(update to 14.04) unity is not loading after I login to the admin profile after upgrade
Problems after upgrading to 14.04 (only background and pointer after login)
Check whether $\sum _{m=1}^{\infty }\sum _{n=1}^{\infty }\frac{1}{\left(m+n\right)^2}$ converges or NOT? iOS Calendar Access Permission Dialog, force it to appear? Splitting raster into smaller chunks using GDAL? I have a raster (USGS DEM actually) and I need to split it up into smaller chunks like the image below shows. That was accomplished in ArcGIS 10.0 using the Split Raster tool. I would like a FOSS method to do this. I've looked at GDAL, thinking surely it would do it (somehow with gdal_translate), but can't find anything. Ultimately, I'd like to be able to take the raster and say how large (4KM by 4KM chunks) I would like it split up into. How do I set up a "secure" open resolver? This is a  about securing public DNS resolvers   Open DNS servers seem pretty neat and convenient, as they provide IP addresses that we can use consistently across our company regardless of where they are located. Google and OpenDNS provide this functionality, but I'm not sure that I want these companies to have access to our DNS queries.  I want to set up something like this for use by our company, but I hear a lot about this being dangerous practice (particularly in regards to ) and I want to make sure that we do this right. What things do I need to keep in mind when building this type of environment? I have a site with Google Maps on most of the pages. When inspecting content keywords in Google Webmaster tools, content keywords identified by Google-bot for the site include "imagery", "sorry" and "here". These turn out to be part of an error message returned by Google Maps: "Sorry, we have no imagery here". I cannot reproduce this error with normal clients, nor does "fetch as Google" show it. The problem is presumably that Google-bot tries to execute some of the Google Maps Javascript but then shoots itself on the foot and records the error message.  A  shows that this problem is endemic to sites across the internet, including Yelp and many others.  I'd like to convince Google that my site is not about imagery and being sorry, but I'd also like to keep the maps in place. I guess one option would be to transition to , but that's not a great alternative.  There's some , no resolution. I'm working on an app that requires no user input, but I don't want the iPhone to enter the power saving mode.  Is it possible to disable power saving from an app? We don't get much snow in the UK, so I don't have much experience photographing it, and when I tried photographing falling snow last year I found it very hard to capture the snowflakes in the air — they either didn't show up or were just streaks. Is there a shutter speed that is best for this? I don't want to use flash to do so.  Any other snow photography tips welcome from those in snowier places! I used osm2pgsql to import data into my PostgreSQL database and it put gave me the following 4 tables, planet_osm_point, planet_osm_line, planet_osm_polygon and planet_osm_roads.   I have looked at the schema for osm2pgsql and inside the planet_osm_point table there is a column 'way' of type point. I tried to query it as an array like it says in the documentation here ():     It is possible to access the two component numbers of a point as   though the point were an array with indexes 0 and 1. For example, if   t.p is a point column then SELECT p[0] FROM t retrieves the X   coordinate and UPDATE t SET p[1] = ... changes the Y coordinate. In   the same way, a value of type box or lseg can be treated as an array   of two point values.   Anyone know the correct query the planet_osm tables from osm2pgsql based on long/lat? For example if I wanted to retrieve the information for Big Ben (London) I would query along the lines of:      SELECT * FROM planet_osm_point      WHERE ST_Y(ST_Transform(way, 4326)) = '-0.12'        AND ST_X(ST_Transform(way, 4326)) = '51.5';   There is no error message, it comes out with the table names, but no data is output either. (Its an empty table). What am I doing wrong here?  Perhaps it is too precise, i.e. there are no coordinates that match it exactly? Perhaps I need to try being more general, say 51 &lt; long &lt; 52 and -0.5 &lt; lat &lt; 0. Although this would throw back multiple results so would not be quite as accurate. Difference of Gamma random variables What is the rule for omitting/including the definite article in the following sentences:     I used to play piano.   I used to play the piano.   I would pick the first sentence, but I've heard people say the second sentence even when they are not referring to a specific piano. Which one is correct? How does Ubuntu partition the disk when we choose "Erase disk and install Ubuntu" during installation? Is the set of all unitary matrices in $M_2(\mathbb{C})$ is compact? I can show that as determinant map is continuous so unitary matrices are closed but how to show they are bounded?   Please help. Show that the set of functions $\mathbb{N}\to\{0,1\}$ is not countable Recall that a countable set $S$ implies that there exists a bijection $\mathbb{N}\to S$. Now, I consider (0,1). I want to prove by contradiction that $(0,1)$ is not countable.  First, I assume the contrary that there exists a bijection $f$, and I can find an element in $S$, but not in the range of $f$. But I can't find such element. How can you construct such $f$? Are split infinitives grammatically incorrect, or are they valid constructs? Mark's generosity in this crisis seems to more than make up for his earlier stinginess.   Should those sentences always be avoided, or are there cases where they are valid? I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the &quot;official  requirements&quot;, the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below. I am looking for either an online tool or one that I can download to convert DD to DMS.  For example, I want to convert from:  41.590833, -93.620833 to 41° 35′ 27″ N, 93° 37′ 15″ W ...  Those are the coordinates, according to , for Des Moines. I asked a question  but, rather stupidly, added extra information after it had been answered.  My additional question is this: I have a table with varying lengths of words. I want to encircle different groups of cells, including diagonals. If possible, it would be great if the rectangles don't overlap each other where possible.  I looked at the answer , which, whilst tedious, worked except for the overlap.    This is where I've got to so far:  \documentclass[fleqn,12pt,a4paper,landscape]{article}  \usepackage{tikz} \usepackage{tabularx}  \begin{document}  % Introduce a new counter for counting the nodes needed for circling \newcounter{nodecount} % Command for making a new node and naming it according to the nodecount     counter \newcommand\tabnode[1]{\addtocounter{nodecount}{1} \tikz \node     (\arabic{nodecount}) {#1};}  % Some options common to all the nodes and paths \tikzstyle{every picture}+=[remember picture,baseline] \tikzstyle{every node}+=[inner sep=0pt,anchor=base, minimum width=1.8cm,align=center,text depth=.25ex,outer sep=1.5pt] \tikzstyle{every path}+=[thick, rounded corners]  \begin{table}[ht]   \begin{minipage}[b]{1 \linewidth}\centering    \begin{tabular}{cccccc} % Turn the cells needed for defining the circling paths into nodes with our     custom command \tabnode{Long ago}&amp; \tabnode{A few days ago}&amp; \tabnode{Day before         yesterday}&amp; \tabnode{Yesterday} &amp;  &amp;  \\      &amp; &amp; &amp;  &amp; \tabnode{Today} &amp; \tabnode{Now}\\      \tabnode{Long time in the future}&amp; \tabnode{A few days on}&amp;     \tabnode{Day after tomorrow}&amp; \tabnode{Tomorrow} &amp;  &amp; \\      \end{tabular}    \end{minipage}   \begin{tikzpicture}[overlay] % Define the circle paths \draw [blue](1.north west) -- (1.north east) -| (7.north east) |- (7.south     west) |- (1.north west); \draw [red](8.south west) -| (2.north east) -| (2.south west) |- (8.south     west); \draw [yellow](9.south west) -| (3.north east) -| (3.south west) |- (9.south     west); \draw [green](8.south west) -| (3.north east) -| (2.south west) |- (8.south     west);   \end{tikzpicture}  \end{table} \end{document}  %%% Local Variables:  %%% mode: latex %%% TeX-master: t %%% End: I am lost in normalizing, could anyone guide me please.  I have a minimum and maximum values, say -23.89 and 7.54990767, respectively.  If I get a value of 5.6878 how can I scale this value on a scale of 0 to 1. Is anti-gravity (i.e. repulsive gravity) possible in theoretical physics? Is  (i.e. repulsive gravity) possible in string theory?  I have read some articles about scientists making assumptions about the existence of anti-gravity, but is it possible in string theory? I'm reading a proof about Lagrangian => Hamiltonian and one part of it just doesn't make sense to me.  The Lagrangian is written $L(q, \dot q, t)$, and is convex in $\dot q$, and then the Hamiltonian is defined via the Legendre transform  $$H(p,q,t) = \max_{\dot q} [p \cdot \dot q - L(q, \dot q, t)]$$  Under the right conditions there exists a function $\dot Q (p,q,t)$ such that  $$H(p,q,t) = p \cdot \dot Q(p,q,t) - L(q, \dot Q(p,q,t), t)$$  i.e. when some $\dot Q(p,q,t)$ satisfies $p = \frac{\partial L}{\partial \dot q}\rvert_{(q, \dot Q(p,q,t), t)} = \frac{\partial L}{\partial \dot q}(q, \dot Q(p,q,t), t)$  (Finding this function is usually called "inverting p")  By taking partials in the $p$ variable and using the relationship, we can obtain the relationship  $$\dot Q = \frac{\partial H}{\partial p}$$  Because of the notation I chose, I get the strong urge to say $\dot q = \frac{\partial H}{\partial p}$  , and in fact this is what the textbook does. But have we proved this?    In other words, how can we deduce that  $$q'(t) = \frac{\partial H}{\partial p}(p(t), q'(t), t)$$ for any differentiable vector valued function $q$? (or maybe there are more conditions we need on $q$? Here  $$p(t) = \frac{\partial L}{\partial \dot q}(q(t), q'(t), t)$$ according to Lagrange's equations.