Where is Ubuntu Software in Ubuntu 18.04?
Reinstall software-center in Ubuntu 16.04
"What have you tried" epidemic Statistics  () In Q1 of 2012 - 0.0134 such comments per question (~1.33%) In Q2 of 2012 - 0.0167 such comments per question (~1.66%) In Q3 of 2012 - 0.0169 such comments per question (~1.68%) In Q4 of 2012 - 0.0193 such comments per question (~1.92%) In Q1 of 2013 - 0.0223 such comments per question (~2.22%)  The vast majority of these questions need serious help.  Unfortunately, there is a growing trend towards abuse Along with the good, comes some bad -- as usual in life. These comments are bad when  Posting &quot;what have you tried&quot; multiple times per question is severely obnoxious Posting &quot;what have you tried&quot; when the user has clearly shown that they have tried to solve it on their own  It is becoming increasingly common to see &quot;what have you tried?&quot; comments in these scenarios. Some examples     Workarounds Flagging Comments - It is considered a good thing to be liberal with comment flagging -- that helps us clean up after the fact. &quot;Too Chatty&quot; is a no-brainer here. Unfortunately, that only cleans up after the damage has been done. All signs point toward the continued increase of the trend of using &quot;what have you tried&quot; comments. I spend a lot of time editing and cleaning up bad questions. This trend came up on my radar toward the end of last year and it is getting worse. So, I thought at the very least that I'd raise some awareness. Enable fractional scaling for Ubuntu 18.04 Changing pemalink structure to /%post_id%/%postname%/ I'm currently using permalink structure: /%year%/%monthnum%/%day%/%postname%/  I want to change that to: /%post_id%/%postname%/  I expect it to be:   faster (database is sorted by post_id?) shorter URLs (and clearly visible short verstions, just leaving the %postname%/ out) more SEO friendly - since my content is "evergreen" so publishing date is irrelevant (and written at each post, along with last update date) - so this would give shorter URLs, with no downsides compared to using year/month/day structure.   THE QUESTION: Does WordPress handle all the 301 redirects automatically? I can fix internal links to the new structure (though I'd expect that to be automatic as well), but worry about outsite links, pointing to my posts/articles.  If not, what's the best way to implement this change? Any links or full answers here are welcome.  I have about 120+ posts already, will this change affect the speed since it's not been done from the start? A common good practice in Machine Learning is to do feature normalization or data standardization of the predictor variables, that's it, center the data substracting the mean and normalize it dividing by the variance (or standard deviation too). For self containment and to my understanding we do this to achieve two main things:   Avoid extra small model weights for the purpose of numerical stability. Ensure quick convergence of optimization algorithms like e.g. Conjugate Gradient so that the large magnitude of one predictor dimension w.r.t. the others doesn't lead to slow convergence.   We usually split the data into training, validation and testing sets. In the literature we usually see that to do feature normalization they take the mean and variance (or standard deviation) over the whole set of predictor variables. The big flaw I see here is that if you do that, you are in fact introducing future information into the training predictor variables namely the future information contained in the mean and variance.  Therefore, I do feature normalization over the training data and save the mean and variance. Then I apply feature normalization to the predictor variables of the validation and test data sets using the training mean and variances. Are there any fundamental flaws with this? can anyone recommend a better alternative? Unable to 'apt-get dist-upgrade' due to appstreamcli database error I have created a USB stick with a persistent Ubuntu 16.04 (release version). I tried a couple of ways, using Startup Disk Creator and MultiSystem, but I get the same end result.  When I boot into the USB and do 'apt-get update', all is well.  When I try 'apt-get dist-upgrade' I get:     ** (appstreamcli:2761): CRITICAL **: Error while moving old database out of the way. AppStream cache update failed.   The only reference to this error message I can find is  but would appear to be fixed, at least fixed by the time the release version of Ubuntu 16.04.  Aside: I want to test Unity8, which includes installing software.  I don't have a spare computer, so I thought a persistent USB would do the trick.  Any takers? Non trivial valuation over a finite extension $F/\mathbb{Q}_p$ is equivalent to the one induced by $v_p$ I was watching some videos on YouTube showing how to get the Duke O' Death in GTA 5, however what I have seen is sort of unclear.  Some people say you must be a returning player on GTA 5 to get it (what does this mean too BTW?), some people don't say that. Some people say you have to be Trevor, some people don't. Some say the time of day matters, some don't. And apparently you can buy it from Warstock website (I can't).   Can someone please tell me how to get it?! GTA 5 came with my PS4 (I didn't play it on PS3) if that helps. Upon searching for the OpenLayers plugin, it shows that this plugin is incompatible with version QGIS 3.0. Will this be updated? Is there another way to add Google imagery or any other aerial imagery other than through this plugin?   I noticed the OpenStreetMap layer I had been using with QGIS 2 is still working now that I am using QGIS 3, but the Google Satellite layer no longer appears. Can anyone hint me to prove:  $\forall n\in \mathbb{N}: \exists$ Fibonacci numbers $ F_{i_1},\ldots,F_{i_k}$ such that: $$\sum F_{i_k}=n$$    Note: Every Fibonacci number can appear only once. Thanks Automatically logging into Windows XP Uncountable $\sigma$-algebra I'm stuck on the following problem (Source: Real Analysis for Graduate Students; Exercise 2.6; ):     Suppose $\mathcal A$ is a $\sigma$-algebra with the property that whenever $A \in \mathcal A$, there exists $B, C \in \mathcal A$ with $B \cap C = \emptyset$, $B \cup C = A$, and neither $B$ nor $C$ is empty. Prove that $\mathcal A$ is uncountable.   I think there is the added assumption that this is only true for $A \in \mathcal A$ having at least two elements, so it doesn't hold for singletons and the emptyset?  I tried to show this by way of contradiction and say that $\mathcal A = \{A_k\}$ is countable, but I didn't see how this could get me to a contradiction.  The other approach I tried was to look at $X = B_1 \cup C_1$ where $B_1 \cap C_1 = \emptyset$, then look at $B_1 = B_2 \cup C_2$ where $B_2 \cap C_2 = \emptyset$ and so on. If I look at the $C_k$'s they are pairwise disjoint and I either have a finite number of them or an infinite number of them in which case I've created a countable sequence of pairwise disjoint nonempty elements of $\mathcal A$. This path looked promising, but I couldn't see what to do next. Any ideas?  As a secondary question: I think this result is supposed to be used to show that if $\mathcal A$ is a $\sigma$-algebra with infinitely many elements, then it's uncountable, but I wasn't able to show that the property mentioned above (the one I'm trying to show) was satisfied in this case. It is common to see things described as the &quot;gold standard&quot;. It means that something is the best and is the ideal against which other things are to be compared; it cannot be superseded. I often , where a certain diagnostic test (e.g., the nasopharyngeal swab PCR test for infection with the Coronavirus causing COVID-19) is considered the most accurate and then other tests (e.g., cheaper or faster tests) are then evaluated against this benchmark. The etymology is covered in . In short, it is derived from the . Thus gold was the thing against which the value of all other currencies was measured. I don't like this term and would like to avoid using it. First, the desired meaning is not predominant; if you  you will mostly get results for the monetary system, not the more general phrase. Second, the etymology is outdated; the original meaning of the term now has the opposite connotation. The monetary gold standard was abandoned in the 1970s. Economists consider the gold standard to be a bad monetary system. Thus, if you are interested in economics and history, the term &quot;gold standard&quot; actually is associated with being outdated and flawed -- which is close to the opposite of the intended meaning. (Of course, many people are unaware of the original meaning of the term. ) (A note in response to comments: Why I want to avoid this term is relevant, but not essential, to the question. If you don't see a problem with the term, the question can be answered regardless.) My question: Is there a better phrase to use in place of &quot;gold standard&quot;? For example, what term could be used in a medical study comparing a new diagnostic test against the gold standard test? I'm not aware of any good substitute that has essentially the same meaning. Here are two example sentences where I would like a replacement:   A nasal swab is the gold standard for diagnosing COVID-19.     The  served as the gold standard for all scales from 1889 until 2019.   The best substitute I can think of is &quot;official,&quot; as in &quot;a nasal swab is the official way to diagnose COVID-19&quot;. &quot;Official&quot; implies some form of uniqueness. But &quot;official&quot; implies the existence of some authority that gives it this designation (as opposed to scientific consensus). A  asks for a &quot;perhaps humorous&quot; alternative -- the suggestion there, &quot;mother of all&quot;, is not appropriate here. (There is also .)  In response to the answers and comments doubting the premise of this question: I personally have a negative association with the phrase &quot;gold standard&quot; because I know people who advocate for returning to the gold standard or its modern equivalent, , and have discussed the topic at length. Several  US  continue to advocate for a return to the gold standard. Thus asserting that no one will interpret the phrase in terms of monetary policy is simply not convincing. Is there a theorem that says that QFT reduces to QM in a suitable limit? Of course, it should be, as QFT is relativisitc quantum mechanics. But, is there a more manifest one? such as Ehrenfest's theorem which dictates the transition from QM to Classical Mechanics.  I am curious as the basic object in QM is wave function whereas the basic object in QFT is quantized operator, which looks very different, and wondering how the comparison works.  (Of course, I am aware that QFT can calculate corrections for Coulomb potential energy, which may seem to be a transition from QFT to QM, but I want one more manifest than that.) I installed or upgraded to Ubuntu 16.04, but I'm having some problems with my graphics card.   The display is blank The display flickers Items on the screen do not display correctly Certain programs complain of graphics issues The computer boots to low-graphics mode Your specific issue may not be here, but try the solutions described in the answers anyway.   This question is very broad, but each one of these issues likely has one solution.    If you are experiencing a login loop, check the last part of my answer.    If you experience one of the listed issues and have your own solution (mine didn't work, or there's a faster way), feel free to post another POLITE answer, describing your problem and how you fixed it.    Those attempting to install Ubuntu, please refer to the section titled: If you are unable to enter a TTY or are trying to install Ubuntu. Proving that $\mathbb{Z}[\sqrt{2}]$ is a Euclidean domain We're proving that $\mathbb{Z}[\sqrt{2}]$ is a Euclidean domain, using the norm function $$\nu (a + b\sqrt{2} ) = |a^2 - 2b^2|$$ and the first part says that since $\nu (a + b\sqrt{2} ) = |(a + b\sqrt{2})(a - b\sqrt{2})|$ it's clear that $\nu (xy) = \nu(x) \nu(y)$? ... Can someone please explain to me how this is clear? How to Redirect Pages with Query String? I want to Redirect as seen below:  https://example.com/p1/p2?sort=p.model&amp;order=ASC&amp;page=2   to  https://example.com/p3/p4?sort=p.model&amp;order=ASC&amp;page=2   Also, I have this code in my .htaccess file :  RedirectMatch 410 ^/p1/p2&amp;   I have used below code, but I just see 410 code for that URL :  RewriteRule ^/p1/p2?sort=p.model&amp;order=ASC&amp;page=2$ /p3/p4?sort=p.model&amp;order=ASC&amp;page=2 [QSD, R=301,L]   So, I have changed RedirectMatch 410 ^/p1/p2&amp; to Redirect 410 ^/p1/p2&amp; , but this time I have seen 404 Code for my Request URI. What should I do? $A$ is normal and nilpotent, show $A=0$ Given a matrix $A \in R^{n \times n}$ which is normal ($AA^H=A^HA$ where $A^H$ is hermitian of $A$) and nilpotent ($A^k=0$ for some $k$). Now we need to show that $A=0$. (This is essentially exercise 5(b) in sec. 80 on p.162 of Paul R. Halmos' Finite-Dimensional Vector Spaces.) I tried to show in the following way, we know that, $AA^H=A^HA$ pre-multiply by $A^{k-1}\implies A^kA^H=A^{k-1}A^HA$ Now, we have $0 = A^{k-1}A^HA$, since $A$ nilpotent. I am not sure how to proceed from here to show $A=0$. Can someone help me in this problem? I'm a quarter Draconian, a quarter Dragonborn and half Half-Dragon? What are the differences between "Dragonborn", "Half-Dragon", and "Draconian" races in D&amp;D?  In the Hoard of the Dragon Queen adventure, for example there is  a Half-Dragon npc. I had assumed that when writing the adventure they were only allowed to use known material from Basic, and so renamed the Dragonborn into "Half-Dragon" for the sake of compatibility etc. However, the dragon breath rules are not at all similar for the half-dragon and the dragonborn, and I've also noticed wiki article that imply that they are different races entirely. (Thus introducing me to the term Draconian)  Are there clear differences between these three races, (in the same way there are differences between Goblins and Hobgoblins, or Dragonborn and Lizardfolk and Kobolds,) or are they really just three different setting names for the same basic race?  Answers can either be D&amp;D 5e specific, or be based on the lore from all editions of Dungeons and Dragons. (I'm assuming here that the answer will be the same regardless)  Here are two images, the first one is a "half-dragon" from the front of the Hoard of the Dragon queen module, and the second one is a "dragonborn" from the 5e player's Handbook.  I've included these images to help explain my confusion. How to avoid bad box with long words with no hyphenation? Tips for getting really good answers on SO