I dissolved the inner polygons of a shp file and was left with some lines inside. I'm not sure how they got there, since the original file does not seem to have them. I've also tried deleting them, but have not been able to do so.
I work with QGIS 2.10.1 on Windows 7 (x64). I have dissolved polygons from an attribute value and the polygons geometries being not perfectly joined together, I get some 'garbage' nodes I need to delete. I have tried to edit the layer and using nodes tool, selecting and deleting the nodes, but it seems impossible to do (nodes are not deleted at all!). Any idea on how to process this kind of clean-up?  EDIT : you can  for testing.
Grub menu at boot time... "holding shift" not working I read here at  that holding Shift during boot can bring up the GRUB menu. However I try holding one or the other Shift keys, tapping, tapping then holding, nothing works. Am I missing something? How does one access the GRUB menu during boot time?   No dual boot here, just standard Lubuntu 14.04 install. Applications Not Reopening After Restart Can't Add css-columns Tag I've tried at least 4 times on  to add the tag css-columns, but each time after I save it disappears. When I type it in the tag box, it shows up and even has a tag wiki associated with it, but it will not stick when I save. Basic buoyancy question: Man in a boat with a stone This comes from a brain teaser but I'm not sure I can solve it:     You are in a rowing boat on a lake. A large heavy rock is also in the boat. You heave the rock overboard. It sinks to the bottom of the lake. What happens to the water level in the lake? Does it rise, fall or stay the same?   I'd say that the water level drops, because when you drop the stone in the lake, the water level rises according to the volume of the stone, BUT the water level decreases by a volume of water weighting the stone's weight, when you take it off the boat.  Is that correct? Basic photo editing on OS X I need to edit a photo on my Mac. I wish to take two photos and paste them together to create one that's larger, containing both. I couldn't figure out how to do this with iPhoto.   For Windows you have Paint.NET.    For Linux you have Kolourpaint.   What would be the equivalent on OS X?  Please note that it must be of quality both in code and in UI. I wouldn't want to install buggyware on my Mac. Hyperref - Token not allowed Possible Duplicate:          The following code:  \subsection{The classes $\mathcal{L}(\gamma)$}   generates the errors:  Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `math shift' on input line 1938.   Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `\gamma' on input line 1938.   Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `math shift' on input line 1938.   What do I have to do to keep \gamma in the subsection, so that it is also listed in the table of contents? I assume that the following sentences are grammatically correct:   He resents your being more popular than he is. Most of the members paid their dues without my asking them. They objected to the youngest girl's being given the command position. What do you think about his buying such an expensive car? We were all sorry about Jane's losing her parents like that.   I'm still getting used to this possessive gerund structure. It sounded so weird to me at first. Is the structure used in both formal and informal contexts? Are there any alternative structures that result in the same meaning and are more frequently used? (Examples taken from ) Is there the easiest way to toggle (show/hide) navigational grids in TikZ? In PSTricks, we can toggle the grids easily by showgrid=[false/true]. How to do it in TikZ? Doing as follows is tedious.    \documentclass{minimal} \usepackage{tikz}  \begin{document}   \tikzpicture  \draw[gray,very thin] (-4,-2) grid (4,2); \foreach \x in {-4,...,4}   \draw[red] (\x,-1.9) -- (\x,-2.1) node [below] {\x};   \foreach \y in {-2,...,2}   \draw[red] (-3.9,\y) -- (-4.1,\y) node [right] {\y};  \draw (0,0) circle (2);   \endtikzpicture    \end{document}   Is there the easiest way to toggle (show/hide) navigational grids in TikZ?  Edit  The navigation needs not only the grids but also the labeling numbers. Log4Net: Programmatically specify multiple loggers (with multiple file appenders) How to (programmatically, without xml config) configure multiple loggers with Log4Net? I need them to write to different files. Prove that $\mathbb{N}^k$ is countable for every $k \in \mathbb{N}$.  I am told that we can go about this inductively.   Let $P(n)$ be the statement: “$\mathbb{N}^n$ is countable” $\forall n \in \mathbb{N}$.  Base Case: $\mathbb{N}^1 = \mathbb{N}$ is countable by definition, so $\checkmark$  Inductive Step: $\mathbb{N}^{k+1}$ $“=”$ $\mathbb{N}^k \times \mathbb{N}$  We know that $(A,B)$ countable $\implies$ $A \times B$ is countable. I am stuck on the part where I have to prove the rest, but I know that, for example, $(1,2,7) \in \mathbb{N}^3 \notin \mathbb{N}^2 \times \mathbb{N}$ but instead $((1,2),7) \in \mathbb{N}^2 \times \mathbb{N}$. So how would I go about proving the statement. How do I diagnose not being able to reach a specific website as an end user? In an Integral Domain is it true that $\gcd(ac,ab) = a\gcd(c,b)$? Which is better: side quests after killing the warrior or Playthrough 2? My question is, once I beat the warrior should I do all the sidequests in Normal before starting TVHM or should I go right to TVHM once it becomes available?    I just bought the game and have been playing with some friends who are higher level than me so that we could enjoy the Tiny Tina DLC together.  As a result, I leveled up pretty fast without doing much of the main story quest or side quests.  Now I'm a level 32 commando and haven't finished the main storyline in normal (Just finished "Where angels fear to treat Pt 2").  I get almost no XP from kills on missions.  I still have tons of sidequests.  I imagine some of them might give good loot, or be fun to play.  It it better to go to Playthrough 2 or should i do the sidequests in Normal first?  EDIT: changed question title and some wording for clarity How to cross-reference items in description lists? Every now and then I use the description list environment  \begin{description} \item[foo]  foo is good \item[bar]  bar is bad \end{description}   to create lists with non-numerical labels. Unfortunately the description list does not support the label-reference pair as normal latex: i.e. if I write  \begin{description} \item[foo] \label{foo} foo is good .... \end{description} .... For good things (see, for example \ref{foo})...    the reference does not point to the item in the list. Instead it points to the closest environment that supports labeling (usually the subsection). So instead of showing the text foo (in boldface), it shows something like 2.2.1 (the subsection corresponding to where the description environment is sitting).  My question: is there a way or a package which allows references to description list items? My current work-around is to just type the text myself in the spot (since I named it myself, and it is not numbered, the formatting is unlikely to change the label =). But one of the good things about the label/reference pairs in latex is the implementation in pdflatex that allows in PDF hyperlinks between references and the objects referred to, this I cannot replicate myself.   Edit: let me rephrase my question. The primary goal is not to display \ref to something other than what LaTeX thinks the \label is. There are many ways to deal with it, some of which outlined in Michael Underwood's helpful answer below. What I am looking at is whether there exists an implementation of a list environment which is like the built-in description environment in that the displayed "title" for the list item is completely customized, while having support for \labels. (The built-in description environment does not support \labels, whereas the built-in enumerate environment does not support customized "title"s.) The enumitem package adds some customizability to the environments, but as far as I can tell it doesn't support exactly what I want. While working on a project, I came across a JS-script created by a former employee that basically creates a report in the form of  Name : Value Name2 : Value2   etc.  The peoblem is that the values can sometimes be floats (with different precision), integers, or even in the form 2.20011E+17. What I want to output are pure integers. I don't know a lot of JavaScript, though.  How would I go about writing a method that takes these sometimes-floats and makes them integers? single word that means which can be constructed at home Proving a limit of a trigonometric function: $\lim_{x \to 2/\pi}\lfloor \sin \frac{1}{x} \rfloor=0$ $$\lim_{x \to \frac{2}{\pi}}\lfloor \sin \frac{1}{x} \rfloor=0$$    I need to prove the limit of this using the $\epsilon - \delta $ way but I don't know how to find $\delta$ when I'm given a trigonometric function I know only how to do it with polynomial functions Migration stats not consistent between sites Apparently, as a result of  it appears that Yannis and myself see different statistics when going to the programmers.SE.com migration stats tool and the stackoverflow.com tool respectively.    :        while I see:        Why are the rejection rates so radically different?  Which is correct?  (Or am I simply misinterpreting the data somehow and these are representing different statistics) Which is the correct gerund clause? 'People's killing animals', or 'People killing animals ... '? Importing 3D DXF file into QGIS with z information as attribute value?