How to make each letter in a string not case sensitive

I'm learning C++ right now, but I can't seem to find out how to make an input be accepted whether or not there are any capitals anywhere. For example, if someone input "sAndwiCh" in a case in a switch statement desiring "sandwich," how could I perform the following action by making the program allow the input to be any case of every letter? Thank you.


What are the differences between "-" and "--" in commands?

I often see a single dash - or double dash -- followed by linux commands or other installed linux programs.   What are the differences between single dash and double dashes?  Is it just about abbreviation?  For example, -v means --verbose most of the time.


No input field for Apple ID Verification Code

I have an older iPad Mini and when I try and use a game iOS Game Center asks for my password, which I enter, and is accepted. Then it asks to type in the Apple ID Verification Code, although there is nowhere to type it in.     EDIT: Thanks to fsb's suggestion the verification code was accepted by typing it directly after the password into the Game Center login password field. I'm shocked Apple would expect anyone to know to do this without prior knowledge!


Linux see only 1/2 of my ram My RAM size is 2048mb, but linux see only 1300mb. Why? No, it's not buffered, because ubuntu free command don't print free buffered RAM Here is output of command free    Lubuntu 16.04 x32


How to handle ordinal categorical variable as independent variable

I am using a logit model. My dependent variable is binary. However I have an independent variable which is categorical and contains the responses: 1.very good, 2.good, 3.average, 4.poor and 5.very poor. So, it is ordinal ("quantitative categorical"). I am not sure how to handle this in the model. I am using gretl.  [Note from @ttnphns: Although the question says the model is logit (because the dependent is categorical), the crucial issue - ordinal independent variables - is basically alike, be the dependent categorical or quantitative. Therefore the question is equally relevant to, say, linear regression too - as it is to logistic regression or other logit model.]


How can I use JavaScript/HTML/CSS to load a new page when a key is pressed down?

What would be the code for moving onto a new screen after a user presses a key. For example I have coded a blank screen that says press any key to begin.   I have been looking all over the web, but I am unable to find such a code that does not involve jQuery etc.   Thank you in advance.


How to solve questions like arcsin(sin 10)?

Ive been reading properties of inverse trigonometrical functions and the questions like:     What will $ \arcsin(\sin 10)$ be equal to?    confuse me a little.  Okay so I understand that $\arcsin(\sin 10)$ cant be directly equal to $10$ as it isn't an element of the principal branch of $\arcsin(\cdot)$ function. But then in the book it is given that   $3\pi-10$ will be the answer and $\sin(3\pi-10)=\sin(2\pi+(\pi-10))=\sin(\pi-10)=\sin10$  Now I understand it but I don't understand from where to get $3\pi-10$,I mean in questions like this what is the first step or the trick to get $3\pi-10$?


Calculate the tendency of a set of samples

I develop an application in which i constantly get samples of heart pulse.  I defined an interval of t seconds.  In each t seconds I have n samples.  In every interval, I want to calculate the tendency of those n samples. For example, lets say I have n = 5, and I have samples with values {70, 88, 95, 103, 115}. I want to recognize I have a growth in the heart pulse, and I want to have some measure for the rate of grows/decrease/almost no change.  I thought on two approaches for solving this problem.   I calculate the linear approximation for the n samples using linear regression by applying least squares implemented by the normal equations. (I treat each sample as two coordinates vector with x coordinate as time and y coordinate as heart pulse). I get from the normal equations a linear function of the form y = mx+b and my measure for the tendency is the slope, i.e. the m value. The second approach is to calculate the correlation (pearson's correlation) between vector x and vector y when x is the time and y is the heart pulse.   I'm asking which approach do you think is better for my problem (determining the tendency of heart pulses). Or, do you have a better algorithm for solving this problem?


I wanted to get a grounding in quantum mechanics, and was directed to the Feynman lectures. I was told to start from Vol I and work my way up to Vol III, where all the quantum mechanics stuff is. As a mathematician, I figured that the subject shouldn't be too difficult.  However, the books are far too broad, and full of stuff that was covered in my High School physics classes. I've also heard that the section on quantum mechanics doesn't really go into much depth.   My question is what should I read to gain a solid and deep understanding (as deep an understanding one can get without a physics degree) of quantum mechanics. Certain chapters of the Feynman lectures? A different book entirely?  Thanks


Which is proper/acceptable?  Take for instance this sentence:     We would like to use IBM machines.   Now consider that I needed to fully qualify IBM... How do I make this not read strangely?     We would like to use IBM (International Business Machines) machines.   or      We would like to use International Business Machines (IBM) machines.   (Please note that IBM is not the real acronym but it's similar to what I need to pull off)  EDIT:  I should add that part of my question is that if it's incorrect or less correct to put [Fully qualified name] (Acronym) or [Acronym] (Fully qualified name)


If $ Y $ is irreducible set so is $cl(Y)$.  If $cl(Y)$ is reducible then $cl(Y)= A \cup B$ where both $A$ and $B$ is closed in $cl(Y)$. Now how do we proceed?


Compute the series $\sum_{n=1}^{+\infty} \frac{1}{n^3\sin(n\pi\sqrt{2})}.$

I need to compute $$\sum_{n=1}^{+\infty} \frac{1}{n^3\sin(n\pi\sqrt{2})}.$$ This an exercice of "Amar and Matheron, complex analysis". I proved the convergence and now to compute the sum, I follow the hint of the book which is : Consider integrals of the form $$\int_{\gamma}\frac{dz}{z^3[\sin(\pi z)\sin(\sqrt{2}-1)\pi z]}$$ for a well-chosen $\gamma.$ I know this a residue theorem application but it seems a bit hard to have the good idea. I also tried with a summation factor. Any help will be greatly appreciated.


How does $(ab)^{3}=a^{3}b^{3}$ and $(ab)^{5}=a^{5}b^{5}$ for all $a,b \in G$ implies that $G$ is abelian? I know that the first criteria alone isn't enough because there's a counterexample. What could we say if in those equation instead 3 and 5 we had two other relatively prime numbers?


Need help, tips, suggestions on downgrading Catalina to Mojave and dual-boot

iMac 21.5-inch, 2019 Shipped with Catalina Goal is to have two volumes. One with Catalina, the second with Mojave. I have already downloaded Mojave and plan to create a bootable drive using disk utility. Then follow steps to downgrade. Wondering if I can shorten the process...but I can't find a guide that combines downgrading and creating a second OS volume. Can I create a second volume, erase Catalina on new volume, and then install Mojave without losing data on original volume? Or do I need to downgrade, create second volume and then upgrade that to Catalina? Other tips and suggestions for this process are appreciated too.


I am new to Ubuntu. After installation I am unable to play the media files like MP4, MP4 etc. What to do?? Thanks in Advance


If $F$ is a field then every ideal in $F[x]$ is a principal ideal.

I have got no clue of how to start with the problem .Now I know that an ideal is a kernel of a ring homorphism but why would it be a principal ideal in $F[x]$.What is the intuition behind this ?(I would like to know why is it happening instead of a formal proof)


If $f: \mathbb N \mapsto \mathbb N$ is one-to-one and $f(mn) = f(m)f(n)$, what is the smallest possible value of $f(999)$?  Easily $f(1)=1$, and I think $f(n)=n$ must be the only map, but not able to prove it. The other alternative is if $f(999) = f(3)^3f(37) \ge 24$, which looks somehow odd.


Obtaining covariance matrix from correlation matrix

I am trying to figure out how to convert a correlation matrix (R) to a covariance matrix (S) for input into a random number generator that only accepts S (rmvnorm("mvtnorm") in R)   library("mvtnorm")   TRUTH= 0.8 # target correlation value between X1 and X2 R <- as.matrix(data.frame(c(1, TRUTH), c(TRUTH, 1))) V <- diag(c(sqrt(1), sqrt(1))) # diagonal matrix of sqrt(variances) S <- V %*% R %*% V cor(rmvnorm(100, sigma=S) )  # repeat this to get an idea of the variance around Pearson's estimator   Instance where variances are not equal to 1  V <- diag(c(sqrt(3), sqrt(2)))  S <- V %*% R %*% V cor(rmvnorm(100, sigma=S) )   This seems to be correct, but I would like expert criticism.


Why is that x = 10, y = 10; z = x++ + y++;  Is still 20? They have increment both but the output is still 20 why? But when i do this z = ++x + ++y;   the output became 22. Why and how??? Someone can explain it to me? Thanks


Is the latest version of Ubuntu 100% FREE

I really need to know if the latest version of Ubuntu is free ?


How do I revoke Gatekeeper permission to launch from an unsigned app?

is a feature of macOS that prevents unsigned applications from being launched. It can be disabled host-wide in System Preferences, or you can keep the protection in place and exempt a single application by right-clicking and choosing "open" which prompts a dialogue with the option to "launch anyway" (rather than simply double-clicking, which prompts a dialogue with no option to launch, only dismiss).  Forever after, that application will launch without issue. Gatekeeper has presumably whitelisted it. How can I revoke this exemption and remove the application from the whitelist after once approving it?   suggests consulting the manpage for spctl for more information. Going from there, I've tried spctl --disable <path to app>, spctl --remove <path to app>, and spctl --add --label disable <path to app>; spctl --disable --label disable, but the app still launches successfully when double-clicked in Finder.   suggests that spctl --remove <path to app> should have done the trick, and indeed after running that command, the application no longer shows up under the whitelist of exempted applications with spctl --list | grep <app name>. But the app still launches. How do I get this revocation to stick?


How do I play a character with only one arm, and what penalties should he have?

I've been wanting to play a character who had lost his arm in a war, but I've never done a disabled character before. What penalties should I give him and how would I go about it?


Is spell level a character concept or a player concept?

Is there anything in RAW that supports spell level as a character concept, or alternatively that supports it as solely a player concept?  On the one hand, I see nothing that explicitly states that a character knows that there are spell levels. On the other hand, I don't see how a spellcaster could manage spell slots without knowing about spell levels.


I want to have ports 80,8080,443,8443,9990,9993 open, accessible from everywhere. port 8080 seems to be blocked, the browser says: ERR_CONNECTION_REFUSED syslog: [ 6021.847345] iptables denied: IN=eth0 OUT= MAC=12:85:11:63:da:cb:f6:6d:05:71:95:80:08:00 SRC=my.ip.here DST=server.ip.here LEN=60 TOS=0x00 PREC=0x00 TTL=56 ID=51418 DF PROTO=TCP SPT=37536 DPT=8080 WINDOW=65535 RES=0x00 SYN URGP=0 What am I doing wrong here? "iptables -L" result target     prot opt source               destination ACCEPT     all  --  anywhere             anywhere REJECT     all  --  anywhere             127.0.0.0/8          reject-with icmp-port-unreachable ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:https ACCEPT     tcp  --  anywhere             anywhere             state NEW tcp dpt:ssh ACCEPT     tcp  --  anywhere             anywhere             state NEW tcp dpt:postgresql ACCEPT     tcp  --  anywhere             anywhere             state NEW tcp dpt:9990 ACCEPT     icmp --  anywhere             anywhere             icmp echo-request LOG        all  --  anywhere             anywhere             limit: avg 5/min burst 5 LOG level debug prefix "iptables denied: " REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:9993 ctstate NEW,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports http,https ctstate NEW,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports http-alt,8443 ctstate NEW,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports 8009,8009 ctstate NEW,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http-alt  Chain FORWARD (policy ACCEPT) target     prot opt source               destination REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable  Chain OUTPUT (policy ACCEPT) target     prot opt source               destination ACCEPT     all  --  anywhere             anywhere ACCEPT     tcp  --  anywhere             anywhere             tcp spt:9993 ctstate ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports http,https ctstate ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports http-alt,8443 ctstate ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere             multiport dports 8009,8009 ctstate ESTABLISHED ACCEPT     all  --  anywhere             anywhere ACCEPT     all  --  anywhere             anywhere```


what rar password recovery tools are available?

Long ago I made an archive of images and protected it with a password but I have forgotten the password and I made many trails to crack it with my general combinations but failed.   Are there any reliable solutions?


What's the easiest way to make my old init script work in systemd?

I don't want to do the right thing by creating a new systemd script, I just want my old init script to work again now that I've upgraded my system to an OS that's using systemd.   I've briefly researched how to convert init scripts and how to write systemd scripts, but I'm sure learning it properly and doing it right would take me several hours.   The current situation is:  systemctl start solr Failed to start solr.service: Unit solr.service failed to load: No such file or directory.   And:  sudo service solr start Failed to start solr.service: Unit solr.service failed to load: No such file or directory.   Right now, I just want to get back to work. What's the path of least resistance to getting this working again?   Updates  I didn't want to figure this all out – I really didn't – but I have to and I've unearthed my first clue:  sudo systemctl enable solr Synchronizing state for solr.service with sysvinit using update-rc.d... Executing /usr/sbin/update-rc.d solr defaults insserv: warning: script 'K01solr' missing LSB tags and overrides insserv: warning: script 'solr' missing LSB tags and overrides Executing /usr/sbin/update-rc.d solr enable update-rc.d: error: solr Default-Start contains no runlevels, aborting.   The  says that:     LSB header dependency information matters. The SysV implementations on many distributions did not use the dependency information encoded in LSB init script headers, or used them only in very limited ways. Due to that they are often incorrect or incomplete. systemd however fully interprets these headers and follows them closely at runtime   I think that means my script won't work until that's fixed.  The script in question:  #!/bin/sh  # Prerequisites: # 1. Solr needs to be installed at /usr/local/solr/example # 2. daemon needs to be installed # 3. Script needs to be executed by root # 4. $INSTALL_ROOT must be set  # This script will launch Solr in a mode that will automatically respawn if it # crashes. Output will be sent to /var/log/solr/solr.log. A pid file will be # created in the standard location.  start () {     echo -n "Starting solr..."      # Reset ulimit or else get issues with too many open files (https://issues.apache.org/jira/browse/SOLR-4)     ulimit -n 10000      # start daemon     daemon --chdir='/usr/local/solr/example' --command "java -jar -server start.jar -DINSTALL_ROOT=$INSTALL_ROOT" --respawn --output=/var/log/solr/solr.log --name=solr --verbose      RETVAL=$?     if [ $RETVAL = 0 ]     then         echo "done."     else         echo "failed. See error code for more information."     fi     return $RETVAL }  stop () {     # stop daemon     echo -n "Stopping solr..."      daemon --stop --name=solr  --verbose     RETVAL=$?      if [ $RETVAL = 0 ]     then         echo "done."     else         echo "failed. See error code for more information."     fi     return $RETVAL }   restart () {     daemon --restart --name=solr  --verbose }   status () {     # report on the status of the daemon     daemon --running --verbose --name=solr     return $? }   case "$1" in     start)         start     ;;     status)         status     ;;     stop)         stop     ;;     restart)         stop         sleep 15         start     ;;     *)         echo $"Usage: solr {start|status|stop|restart}"         exit 3     ;; esac  exit $RETVAL


Easily disable/enable all network connectivity

My work involves trying stuff online and offline, on a Mac. Sometimes a try can be less than 10 seconds of needed offline time. Most of the time I still need to be online.  Instead of going to Network -> Ethernet/Wifi and disable everything manually, I'd like to know if there is a way to disable it all at once, and re-enable it just as easily.  I've also simply removed the ethernet cable for a while but that's just ridiculously annoying. Since I'm working on a Mac Mini, that also forces me to have it's back facing me for easier reach, and all cables lying just under my screen/behind my keyboard. While that is an "okay" option, I'd like to get rid of it.  I'm thinking maybe there is an App that could be on the top bar and I'd just tap On/Off.  I already use the NetworkConditioner which is amazing for simulating lag, but the only "offline" I can get here is just "100% packet loss" which isn't really offline, it's just infinite lag.  If you have an easy on/off switch (ideally on the top bar so I don't have to Alt-Tab between apps) or something similar to airplane mode, I'm all ears !


Unable to find matching string in ArrayList

The idea is simple:   Load a text file into a string. Split this string into paragraphs. Split all paragraphs into words. Add each individual word to an ArrayList.   The result is an ArrayList containing all of the words in the text file.   The procedure works; it loads all of the words in an ArrayList fine.  HOWEVER, any "IF" statements to find a specific item in the ArrayList do not work.  EXCEPT: if the word is a newline.  public String loadText(String resourceName){       // Load the contents of a text file into a string     String text = "";     InputStream stream = FileIO.class.getResourceAsStream(resourceName);     BufferedReader reader = new BufferedReader(new InputStreamReader(stream));     String str = "";     try {         while ((str = reader.readLine())!=null){             text += str + "\n";         }     } catch (Exception e) {         System.out.println("Unable to load text stream!");     }     return text; }  public void test(){      ArrayList<String> collectionOfWords = new ArrayList<String>();     String text = loadText("/assets/text/intro.txt");      // Split into paragraphs     String paragraphs[] = text.split("\n");     for (String paragraph: paragraphs){          // Split into words         String words[] = paragraph.split(" ");          // Add each word to the collection         for (String word: words){             collectionOfWords.add(word);         }          // Add a new line to separate the paragraphs         collectionOfWords.add("\n");     }      // Test the procedure using a manual iterator     for (int i=0; i<collectionOfWords.size(); i++){           // ===== WHY DOES THIS WORK?         if (collectionOfWords.get(i)=="\n")             System.out.println("Found it!");          // ===== BUT THIS DOESN'T WORK???         if (collectionOfWords.get(i)=="test")                 System.out.println("Found it!");          // NOTE: Same problem if a I use:         // for (String word: collectionOfWords){         //   if (word=="test")         //     System.out.println("Found it!");     } }   Sample of text file: The Quick Brown\n Fox Jumps Over\n test the lazy dog\n  Any ideas?  I am at the point to just scratch my design and try something totally different...


How can the Cantor set be uncountable, yet its complement is the union of only countably many disjoint open intervals?

$C$ = Cantor set. $C$ is closed, so $C^c$ is the . So let $$C^c = \bigcup\limits_{\substack{i~\in~\mathbb{N} \\}} A_i $$ where $A_i$ are disjoint open intervals. For each $i \in \mathbb{N},\ A_i\ $ differs from a closed set by just two points, namely the endpoints of the interval $A_i.$ For each $i \in \mathbb{N},\ $ let $$ B_i = \{x_{i1}, x_{i2} \} = \{ \text{ the two endpoints of } A_i \}. $$ Then $\left|\bigcup\limits_{\substack{i~\in~\mathbb{N} \\}} B_i\right| \leq 2 \left|\mathbb{N}\right| $ is countable. However, $\bigcup\limits_{\substack{i~\in~\mathbb{N} \\}} B_i$ is surely the Cantor set, which is uncountable. Something is incorrect in all of this, but what?


What changes when you go into safe mode? Can you use the internet? What is safe about the safe mode? I have also tried to go into safe mode and wasn't able to get into the mode.


Resource recommendation for a thorough coverage of rotational mechanics (especially gyroscopes)

I am looking for a book which covers classical rotational mechanics in full detail using all the specialized powerful tools of Lagrangian and Hamiltonian formalism (if needed). I have already studied  and  as a reference alongside a one-semester undergraduate course on classical mechanics. And although I found rotational mechanics most interesting I could not grasp it as well as I would like to through these books. I suppose it is because neither of them offers a thorough discussion of this topic.  Note: This is not a regular "recommend me some books for classical mechanics" query. I could I have easily Googled that up if that was the case. What I seek is a particular emphasis on or an exclusive coverage of rotational mechanics with the help of the most advanced tools that we currently have. That is particularly hard to find because most classical mechanics books and courses aim only to prepare students for quantum mechanics or chaos theory and so give rotational mechanics only a brief treatment.  My aim specifically is to thoroughly understand gyroscopes and to develop an intuition about them for application in toys, experimental demonstrations, etc. Any resource on theory, mathematical development, application or history would be appreciated.


How to add extral level with outlines package?

How can I add a 5th level of depth with the outlines Package?  \setlistdepth{5}   does not work.  \documentclass{article} \usepackage{outlines} %\setlistdepth{5} \begin{document} \section{start} \begin{outline} \1 foo \2 bar \3 too \4 foo %\5 bar \end{outline} \end{document}   -  This is the solution to expand Outlines Package in depth   ->


What is the probability that $x_1+x_2+...+x_n \le n$?

Given that $X_1, X_2...$ are mutually independent random variables. For each $i$ with $1\le i \le n$   the variable $X_i$ is equal to either $0$ or $n+1$ $E(X_i)$ = $1$   also.. if $X_i$ is equal to either $0$ or $n+1$, doesn't that mean that all $X_i$ need to be $0$?  Thanks


Toggle function to Hide or Show element [jQuery]

I'm creating a Toggle function I've done the bigger part (I hope). But now I'm facing two problem :  • I can Show and Hide my resume but I can't do it again (more than once in each direction).  • I Dont get how to apply this to a specific resume and not to every one; shall I use .each() ? I'm a bit lost on it I admit.  This is what I've manage to do for now :   HTML
Lorem Ipsum ....
   jQuery  $(document).ready(function(){      if($('.resume').text().length > 100)     {         complet = $('.resume').text();         complet += ' Cacher';         html = $('.resume').text().slice(0,100);         html += '...';         $('.resume').html(html);     }      $('.showMore').on('click',function(){         $('.resume').html(complet);         showLess();     });      function showLess(){     $('.showLess').on('click', function() {         $('.resume').html(html);     });     }  });   And here is the


I'm a hard mode mobile terraria player. I have 2 amazing worlds(my main ones). But both of them are being over-run by the corruption. I've tried powder, but it always comes back. Is there any way to get rid of it or contain it?


Proving the following false: $f(x)=2x+1$ produces a prime number if and only if x is prime

$f(x)=2x+1$ produces a prime number if and only if x is prime, how can we prove this false?  I know this isn't very math-proofy, but can't we just plug in a number we know that is prime, i.e. $x=7$, and observe $f(7)=15$, which is not prime?  I'm intersting in writing a math proof for this, but I'm not exactly sure if my "proof" is good enough/proper.  How should I do this?


$i+i=2i$, $i\cdot i=-1$, $i^i=e^{-\pi/2}$, but what is the result of ${^{i}i}$? That is, what is the $i$-th  of ?


Do placed items deal more damage per tick after the initial tick if an item is purchased?

As a follow up to , what if I put a shroom, someone steps on it, takes one tick damage, before second tick I buy a deathcap. Does the second tick deal more damage?


May I Carry a Power Bank from Vancouver CA to Frankfurt DE?

Can I carry power bank in carry-on on Lufthansa airplane? I have RavPower Model: RP-PB19, Capacity: 55.5Wh.


I have defined cap in   def fingerCursor(device):     global cap     global cap_height     global cap_width     cap = cv2.VideoCapture(device)         #cap.set(cv2.cap_PROP_FRAME_HEIGHT,720)         #cap.set(cv2.cap_PROP_FRAME_WIDTH,1280)     cap_height = cap.get(cv2.cap_PROP_FRAME_HEIGHT)     cap_width = cap.get(cv2.cap_PROP_FRAME_WIDTH)         #print(cap_height,cap_width)   But still whenever I am running this part of my code, it says cap not defined. It also has the same problem with cap_height and cap_width.  while(cap.isOpened()):         ## capture frame-by-frame         ret, frame_raw = cap.read()         while not ret:             ret,frame_raw = cap.read()         frame_raw = cv2.flip(frame_raw, 1)         frame = frame_raw[:round(cap_height),:round(cap_width)] # ROI of the image         cv2.imshow("raw_frame",frame)


I have got an AMD R9 290, with a 600 watt power supply(Coolermaster GX 600 watt). Now, when i am playing a game everything works fine, but when i am trying to mine bitcoins, my system crashes(no signal hdmi, all fans got to 100%). I have got an I5 3570, and I have nothing overclocked(windows 8.1) Is it possible that my video cart is asking more power then my power supply can give it?


I came across this error while installing cpusim3.9.0:  Exception in thread "main" java.lang.NoClassDefFoundError: cpusim.util.CPUSimConstants     at cpusim.Main.main(Main.java:135)   I followed this installation process:  Open a Terminal with Ctrl + Alt + T. Download the CPUSim-Zipfile:  wget http://www.cs.colby.edu/djskrien/CPUSim/CPUSim3.9.0.zip   Install unzip  sudo apt-get install unzip   Unzip the CPUSim3.9.0.zip-file  unzip CPUSim3.9.0.zip    Go into the newly created folder  cd CPUSim3.9.0/   If you haven't install a Java JRE or JDK yet, you need to install it now. If you are unsure write java -version. if this results with an error you must install it.  You need to first enable the universe repository. Then you can install the Java Runtime Environment (JRE).  sudo apt-get install openjdk-7-jre   Create an executable start script  cat <<'EOF' > cpusim #!/bin/bash java -cp CPUSim3.9.jar:jhall.jar:CPUSimHelp3.9.jar cpusim.Main -m SampleAssignments/Wombat1.cpu -t SampleAssignments/W1-0.a EOF chmod +x cpusim   the error came after I pressed ./cpusim (also I'm using ubuntu on virtual box)


how to remove a letter that shows multiple times if you only want on of it to show up?

Can someone help me to go from  this:  'BANANARAMA'   to  'BANRM'   in Python? I already tried this:   def reduceer(woord):     return ''.join(c for c, in list(woord()))   but it won't work


I have a clone of a branch from git repo. I made changes commited and pushed to remote branch. Now I want to update my clone to remote branch, so that changes made by anybody else should appear in my clone. How to do that ? Thanks


Cannot attach file and include a body while sending an email in Linux

The command below will send an email with a Subject and Body, but no Attachment. If I remove < /usr/tmp/BODY_OF_EMAIL I receive the email with Subject and Attachment, but no Body.  cat /usr/tmp/ATTACHMENT.xls | uuencode ATTACHMENT.xls | mailx -s "Subject of email!" emailaddress@company.com < /usr/tmp/BODY_OF_EMAIL   /usr/tmp/BODY_OF_EMAIL contains the text "Email Body."


I've got ubuntu server on my "home server" with 5 software raid 0 partitions and one software raid 1. I have to reinstall OS. Is it possible to do that without losing existing partitions with data?


I am trying to use accessors (Set/Get) methods in my program, and when I try to use the Get method in the main method, I get this error:  Cannot make a static reference to the non-static method getID() from the type Student.   I am unsure how to go about fixing this. I'm a beginner at Java programming.         Here are the particular lines in question:  The set/get methods:  public void setID (String ID) {this.ID = ID;} public String getID() {return this.ID;}   The error line:  System.out.println(Student.getID());   Any advice would be appreciated!*


Do I need a transit visa if I'm a Jordanian citizen traveling to Istanbul but have a connection in Athens (athletes) for 3 hours?


Need help solving - $ \int (\sin 101x) \cdot\sin^{99}x\,dx $

I have a complicated integral to solve. I tried to split ($101 x$) and proceed but I am getting a pretty nasty answer while evaluating using parts. are there any simpler methods to evaluate this integral?  $$ \int\!\sin (101x)\cdot\sin^{99}(x)\, dx $$


Why do you see future Trinity in Architect's scene

In the Architect scene, on the monitors, when The Architect mentions that Neo loves Trinity and the screens starts showing her, you can see scenes that will be shown within next 2 min - Trinity is fighting Agent.   This can't be previous versions of the Matrix as the previous ones didn't have Trinity (I think?). Hmmm, now that I think about it, Trinity could have been in previous versions and everything could have played out same way on all versions of the matrix. Just in previous ones Neo didn't love Trinity... But then many things would have played out differently in original Matrix movie, and only Neo was engineered... Any thoughts?


How can messages in a chat transcript be flagged?

For messages in chat, clicking on the drop-down icon will allow rude or abusive messages to be flagged. I've noticed that messages in a transcript can no longer be flagged. I seem to recall that it used to be possible. How can one flag a problematic message that is in a transcript for abuse or mod attention?


Place a text on top of an image [SOLVED]

I want to place an image in the center of my white page and add a title over it (the title would be larger than the image || also the title center must be the image center). The problem is that the title won't go on top of the image. I use Django and bootstrap ^^ Here is the code : HTML :

                 Brand

Title

  CSS: .hero {     width: 65%;     height: auto; }  .title {     position: absolute;     background-color: cadetblue;     top: 50%;     left: 50%; }  .ctr {     position: absolute;     transform: translate(-50%, -50%); }  What happens currently :  EDIT : I found the answer !! I hope it can help the ones who still wonder how to do it :)


Calculate the Fourier transform of $b(x) =\frac{1}{x^2 +a^2}$

I need help to calculate the  Fourier transform of this funcion  $$b(x) =\frac{1}{x^2 +a^2}\,,\qquad a > 0$$ Thanks.


Differentiating between verb-ing and gerunds

In sentences like, "I'm dying to get to you and "I'm learning to live again" and "i was preparing to go for surgery when you called" what are "dying", "learning" and "preparing" functioning as? Are they verb(ing) or are they gerunds.


We have a fresh server setup where a team member exidently has changed the rights for other and group users for the entire root directory.  chmod -R go-rwx /   This has lead to the fact that e.g. nobody exept of root can login anymore.  Is there an easy way to revert this? It looks to me as this is impossible as there are many folders affected.  The system is Ubuntu 18.04 LTS


Is there a hotel search tool that allows me to see prices for potential dates?

I don't know if this is considered common knowledge, but personally I have found that for a typical week-long trip, the price of the hotel is greater than the price of the flight.  My trip planning, however, relies on choosing travel dates based on optimal flights, and then the traveler begins shopping for hotel rooms.  I would like to plan my holiday the other way around: shop a very particular hotel I would like to return to, and choose a week-long trip there based on the lowest hotel demand, or cheapest price. BUT: I have been unable to find anything like this.  Does such a website exist? (Search for a hotel, with no dates specified, and browse cheap/expensive times to visit that hotel)


$ \int e^{x^3}\;dx$   so, i'm searching for answer this question, i think that this not is too easily, but i think this integral not exist solution undefined, this integral would be easy if  had the derivative out but i'snt happen


Parenthesis and number? What is it after a command?

I recently came across the useradd command and looked at the manual page. It alluded to useradd(8). What is the significance of the number and how is the command applied?


show that if ${a_n} \to a$, and $a>0$, then $\exists N$ such that $a_n>0$ for $n \ge N$.

Here is the question from my textbook,      "Suppose that the sequence ${a_n}$ converges to $a$ and that $a>0$. Show that there is an index $N$ such that $a_n>0$ for all indices $n \ge N$"   by the definition of convergent sequence:  because ${a_n} \to a$, for all $\epsilon > 0, \exists N \in \mathbb{Z}^+$ such that for all $n>N$, $|a_n-a| < \epsilon$.  But then I don't know how to proceed. I can figure out the situation (even if it is an oscillating sequence around a), if ${a_n} \to a$, then there exists a positive integer $N$ such that for all $n>N$, $a_n > 0$.  p.s.: this is the first time I post a question. If there are any unclear/ improvement, please let me know


Difference between standard error and standard deviation

I'm struggling to understand the difference between the standard error and the standard deviation. How are they different and why do you need to measure the standard error?


Proving $\sum\limits_{i=0}^n  i 2^{i-1} = (n+1) 2^n - 1$ by induction

I'm trying to apply an induction proof to show that $((n+1) 2^n - 1 $ is the sum of $(i 2^{i-1})$ from $0$ to $n$.   the base case: L.H.S = R.H.S we assume that $(k+1) 2^k - 1 $ is true. we need to prove that $(k+2) 2^{k+1} - 1$   My try to prove 3 is as follows:  $(k+2) 2^{k+1} - 1$  $(k+2) (2^k * 2) - 1$ , from 2: $2^k = 1/(k+1)$  $(k+2) (2 / (k+1)) - 1$  $(k+1) 2 - 1$  My question is, how could I get to $2^k$ from the last line to prove this formula is right?


I'm working on a homework set and I need some help. I have a list that looks like this:  list = [1, 2, [3, 4], 5]   The problem is asking me to use list slicing to extract the last element of the nested list. Can someone help me with this?


Let $\alpha(t)$ be a regular curve. Suppose there is a point $a$ in $R^3$ such that $\alpha(t)-a$ is orthogonal to $T(t)$ for all t. Prove that $\alpha(t)$ lies on a sphere.  So, I let $\alpha(t)=(x(t), y(t),z(t))$ and $a=(a,b,c)$.  Since, $\alpha(t)-a$ is orthogonal to $T(t)$,  $<\alpha(t)-a,T(t)>=0$.  But I don't know how to solve this..


How to keep cycles material when exporting to unity?

I have an example of what I mean, for this I use a cube adding a simple cycles material I select toon  How do I bake this material, thanks for reading.  Cheers!


Find records present in file 1 also in both file 2 and file 3

I have three files file1.txt, file2.txt, file3.txt and they are of same format.  I want to select records from file1.txt which are present in both file2.txt and file3.txt based on column 2 and column 3 respectively to the output file out.txt.   Also, I need to create another file, out2.txt, with additional columns (column 4 from file2.txt, column 5 from file3.txt).  Sample Input:  file1.txt  1. abc 1 a f11 f13 f14  2. abd 2 b f12 f14 f13   3. abe 4 d f13 f16 f12  4. acf 6 s f14 f15 f19   file2.txt   1. abc 1 a f21 f23 f24   2. abd 1 b f21 f24 f23    3. abe 4 d f24 f26 f22   4. acf 6 s f23 f25 f29   file3.txt   1. abc 1 a f31 f33 f34   2. abd 2 b f31 f34 f33    3. acf 5 s f33 f35 f39   4. abe 4 d f34 f36 f32   Desired output  out.txt   1. abc 1 a f11 f13 f14   2. abe 4 d f13 f16 f12    out2.txt   1. abc 1 a f11 f13 f14 f21 f31  2. abe 4 d f13 f16 f12 f24 f34


I have Debian 6 installed on my computer and when I installed it a year ago, I was all about having a stable system for my needs; I didn't care about the recency of the packages. Now, my opinions have reversed, I feel that I need bleeding edge more than stability. Is there any way to make Debian Bleeding Edge? For Ubuntu, I found a couple of PPAs which sort of keep certain packages updated but haven't found a good guide to do so for Debian.   Any tips?


Difference between "theoretical computer science" and (beta) "computer science"

Possible Duplicate:          Title says it all. From what I can see, "theoretical computer science" questions seem to be slightly more isolated to discussing algorithms, whereas "computer science" seems to have questions that are slightly broader and higher-level. Is there any place on the Stack Exchange sites where they give a longer description?  I'm just curious as to what niche the beta "computer science" site is meant to fill, as I see many topics in both forums that overlap.


Suppose $V$ and $W$ are subspaces of a finite-dimensional vector space $U$.      (a) Show that $W \subset V$ if and only if $V^0 \subset W^0$.      (b) Show that $(V \cap W)^0 = V^0 + W^0$. (Hint: Show $\supset$ holds, then use lots of fomulas for dimension.)   I am trying to show this question. My understanding of annihilators is that for a vector space $V$ over $K$, with $S$ being a subset, the annihilator of $S$ is the subspace $S^0$ of linear functions $f$ in $V^*$ so that $f(s)=0$ for every $s$ in $S$. However, I don't know how to use this definition to prove (a) and (b). The hint for (b) suggests I should use formulas such as   $$\dim(V + W) = \dim V + \dim W − \dim(V \cap W)$$  but I don't know how to reach this stage.


How shall I split a partition containing `/` and `/home` into two logical volumes?

I have a laptop running Lubuntu 18.04, with a single hard drive as a bootable disk, and two partitions on it: EFI System Partition and a bigger partition contains everything else (e.g. / an /home).   $ sudo parted -l Model: ATA TOSHIBA MQ01ABF0 (scsi) Disk /dev/sda: 500GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags:   Number  Start   End    Size   File system  Name                  Flags  1      1049kB  538MB  537MB  fat32        EFI System Partition  boot, esp  2      538MB   500GB  500GB  ext4   I want to separate / and /home in some way, so that messing up with / will have limited interference with /home. For example, I am considering to separate them  into  two different logical volumes using LVM, as suggested by Stephen Kill below. But it seems that , so what shall I do now? (Besides the laptop, I have a Lubuntu bootable flash drive and another laptop also running Lubuntu 18.04).  $ sudo lvmdiskscan   /dev/sda1 [     512.00 MiB]    /dev/sda2 [    <465.26 GiB]    0 disks   2 partitions   0 LVM physical volume whole disks   0 LVM physical volumes  $ sudo pvcreate /dev/sda2   Can't open /dev/sda2 exclusively.  Mounted filesystem?   If I can afford to reinstall Lubuntu on the laptop, will reinstalling the OS help to separate / an /home into different logical volumes? How shall I do exactly?   If I don't want to reinstall Lubuntu on the laptop, what shall I do then?  Did telcoM and Stephen Kitt recommended  the same? What are the steps so that  I   can follow their suggestions  respectively?  :     The problem is that you cannot just add LVM to an existing non-LVM   partition. You would have to shrink your existing partition as much as   you can, then create a new partition to be used as a LVM PV, create   the LV(s) you desire into it, copy the data, update your boot   configuration and initramfs to be aware of LVM, then boot to the LVM   version of the system, and then either repurpose the old non-LVM   partition as a second LVM PV on the same disk and add it to the   existing VG, or remove it and resize the only LVM PV on the disk.        On bootable disks, I have whatever partitions are needed to boot the   system (such as the ESP on EFI systems, or /boot on BIOS or U-boot   systems), and one big partition occupying all the available space,   which is used as a PV in LVM.      you can have one partition for the ESP, and another partition which   you use with LVM: that large partition (/dev/sda2) is a PV, used in a   VG, containing however many LVs you want (one for / and one for /home)


Antiresonance of multiple parallel decoupling capacitors: use same value or multiple values?

My quesiton: Is it better practice to put same-valued capacitors in parallel of capacitors of different values to decouple the high-frequency noise caused by digital ICs? Background Digital IC need a decoupling capacitor close to their supply pins to ensure a stable voltage during power transients and to deal with noise (mostly to prevent noise generated by the IC to affect neighboring circuitry). It seems sensible to place a bulk capacitor (say 10-100uF), to act as an energy reservoir, and several smaller capacitors to deal with higher frequencies. The reason to place several small capacitors instead of just one is to deal with their Equivalent Series Inductance (ESL), which in practice, causes them to behave like an LC circuit. The effect of anti-resonance Yet, here is where best design practices and electronic myth seem to get mixed up and confusing to me. Most electronic engineers I have met like placing several decoupling capacitors of different values in parallel (with the smaller capacitors closer to the IC). The logic behind it is that the each capacitor takes care of a different noise frequency as depicted in Figure 1.  Figure 1: Impedance over frequency of three different value capacitors in parallel (cyan) vs their individual contribution (brown, blue, red). Image taken from . Note the small anti-resonance peak. It seams no major trouble , and the overall behavior of the three different capacitors in parallel is vastly superior to their individual decoupling capabilities. However, I have read in  by [Henry W. Ott] that placing capacitors of different values may cause a much greater antiresonance-peak which can be very harmful for our designs (see Figure 2). In fact, it amplifies any noise that falls into the anti-resoance frequency range, which is corroborated by .  Figure 2: from Electromagnetic Compatibility Engineering, by Henry W. Ott, section 11.4.4. The 15nH inductance makes reference to the capacitors ESL.


Ubuntu 17.04 LTS black screen after login after upgrade from 16.04 to 17.04

I have recently upgraded from Ubuntu 16.04 LTS to 17.04 LTS via the upgrade notification I received.  The computer boots up and I am shown the login screen with my existing account.  If I log in with the account in GUI mode, I get a black screen with desktop items (blinking those items when I click on the desktop screen). I can switch to a terminal and log in with the admin account, so the credentials are ok.  Any ideas as to why this is happening and how I can get the GUI mode back for my account?  I am aware of all the commands and direct command line with ALT + CTRL + F1 but there is no upgrade required. All packages are fully updated.


Does Ubuntu 1604 LTS support Intel 2011-3 CPU and the X99 support chips?

The question is fully stated in the title.  There have been articles stating that Ubuntu has updated their code to support the 2011-3 CPU.  I have not found a statement saying that 1604 is that specificallly updated version


Prove that every self-adjoint unitary linear operator can be expressed in the form $U\alpha = \beta - \gamma$

This problem is from Kunze Hoffman book. I think I go in the right direction to solve this but I miss some point to finish it. Can anyone help me?          Suppose $U$ is a self-adjoint unitary linear operator on a finite-dimensional inner product space $V$. Prove that we can find a subspace $W$ such that, if we express every $\alpha$ in $V\,$ in the form $\alpha = \beta + \gamma$, here $\beta$ in $W$ and $\gamma$ in $W^{\bot}$, then we have $U(\alpha) = \beta - \gamma$      If we denote $W = range(U+I)$, $W' = range(U - I)$,then must have $W \subset null(U-I)$ and $W \subset W^{'\bot}$. We can finish the proof if we can prove that $W' = null(U+I)$ or $W' = W^{\bot}$. But I can't prove this...  Thanks


PHP script sometimes inserts data into database and sometimes not

I am writing simple PHP program to insert student information into mysql database and respond back with user id. This script sometimes works good. But sometimes it is not working. What are the possible reasons for this kind of behavior. If my program has any bugs then please suggest corrections. Below is my student registration script and mysql database function. I am not good at PHP, PLEASE SUGGEST CORRECTION IF ANY  <?php     $username = $_POST['name'];     $clgName = $_POST['clg_name'];     $branch = $_POST['branch'];     $sem = $_POST['sem'];     $mobile = $_POST['mobile'];     $email = $_POST['email'];     $profile_pic_color = $_POST['profile_pic_color'];     $deviceId = $_POST['device_id'];      include "DatabaseHandler/DBFunctions.php";      $db = new DBFunctions();      $query = "INSERT INTO user_details(user_name, user_clgName, user_branch, user_sem, user_mobile, user_email, profile_color, device_id) values('$username', '$clgName', '$branch','$sem', '$mobile', '$email', '$profile_pic_color', '$deviceId')";      list($result, $mysqli) = $db->select($query);      $query = "SELECT MAX(user_id) FROM user_details";      if($mysqli->affected_rows > 0){          list($result, $mysqli) = $db->select($query);          $arr = array();          if($result){             $row = $result->fetch_array();             $arr[] = $row;             echo json_encode($arr);         }     }  ?>   And this is my Database Manager PHP SCRIPT.  <?php       class DBFunctions{            public function connect(){             include "DBConfig.php";                  $mysqli = new mysqli($domain, $username, $password, $database);              return $mysqli;         }          public function query($query){                 // Connect to the database             $mysqli = $this -> connect();              // Query the database             $result = $mysqli -> query($query);              return array($result, $mysqli);         }          public function select($query){              $mysqli = $this -> connect();              $result = $mysqli -> query($query);              if($result === false) {                         return false;                 }                  return array($result, $mysqli);         }     } ?>


The MOV video files from my Canon S110 are huge files. A 20 second clip is 90MB. They are 1080HD videos. Is this simply the nature of HD video size, or is there another format I could convert them to which would save on space?  I'd like to use something like FFmpeg to convert all the videos I've taken. Could someone suggest a format and some settings that would mostly maintain the video quality, while saving some space for storage or sharing?


I have 3 old bikes all have been in a shed out of the weather for about 20 to 25 years. tires are rotted. on has a front fork suspension not working. #1 is a Trex zx 6500 #2 Giant Ricon girls bike and the last one is GT terain outpost. where do i go for parts . I can do the work they all have very very little time riding on them . all the bike stores want to do is sell new bikes but i believe they can be fixed and used again any help would be greatly appreciated.


Translating English into Predicate Logic

Which of the following are possible (semantically and syntactically correct) first-order-logic translation of "Salma loves any class which is harder than every Algorithms class". Is the following translation correct ? and Why ? $\forall x \forall y[[Class(x) \land AlClass(y) \land Harder(x,y)] \to Loves(Salma,x)]$ My prof considered it as a wrong translation.


Here are some sentences about 'after being'        Schoolgirl awarded €20,000 after being locked in classroom.              Girl dies after being struck by lightning.              Two people die after being swept away by river.        I think we can use 'after being+past participle' when one action immediately follows another action. For example: Girl dies after being struck by lightning.  Here, It means: Girl dies after she was struck by lightning.  Am I correct?  I think I can change 'dies' into 'died'.  For example:     Girl died after being struck by lightning.   Why has 'Girl dies' been written in the news even if she died in past?


I have made some chain links. I used the Rigid Body Tools and made the two end links passive and the others active. They are all set to shape Mesh. I've tried setting the weight to acrylic, cardboard, etc to lessen the pull they have when falling. How do I prevent these links from coming apart? I've even tried scaling up the scene but that also doesn't work.  Peter


Keyboard shortcut to switch between sheets in Excel

Does Excel 2007 have a keyboard shortcut that switchs between worksheets?


Mr. Dursley arrived in the Grunnings parking lot. We use "at" for a specific place. So why "in" used in this sentence?


Virtual destructor - when it is necessary

Let's say that I have a base class X with only one virtual function.  I extend it to Y and override that function.  I didn't provide explicit destructor for X and Y.  What happens during the destruction in this statement.  Y y; X *x= &y; return; . . . X*x = new Y; delete x; return;   Which will cause memory leak..


At the end of Revenge Of The Sith, Leia was adopted by Bail Organa, following the death of her biological mother. At the end of Rogue One, Bail refers to Leia as being his daughter. During A New Hope, Leia is known as "Leia Organa, daughter of Bail Organa".  But did she know she was adopted by the Organa? Did she know that she's not the biological daugther of Bail Organa?  This could change the vision of the following scene: at the end of Return of the Jedi, Leia talks to Luke about her mother, and tells him that she was very beautiful... Did Leia talk about her birth mother? Or her adoptive mother?


I am triyng to solve this interesting problem, but I have no idea. I tried induction, but it didn't work. Let $(x_n)_{n \ge 1}$ be a sequence, where $x_1=1$ and defined as follows: $$x_{n+1}=x_n+ \frac {1} {3x_n^2},$$ for every $n \ge 1$. Show that there exists a real number $c \gt 0$ so as $x_n \lt \sqrt[3] {n+c}.$


I can't find a way to modify the touchpad gestures Unity uses by default on Ubuntu 12.04/12.10.  Tried with Ginn, but it shows error subscribing to gestures and it seems because of Unity.  Is there a way of customize the trackpad gestures of Unity?


Can a wizard transcribe prepared spells from multiclassing?

Say you're a 1st-level wizard and also a 1st-level druid. Could you, as a druid, prepare spells that both classes have, like Detect Magic and Ice Knife, then, since they're now "prepared" for you, write them in your spellbook so that you can cast them as a wizard, allowing you to cast with intelligence without needing to choose them on level-up or find them in a book/scroll?  Also, would it cost 10 gp per level or 50 gp?  As far as I can tell RAW seems to say yes but I just wanna make sure I'm not missing anything.


Calculate correlation on categorical data

I have categorical data where values are string. Gender, City and Country are my input data. My output class is also string values. The below table explains the data:  Gender      City      Country      Output  M           XYZ       A            Converted  F           KLM       Z            Converted  M           KLM       M            Not Converted  F           ABC       M            Converted  First question, can I calculate correlation between input columns and output? If yes, how and by which method? I am using Python, any suggestion on library function would be great.


I am fairly new to the system administration world. I've been working on an application recently and when I check my application server logs, I constantly get various IP addresses trying to ssh into my server by brute force. Here is an example of my server log:   Feb 14 04:07:20 foodwiz3 sshd[1264]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key Feb 14 04:07:21 foodwiz3 sshd[1264]: reverse mapping checking getaddrinfo for coenamor.columbiansabbatical.com [23.249.167.223] failed - POSSIBLE BREAK-IN ATTEMPT! Feb 14 04:07:21 foodwiz3 sshd[1264]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=23.249.167.223  user=root Feb 14 04:07:23 foodwiz3 sshd[1264]: Failed password for root from 23.249.167.223 port 32997 ssh2 Feb 14 04:07:23 foodwiz3 sshd[1264]: Received disconnect from 23.249.167.223: 11: Bye Bye [preauth] Feb 14 04:13:04 foodwiz3 sshd[1289]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key Feb 14 04:13:05 foodwiz3 sshd[1289]: reverse mapping checking getaddrinfo for coenamor.columbiansabbatical.com [23.249.167.223] failed - POSSIBLE BREAK-IN ATTEMPT! Feb 14 04:13:05 foodwiz3 sshd[1289]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=23.249.167.223  user=root Feb 14 04:13:07 foodwiz3 sshd[1289]: Failed password for root from 23.249.167.223 port 41562 ssh2   Is this something that is fairly normal, or should I be worried/doing something about it?


Controlling a 3 volt motor with a potentiometer

I would like to control the speed of a small 3 volt dc motor with a potentiometer. What specification for the potentiometer would I need for this?


The dimension of the vector space of all trace-zero symmetric matrices

Find the dimension of the vector space of all symmetric matrices of order $n \times n$ (real entries) and trace equal to zero.


Make searches for user:xxx work for deleted users as well

We can do searches for content by user with the syntax user:xxx where xxx equals the user number. However, this does not work with deleted users.  This could be useful for the same reasons the user-based search is useful in general, of course. In the case of deleted users, this can sometimes be especially useful, though; for 10k and diamond users doing moderation duties, in particular.  In fact, this would also be a great thing to simply link directly to on the moderator's page for deleted users (perhaps in conjunction with showing deleted posts)


Hide notice for migrated questions after 30 days

When a question is migrated from another site, a stub is temporarily left on the original site before being automatically deleted after 30 days. (See )  While questions stubs are automatically deleted from the origin site after 30 days, questions that are nearly a decade old will prominently display their migration status.   Migration notice for   I can't think of any reason a 7-8 year old migration notice would be helpful for the average user, or why it should displayed before protected notices.  If a user does want to see if a question was migrated, they can check a question's , or search .


i want to center my paragraph but its not working

I simply just want to center my  while changing the width this is my html code

Like what you see?

Hire me

My work

My skills

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                           Alkhazriji

  my css code inside the media query .s-footer p     {         display: block;         width: 50%;         text-align: center;     }  before the media query .s-footer p {     background: #852EF8;     border-radius: 50px;     margin: 0 5em;     font-size: 1.5em;     width: 33.33;     font-weight: bold;     color: #FF57E9;     cursor: pointer;     display: block;     position: relative; }  .sss {     padding-top: 0;     margin-top: 0;     display: block;     padding: 0; }  i tried everything its usually centered but when i change the width it goes to the left side i tried text align, postion, grid, display, nothing worked. (im new to coding so my problem might seem stupid)


I would like to learn Plain TeX and I'm reading Knuth's "The TeXBook". At Chapter 7, Knuth talks about the \string command and how it converts control sequences into lists of characters tokens.  Why when I typed  \string\TeX, I got "TeX, but when I wrote {\tt \string\TeX} I got \TeX ?  I guess it's something related to \escapechar, because when I changed that control sequence the output changed too:  \escapechar=`^ \string\TeX   it generates ^TeX.


Modular exponentiation by hand ($a^b\bmod c$)

How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and .


divisibility remains by scaling multiplicative order

I want to show that if  p | $a^{e}-1$ then also p | $a^{ek}-1$ where k is any integer. Def. of order in terms of divisibility: Let $m ≥ 2$ and a be any integer coprime to $m$. The order of $a$ mod $m$ is the smallest $e > 0$ so that $m$ divides $a^{e}-1$. In terms of congruence I can see why this is the case: e.g. let $a = 2, e = 4, m = 5$. Then $2^{4} ≡ 1 $ (mod $5$), lets scale $e$ with $k=2$, then $2^{4^2} ≡ 1 $ (mod $5$) = $2^{4}2^{4} ≡ 1 $ (mod $5$). So it does not matter what $k$ is, the congruence is still valid. I don't know exactly how to show why the scaling of $e$ with any $k$ does not change the fact that $p$ divides  $a^{e}-1$.


Removal of old kernels without deleting all

I am looking for a way to remove all the old kernels but keep 1 just in case.   dpkg --list | grep linux-image | awk '{ print $2 }' | sort -V | sed -n '/'`uname -r`'/q;p' | xargs sudo apt-get -y purge   This command has worked fairly well but removes all old kernels. Is it possible to leave a spare kernel?


Is Ubuntu Studio suitable for full-stack software development?

I've been using Linux Mint 19.3 for learning full-stack software development and everything works fine (VS Code, Ruby, React, etc.). Soon I'll begin producing music (I'm starting a home studio) and after some research, I've come to the conclusion that Ubuntu Studio is a good distro for this purpose. So I'm deciding whether should I make a dual boot or simply migrate to Ubuntu Studio. I'm not a big fan of multi-boot (I had Windows/Linux for a while and in the end, I prefer to use a virtual machine whenever I need a different OS). Also, I've read in some forums that sometimes a dual boot with Linux alongside Ubuntu can cause some trouble, especially in the UEFI configurations. If this is true, I would prefer to simply migrate to Ubuntu Studio, but I'm afraid that some things might not work the way I expect. For example, could the low latency kernel affect some of the packages commonly used in software development? I'd appreciate your advice on this. Thanks!


Before line break  After line break   An empty line between two sentences usually gets me a line break without any additional spacing. For some reason, on the second page of the same chapter, there is additional spacing after each line break and also more spacing after \\.  Why is that? Is TeX somehow trying to fill the page before the following section? I'd like to constantly have no extra spacing after line breaks and \\.


how can is it possible to inherit from multiple classes in c#

I have 2 classes base1 and base2     public class base1     { public base1(int I, string s) { }       public void f1()     {     // code     }     public void f2()     {     // code     }     public void p()     {     // code     }      }     public class base2     { public base2(int x) { }       public void f3()     {     // code     }     public void f4()     {     // code     }      protected void f5()     {     // code     }      }   I need to implement 5 classes that derive from both of them but there is no multiple inheritance in c#....so how can I do it?-one class base1i can`t change. with the second one i can expirement.so the only idea i have is to make it  to be interface? but both classes constructors have arguments!so it is not possible to make a interface may be you have better ideas...


Can anyone help me with this one please?! I want to find the total resistance but the circuit seems neither parallel nor serie. What should I do?!


Google Search Console Adding Sitemap "Couldn't fetch" and "Sitemap could not be read" txt file

I made a fairly simple .txt file I am getting the following errors   I find it very odd. The 2.txt is just the .txt with fewer than 50,000 results. Somehow it seems like Google can read the longer .txt file but not the shorter 2.txt file.


How to reconstruct a number from its integral, fractional and exponent parts?

I am writing a parser where I need to parse numbers.  Numbers are in the JSON format, i.e. simplified, something like:  [+|-] integral [. fractional] [e|E exponent]   So these are the 3 parts of the number I have. Each part is an integer.  For example:  0.4 Integral = 0 Fractional = 4 Exponent = 0  2.84e+6 Integral = 2 Fractional = 84 Exponent = 6   I know how to compute the number in Java in a very crude manner. Something like this:  long integral; long fractional; int exp;  double decimal = fractional; while (decimal >= 1.0) {   decimal *= 0.1; }  var n = (integral + decimal) * Math.pow(10, exp);   But this has terrible properties like losing precision completely, overflowing etc. specially for very large numbers (e.g. 10e99, 2.7e-23).  Is there a way to create a number in Java from its constituent parts such that the number keeps the properties as close as possible to the floating point literal?  My current idea is to try to create the exact bits in memory that would represent the floating point number using the IEEE 754 representation Java (and many languages) uses.   helped me understand the floating point representation, but I am still kind of stuck.  My current try to do that uses a ByteBuffer which can do:  ByteBuffer buffer = ByteBuffer.allocate(8); buffer.put(<bits representing the number exactly in floating point>);  buffer.flip(); double n = buffer.getDouble();   The "only" problem being, figuring out the right bits, which is not trivial (if someone knows a method to do that , please do share).  EDIT: Performance is important, so I am trying to avoid creating a String then throwing it at Double.parseDouble(str)... as that feels pretty expensive compared to writing the bits into memory... but I might be wrong and this is indeed the most "efficient" option? Really don't know at this point, hopefully I can benchmark when I have a few options.


Cannot set LED monitor to native resolution

I cannot get windows 7 pro to set my monitor to its native resolution of 2650x1440.  I have Windows 7 pro, an NVIDIA GT730 and two monitors(AOC e2752She, BenQ GW2765) attached to the NVidia card using the DVI ports using this cable: (). I originally only had the AOC with a native resolution of 1920x1080. Then I got the BenQ, but on setting it up Windows would only allow 1920x1080 for it. So I went into the Nvidia control panel and created a custom resolution 2560x1440 and set it to that. Superficially it looks like it did it as the background got small for it and the conrol panel/display/screen resolution setting SAYS 2650x1440, but the image is "soft", not crisp and when I look at the information panel on the display itself, the monitor says it is being driven at 1920x1080 and its recommended setting is 2650x1440, so I'm thinking that windows must be doing some emulation of 2560x1440 and not actually pushing it natively at 2560x1440. Even if I set the monitor to 1920x1080 the image is really "soft".  I want to use this monitor (gw2765) for graphic design and video editing, so I really need it to show it's true resolution. I have searched for quite a long time and have not found anything that seems to address this issue.  Any suggestions?  Thanks!!


Why would Narcissa Malfoy trust what Harry potter said?

How would Narcissa Malfoy know if Harry was lying to her about her son Draco?


Why can I add a horizontal loop cut, but I can't add a vertical loop cut

In the images I'm trying to add a loop cut vertically through the rectangles, however, it only allows me to add a horizontal loop cut.  The mesh is only a plane and I am using the mirror modifier.  I'm not sure if the mirror modifier is somehow messing it up or if it's something else.  Also, the mesh is part of a larger mesh that I have hidden, not sure if that helps or not either.  I've already tried removing any duplicate vertices and such but to no avail. Can someone tell me what I'm doing wrong?


How to arrive on the diffraction pattern for the double slit experiment using path integrals for the Gaussian slit case?

I wish to take the path integral route to derive the diffraction pattern for the double slit experiment using the Gaussian slits as the nature of the slits. The kernel looks like: \begin{equation} K((x,L+D),T;(0,0),0)=\\\int_{t=0}^{T} \int_{y= -b+a}^{-b-a} K((0,0),0;(y,L),T)*K((y,L),t;(x,L+D),T)dy *dt+\\\int_{t=0}^{T} \int_{y= b+a}^{b-a} K((0,0),0;(y,L),T)*K((y,L),t;(x,L+D),T)dy *dt \end{equation} if we approximate the slit to be of a Gaussian distribution, we can say the slits are represented by $G_1$ and $G_2$:  \begin{equation} G_1 = \frac{1}{\sqrt{2\pi}}\exp[{(y-d)^2/8b^2}]\\ G_2 = \frac{1}{\sqrt{2\pi}}\exp[{(y+d)^2/8b^2}].\\ \end{equation} If we assign the values: \begin{equation} K1=\int_{t=0}^{T} \int_{y= -b+a}^{-b-a} K((0,0),0;(y,L),T)*K((y,L),t;(x,L+D),T)dy *dt\\ K2=\int_{t=0}^{T} \int_{y= b+a}^{b-a} K((0,0),0;(y,L),T)*K((y,L),t;(x,L+D),T)dy *dt \end{equation} Then the kernel becomes: \begin{equation} K=\int_{t=0}^{T} \int_{y= \infty}^{-\infty}K1*G1*dy*dt +\int_{t=0}^{T} \int_{y= \infty}^{-\infty}K2*G2*dy*dt \end{equation} But if I assume: \begin{equation}  K((0,0),0;(y,L),t)=(\frac{m}{2\pi i \hbar t})\exp[\frac{i}{\hbar}\frac{m}{2}\frac{y^2+L^2}{T}]\\ K((x,L+D),T;(y,L),t)=(\frac{m}{2\pi i \hbar (T-t)})\exp[\frac{i}{\hbar}\frac{m}{2}\frac{y^2+L^2}{(T-t)}] \end{equation} which is the kernel for free particles, I get a solution of the form: \begin{equation} K=  \int_{t=0}^T  \delta* \sqrt{\frac{\pi}{\alpha}}\exp[\beta^2/4\alpha]dt\\ where:\\ \delta = (\frac{m}{i \hbar})^2*\frac{1}{(2\pi)^{5/2}}\frac{1}{t(T-t)} \exp(\frac{im}{2\hbar}[\frac{L^2}{t}+\frac{D^2}{t'}+\frac{x^2}{t'}])\exp[\frac{d^2}{8b^2}] \\ \alpha = \exp[\frac{im}{2\hbar}[\frac{1}{t}+\frac{1}{t'}]+\frac{1}{8b^2}]\\ \beta = \exp[\frac{-2d}{8b^2}-\frac{2x}{t'}]\\ t'=T-t \end{equation} Now the problem is, I don't know how to integrate this over the time domain. Can someone tell me if I'm on the right track, and what I need to do to arrive at the right interference pattern on the screen, but finally taking the square of the thusly obtained amplitude? And possibly what the final what the final expression looks like?


Is it normal that a laptop battery drains when the laptop is off?

I have an HP ProBook 450 G2. Every time I shut down the computer and turn it back on after a day, the battery level decreases by about 5%. I'm sure that the computer is shut down, not in sleep or hibernate. I removed the battery from laptop and after inserting it, the battery percentage does not change. I tried updating the BIOS, disabling wake on LAN in BIOS options, and calibrating the battery several times.  Is this drain normal? If not, is it a hardware failure or can I fix it with software?


How to show that if p is prime and m,n are natural numbers then $p^m -1 | p^n -1$

How to show that if $p$ is prime and $m,n$ are natural numbers such that $m|n$  then  $p^m -1 | p^n -1$  I'm really stucked with this problem. Please help? Thanks!


How do I backup email messages in Dovecot? Where are they located in the file system?

I run Postfix with Dovecot. Now I need to begin to backup email messages. What directories should I backup? Such that later, if a server breaks down, I'll be able to restore all the email message on a new server with Postfix and Dovecot.


File transfer rate to USB stick is totally variable

I just rebuild my old desktop, which is now running Lubuntu 15.04, and tried to transfer a 1.3GB file into my 8GB thumb drive. I was immediately reminded of a problem that has plagued me for a long time.  If I use PCManFM the transfer starts at about 68% complete and slowly (and I mean slowly) gets up to 100%. So the progress bar is barely even a suggestion.   I then used rsync (with the progress argument) to see what was going on. A similar thing happened. The data transfer started off at about 4MB per second and then crawled down to 1MB per second. And it took about the same amount of time.  The transfer will eventually complete but I was curious as to why this might be happening? Is there any way to get the progress to be a bit more accurate?


How can we edit www.example.com/user page?

The user page doesn't look good. I want to edit it, but (If I am right) that is a default page. I am not able to find where to edit it.  How can I edit the user page?


Connect MacBook Pro Retina to VGA data projector

What's the best adapter to connect a MBP Retina to a VGA data Projector?


Bibliography processing issue with TeXstudio: "I couldn't open file name `build/bibliographyCitation.aux'"

I'm new using TeXstudio and I'm trying to cite the references in my work. But unfortunately I had an error says:  Process started: bibtex build/"bibliographyCitation"  I couldn't open file name `build/bibliographyCitation.aux'  Process exited normally   I searched about solutions for this problem but no one specify how can I know the default folder that has the .aux file? and how can I change it step by step?!  This is the current settings I have:   Thank you


The projection of an ellipse is still an ellipse

While studying the problem of determining the orbit of a binary star system, my astronomy notes say: "the projection of an ellipse onto a plane is still an ellipse (except the special case in which it's a segment)". How could I prove this?  EDIT: As suggested i'm adding what I know about ellipses. I know the basics of ellipses in the plane, the equation of an ellipse in a plane in cartesia coordinates, the equation of an ellipse in polar coordinates, the fact that ellipses can be obtained by the intersection of planes with a cone. In my geometry course we defined ellipses as the the points of the plane such that the ratio between the distance from a point and a line is constant and less than 1. I also know that the sum of the distances of the points of the ellipse from the foci is constant.


How to set user passwords using passwd without a prompt?

I am writing a script to add a large amount of users to a system. Part of this involves setting default passwords for each user. How can I set users' passwords without it prompting me for the password up front?  Unfortunately passwd doesn't seem to take an argument stating the new password to set. I'm using Ubuntu 11.10.


Is there something similar to the OEIS wiki page on mathematical symbols for vanilla LaTeX?

The The On-Line Encyclopedia of Integer Sequences (OEIS) maintains a  describing how to produce various mathematical symbols in LaTeX. However, several of the OEIS commands are custom defined. For example, they say that the symbol for the real numbers (ℝ) can be produced by writing $\R$. However, doing that will result in an error unelss you import a package or define a new command. In "vanilla" LaTeX, blackboard-bold ℝ is often achieved by writing $\mathbb{R}$ To get the  to work, you have to write something like \newcommand\R[...]         Is there a webpage similar to the OEIS wiki page on mathematical symbols for vanilla LaTeX? When I say a "vanilla" copy of LaTeX, I mean an unmodified copy of LaTeX. The Vanilla distribution of LaTeX might have some additional libraries if those libraries are standard or very popular. However, we don't define any new commands inside of our document or import any esoteric packages having fewer than two dozen users.


After I upgraded to Windows 10, free disk space went from 100 GB to 5 GB on my 205 GB system disk over the course of about two months. I am not aware I installed any programmes that could cause such drop in free disk space.  I tried Disk Cleanup, but it did not free much disk space.  What are some tips reclaim the disk space on Windows 10?  Any help is appreciated.


Are there popular but poorly paved roads on Big Island which require an SUV?

My grandparents will drive only on roads recommended in printed travel guides; they'll ask the rental car company if Waipio Valley Road and the road to the top of Mauna Kea are sanctioned.       A rented 4WD vehicle is allowed by law to travel ANY public roadway in Hawaii. AND there are some places that require a 4WD vehicle.      [...]      If you travel down into  or to the top of , you are legally allowed to do so, but your rental company will expect you to pay for any damage incurred whether you selected the insurance or not, as the insurance is null and void when you violate the contract.        I do not believe a 4x4 rental is necessary for 99% of visitors. For the other 1%, "necessary" is too strong a word!      But, being in that "1%" category, there ARE worthy places to go on the BI that require 4x4 (the kind you can rent from a normal rental outlet, not the kind locals may drive). I won't publicize those places because I don't want such places to become overused. [I bolded.] Just don't believe it when you read here that there is absolutely no place at all worth visiting that would require 4x4.    I doubt the Tripadvisor comments overhead, as none of them discussed potholes:          Please see the bolded phrase. Where on the BI requires an SUV?


Remove "How to Ask Questions in Private Beta" from final sites

Apparently "How to Ask Questions in Private Beta" is part of help center > asking of each site. (At least I've checked on  and )  It's relevant only for sites still in beta stage. Is it possible to remove it for sites not already in private-beta?   I know very similar  has been already asked, but it didn't received any answer, so I ask it again.


I've noticed lately that depending on what zoom level I'm viewing my document in Adobe Acrobat, my table borders will disappear and come back. For example, here is a table in my most recent homework seen at 125% zoom:  Here is the same document, now viewed at 150% zoom:  I write my documents in Overleaf, and it happens no matter which machine I'm on (school and home).  I guess in the grand scheme of things it's no big deal, but it does bother me to think my documents may not be displaying as I want them to on the receiving if the person viewing it changes their zoom. Any ideas?


I'm using Putty on Windows to connect with remote Linux server. For some reason, windows F15 kept got pressed (not by myself) and it get translated into ~ remotely. I'm wondering how does this happen and how to prevent this? I'm thinking of disable F15 key through registry but so far I can't make it work.  Thanks in advance!


Was Wondering when will 13.00 be available to purchase on a disc from your store, right now the only thing i see to purchase is 12.00


Command hangs when directed at a shared network drive

In an effort to become more familiar with ubuntu/linux, I have recently installed a VM with Ubuntu 14.04 on it.   I mounted a shared network drive to my home directory, which is named ostenso. Sometimes when I try to get a listing, move a file or move into the shared drive the command will just hang as I am typing it.   For instance I try moving to ostenso/Tmpxfer and the following happens:  I type cd ost(-tab complete-) and nothing happens. The terminal then is hung up and I cannot kill the command with Ctrl + C.   If I close the terminal and open another, the problem persists. I have been recovering from this by doing a reboot afterwards everything works fine for a while.   I notice this mostly only happens when the VM has been running for a while but not in use. The network drive I am trying to access is using the cifs file system and has total size of 1.8TB. At the current time it is 89% used (1.6TB).   Could anyone provide some insight as to why this happens and how I could recover from it?


I'm recovering a server from getting hacked and there is one thing I can't fix:  When I ssh (or scp) to the server, no matter what password I give, it lets me log in. I don't know much about the ssh protocol but I'm pretty sure it's not supposed to do that.   I've checked in the sshd_config file and the only changes are the ones that I've made (as far as I can remember).   Another thought that I had was that there might be something screwed up in the /etc/passwd file that I'm missing. Has anyone seen this?


What is the difference between the followings?  A. I have been living here for 5 years. B. I have lived here for 5 years.  Am I correct that these two represent the same event, but A emphasizes the continuity of living while B simply states a fact that you lived there from 5 years ago to the present? Is it true that the difference in present perfect and present perfect continuous is whether a speaker intends to emphasize continuity or a fact?


I can't allocate more than Xms1G into Minecraft. I've looked at every tutorial and still, I can not allocate more. I have 8gb of ram and a 64-bit operating system. How can I allocate more? I've tried putting Xmx-4G but it crashes and says something about my Java Virtual Machine.


How to copy filename as text from a folder in windows 7?

I am looking to copy the filename as text from a folder as seen in windows explorer in windows 7, so that i can paste in other editor.  I there any way to achieve this. I don't see any such feature in the context menu.  Note: I am looking for a windows solution, i don't want/can't install new software.


How to enable Hardware Encryption on SSDs like Samsung 840 EVO?

Just got Ubuntu 14.04 running on a Zotac Zbox CI320. I want to enable the Samsung 840 hard ware encryption that comes with this hard drive, but I don't know how.  Is there anyone that can help me set this up? Much appreciated.


How would you be solve sin x = 1 - x, without drawing the graph and manually measuring the point of intersection?


Is the Axiom of Choice required to prove $|\alpha|=|L_\alpha|$, for infinite ordinals?

The proofs of this fact I've seen all rely on appealing to AC at some point or another. But is this required? Is there a choiceless proof?


Latex put the figure then the text but I want the opposite order

I have the following code :      \begin{figure}[h]    \includegraphics[width=0.9\textwidth]{images/partie_2/module_S0_surf_10000}    \caption{\label{module_S0} $|S_0|=f(\epsilon,\lambda)$.}    \includegraphics[width=0.9\textwidth]{images/partie_2/argument_S0_surf_10000}    \caption{\label{arg_S0} $Arg(S_0)=f(\epsilon,\lambda)$. Blablabla).} \end{figure}  SOME TEXT HEEEEEEEEEEEEEEEEEEEEEEEEEEEEERE   My problem is that latex first right "SOME TEXT HEEEEEEEEEEEEEEEEEEEEEEEEEEEEERE" on a blank page and then he puts my figure on a blank page too. So I know it is not a problem of spacing because both my text and my figures are alone on their pages. Latex just dont write things in the same order as I wrote the code.  Could you explain me why it does this ?  Thanks


How To Find The Command Is Internal Or External In Ubuntu

Those Command Are Present In 'help' Command They Are Internal Command Or Not....


I recently bought a Minolta film camera and it had some film with it. The film is dated 1991 - 1994. Can I use the film?


Prove that $a, b, c, a+b, a+c, b+c, a+b+c$ can all be the same colour.

Suppose that every integer is coloured one of three colours. Prove that there exist distinct integers $a, b, c$ such that all of the following are the same colour: $a, b, c, a+b, a+c, b+c, a+b+c.$   I initially thought of splitting the integers into $3$ sets, one of which has infinitely many colours. Obviously, if two of the sets are empty, then there exist such integers. However, I wasn't sure how to ascertain that there exist such integers when more than one set has arbitrarily many elements.   An alternative approach I thought of involved showing that $\exists a, b, c\in \mathbb{Z}$ such that for any function $f: \mathbb{Z}\to \{0, 1, 2\},f(a) = f(b) = f(c) = f(a+b)=f(a+c)=f(b+c)=f(a+b+c),$   but I'm not sure how to show this.


A curve where all tangent lines are concurrent must be straight line

I'm trying to solve this question in the classical  (page 23):        A regular parametrized curve $\alpha$ has the property that all its tangent lines pass through a fixed point. Prove that the trace of $\alpha$ is a (segment of a) a straight line.      My attempt  Following the statement of the question, we have $\alpha(t)+\lambda(s)\alpha'(s)=const$.  Taking the derivative of both sides we have $\alpha'(s)+\lambda'(s)\alpha'(s)+\lambda(s)\alpha''(s)=0$ which is equal to $(1+\lambda'(s))\alpha'(s)+\lambda(s)\alpha''(s)=0$.  Since $\alpha'(s)$ and $\alpha''(s)$ are linearly independent, we have $\lambda'(s)=-1$ and $\lambda(s)=0$ for every $s$ which I found strange, since the derivative of the zero function is zero.  I need a clarification at this point and a hand to finish my attempt of solution.


I work with this polygon and try to find a way to create a new polygon from the empty gap (not distinguish it) in the middle of the polygon.  I succeed to do it with a "Difference" tool but used with another layer on the polygon and then using the difference tool.  I can also digitize the shape of the hole and create a new layer I seeking an automated way to do it and not doing in manually.   I read:        Is it possible to do it with a direct tool in QGIS 2.18.1, without the aid of another layer?


how to remove duplicate objects from java arraylist

I have requirement to remove the duplicate object from my arraylist of object. I tried it by making to arraylist of objects. First one contains all objects including duplicate and the another contain only the unique one.   ArrayList<ListTableClass> ltc = new ArrayList<ListTableClass>();//has duplicate ArrayList<ListTableClass> ltc2 = new ArrayList<ListTableClass>();//unique   And i used contains method to check for dublicates like this:  for (ListTableClass element : ltc) {           if (!ltc2.contains(element)) {             ltc2.add(element);           }     }   but this does not remove duplicates. It adds all the elements of ltc to ltc2. Don't know why? ltc does contain duplicate objects.


Everytime I try to use a command to do an enchanted item it never works and there's just a 0 next to the item. I tried to spawn a diamond sword with sharpness in a chest but instead in the chest there was a normal diamond sword with a 0 next to it. Is it possible to put an enchanted weapon/item in a chest?


how do I center the anchor tag inside a div whose parent is working as an overlay

what I want is to center the anchor tag texts vertically also I want the "contents" div to fit the screen so that if the screen gets smaller or bigger the anchor tag doesn't run off the margin creating overflow which I don't want, I tried a bunch of different ways to fix this but none seem to work, any help is appreciated! here's the code...   $(function() {    $(".menu-link").click(function(e) {     e.preventDefault();      $(".menu-overlay").toggleClass("open");     $(".menu").toggleClass("open");    });  });  $('.menu-link').click(function() {   $('body').toggleClass('no-scroll'); }); .nav {     display: flex;     justify-content: space-between;     padding: 0 5%; }  #brandname {     color: black;     font-weight: bold;     font-family: Circular Std Black;     line-height: 60px;     font-size:20px;     margin-top: 45px; }  .menu {   position: absolute;   margin-top: 50px;   right: 5%;   height: 46px;   width: 46px; }  .menu-link {   width: 100%;   height: 100%;   position: absolute;   z-index: 1002;   cursor: pointer; }  .menu-icon {   position: absolute;   width: 20px;   height: 15px;   margin: auto;   left: 0;   top: 0;   right: 0;   bottom: 1px; }  /* ------------- */ .menu-line {   background-color: white;   height: 3px;   width: 100%;   border-radius: 2px;   position: absolute;   left: 0;   transition: all 0.25s ease-in-out; } .menu-line-2 {   top: 0;   bottom: 0;   margin: auto; } .menu-line-3 {   bottom: 0; } .menu.open .menu-line-1 {   transform: translateY(7.5px) translateY(-50%) rotate(-45deg); } .menu.open .menu-line-2 {   opacity: 0; } .menu.open .menu-line-3 {   transform: translateY(-7.5px) translateY(50%) rotate(45deg); }  /* ------------- */ .menu-circle {   background-color: #E095F0;   width: 100%;   height: 100%;   position: absolute;   border-radius: 50%;   transform: scale(1);   z-index: 1000;   transition: transform 0.3s ease-in-out; } .menu:hover .menu-circle {   transform: scale(1.2); } .menu.open .menu-circle {   transform: scale(60); }  /* ------------- */ .menu-overlay {   transition: opacity 0.2s ease-in-out;   opacity:0;   display:hidden; }  .menu-overlay.open {   position: fixed;   top:0;   left:0;   height: 100vh;   width: 100vw;   opacity:1;   display:block;   z-index: 1001;   background-color: black;   overflow: hidden; }   .no-scroll{     overflow: hidden; }   /***********anchor tag************/ .contents {     display: table;     margin-left: 5%;     margin-right: 5%; }  .contents a{     display: table-cell;     text-decoration: none;     font-family: Circular Std Book;     font-size: 30px;     padding-left: 60px;     padding-right: 60px;     color: white;     vertical-align: middle; }
Test

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Why $\sqrt[3]{{2 + \sqrt 5 }} + \sqrt[3]{{2 - \sqrt 5 }}$ is a rational number?


Area 51 site stats are weirdly formatted on beta sites in new design

There is some space missing between the table columns which looks especially weird if most of the values are four digit values. This just looks wrong without spacing. A bit of column spacing would be great there. An empty row after the actual stats would also be an improvement.


I accidentally discovered () that a closing square bracket within an optional argument delimited by [ ] can cause problems.  Here is example code illustrating the issue:  \documentclass{article}   \begin{document}  \tableofcontents  \section[Square brackets ([ and ])]{Square brackets: [ and ]} % bad: the TOC now has "Square brackets ([ and", and the actual title is a mere ")".  Some text.  \section[{Square brackets ([ and ])}]{Square brackets: [ and ]} % good (works as originally intended)  Some text.  \end{document}   The text to be used as the optional (as well as the non-optional) argument contains a ], and this character is not supposed to function as the optional argument terminator but as a matching square bracket/parenthesis. Perhaps this is as it should be, but the question is how to best circumvent any potential problems. Enclosing this in a group works, but I don't know whether doing this has other side effects (perhaps not here in the case of \section but hopefully someone else has a better example of where grouping could lead to a problem). There is no (obvious) way other than writing [{ }] because [ and ] are not normally escaped. That [ and ] are normal characters and bear syntactic function (as optional argument delimiters) creates this potentially problematic situation.  Is simply enclosing the entire optional argument in a group ({ }) a good solution? Are there other/better ways?


Find the derivative of the inverse of this real function $f(x) = 2x + \cos(x)$

I don't know how to attack this problem. The last I've tried is using a differential equation, but I don't know how to solve it.  Let $y$ be $f^{-1}(x)$. Knowing that $x=f(y)= 2y + \cos(y)$ and derivating I obtained the following non-linear first order differential equation: $y' \cdot (2-\sin(y))=1$  I would thank you if you can help me.  Edit: I haven't said, but it is trivial to check that the function is injective, so it has an inverse, because $\forall x \in \mathbb{R}$ $f'(x) \neq0$


Comparable to standard house wire, which carries much more current for powering high power devices like vacuum cleaners etc, speaker wire seems to be unusually thick, and tends to be stranded, which correlates to even more efficient power transfer.  Why is this speaker wire so thick?


Ran boot camp assistant, stalled out and didn’t create a second partition. How do I reclaim the space?

Disk Utility.app displays my internal HDD "APPLE HDD" to be entirely taken up by "Macintosh HD" at 759.65 GB. Seeing as it’s a 1 TB hard drive, that’s a little disconcerting.   I also can’t reclaim the space using the partition tool, because there’s no partition to remove.  How do I fix this? Do I need to do a fresh install or reformat or something?  EDIT: Found the answer to it


Can the category of chain complexes be realized as a functor category?

As the title says, is there some sort of category $\mathsf{C}$ which can be thought of as the "walking chain complex", so that the category of chain complexes in some other category $\mathsf{A}$ can be realized as $\mathsf{A}^\mathsf{C}$ (or perhaps some subcategory thereof)?


another go on fractional scaling with 18.04

I read a lot of posts on how to achieve fractional scaling with ubuntu 18.04 and none of them did the trick for me. Like many users, I run ubuntu on a laptop with large resolution (2560x1440) and neither 100% nor 200% scaling from default options look usable. What I tried so far:  gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']" with wayland activated --> Doesn't do anything gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']" with x11 --> Doesn't do anything as well xrandr --output eDP-1 --scale 1.25x1.25 screws up icon sizes and leaves some things like close/maxi-/minimize buttons unchanged font scaling in unity tweak tools, gnome tweaks or tweak tools don't really address the problem  is there any other way to make wayland/x11 accept floats as scaling factor? luggie


I use a custom float example, but some of the code is running longer than a page.  Is there an easy way to split the float across pages?  The definition is as follows:  \floatstyle{ruled} \newfloat{example}{thp}{lop} \floatname{example}{Example}


Impossible to downgrade Mac Pro's operating system to original system

My Mac Pro ( late 2009 custom assembled in Ireland by Apple)   Processor Name:   3.32GHz Quad-Core Intel Xeon Memory:   32 GB Processor Interconnect Speed: 6.4 GT/s Boot ROM Version: MP41.0081.B07 NVIDIA GeForce GTX 680 VRAM (Total): 4096 MB   came originally with Snow Leopard. I still have the original DVD in mind conditions and the DVD disk reader (very seldom used) works perfectly  After I upgraded to El Capitan, I am totally unable to reinstall Snow Leopard in any of the additional disk slots in the machine.  I removed all the hard drives, bought a new 1 TB Seagate drive and installed it in bay 1.  The computer boots with Snow Leopard and allows installation, however after the message telling me the install was successful the Mac doesn't boot - an error message tells me the software is not meant for my particular machine. I tried every kind of keyboards combos I am aware of.  People at the local Apple store told me that I will never be able to go back to Snow Leopard as after Yosemite the system patches the computer ROM making the downgrade impossible.  But I do need Snow Leopard as I have a number of  PowerPC apps and files I need to use.  Any hints please?


What is Work? What does the quantity suggest intuitively?

The mathematical formula for  says that work is force into displacement, but what is the philosophy behind it? I mean what does the quantity suggest?


Fractional scaling in Ubuntu 17.10 gives blurry font

As noted in several posts, the display scaling in Ubuntu 17.10 can only be set to 100, 200 or 300%.  For fractional scaling such as 125, 150%, the work around proposed  works but leave blurry font in applications. It there a way to restore sharp font and still maintain the fractional scaling?


How do I convert simulated values from a copula to "real" observations? R

I have managed to  fit different kinds of copulas to my data in R (mostly Archimedean copulas) using the copula package.  I have no problem simulating pseudo observations (u and v), my questions are:  1) how can I convert these simulated data into values of the random variables I am trying to model? From what I get from Sklar's theorem I should use the inverse of the cdf, is it correct?  2) Assuming I am right in 1), another problem is I do not know which is the right inverse cdf to use, as a first approximation I can assume x and y are normally distributed (which is not entirely true due to fat tails), can't I?  Here is my code:  library(copula)  x <- read.table("x.txt") y <- read.table("y.txt")  mat <- matrix(nrow=100,ncol=2)  for(i in 1:100) {     mat[i,1] <- x[,1][i]     mat[i,2] <- y[,1][i] }  #Actual observations plot(mat[,1],mat[,2],main="Returns",xlab="x",ylab="y",col="blue")  #Copula fitting normal.cop <- normalCopula(dim=2) fit.cop<- fitCopula(normal.cop,pobs(mat),method="ml")  #Coefficients rho <- coef(fit.cop) print(rho)  #Simulate data u1 = rCopula(500,normalCopula(coef(fit.cop),dim=2)) points(u1[,1],u1[,2],col="red")   EDIT: Here you can find the data for x and y should you need them to run the code.   x and y are returns from two stocks


Why do I have files like my_file.txt~ showing in the terminal?

I have files like my_file.txt in my folder in ubuntu system, but when I ls on the command line terminal it shows my_file.txt~ and not my_file.txt. I need to read this file using R program which is causing it to read the file incorrectly in R. What could be the reason it show .txt~ extension in my terminal?


If Cauchy-Riemann equations are satisfied everywhere does that mean the function is analytic?

Let $f(z)=\frac{z^{5}}{|z|^4}$ for ($z\neq 0$) and $f(z)=0$ for $z=0$ then $u$ and $v$ satisfy Cauchy-Riemann equations everywhere but $f(z)$ is not differentiable at $z=0$ which means its not analytical because for a function to be analytic it must be differnetiable everywhere. I am confused because my teacher said that if $u$ and $v$ satisfy Cauchy-Riemann equations then $f(z)$ is analytic but this example proves that this is false. Am I misunderstanding something or is my teacher wrong?


Everytime i try to get the ingredients to make smithing potion but they never work but my alchemy is only level 32


What is the most efficient way to get the values of a previous row in a table using ArcPy?

I am very new to ArcGis and I would like to get a specific value of the previous row in a table.  I found this  here on gis.stackexchange.com and experimented a little bit. However, I found out this modified version:  Pre-Logic Script Code:  import arcpy  def getLastASTDate(tableName):     return [r[0] for r in arcpy.da.SearchCursor(tableName, "date")][-1]   test =   getLastASTDate("name_of_table")   Unfortunately this version doesn’t work and is -- in my opinion -- very inefficient. Do you know any better solutions?


ffmpeg - Overlay one video on to another

I want to overlay one video on to another.I have two videos with same time duration.  Aim is to make upper video little transparent so that one can see whats happening in background video.  I've tried below command :  String command="ffmpeg -y -i /sdcard/videokit/two.mp4 -i /sdcard/videokit/inone.mp4 -filter_complex [0:v][1:v]overlay=100:100:eof_action=pass[v] -map [v] /sdcard/videokit/output.mp4";   In this command upper video isn't matching(In context of height and width) with video at back.  Confusion :  There may be a possibility that background video wont have same height width as upper video cause it comes dynamically in that case how should I manage..!!!  Any help or suggestions would be appreciated.


Why I am not awarded Reversal badge for answering   Question?


Changing Reference List for author year/biblatex

I am using author year together with biblatex. Q: How can I change the reference list: Instead of     Name,S. (1930) Titel etc.   Name2, S2 (year) ....     I would like to have     Name, S.     (1930)  Titel etc.      Name2, S.     (year) , ....     If I have several items for the same author, then the reference list looks similar, but not for the first item.  Thanks ind advance (reference to the manual would be fine)  Here the code:  \documentclass{scrartcl}             \usepackage[style=authoryear,sorting=nyt,backend=biber]{biblatex}             \bibliography{mathematik_bibliothek}   \begin{document}   %%   \nocite{achieser:1975,tao-compactness,tao:analysis1,tao:analysis2,schaefer:tvs}   \printbibliography   \end{document}     There should be a break after Glasmann and the (1975) should be on the next line like in the case of Tao.


local variable is not accesible inside ssh block

#!/bin/sh flag="False" ssh -n  $Domain_1@$IP "$( cat <<'EOT' $flag="True" cat << 'EOT' )"   flag is equal to false before connecting to the remote location.I just want to change the value of flag inside the ssh block after doing some operation in remote location and return the value of flag to my local variable flag. –