Why there is "?" sign in WiFi icon even if wifi is working properly?
My network icon is always a question mark but I have acces to internet
I want to click on file to inherit the name for the file being saved. I can't read file names in the dialog box because the color is too faint. This is the same question as   That question does not have an answer but I don't have enough points to interact there so I have to post a new question.    Edited to add screen shots I tried to calibrate the monitor which no effect and did not change the readability of "unavailable" file names. I have added screenshots of previous operating systems to compare: Please tell me how Mojave is not to blame here: What is a good criterion or rule-of-thumb for determining when a control should be greyed-out and when should it be completely invisible? How does virtualizing differ from emulation, in terms of structure? Someone told me that a virtualizing program like VirtualBox does not work like an emulator does in the sense that it doesn't emulate registers and uses the actual ones for the virtualized data that are on the CPU. Emulators must emulate the registers since they are mostly to execute software that depends on a foreign environment (e.g. a Genesis emulator needs Motorola 68000's registers and memory addresses, so developer must make these resources available as emulated registers).  My main question is, how is virtualization developed? How do we enable an entire OS to run as a process in a virtual machine, but get it to run independently while still making use of the actual CPU? I only know emulation, not virtualization, so if anyone could help that'd be nice!  PS: I am not asking solely what the difference is, but differences in how they run software. I'm trying to get a Schengen Visa from my first port of entry, France. I am trying to book an appointment with the French Consulate in SF, and the URL I am using is the following:   I've been checking this page periodically for the past few weeks, and I always see a dialog that that says "We are currently at full capacity. Please try again later." Their calendar provides no direct option for going to the next month. (Using the in-browser developer tools, I noticed that the button for next month is hidden. Un-hiding it and clicking on the Next Month button displays no available appointments either. I checked all the way until September 2016).  My guess is that there are absolutely no appointments for the next 6 months. Or, more likely, their page isn't functioning properly. I'll be traveling in July. Does anybody have any alternate suggestions to book an appointment? What oil is best for seasoning a cast-iron skillet How to do "Files to store without compression" in 7-zip? Is there any way to selectively prevent certain file types from compression in 7-zip, like in WinRAR?  I'm trying to compress a huge folder (many gigabytes), and I don't want the already-compressed files (e.g. ZIP files) to be re-compressed -- they should be stored without compression. Suppose that $X_1,X_2,\ldots,X_n$ is a random sample from a distribution with probability function:  $$p_X(x)=\begin{cases} 1/2 &amp;x=-1,1 \\ 0 &amp; \text{otherwise} \end{cases}$$  Now if we define the average   $\bar{X}= \frac{1}{n} \sum X_i$, I need to show that that for an odd $n$ the probability function for $\bar{X}$ is:  $$p_{\bar{X}} (x)= \frac{\binom{n}{\frac{n}{2} (x+1)}}{2^n}$$ for $x=\pm 1/n,\pm 3/n,\ldots,\pm 1$, $0$ otherwise.    Since $P[\sum X_i=k] =P [\bar{X}=k/n ]$, I thought it would be easier to first derive the probability function for the sum. Since they are still $2^n$ n-tuples and each one is equilikely, I need to count the ones whose sum is $k$ for:  $k=\pm 1,\pm 3,\ldots \pm n-2,\pm n$ (since even numbers are not a feasible combination)  The problem here though is that I do not immediately recognize how I could count all these tuples. Could you please help me with this? If it is easier to proceed another way, I am of course all ears. Moving Around Other creatures      You can move through a nonhostile creature's space [but] you can't willingly end your move in its space.   Is that "end your move" at the end of your turn or if you stop to attack? I had a player who wanted to move into another friendly character's space, attack a hostile, then sidestep behind a wall. Interpretation of interaction term I have a model: $$ \ln({\rm earnings}) = a+b_1{\rm female}+b_2{\rm white}+b_3{\rm female}\times{\rm white} $$ ${\rm female}$ and ${\rm white}$ are dummy variables.  I have interpreted $b_1$ and $b_2$:    $b_1$ = change in female earnings comparing to male given you are non white $b_2$ = change in white earnings comparing to non white given you are male   But I am unable to interpret the coefficient of the interaction term ($b_3$). Please help me with this.  Let me make it more clear what I need out of this regression $$ \ln({\rm earnings}) = 2.618656-.0899657{\rm female}+.382019{\rm white}-.2754126 {\rm female}\times{\rm white} $$ Now i know there is gender pay difference with b1, i also know there is race pay difference with b2. Now with b3 i need to know is their a gender pay gap for whites only. How can i figure that out with regression above and without test. I got a situation where i need to invoke future method from batch class. And i know that it is not possible to do. But there might be some workarounds to achieve it, right? And i dont want to invoke future method using shedule apex as my requirement will hit governor limits of "Total number of schedule jobs exceed". So i tried in below ways, but still fighting with same issue.  My design is  Scenario 1 :   Schedule Apex ===> 2. BatchClass (Runs every hour) (Generates a map with "N" records for every batch context, and passes it to Future method in an apex class)  ===> 3. Future method ( then it will login to a salesforce account and generates an attachment and sends an email to a corresponding email address) .   Scenario 2 :  Since, It is not possible to invoke future method from batch, i tried implementing an apex class with a normal static method  invoking future method and in a batch class, for every context i.e., execute() method, it will invoke a normal method which in turn invokes future method, but still got the same error      FATAL ERROR: Future method cant be called from future or Batch   ie.,   global class BatchClass implements Database.batachable&lt;Sobject&gt; {    global Iterable&lt;ScheduledReport__c&gt; start(Database.BatchableContext BC)  {         query=[];        return query;  }  global void execute(Database.BatchableContext BC, List&lt;ScheduledReport__c&gt; scope) {      FutureClass.normalMethod(mapRecords);   }    global void finish(Database.BatchableContext BC){   }  }   Future Class:   global class FutureClass {  global static void normalMethod(Map&lt;&gt; mapR) {      futureMethod(mapR);  }  @future(callout=true)  global static void futureMethod(Map&lt;&gt; m) {      //some code;   }  }   Scenario 3 :  Instead of invoking future class method from batch i tried updating list of records and done checkbox value to true and i've implemented after update event trigger to get the all the records in which checkbox values are true and from trigger i tried invoking future method , still didnt work , i got an error      FATAL ERROR: Future method cant be called from future or Batch   Please help me out.   Thanks ! Why do Kurama and Gyuki appear as chakra while other bijuu don't? In Naruto, Kurama (the Nine-tailed bijuu) appears as chakra, as does Killer B's bijuu, Gyuki.      Other bijuu, however, don't appear that way. What is different between them? On the bash command-line, ↑ gives me the previous command. On the command-lines in ipython or matlab, when I type a few characters, ↑ gives me the previously entered command starting with those characters. How can I enable exactly this behaviour in bash? I am aware of more advanced ways of searching through the command-line history, but sometimes a simple way is more convenient. Exporting symbols rather than points in .dxf I have a map I've made in QGIS which is points from a .csv file. These have then be turned into different symbols based on what they represent and then the sizes of said symbols based on values in the .csv.  I need to export this as a .dxf to use in AutoCAD so it basically looks the same as it does in QGIS. However, when I do so it just exports as single dots (points). Is there a way I can export them as the symbols as I can see in QGIS? How to create posters using LaTeX I want to create posters for my poster presentation on a conference. What tools or LaTeX classes are available for preparing posters ? Setting DIV width and height in JavaScript Given a real, skew-symmetric matrix $\mathbf{A}\in\mathbb{R}^{m\times m}$, and a nonzero vector $X\in\mathbb{R}^{m}$, classify the scalar $\lambda$ (real, complex, imaginary, etc.) in the eigenvalue equation $$ \mathbf{A}X = \lambda X $$  The matrix $\mathbf{A}$ is skew symmetric if $\mathbf{A}^{T}=-\mathbf{A}$.  My try : I am new to matrices , so can not get a idea how to deal with it , Any hint will help Find all continuous functions $f$ satisfying   $$\int_0^xf=(f(x))^2+C$$ for some constant $C \neq 0$, assuming that $f$ has at most one $0$.  I have a question about the solution to this problem. It says that   Clearly $f^2$ is differentiable everywhere, its derivative at $x$ is $f(x)$ (I'm assuming that this is because the left hand side is differentiable, the right hand side must be differentiable as well). So $f$ is differentiable at $x$ whenever $f(x) \neq 0$, and  $$f(x)=2f(x)f'(x),$$ so $f'(x) = \frac{1}{2}$ at such points. Thus, $f= \frac{1}{2}x+b$ for some $b$ on any interval where it is non-zero; if $f$ has a zero, this gives two possible solutions, with two possible values of $b$, but since $f$ is assumed continuous, they must be the same. So we need $$\int_0^x(\frac{1}{2}t+b)dt=(\frac{1}{2}x+b)^2+C$$  so we must have $b=\sqrt{-C}$ or $-\sqrt{-C}$, leading to two solutions for $C \lt 0$.  I don't understand the bolded statements. First, how does the differentiability of $f^2$ guarantee that $f$ is differentiable, and why only at $x$ where $f(x) \neq 0$?  Next, why are there two possible solutions if $f$ has a zero, but since $f$ is continuous they must be the same?  Finally, does the last statement mean that if $C \gt 0$, then there is no solution, since we're restricted to real numbers here?  I would appreciate it if anyone answers my questions. Regex exec only returning first match How to make a circle with grid on the outside ring I made something like this:    I did this with the Ellipse Tool and the Line Tool.  Now the circle is accurate, but the lines inside are very inaccurate. Is there another tool that does the same thing but with a lot more accuracy? What is the optimal path between $2$ fixed points around an invisible obstructing wall? Every day you walk from point A to point B, which are $3$ miles apart. There is a $50$% chance each walk that there is an invisible wall somewhere strictly between the two points (never at A or B). The wall extends $1$ mile in each direction perpendicular to the line segment (direct path) between A and B, and its position can be at any random location between the two points. That is, it can be any distance between A and B such as $0.1$ miles away from A, $1.5$ miles away, $2.9$ miles away.... You don't know if the wall is present or where it is until you walk into it.  You must walk around the wall if present as there is no other way to circumvent it.  Assume the wall is negligible thickness (like a force field), all ground is perfectly flat, and the y coordinates at both A and B are $0$ (although I don't think the optimal path will change much if they weren't).  What strategy minimizes the average expected walk distance between A and B?  How do we know for certain this strategy yields the shortest average walking distance?  To get the $100$ bounty points, I would like a convincing argument from you as to why you feel your solution is optimal and cannot be beaten.  For those of you using computer simulation, anything reasonably close to optimal is a candidate for the bounty.   Can anyone beat the optimal solutions submitted so far?  There are still a few days to try.  Even a slight beat (if not due to roundoff error or some other error) would help prove previous solutions are non-optimal.  You can just use the table of $31$ points (x-y coordinates) and compute that path length and then if you can find better then I will accept that answer.  I think by Sunday night I may have to award the bounty otherwise it may get auto-awarded.