After upgrading from Desktop 12.04 LTS to Desktop 14.04 LTS. The File Manager seems to be severely degraded. The sidebar no longer allows a tree-structured view of directories. The menu bar is very limited with no File, Edit, View, etc. There does not seem to be any alternate means of doing what these things did in 12.04. Any insights appreciated. -chaz
Using dconf-editor I tried enabling   org -&gt; gnome -&gt; nautilus -&gt; list-view -&gt; use-tree-view     but even after the check box is selected, plus a reboot, it still doesn't switch to the tree view on the side bar.  In previous versions of Nautilus / Ubuntu the side-pane-view setting used to be in the window-state section (which is now missing)    I'm I missing something, or is there no way to enable Tree View on the side bar in 14.04?  Is there a way to manually create the missing entry back in window-state ?
How to stop apt from doing anything Carry over long sequence of missing values with Postgres I have a table like this:  create table foo (foo_label text, foo_price int, foo_date date);  insert into foo (           values           ('aaa', 100,  '2017-01-01'),           ('aaa', NULL, '2017-02-01'),           ('aaa', NULL, '2017-03-01'),           ('aaa', NULL, '2017-04-01'),           ('aaa', 140,  '2017-05-01'),           ('aaa', NULL, '2017-06-01'),           ('aaa', 180,  '2017-07-01')         );   As you can see a few values on the foo_price column are missing.  What I need is that missing values get filled up with the "previous" available value in this way:   foo_label | fixed_foo_price | foo_date -----------+-----------------+------------  aaa       | 100             | 2017-01-01  aaa       | 100             | 2017-02-01  aaa       | 100             | 2017-03-01  aaa       | 100             | 2017-04-01  aaa       | 140             | 2017-05-01  aaa       | 140             | 2017-06-01  aaa       | 180             | 2017-07-01   My attempt:  select      foo_label,      (case when foo_price is null then previous_foo_price else foo_price end) as fixed_foo_price,     foo_date from (   select        foo_label,        lag(foo_price) OVER (PARTITION BY foo_label order by foo_date::date) as previous_foo_price,        foo_price,       foo_date       from foo ) T;   As you can see from here:    It doesn't fill completely the '100' series.  Any idea how can I get the wanted result? Why can't I seem to grasp interfaces? Could someone please demystify interfaces for me or point me to some good examples? I keep seeing interfaces popup here and there, but I haven't ever really been exposed to good explanations of interfaces or when to use them.  I am talking about interfaces in a context of interfaces vs. abstract classes. I found a good replacement IDE for Delphi called Lazarus. But I don't have a question for programmers.  Will the statically linked Linux binary work on all Linux distributions? I.e. it does not matter on what Linux distro I built it and it will work on Debian / ArchLinux / Ubuntu / OpenSUSE / ... whatever?  As a result of my findings, does really only matter 32bit vs 64bit? I want to be sure before I publish. Adding Multiple Maps in QGIS Composer? Differential Equations: solve the system Solve the following system:   $$dx/dt=-.2(y-2)$$ $$dy/dt=.8(x-2)$$  This is what I have so far, but I got stuck.. $$\begin{eqnarray} dx/dt&amp;=&amp;-.2y-.4\\ x'&amp;=&amp;-.2y-.4\\ x'+.4&amp;=&amp;-.2y\\ y&amp;=&amp;-x/2'-2\\ y&amp;=&amp;-x''/2-2\\ \\ dy/dt&amp;=&amp;.8(x-2)\\ dy/dt&amp;=&amp;.8x-1.6\\ y'&amp;=&amp;.8x-1.6\\ -x''-2&amp;=&amp;.8x-1.6\\ -x''&amp;=&amp;.8x+.4\\ x''+16x+.8&amp;=&amp;0 \end{eqnarray}$$  when I used the quadratic formula I got stuck. Is this correct so far? Can someone finish it off for me? How do I fix Google Chrome's latest new tab page? I've just updated to the latest Google Chrome Dev build, and they've changed from the annoying-but-ok new tab page to an ugly and less usable page.  On the old one, nine thumbnails was not enough, and now they've restricted it to eight.  There's an empty "Tips and Suggestions" box which I wouldn't want even if it had stuff in; they've added Recent Downloads - on the rare occasions when I need that, I'll hit Ctrl-J to open the Downloads tab; and the site-specific search box on the right has now gone!  Is there a way to get the old new tab page back, or a plugin to provide a superior one?   Update: I launch Chrome by pressing Win+R and entering "chrome" - I have a shortcut on the Path with a Target of "C:\Documents and Settings\&lt;user&gt;\Local Settings\Application Data\Google\Chrome\Application\chrome.exe" --old-new-tab-page and whilst double-clicking this shortcut brings up the previous new tab page, using the keyboard method results in the old one.  How do I get it working via the Run box? (Without using a batch file, which slows things down too much.)  Update 2: GRRR! Now they've gone and stopped the --old-new-tab-page parameter from working at all! I hate this new version of the page that they're forcing upon us - can anyone provide a method to get rid of it and get the decent page back? How are Stack Exchange sites officially branded? How are sites in the Stack Exchange network, including Stack Overflow, officially branded? How are their names abbreviated? What conventions should be used in the FAQ? Send authors an inbox message if their question is closed I think it would really help if you get notified that a question of yours was closed.  Especially for the multi-site power user, usually (at least for me) a question is asked and then left alone for while. I rely on the network-wide inbox to tell me when someone has commented or answered, but if I don't receive any messages then I tend to assume that the question wasn't answered or even noticed. It's only when I check the question a day or two later to see what I can add do I find out it was closed.  This would be especially helpful for duplicates, where the answers you need are already there. A message to the effect of, "Closed as duplicate of question" is just like notifying me that a new answer has been added!  Unfortunately, question closures can remain unnoticed by their askers until months have passed. By then, the questions may either be too old to migrate to the correct site, or may , depending on the specific closing reason. We should notify users of these question closures so that they can improve them and learn from their mistakes.  Could closed questions get added to the inbox? How to build a dmg Mac OS X file (on a non-Mac platform)? Is it possible to build a .dmg file (for distributing apps) from a non-Mac platform? And if yes, how? I played around with it for a while, but I simply can't figure it out.  I made a tank that fires missiles, and when the missiles hit the walls, I want them to bounce off, but I want them to bounce off to the right angle.  Right now I haven't got any obstacles, the missiles just bounce off when they get outside the viewportRectangle I made.  Is the solution I'm looking for quite advanced?  Is there a relativly simple way to do it? Disable Screenshot Security Delaunay triangulation to generate abstract networks and nodes Is it possible to use Delaunay triangulation to generate an image like the below from a raster or vector of an object (in this case, a human heart)? What software and techniques would be required to make something like this? My intention is to make and use something like this in Inkscape without having to draw all the nodes/lines/effects manually. In my question  I asked about the definition and usage of the word "model", for which I was told the following definition:     A formula of propositional logic is true under an interpretation iff   the interpretation assigns the truth value T to that formula. If a   formula is true under an interpretation, then that interpretation is   called a model of that formula.   An interpetation satisfies a formula φ iff it is a model of the formula. Same for a set $\Gamma$ of formulas, if an interpretation satisfies all the formulas in $\Gamma$ then it is a model of $\Gamma$. Then if we say $\Gamma \vDash \varphi$ then $\varphi$ is a semantic consequence of $\Gamma$ / is satisfied in all "models" of $\Gamma$ (true whenever everything in $\Gamma$ is true).  This also matches the definitions for model as seen on the Wiki for  and .  All good so far. But when I get really confused when I see posts like  where they use "models" as a word meaning "satisfies all the axioms in a theory."  From Asaf's answer:     Models are structures, and structures are models. But when we say   "model" we mean that there is a particular theory which holds in the   structure, and when we say "structure" we are mainly interested in an   arbitrary interpretation of the language.   From Metin's answer:     A structure is a set with some interpretable symbols(constants,   relations and functions) within a fixed language. You do not ask for   more from a structure.      However...      A model (of a theory) is a structure which satisfies the axioms of the   theory. It makes more "structural sense"...   And then from one of Asaf's comments:     When I say "a model of 𝖹𝖥𝖢" they also know, immediately, that I am   talking about a model which satisfies all the axioms of 𝖹𝖥𝖢.   So I am unclear on which definition is correct or if this is the same word being used in two different ways or if this is "logical model" versus "semantic model" or something else entirely.  On the one hand we seem to have "model" meaning "any interpretation that satisfies a formula or set of formulas." On the other hand we have "model" meaning "Interpretation that satisfies all the axioms of a theory".  From the Wiki article on  we see also:     For a given theory in model theory, a structure is called a model, if   it satisfies the defining axioms of that theory.   So which is it exactly? Does "model" have a different meaning in propositional logic compared to model theory or first-order logic or set theory etc? Let's say that a player uses the ready action and says "If a character aims at me with a weapon, I'll use Teleport to move behind cover."  What happens? Does this work? If not, please cite the rules to explain why not. I tried to install Tor on my new version of Ubuntu, but it seems that Tor is not available in the repositories.  How else can I install and use Tor? I need to use an alias in the WHERE clause, but It keeps telling me that its an unknown column. Is there any way to get around this issue? I need to select records that have a rating higher than x. Rating is calculated as the following alias:  sum(reviews.rev_rating)/count(reviews.rev_id) as avg_rating Spurious @ symbol at start of bash prompt in Debian Jessie Why the "service --status-all | grep mysql" get many unrelated result? Why can mathematical equations describe this world? Since I want to understand the world, I learn physics from textbooks. But I feel there is a gap between the textbook and the world. I do not know     why the equations in the textbook can control the whole world? How can I bridge the gap? In research, how can one distinguish whether what we do is meaningful in reality or not?   Any help or suggestions or comments will be appreciated.