WPF Binding Fundamentals
When to use Path in WPF Binding?
How to test with Math.random in JavaScript? Answering your own question? Accept it. Iterate over all pairs of consecutive items in a list ubi-partman failed with exit code 10 - ubuntu 18.04 I'm trying to install Ubuntu 18.04 on my laptop. After choosing the partitionn i have the following error message: grub-efi-amd64-signed package failed to install into / target/.    Then I tried to install via "try ubuntu" and i get:  ubi-partman failed with exit code 10     What should I do? Video showing up as white space On  question, there is a YouTube video in , on the Android app the video shows up as a white space. There is no indication that it is a video.  Would it be possible to show the video in the app or link to the video on YouTube instead? To evaluate limit of sequence $\left(\left( 1 + \frac1n \right) \left( 1 + \frac2n \right)\cdots\left( 1 + \frac nn \right) \right)^{1/n}$ How do I evaluate the limit of the following sequence $$a_n  = \left(\left( 1 + \frac1n \right) \left( 1 + \frac2n \right)\cdots\left( 1 + \frac nn \right) \right)^{1/n}$$   I tried to take log and then using cauchy $1^{st}$ theorem of limits but I coudn't do it.  Could someone kindly help? Sorting grid cells in fishnet grid by location and number using QGIS? I am using QGIS 3.2.0 on a Mac (and also have QGIS 2), and I have a fishnet grid (probably created in Arc) that comprises of nearly 2 million grid cells. As a result, every change I make to the attribute table takes hours, so I can't experiment as I would usually.  I need to label each grid cell such that the north-westernmost cell is "1", and the numbers proceed by rows, until the last number goes into the south-easternmost cell. Using the row-number doesn't work, as that's not how the table is sorted. I've done this before, but cannot remember how. folder content doesn't get refreshed automatically in ubuntu 14.04 I'm using Ubuntu 14.04 and when I'm doing experiments which creates new files inside a particular folder X. But I can't see these new files inside X without refreshing X.  I have increased the count to 1M in  /proc/sys/fs/inotify/max_user_watches   but still the issue is not fixed.   How to fix it?  EDIT As suggested, output of cat /etc/xdg/autostart/user-dirs-update-gtk.desktop  [Desktop Entry] Encoding=UTF-8 Exec=xdg-user-dirs-gtk-update Name=User folders update Comment=Update common folders names to match current locale Terminal=false OnlyShowIn=GNOME;LXDE;Unity; Type=Application StartupNotify=false X-KDE-autostart-after=panel NoDisplay=true X-Ubuntu-Gettext-Domain=xdg-user-dirs-gtk I have a consideration about new off-topic close reason:     Questions asking us to recommend a tool, library or favorite off-site   resource are off-topic for Stack Overflow as they tend to attract   opinionated answers and spam. Instead, describe the problem and what   has been done so far to solve it.   For example take that question:   It has a close vote with the reason above. But if it would be formed     How to zoom image in an absolute position div to the side?   The answer would be probably also a jQuery plugin or javascript library, but it would follow the patter of most questions about jQuery.  Take that question:   This is the good question about real-life problem. The answer is to use a maven plugin. It is correct, there's no need to reinvent the wheel or rediscover the America.   But  I'm afraid the off-topic text could be misleading and could be misused to close such a questions as that about maven simply because a tool, library or plugin is the answer.   Is it a new guideline that the questions such as cited above should be banned, no matter how they are formed (this would make most how-to-do-in-maven/jquery) questions illegal? Or the close reason should be changed to make more clear what the guidelines are (it's not clear to me now)? How to configure logback to skip logging messages from org.package.* with all levels below WARN? Grep in couple thousands files I have directory with cca 26 000 files and I need to grep in all these files. Problem is, that I need it as fast as possible, so it's not ideal to make script where grep will take name of one file from find command and write matches to file. Before "arguments list too long" issue it took cca 2 minutes to grep in all this files. Any ideas how to do it? edit: there is a script that is making new files all the time, so it's not possible to put all files to different dirs. What to do if I can't get a visa to attend a conference that accepted my paper? My work got accepted into a very good category in a very good conference in my field. Due to complicated visa issues it will be very hard for me to attend that conference.   If I don't attend the conference they are certainly going to remove my work from the proceedings.  I am worried I won't be able to claim any sort of achievement if I don't attend this conference.  Can I still add it to my CV and specify that my work got accepted in this conference in a very good category? If a linear operator has an adjoint operator, it is bounded This is a question I'm struggling with for a while:  Let $H$ be a Hilber space. Let  $T,S: H\rightarrow H$ be linear operators (not neccessarily bounded) such that for every $x,y\in H$: $\langle Tx,y\rangle=\langle x,Sy \rangle$.  Prove $T,S$ are bounded.    What I did so far:  First attempt:  $||Tx||^2=\langle Tx,Tx\rangle=\langle x,STx\rangle\le||x||*||STx||\le||x||*||S||*||Tx||$  I'm not entirly sure I'm allowed to do the last inequallity, since $||S||$ might be $\infty$.  It follows $||Tx||\le ||x||*||S||$  and analogly  $||Sx||\le ||x||*||T||$  From the first I'd get $||T||\le ||S||$ and from the second $||S||\le||T||$. Therefore $||S||=||T||$. I don't know where to go from here.  Second Attempt: assume  $T$ isn't bounded, therefore so is $S$, therefore there are series $(x_n),(y_n)\subset H$ such that $||x_n||=||y_n||=1$ and $\lim ||Tx_n||=\infty,\lim ||Sy_n||=\infty$. I'll keep it going soon, but it didn't go so well..    I'd love some guide. Not neccessarily the whole solution, but something that would tell me what i'm missing.  Thanks :) Calling the base constructor in C# Is $\frac{1}{\sqrt{2}}$ a fraction or not?   I just came across a Grade 8 student's class work where the teacher has given the above as an example to differentiate fractions from rational numbers. I think this is wrong fundamentally, as $\sqrt2$ is irrational while all fractions would be rational. Please advise. Thanks! How to find the limit of a sequence? Question:  If $0 &lt; x &lt; \frac{\pi}{2}$ and $f_k(x) = \tan(x)+\frac{1}{2}\tan(x/2)+ ...+\frac{1}{2^k}\tan(x/2^k)$.  In Sigma Notation: $$f_k(x) = \sum_{n=0}^k \frac{1}{2^n}\tan\frac{x}{2^n}$$  Find $$\lim_{k\to \infty}f_k(x)$$  I'm not quite sure how to take the limit of a sequence, I've never seen this before, If someone could help me solve this it would be greatly appreciated. Is there a way of maintaining malleability in a homomorphic encryption system while making it infeasible to perform chosen ciphertext attacks?   I have been reading about homomorphic encryption and malleable cryptosystems lately and have found it fascinating. I still have a lot of reading to do, however, I came across a statement in my reading that suggested malleability is inherently counter to security against chosen ciphertext attacks.  While I read up more about this relationship, I am curious to learn if there a way to maintain malleability while making a chosen ciphertext attack computationally infeasible? Why or why not? There is an UI issue for the ranking div when a user crossed 200 reputation When a user just crossed 200, or 200+ reputation, the ranked div (i.e., top 10% overall) is trying to display. But rank calculation can be done on end of the UTC day. So instead of the ranking div, there is a blue colored hyphen is visible to users, it may be the initial loader for the ranking div.  I saw this UI issue previously too for the same scenario. Can this be fixed? Methods to compute $\sum_{k=1}^nk^p$ without Faulhaber's formula As far as every question I've seen concerning "what is $\sum_{k=1}^nk^p$" is always answered with "Faulhaber's formula" and that is just about the only answer.  In an attempt to make more interesting answers, I ask that this question concern the problem of "Methods to compute $\sum_{k=1}^nk^p$ without Faulhaber's formula for fixed $p\in\mathbb N$".  I've even checked this  without finding what I want.  Rule #1: Any method to compute the sum in question for arbitrary $p$ is good, either recursively or in some manner that is not in itself a closed form solution.  Even algorithms will suffice.  Rule #2: I don't want answers confined to "only some values of $p$".  (A good challenge I have on the side is a generalized geometric proof, as that I have not yet seen)  Exception: If your answer does not generalize to arbitrary $p$, but it still generalizes to an infinite amount of special $p$'s, that is acceptable.  Preferably, the method is to be easily applied, unique, and interesting.  To start us off, I have given my answer below and I hope you all enjoy. What is the reason behind "non-static method cannot be referenced from a static context"?