I can't upgrade my system, what should I do now?
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Specify a field in attribute table with raster calculator Disposing WPF User Controls Combinatorial Proof Question: Vandermonde convolution identity I'm really iffy on combinatorial proofs in general and now that there is a sum, it's just confused me even more. Can someone try and walk me through this proof?  $$ \binom{m + n}{r} = \sum_{k=0}^r \binom{m}{k}\binom{n}{r - k} $$ Difference between LiveCD, LiveUSB, full-install, and persistence? I am currently running Ubuntu as a guest vm on a Win 7 host via VirtualBox, but I would like to have a portable version of Ubuntu when I am not using my laptop.   I am unsure as to the difference between the following:  1)LiveCD with persistence; 2)LiveCD without persistence; 3)LiveUSB with persistence; 4)LiveUSB without persistence; 5)Full-install.   I have a USB flash drive (32GB), and I also have empty DVDs lying around. I know that persistence means that data can be saved, but I am unsure as to which option to choose. What is the difference between a LiveUSB and a full-install on a USB thumbdrive and why would I want to pick one over the other? Thanks for any help. How to run "sudo apt-get update" through proxy in commandline? In my office i want to update and download through (wget) and here they are using proxy?  How can i do this by commandline? How can mixed content compromise an entire HTTPS session? Index entries duplicated for captions Loading PyQt5 modules from QGIS3/PyQGIS I am trying to talk to the PyQGIS API for use in a 3rd party application using the offical .dmg image provided on the QGIS homepage.  After setting PYTHONPATH to /Applications/QGIS3.4.app/Contents/Resources/python and initializing everything as stated in , I am facing the following error when running from PyQt5.QtGui import or from qgis import *:    ImportError: dlopen(/Applications/QGIS3.4.app/Contents/Resources/python/PyQt5/QtGui.so, 2): Library not loaded: @executable_path/../Frameworks/QtGui.framework/QtGui   Referenced from: /Applications/QGIS3.4.app/Contents/Resources/python/PyQt5/QtGui.so   Reason: image not found   Looks like I need to set some linkers or similar?   Side facts: - I have no problems when using the homebrew version of QGIS). - I am on macOS 10.14.6 (Mojave) The Half-Elven and their choices Earendil and Elwing were given the choice of kindreds after their journey to Valinor, This choice was extended to their sons (specifically sons, not daughters or grandchildren)  Elrond chose the race of the Eldar and his brother Elros chose to be counted amongst the Edain. Thus far Manwë's proclamation has been fulfilled.  There are some inconsistencies here:   Arwen was given the choice, but Elladan and Elrohir remained as Eldar in Imladris Tar-Vardamir was not given the choice The offspring of Imrazor and Mithrelas in Dol Amroth dont seem to have been given a choice   I can think of only one explanation, that the Mannish blood is dominant over the blood of the Eldar, thus, As Vardamir was the offspring of two mortals he did not fall under Manwë's proclamation despite being the son of a half elven.  However this does not seem to explain the other inconsistencies, Is it possible that Elladan and Elrohir and also the princes of Dol Amroth weren't considered important enough by Manwë or Eru to give them the choice.  Also as a side note Tolkien states there were only three unions between man and elf, but this seems to ignore Turin/Finduilas and Imrazor/Mithrelas  My question is, Why was Arwen given the choice and not the sons of Elros? It's taken me almost 10 years of Linux usage to ask this question. It was all trial and error and random late-night internet surfing.  But people shouldn't need 10 years for this. If I were just starting out with Linux, I'd want to know: When to alias, when to script, and when to write a function?  Where aliases are concerned, I use aliases for very simple operations that don't take arguments.   alias houston='cd /home/username/.scripts/'   That seems obvious. But some people do this:  alias command="bash bashscriptname"   (and add it to the .bashrc file)   Is there a good reason to do that? I'm trying really hard, but I genuinely can't think of any circumstances in which I'd want to do that. So, if there is an edge case where that would make a difference, please answer below.  Because that's where I would just put something in my PATH and chmod +x it, which is another thing that came after years of Linux trial-and-error.  Which brings me to the next topic. For instance, I added a hidden folder (.scripts/) in the home directory to my PATH by just adding a line to my .bashrc (PATH=$PATH:/home/username/.scripts/), so anything executable in there automagically autocompletes.  If I needed to.  I don't really need that, though, do I? I would only use that for languages that are not the shell, like Python.  If it's the shell, I can just write a function inside the very same .bashrc:  funcname () {   somecommand -someARGS "$@" }   As I stated, I found a lot of this out through trial and error. And I only truly saw the beauty of functions when my computer died and I was forced to use the computers of the people around me when they weren't using them.   Instead of moving a whole directory of scripts from computer to computer, I ended up just replacing everyone else's .bashrc with my own, since they had never even made a single modification.  But did I miss anything?   So, what would you tell a beginning Linux user about when to alias, when to script, and when to write a function?   If it's not obvious, I'm assuming the people who answer this will make use of all three options. If you only use aliases, or only use scripts, or only use functions—or if you only use aliases and scripts or aliases and functions or scripts and functions—this question isn't really aimed at you. Boxplot interpretation: is it correct that a boxplot is missing a whisker? I have a data set that has customerID and daily visits. This dataset records the number of times customers visited the site in a day.   customerID   TotalVisits  1            6  2            17  3            20  4            25   Just to explore the data further, I tried plotting the TotalVisits values in a box plot. The plot doesn't seem to have a lower whisker. q1=1 and there are no values between q1 and  q1-1.5(IQR). The plot has q1, q2 and q3. The minimum value and q1 are the same.   Is this why the boxplot doesn't have the lower whisker? Could you please help me with the interpretation? Is it correct to draw a boxplot without any whiskers?  [I am new to the site and I am not able to post the image.] How can I evaluate $\sum_{n=0}^\infty(n+1)x^n$? Need help with SQL Server PIVOT I know about the PIVOT feature in SQL Server and I've read a few other questions and answers on here but I just can't seem to grasp it in order to do what I need. I'm trying to run some calculations and I have the following:  TABLE office_settings column office_id (bigint not null) column setting_value (NVARCHAR(500) NOT NULL)  office_id    setting_value -------------------------------------------- 4             0.2 4             0.2 4             2 4             3 5             0.2 5             0.2 5             2 5             3   I'd like to convert this using PIVOT (assuming that's the right tool for the job) to this, basically "grouping by" the office_id column, so:  office_id    value_1    value_2    value_3   value_4 ------------------------------------------------------     4         0.2         0.2         2         3     5         0.2         0.2         2         3   I should also mention that I need to CAST the setting_value column values to DECIMAL(4,2) in the process of this - in case that has any bearing on the T-SQL required to accomplish it.  Any ideas? I'm travelling from Madrid to Brisbane, but I have a 9 hours layover at Dubai Airport. I do not plan to leave the airport, and the connection is with the same airline (Emirates). I'm from El Salvador.    Do I need a transit visa? How to import a jar in Eclipse I am trying to calculate the force of impact of a falling object. I did my egg drop project. I dropped the egg from 10m with a mass of 126kg and with the velocity of 14.1 m/s. Which formula should I use to calculate the force of impact? I found the kinetic energy first and later I used the following formula: $W=Fs$ to find the force of impact. Is that the right formula? Got 2,919 PB/s in Ubuntu Terminal I have problem (seems to be trivia) about Ubuntu Terminal. Once my network connection slow down then it (sometimes but very rare to happened) showed some information like this.     I shocked because I have been got 2,919 PB/s. Sorry my mouse block some part of letter 'P' (I actually rush to print screen) but I believe you can recognize it.    EDIT    based on answer given to me, and I got similar info then, I'd like to add more clearly new image after.    Can someone explain it to me?  Best Regards! Maintaining the final state at end of a CSS3 animation Every finite set contains its supremum: proof improvement. Every finite subset of $\mathbb R$ contains its supremum (and its infimum)   Proof Let $A=\{a_1,...,a_n\}$ be a finite subset of $\mathbb{R}$. Since it is non-empty and it is bounded ($\max A$ is an upper bound), it has supremum, that is $\exists \sup A$ and by definition $\forall a \in A \;\, a \leq \sup A$. Let's suppose that $\sup A  \not\in A$ then, since $\max A \in A$ we have that $\max A &lt; \sup A$. But considering that $\mathbb Q$ is dense in $\mathbb R$ we can conclude that $\exists r \in \mathbb Q$ s.t. $\max A &lt; r &lt; \sup A$, but this is absurd since $r$ is an upper bound of $A$ and it is lower than the supremum. Necessarily, $\sup A\in A$.  Is there anything wrong? Is there any way to prove this without using density of $\mathbb Q$ or another property? Thanks in advance. I would like to be able to render several files one after the other, when I am not using my computer, e.g. at night. Is there a way of doing this?