Here is my output after running df -h --total:  Filesystem      Size  Used Avail Use% Mounted on udev            3.9G     0  3.9G   0% /dev tmpfs           784M  9.9M  774M   2% /run /dev/nvme0n1p3  216G  182G   24G  89% / tmpfs           3.9G   33M  3.8G   1% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup /dev/nvme0n1p1  496M   28M  469M   6% /boot/efi cgmfs           100K     0  100K   0% /run/cgmanager/fs tmpfs           784M     0  784M   0% /run/user/0 tmpfs           784M  104K  783M   1% /run/user/1001 /dev/mmcblk0p1   60G  1.4G   59G   3% /media/joe/3666-6537 total           290G  183G   96G  66% -   I have a lot of photos and videos on this drive, which are clearly all being kept in /dev/nvme0n1p3. I've recently cleared some space, but certainly not 96G worth (The total Avail). Before I did cleanup (of around 20G, which agrees with the Avail amount on /dev/nvme0n1p3), I was not able to export from photo editing applications or render any videos, having been given warnings bout my disk being full. Obviously, this was only the /dev/nvme0n1p3 filesystem that was full.  So why do I have so much storage in these other dev and tmpfs partitions (is partition the right word here?) that seems to being going unused? I assume that the tmp directories fill up with junk when the system is in heavy use? And what is /dev/mmcblk0p1, which is using hardly any of it's allotted 60G of storage?
I am trying to understand how to see the total size of my hard drive &amp; how much is left. It was recommended on various searches to use the command below   df -h Filesystem      Size  Used Avail Use% Mounted on udev            7.8G     0  7.8G   0% /dev tmpfs           1.6G  9.6M  1.6G   1% /run /dev/sda1       219G   29G  180G  14% / tmpfs           7.8G   18M  7.8G   1% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup cgmfs           100K     0  100K   0% /run/cgmanager/fs tmpfs           1.6G   64K  1.6G   1% /run/user/1000   However I don't understand any of these directories. I mean what are they, are these all directories or partitions or what? And why do they appear under "mounted on"? How does that bit work. I assume the /dev/sda1 is my solid state drive? So now if I install applications, which one of these directories does my software get installed  into? I assume it just gets installs in the / directory (I haven't even got a clue what the / directory is). Can someone explain what the other directories are and what they are used for?
Extremely difficult logic question using conditional statement In this problem, we will only consider (real-valued) functions with domain $\mathbb{R}$. We define two new concepts. Let $f$, and $g$ be two functions.  We say $f$ is a rival of $g$ if   &emsp;&emsp;&emsp;&emsp; $\exists x\in \mathbb{R} \ \text{s.t.} \ \forall y\in \mathbb{R}, x \lt y \implies \lvert f(x)- g(x)\rvert\lt\lvert f(y)-g(y)\rvert$    We say $f$ is a frenemy of $g$ if  &emsp;&emsp;&emsp;&emsp; $\forall x\in\mathbb{R} \ \text{s.t.} \ \  x \lt y \ \ \text{AND} \ \ \lvert f(x)-g(x)\rvert \lt \lvert f(y)-g(y)\rvert$  Below are four claims. Which ones are true and which ones are false? If a claim is true prove it. If a claim is false, show it with a counterexample.  a) If $f$ and $g$ are any two functions and $f$ is a rival of $g$ then $f$ is a frenemy of $g$. b) If $f$ and $g$ are any two functions and $f$ is a frenemy of $g$ then $f$ is a rival of $g$. If $f$ and $g$ are any two functions and $f$ is a rival of $g$, then $g$ is a rival of $f$. Let $f$, $g$, and $h$ be any three functions. If $f$ is a frenemy of $g$ and $g$ is a frenemy of $h$ then $f$ is a frenemy of $h$  What are the four claims stating? Especially for c), the concept is not even present I am having a misunderstanding on how to solve them? This is a generic inquiry on the common practice/standard for determining the acceptable values of RMS when georeferencing topographic maps.  Is there an absolute value?  Some literature suggests that it should be "less than or equal to 1/2 of the side of a cell which make up the total resolution of the image." How to find chromatic number of the $n$-dimensional hypercube $Q_n$? Color change of string delimiter in listings with macro Why does bool(xml.etree.ElementTree.Element) evaluate to False? Per the 's Wild Magic Surge table (PHB, p. 104)     07-08: You cast fireball as a 3rd-level spell centered on yourself.   There's other questionable area spells in that list (grease is a 10 foot square, so your square and which three?), but I'll focus on spheres like  (PHB p. 241):     (...) Each creature in a 20-foot-radius sphere centered on the point must (...)   My problem is, the sources I found so far - including the   to similar questions here - talk about measuring spheres from grid square intersections, whereas this clearly talks about it being centered on the unlucky Wild Magic sorcerer. Plus, since it's a wild magic effect, it doesn't exactly have a caster that can pick a point of origin. Is there an accepted way to measure an effect like this? Determinant of a non-square matrix I wrote an answer to  question based on determinants, but subsequently deleted it because the OP is interested in non-square matrices, which effectively blocks the use of determinants and thereby undermined the entire answer. However, it can be salvaged if there exists a function $\det$ defined on all real-valued matrices (not just the square ones) having the following properties.   $\det$ is real-valued $\det$ has its usual value for square matrices $\det(AB)$ always equals $\det(A)\det(B)$ whenever the product $AB$ is defined. $\det(A) \neq 0$ iff $\det(A^\top) \neq 0$   Does such a function exist? Is there a proof from the first principle that the Lagrangian L = T - V? How do I disable the alt-right click keyboard binding? Using Oneiric 11.10 and Unity. I want to disable the context menu that appears with Alt+RightClick. Alt+RightClick is a much used shortcut in Blender. It's possible to remap keys in Blender, but I was hoping to be able to turn it off in Ubuntu so that Blender get scontrol. I update my Blender installation often, so it's more convenient not to have to change settings every time. Are amounts of money singular or plural? Are the two sentences correct or is one of them incorrect?     1) Five billion dollars is earmarked for the project.   2) Five billion dollars has been earmarked for the project.   I know dollars are countable. So I think both 'is' and 'has been' are correct here.   Also, do they differ in meaning? Prove by induction that for all $n \geq 3$: $n^{n+1} > (n+1)^n$ Modular arithmetic: division, fractions, solving linear congruences I want to ask a question about modular arithmetic. I know, that modular multiplicative inverse exists only if modulo and integer are relatively prime. I want to know, are there any ways of division in modular arithmetic, if modulo and integer aren't relatively prime? I tried to find info about that, but failed. Who is bound to the Prime Directive? In the galaxy there are a fair number of pre-warp societies. A Federation ship is not to contact them. But what about other, non-Federation species?   If for example a Ferengi ship passes by a pre-warp planet, would they be allowed to contact it? What would a Federation ship observing this contact have to do? Are they obliged to intervene? Are they allowed to? Or were they merely allowed to "strongly discourage" the attempt of the Ferengi?  If it is legal to use force to stop the Ferengi, than in essence the Ferengi were bound to the Prime Directive too. And if so: does this go for all Federation territory? Is this confined to the Federation territory? If Janeway observes such an incident, what are her rights to intervene? Or does she have the duty to do so? Brand new disk brakes are barely stopping the bike Help with Dual Javascript countdown clock I am having a little trouble figuring out how to make this work properly, I am trying to put a small countdown clock in the left column and one in the right column, which will show a countdown to two separate dates. I was able to create a single countdown clock using the below code and was hoping to be able to be able to tweak the code enough to allow it to run on a second CEWP with a different date. Is it possible to run two Javascript files on the page without them interferring with eachother? Thank you anyone that can lend a quick hand.      &lt;style type="text/css"&gt; .container{     text-align: center;     background: #f63536;   font-family: sans-serif;   font-weight: 100;   height:115px;   width:215px; }  h3{   color: #FFFFFF;   font-weight: 100;   font-size: 16px;   margin: 0px 0px 5px;   padding-top:3px; }  #clockdiv{     font-family: sans-serif;     color: #fff;     display: inline-block;     font-weight: 100;     text-align: center;     font-size: 20px; }  #clockdiv &gt; div{     padding: 5px;     border-radius: 3px;     background: #ff5b5b;     display: inline-block; }  #clockdiv div &gt; span{     padding: 5px;     border-radius: 3px;     background: #ab0202;     display: inline-block; }  .smalltext{     padding-top: 5px;     font-size: 13px; }  &lt;/style&gt;  &lt;div class="container"&gt;  &lt;h3&gt;Countdown Clock Left&lt;/h3&gt; &lt;div id="clockdiv"&gt;   &lt;div&gt;     &lt;span class="days"&gt;&lt;/span&gt;     &lt;div class="smalltext"&gt;Days&lt;/div&gt;   &lt;/div&gt;   &lt;div&gt;     &lt;span class="hours"&gt;&lt;/span&gt;     &lt;div class="smalltext"&gt;Hrs.&lt;/div&gt;   &lt;/div&gt;   &lt;div&gt;     &lt;span class="minutes"&gt;&lt;/span&gt;     &lt;div class="smalltext"&gt;Min.&lt;/div&gt;   &lt;/div&gt;   &lt;div&gt;     &lt;span class="seconds"&gt;&lt;/span&gt;     &lt;div class="smalltext"&gt;Sec.&lt;/div&gt;   &lt;/div&gt; &lt;/div&gt;&lt;/div&gt;  &lt;script&gt; function getTimeRemaining(endtime){   var t = Date.parse(endtime) - Date.parse(new Date());   var seconds = Math.floor( (t/1000) % 60 );   var minutes = Math.floor( (t/1000/60) % 60 );   var hours = Math.floor( (t/(1000*60*60)) % 24 );   var days = Math.floor( t/(1000*60*60*24) );   return {     'total': t,     'days': days,     'hours': hours,     'minutes': minutes,     'seconds': seconds   }; }  function initializeClock(id, endtime){   var clock = document.getElementById(id);   var daysSpan = clock.querySelector('.days');   var hoursSpan = clock.querySelector('.hours');   var minutesSpan = clock.querySelector('.minutes');   var secondsSpan = clock.querySelector('.seconds');    function updateClock(){     var t = getTimeRemaining(endtime);      daysSpan.innerHTML = t.days;     hoursSpan.innerHTML = ('0' + t.hours).slice(-2);     minutesSpan.innerHTML = ('0' + t.minutes).slice(-2);     secondsSpan.innerHTML = ('0' + t.seconds).slice(-2);      if(t.total&lt;=0){       clearInterval(timeinterval);     }   }    updateClock();   var timeinterval = setInterval(updateClock,1000); }  var deadline = 'October 31 2015 00:00:50'; initializeClock('clockdiv', deadline); &lt;/script&gt; How to resolve ambiguous column names when retrieving results? I have two tables in my database:  NEWS table with columns:   id - the news id  user - the user id of the author)   USERS table with columns:   id - the user id   I want to execute this SQL:   SELECT * FROM news JOIN users ON news.user = user.id    When I get the results in PHP I would like to get associative array and get column names by $row['column-name']. How do I get the news ID and the user ID, having the same column name? How can I install Windows after I've installed Ubuntu? I have Ubuntu on my laptop. Now I want install Windows 7 in a dual-boot. How can I do this? I can't lose my Ubuntu files, and I'm afraid that I might break . Go  for UEFI only! I have to design a circuit in which I have to transfer data through lasers (serial transmission of data). Now what I was thinking was to check if the laser light is on then '1' is passed and when the laser is off '0' would be passed. Now I need to check if a 1 or a 0 was passed.   How would I check for this and another problem I'm facing is if it's on it may keep on passing 1's. How would I check for this? I though of using LDR's (Light Dependent Resistors)? Would this be okay or it there a better method? How to register domain for 15 years? I have heard that Google trust that website which has long expiry date. that want to know how can I register my domain for a long period. Pagination go to first page if i'm on last post I have a custom post type and used get_next_post() and get_previous_post() to create a simple pagination. However i need to create a pagination loop (if that is the correct term). If i'm on the first post i need to browse back to the last post and if i'm on the last post i need to browse to the first post. Is there a simple way to do this that i haven't seen but Google, this site and the codex has not been very helpfull :/  The current code i have is. I've tried to use wp_list_pages and other functions but with little luck.  $next_post = get_next_post(); $prev_post = get_previous_post(); $nav = array(     "next_post" =&gt; array(         "url"       =&gt; get_permalink($next_post-&gt;ID),         "id"        =&gt; $next_post-&gt;ID,         "titill"    =&gt; get_field("vinstri_titill", $next_post-&gt;ID)." - ".get_field("vinstri_undirtitill", $next_post-&gt;ID)     ),     "prev_post" =&gt; array(         "url"       =&gt; get_permalink($prev_post-&gt;ID),         "id"        =&gt; $prev_post-&gt;ID,         "titill"    =&gt; get_field("vinstri_titill", $prev_post-&gt;ID)." - ".get_field("vinstri_undirtitill", $prev_post-&gt;ID)     ), );