to scrap the following configuration: (SOCKET 478)    Motherboard: As Rock P4i65g  Processor: Intel Pentium 4, 3.40 GHz (1MB cache)  RAM: 2GB DDR400  VGA: ATI Rad-eon x1650 Pro 256MB (AGP x8/PCI)  Power Supply: 400W     Been searching for a better socket 478 motherboard, that has max RAM of 4GB, and I found a few... Like this one: MSI 865GM2-LS 478 Intel 865G Micro ATX Intel  and this one: Gigabyte GA-8IG1000MK  Both have somewhat similar setup regarding chip set, CPU compatibility, VGA compatibility etc.. and both allow max RAM up to 4GB.  I found a few that also allow max. 4GB RAM but with one condition: "Due to the operating system limitation, the actual memory size may be less than 4GB for the reservation for system usage under Windows® 32-bit OS"  I am not sure what this means,my questions does it mean no socket 478 motherboard can have more than 2GB RAM or?


Ability to draw and add graphical illustrations, flowcharts, diagrams, etc

I think it would be a very useful and quality-improving feature.  As for me, when I speak on something, I often have a visual representation of how it works, or something. It's obvious there are many things (in algorithms, or, say, UI) which are much easier understood with pictures and diagrams, than from scarce text.  So I'd really like here to be a special answer form, where you can attach some visual things to better explain your ideas.  I imagine this form as just a canvas with few painting tools and some basic blocks and patterns.


Objects are not being created in methods

I keep getting a null pointer exception at run time.   public class MobilePhone { ArrayList<Contacts> contactsArray; private String myNumber;  public MobilePhone(ArrayList<Contacts> contactsArray, String myNumber) {     super();     this.contactsArray = new ArrayList<Contacts>();     this.myNumber = myNumber; } public MobilePhone(){  }   public void addContact(Contacts contact) {     //contactsArray.contains(name);      contactsArray.add(contact); }   I have the addContact method take a Contacts object to add to the arraylist and i call that method in the createContact method in the demo class below, where i also create the object and set the arguments. Ive tried it a couple of different ways, but the object ends up never being created.  public class challengeDemo { static MobilePhone phone = new MobilePhone(); static Scanner input = new Scanner(System.in); public static void main(String[]args){      createContact();     //System.out.println(phone.contactsArray.get(0));  }  public static void createContact(){     System.out.println("Enter Name: ");     String userName = input.next();     System.out.println("Enter Number: ");     String userNumber = input.next();      phone.addContact(new Contacts(userName,userNumber));  }  }  }   I also have a contacts constructor.  public class Contacts { private String name; private String phoneNumber;  public Contacts(String name,String phoneNumber){     this.name = name;     this.phoneNumber = phoneNumber; }


Scaling reputation/badges by number of users

I am not entirely sure how comparable reputation and badges are across Stack Exchange sites. Of course, an obvious concern is that if the reputation points needed to earn certain privileges are uniform across Stack Exchange sites, then sites with a lower number of people will unambiguously be less conducive to mobility.  If this is indeed the case, should the reputation points needed to ascend to a new privilege not be scaled by number of users on the sites?  Reputation is an increasing function of likes, which are in turn an increasing function of number of users. If this is not already the case, this should be taken into account!  For instance, a 10,000 reputation on the Economics site implies much more of an 'impact' as regards the number of users on the site as opposed to, say 10,000 on Mathematics. My point is simple- a user on the 90th percentile in the reputation distribution should have the same privileges across sites.


How to delete everything after the 5th line with awk?

How to delete everything in a file after 5th line using awk?  I can do it by sed, but these days I am moving from sed to awk.


Composite primary key from multiple tables / multiple foreign keys

I want to build a composite primary key made up of foreign keys from two different tables. I'm still pretty green to this...  A great answer was given to building a composite key from multiple foreign keys on  but I want to do this from multiple tables. I am using Oracle 11g.  foreign key (Name, BoughtFrom, TimeBought)    references the_other_table_name (Name, BoughtFrom, TimeBought)   Imagine that the "references" line actually includes multiple tables. I'm not even sure that the above syntax will work with Oracle.  I have one table "Student" and one table "Parent". It is a many-to-many relationship. My association table is named "Relation" and I would like to make a composite primary key from "PAR_ID" and "STU_ID". Both are foreign keys.


Elementary Set Theory: Ordinals, Well Orderings and Isomorphisms

I need to show that for any countable ordinal $\alpha$ there is a set A $\subseteq \mathbb{Q}$ such that (A, <) is isomorphic to ($\alpha, \in$).  To do it I am supposed to show the following stronger statement by induction on ordinals $\alpha$ < $\omega_{1}$:  Let P($\alpha$) be the statement "For every interval (a, b) with rational endpoints, there is an A $\subseteq$ (a,b) such that (A, <) is isomorphic to ($\alpha, \in$)."  I think that the purpose of breaking $\mathbb{Q}$ into intervals (a,b) is to make $\mathbb{Q}$ a countable set, but I don't see the significance of doing this or how it would make the proof easier.  I feel like I need to define a well-ordered set in (a,b) but I don't know how to do this since if a and b are both negative then there is no least element, so no well-ordering.  I believe that I am supposed to be using transfinite induction? But I don't know how P($\alpha$) implies P(S($\alpha$)) for S($\alpha$) successor of $\alpha$.  Any help would be greatly appreciated... thanks in advance.


A maximal ideal among those avoiding a multiplicative set is prime

Let $S$ be a multiplicatively closed subset of a ring $R$, and let $I$ be an ideal of $R$ which is maximal among ideals disjoint from $S$. Show that $I$ is prime. If $R$ is an integral domain, explain briefly how one may construct a field $F$ together with a ring homomorphism $R\to F$. Deduce that if $R$ is an arbitrary ring, $I$ an ideal of $R$, and $S$ a multiplicatively closed subset disjoint from $I$, then there exists a ring homomorphism $f\colon R\to F$, where $F$ is a field, such that $f(x)=0$ for all $x\in I$ and $f(y)\neq 0$ for all $y\in S$.   [You may assume that if $T$ is a multiplicatively closed subset of a ring, and $0\notin T$, then there exists an ideal which is maximal among ideals disjoint from $T$.]  Here is a question I need to answer. For the first part I can show if $x, y$ are not in $I$ then nor does $xy$. The second part is just the field of fractions.   For the third part, I think I need to find an ideal $J$ containing $I$ such $J$ is prime, so that $R/J$ is an integral domain, and use the second part. To find $J$ prime, I think as suggested by the hint, I should go for a maximal ideal disjoint from $S$ containing $I$, but how can I do that?


Fixed point of a Function (monotonically increasing)

Let $\mathbb{F} $ be a ordered field and a function $f:\mathbb{F}\to \mathbb{F}$ is called monotonically increasing if $\forall x,y \in \mathbb{F} $: $ x \leq y \Rightarrow f(x) \leq f(y)$. Let $ a,b \in \mathbb{F} $: and $a <b$ and $f:\mathbb{F}\to \mathbb{F}$ a monotonically increasing function with $f(a) > a$ and $f(b) < b$.  Is there for 1) $\mathbb{F}   = \mathbb{R } $ 2) $\mathbb{F}   = \mathbb{Q }$ a point with $f(x) = x$ ?  Until now we have : Infimum and supremum, axiom of real numbers,intervals etc. but no theorems about monotonically  functions


I applied for sweden last June 2018 unfortunately I denied. Coz of insufficient fund. After 4 mos I applied again but this time for Malta since Sweden is not my lack, but then I denied due to unreliable source of documents with no further explanation unlike in Sweden. This time I'm planning to reapply again as tourist in Europe. What are the preparation should I have to do? And can I change again my destination?thank you!


Covert Double to Integer to String & Output in TxtField - CodeNameOne

Double double;     int integer = (int) Math.round(double);     String string = Integer.toString(integer);      System.out.println(string);     findTxtField().setText(string);   I am using the above code as An EXAMPLE- I have coded my mobile application using CodeNameOne. The variables are initialized.   I am receiving an error message when running the mobile application and hitting the button that executed similar code(above), unfortunately, after troubleshooting I figured out it was the outputting to the text-field that was causing the crash.  My Mobile application has 5 UI sections. The section for user "registration" will take the data, calculate it and then output the data using a text-field on another UI section "Results".  Any Idea why I am having this issue?  Error:  java.lang.NullPointerException at userclasses.StateMachine.onMain_BtnInfoAction(StateMachine.java:171) at generated.StateMachineBase.handleComponentAction(StateMachineBase.java:2251) at com.codename1.ui.util.UIBuilder$FormListener.actionPerformed(UIBuilder.java:2831) at com.codename1.ui.util.EventDispatcher.fireActionEvent(EventDispatcher.java:345) at com.codename1.ui.Button.fireActionEvent(Button.java:397) at com.codename1.ui.Button.released(Button.java:428) at com.codename1.ui.Button.pointerReleased(Button.java:516) at com.codename1.ui.Form.pointerReleased(Form.java:2560) at com.codename1.ui.Form.pointerReleased(Form.java:2496) at com.codename1.ui.Component.pointerReleased(Component.java:3108) at com.codename1.ui.Display.handleEvent(Display.java:2017) at com.codename1.ui.Display.edtLoopImpl(Display.java:1065) at com.codename1.ui.Display.mainEDTLoop(Display.java:994) at com.codename1.ui.RunnableWrapper.run(RunnableWrapper.java:120) at com.codename1.impl.CodenameOneThread.run(CodenameOneThread.java:176)


Deleted all partitions from Mac mini except Boot Camp, now can't reinstall OS X

I have a Mac Mini without DVD drive (2010), and I used Boot Camp to install Windows 8.  Everything worked but after I played in Windows with the partitions (I wanted to expand the partition of the Mac). I made mistake and deleted every partition (even Recovery HD) except from my Boot Camp partition. Since then, my Mac mini only boots into Windows. I can't install OS X now.  I took from my friend an OS X Install DVD and Application Install DVD (he also has a Mac mini). Then I took my PC's external USB DVD drive and connected to Mac mini, inserted the OS X install disk and powered on. During the power on I held the ⌘C button and I saw HDD "BOOTCAMP" and CD "OS X INSTALL" so I selected the CD but after that I only see the gray screen with an Apple logo.  How can I install OS X again on my Mac?


I would like to put an underbrace below the matrix like this:  $$\left(\underbrace{ \left[\begin{array}{ccc}     a&b&c\\     d&e&f\\     g&h&i \end{array}\right]}_{A} \left[\begin{array}{c}     x_1\\     x_2\\     x_3 \end{array}\right]\right)$$     But I don't want the outer brackets \left( and \right) to stretch vertically. I want them to remain as if there was no underbrace. How to achieve that behaviour?


How to know if Ho-oh or any other legend is legitimate?

Yesterday, I placed a Zygarde on the GTS, and I asked in return for a Ho-oh. To my surprise today, I got the Ho-oh, it was shiny, and it had 5ivs! (all in the good places!)  I checked to see the Ho-oh's summary, and it said     Travelled from time and Space from Johto to get to Kalos   What does this mean? is my Ho-oh (gulp) ..not legit?


Is there a word or phrase for walking into a room to get something but then forgetting what you went in there to get?

I'm fairly certain this has happened to all of us at some point: You go into a room to get something, but once you're there, you can't remember what you intended to get. It seems like a specific, common phenomenon like this must have a name, but I can't think of it. Does anyone know a name (either formal or slang) for this?  I don't want a general term like forgetfulness or absent-mindedness, which could apply to all sorts of forgetting, or a term for not being able to remember a certain word. I'm looking for a word or phrase that describes this one specific situation of forgetting what you need to get as soon as you go to get it.


How can we unlock an iPhone backup file if we don't know the password?

I've got a rather peculiar problem. My wife's iPhone got stolen and we bought a new one from the insurance money. When trying to restore the backup file to her new phone, iTunes asks for the password:  Enter the password to unlock your iPhone backup file.  The problem is, that she removed the password a long time ago. Hence she can not remember it. All we know is that it must be a number between 1111 and 9999.  Is there any way to brute force this? Other than by hand?