The code for multi labels eg.: Field1 || '\n' || Field2  works fine, unless you have a missing value (NULL) in one of your fields, in which case QGIS doesn't show any labels at all (for the specific object). I use QGIS 3.10.14-A Coruna. Any suggestions?
I am having some issues trying to show multiple fields for a single label in QGIS. In QGIS2.6, attempting to display labels for a feature consisting of multiple fields results in an empty label if one of the fields is null. So for example, in the label expression dialog:  concat("Temp Site",'\n',"Notes",'\n',"Function")   will function normally unless one of the fields is null, then it results in no label being shown. Using the '||' operator instead in the expression dialog also results in the same behaviour:  "Temp Site" || '\n'  ||  "Notes" || '\n'  ||  "Function"   Is there a way to display the labels even if one of the fields is null?
What is the limit of this sequence? How does it relate to the exponential function? Find $$\lim_{n\to\infty} \left(1+\frac{x^2}{n^2}\right)^n$$   I particular, I am hoping to find the above to be $1+x^kg(x/n)$ where $g(\cdot)$ is a function with uniformly bounded derivatives.  Edit: I'm trying to prove a result that would be true if  $(1+x^2/n^2)^n -1 = x^kO(x/n).$ What does $\lim\limits_{x \to \infty} f(x) = 1$ say about $\lim\limits_{x \to \infty} f'(x)$? Given that $f$ is differentiable, what does $\lim\limits_{x \to \infty} f(x) = 1$ say about $\lim\limits_{x \to \infty} f^\prime(x)$ ? Intuitively I feel that it's $0$.  I attempted to solve this by trying to evaluate $$\lim_{x \to \infty} \lim_{h \to 0} \frac{f(x + h) - f(x)}{h} $$ by trying to interchange the limits after showing that $\frac{f(x + h) - f(x)}{h}$ converges uniformly as $x \to \infty$. But I couldn't proceed further.  Trying to work backwards, as a specific example, $f(x) = \arctan(x)$ came to my mind. It's derivative certainly goes to $0$ as $x \to \infty$. Doesn't this show that $\frac{f(x + h) - f(x)}{h}$ converges uniformly to $0$ as $x \to \infty$ ?  I'm totally confused! I would really appreciate if anyone told me what I am doing wrong. Prove that there is no retraction (i.e. continuous function constant on the codomain) $r: M \rightarrow S^1 = \partial M$ where $M$ is the Möbius strip.  I've tried to find a contradiction using $r_*$ homomorphism between the fundamental groups, but they are both $\mathbb{Z}$ and nothing seems to go wrong... How to make table split in two pages I am writing a paper using the elsarticle document class. However, the article contains a long table which is sent to the next page, in the middle of the page although I have specified the position as 'here'. Is there any way to make the table split if one page is not long enough for the table? Thank you very much for your very kind help. Simple Linq query has duplicated join against same table? GZip of drive image created by using `dd` command I created yesterday a drive image using GZip.  I opened the 51.3 GiB file named ssd.img.gz to see one icon thats a package of 3.9 GiB, yes, thats THree point Nine Gigabytes in size and has the name of the image as ssd.img  That does not seem right to me, has the image creation worked or not?  Yes the drives have data and an operating system on it.  Should I have used cat instead? only I did and it kept on saying that it had nothing to do.  Would using the | zip instead be a better option?    ** EDIT **  The command used was:  mark@zotac:~$ sudo -l Enter password:&lt;entered password to get in to root&gt; root@zotac:~# dd if=/dev/sda | gzip -c &gt; "/media/mark/Seagate External Drive/ssd.img.gz   the terminal spent the best part of 10 Hours at building the image, something in itself that I also found suspect, why so log when copying the files to a folder that I wanted, some 40GiB took 45 minutes...  The source drive /dev/sda had no mounted partitions.     ** EDIT **  Just to clarify, I am trying to make an image of the drive to back up later if things go wrong with a repair, the drive itself needs to be a file on a drive as the target drive partition is using almost all of the drive, the partitions can't be resized on it without formatting it and I am not about to lose 1.4TB of data.   So the dd if=/dev/sda of=/&lt;target&gt; isn't what I need, what I do need is an image of the drive that I can restore the image from to the drive should the repair go wrong.  So what command do I use, dd or cat? Why does | zip keep telling me it has nothing to do when used with cat but no error or warning with dd What happens if both players have the ability to pump their creature an unlimited number of times? Say that both players each had 2 , 2 , and a . (Or any other way to get unlimited mana, and a Nantuko Shade).  Player 1 attacks with his , and player 2 blocks with his . Before damage is assigned, each has chances to pump up their  as much as they want. They can't just declare them to be "infinite," but each can always one-up the other player. What happens?  It seems there would be a loop of events, but would one player eventually be forced to break the loop as per rule 714.3? Is it considered the same game state after each player pumps their creature a bunch as it was before?  This was discussed at length on the Draw3Cards Magic Q&amp;A site (which is no longer available), but no conclusion was reached. Some felt that the game would simply be a draw, others felt that the active player would be forced to make a different decision to break the loop. Others felt that you would just have to call a judge and see what he decides. IndentationError: unindent does not match any outer indentation level When I compile the Python code below, I get      IndentationError: unindent does not match any outer indentation level     import sys  def Factorial(n): # Return factorial     result = 1     for i in range (1,n):         result = result * i     print "factorial is ",result     return result   Why? Python element-wise tuple operations like sum Is there anyway to get tuple operations in Python to work like this:  &gt;&gt;&gt; a = (1,2,3) &gt;&gt;&gt; b = (3,2,1) &gt;&gt;&gt; a + b (4,4,4)   instead of:  &gt;&gt;&gt; a = (1,2,3) &gt;&gt;&gt; b = (3,2,1) &gt;&gt;&gt; a + b (1,2,3,3,2,1)   I know it works like that because the __add__ and __mul__ methods are defined to work like that. So the only way would be to redefine them? How to limit charging to a user defined limit? My UleFone Armor 2 has a 4700mAh battery and I would like to limit the charging to 60% to reduce battery aging. The batteries in most of the phones are not user-replaceable and I am worried that a factory/service battery replacement might affect water resistance negatively.  How can I limit the charging to 60%? (But not limiting charging speed. I love fast charging.)  Lenovo ThinkPads have a built-in feature that does this, called “battery preservation mode”. Restore console session after remote desktop disconnects? Retrieving Maxwell's equations from the minimum action principle Blank white desktop icons on new Windows 7 install Is there way to replace value of symbolic link? Is there way to replace value of symbolic link?  For example I want to replace symbolic link like this:  first -&gt; /home/username/foo/very/long/directories/that/I/do/not/want/to/type/again    to   second -&gt; /home/username/bar/very/long/directories/that/I/do/not/want/to/type/again   I want to change only foo to bar.  Of course I can create a link again, but if it is possible to replace value of the link, it become easier. I've lost a command block, how can I find it? I've placed a command block making it day all the time. I want to turn it off, but I've lost it. What's the quickest way to find it? Editing and manipulating tables with ArcPy? I’m new to ArcMap and was wondering if anybody could help me out. I have a shapefile with counties and wells in that county. In the table I’m trying edit it so that for each county calculate the total numbers of wells that fall into that county, and update the county table with the total count. I also want to calculate how many wells there are per area unit, and update the table with that value as well.  import arcpy featureClass = "C:/Lesson5_Data/Colorado_cities.shp" fieldList = "*"  with arcpy.da.SearchCursor(featureClass, fieldList) as cursor: for row in cursor: print row[4  population = 10000  whereClause = '"POP2007" &gt;= ' + str(population Inspired by question :  When do I need to invoke \phantomsection?  In what condition is invoking \phantomsection necessary? Viewing computer screen through 3D glasses, why the asymmetry? Why, oh why, don't the Weasleys "conjure" up some diamonds/gold/etc, sell 'em to Muggles, and get rich? They could buy a mansion (like the Malfoys), and live there happily ever after.  I know there's  that prohibits one from conjuring food (which doesn't make much sense to me, either). Even if it applied to gold, what about all the other elements/compounds/materials? Could the law really be 'don't let a wizard conjure something if it'll make them richer'? That's totally nonsensical.  Why does Wizard society still have poor people, especially if they're talented? Ubuntu 12.04 comes with Gimp 2.6, so I installed Gimp 2.8 using the instructions below:   sudo apt-get purge gimp*   sudo add-apt-repository ppa:otto-kesselgulasch/gimp   sudo apt-get update   sudo apt-get install gimp    When try to open help, I get the message below. How do I install and configure the help for 2.8 on Ubuntu?