Let us consider a homogeneous rope hanging from the ceiling. I will call the vertical direction $x$ and the horizontal displacement $y$. When we apply the second Newton's Law to a portion of mass $\Delta m$ and proceed in the same way we do for a  we get $$\mu\frac{\partial^2 y(x,t)}{\partial t^2}=\frac{\partial}{\partial x}\left[T(x)\frac{\partial y(x,t)}{\partial x}\right].$$ The difference now is that the tension is not constant. Defining $x=0$ at the free end of the rope and orienting it upwards we have the tension $T=\mu gx$. Therefore, $$\frac{\partial^2 y}{\partial t^2}=gx\frac{\partial^2y}{dx^2}-g\frac{\partial y}{\partial x}.$$  So, my issue is that I have seen in a couple of physics books () that the wave speed of this rope is simply  $$v=\sqrt{\frac{T}{\mu}}=\sqrt{gx}.$$ In my opinion these books are either:  i) Cheating the students: they know it is wrong but assume it is right just to show some nice features (the speed would increase as the wave goes upwards).  ii) Had misconception assuming that the usual wave equation are still valid.  iii) Is doing some obscure approximation, which is another cheat if you do not reveal it.  My questions are:  1) Is there an expression for the wave speed for the "wave equation" above?  2) Is there an approximation leading to the wave speed given above?


SQL Server Cardinality Estimation Warning

How can I fix the following cardinality estimation warning? while exists(select 1 from @images) begin    declare @imageid     int    declare @filename    varchar(max)    select TOP (1)       @imageid = [imageid],       @filename = concat([imageid], '.', [extension])    from       @images    order by       [imageid]    ...    delete @images where [imageid] = @imageid end   SQL Server Compatibility Level: SQL Server 2019 (150)


I am learning the wildcards.  I see that  ls *[0-9]* would list all the files/directories with numbers in its names so shouldn't ls *[^0-9]* list all the files/directories without numbers in the middle of its name? I see that some of the files that command listed has numbers.   file1.txt and file1~ were the once that were listed.


Where is the line between programming-specific tools and programming?

Are questions concerning programming tools acceptable for Stack Overflow, or should they be directed towards ?  I ask because it seems the precedent is that questions about git are acceptable, but questions about an editor (ex. Visual Studio) are not...   There seems to be some discrepancy as to what tools are ok to ask about.  Thoughts?


UserInfo.isCurrentUserLicensed method missing in API Version46

Our team had met a problem that when we update the API version to 46, the UserInfo.isCurrentUserLicensed method seems missing. We have reported an issue on the developer forums.   And I'd like to post it here to see whether or not other guys face the same issue with us.  Thansk


Is there a way to check a users SSH key to see if the passphrase is blank

I'm looking to lock down our Solaris 10, RHEL 5, and SLES 11.2 servers. It has come to my attention that some of the users have no passphrase for their SSH keys. Is there a way I can check for this with a script?  Update  Below I have posted the script I wrote from the answer @tylerl gave me. I'm posting this incase someone else needs this info in the future. There is most likely better ways to do this, but this works. I still need to write additional scripts for the accounts that are not automounted. Thanks everyone for all the help  #!/bin/bash # This script is for checking for a blank passphrase. Meaning no passphrase to secure your SSH key. # Script most be run as root. # Example: sudo ./check-sshkeys  mount share:/vol/home /mnt ls /mnt >/tmp/ls for s in `cat /tmp/ls` do echo -e "\e[1m User $s \033[0m "  if ls /mnt/$s/.ssh/id_rsa 2>/dev/null         then grep ENCRYPTED /mnt/$s/.ssh/id_rsa || echo -e "No RSA passphrase"         else echo "RSA key not found" fi if ls /mnt/$s/.ssh/id_dsa 2>/dev/null         then grep ENCRYPTED /mnt/$s/.ssh/id_dsa || echo -e "No DSA passphrase"         else echo "DSA key not found" fi done rm /tmp/ls umount /mnt


Calculating coupon collector problems without replacement. What is the probability of discovering all types for a given number of samples?

Suppose I buy a big box of assorted sweets. There are 10 distinct types of sweets, all evenly distributed in their assortment. I am separating them out into party bags for a party. I make up 100 party bags, each containing four distinct sweets. As such there are 400 sweets in total, with 40 of each variety distributed amongst the bags.  The question is, if I look inside $n$ bags (without replacement), what is the probability that I will have seen every variety of sweet?   I appreciate that if I knew the exact tally of sweet varieties I wanted to find I could use a multivariate hypergeometric distribution. This is a version of the coupon collecting problem but without replacement. It may be that this problem isn't easily analytically solvable? Am I doomed to be unable to do this for such a large dimension of variables? Any advice or input would be greatly appreciated. Perhaps calculating a Chao index is required?


Convergence of series based on iteratively applying the logarithm function

Context From the Riemann criterion, we know that $$\sum \frac 1{n^s}$$ converges when $s>1$. Continuing in the same path, we know thanks to Bertrand series that $$\sum \frac 1{n\ln (n)^s}$$ converges when $s>1$. And so on, i.e. if we note $\ln^{(k)}$ the $k$-th iteration of the logarithm: $$\ln^{(k)}:=\underbrace{\ln\circ\ln\circ\cdots\circ\ln}_{k \text{ times}}$$ then for all $\ell$ $$\sum \left(\ln^{(\ell)}(n)^s\prod_{k=0}^{\ell-1} \ln^{(k)}(n)\right)^{-1}$$ converges when $s>1$. The problem So I was wondering what happens at the limit. Does it go infinity or does it converge ? Let's consider the following series: $$\mathscr S:=\sum_{n=1}^\infty \left(\prod_{\substack{k=0 \\ \ln^{(k)}(n)\geqslant 1}}^{\infty} \ln^{(k)}(n)\right)^{-1},$$ where the apparently infinite product is in fact finite for all $k$. Basically, we take as much logarithm as we can so it doesn't get smaller than $1$. Concretely  We have $\ln^{(0)}(1)=1\geqslant 1$ and $\ln^{(1)}(1)=0< 1$ so we stop there.  And $\ln^{(0)}(2)=2\geqslant 1$ and $\ln^{(1)}(2)\approx 0.69< 1$ so we stop there.  And $\ln^{(1)}(3)\approx 1.1\geqslant 1$ and $\ln^{(2)}(3)\approx 0.1< 1$ so we stop there. $\vdots$  And $\ln^{(1)}(15)\approx 2.7\geqslant 1$ and $\ln^{(2)}(15)\approx 0.996< 1$ so we stop there.  And $\ln^{(2)}(16)\approx 1.02\geqslant 1$ and $\ln^{(3)}(16)\approx 0.02< 1$ so we stop there. $\vdots$   So it starts like this: $$\mathscr S=\frac 11+\frac 1{2}+\frac 1{3\ln (3)}\ldots+\frac 1{15\ln (15)}+\frac 1{16\ln (16)\ln\ln (16)}+\ldots.$$ The question Does $\mathscr S$ converge ? What could work  We can prove Riemann criterion and Bertrand's one using the Cauchy condensation test:  $$\sum f(n)<\infty \iff \sum 2^nf(2^n)<\infty.$$ But I didn't get anywhere.  We can also notice that since we want $n$ such that  $$1\leqslant \log^{(k)}(n)<e$$ we want $n$ sucht that $$e^{(k)}\leqslant n < e^{(k+1)}.$$ So we can rewrite the series: $$\mathscr S:=\sum_{k=0}^\infty \sum_{n=[e^{(k)}]+1}^{[e^{(k+1)}]}\left(\prod_{\ell=0}^{k} \ln^{(\ell)}(n)\right)^{-1}.$$ Therefore, if we take $n\in \{[e^{(k)}]+1, \ldots, [e^{(k+1)}]\}$ we have: $$\sum_{n=[e^{(k)}]+1}^{[e^{(k+1)}]}\left(\prod_{\substack{\ell=0 \\ \ln^{(k)}(n)\geqslant 1}}^{k} \ln^{(\ell)}(n)\right)^{-1}\leqslant \frac{e^{(k+1)}-e^{(k)}}{\displaystyle\prod_{\ell=0}^{k} \ln^{(\ell)}(e^{(k+1)})}=\frac{e^{(k+1)}-e^{(k)}}{\displaystyle\prod_{\ell=0}^{k} e^{(\ell)}}.$$ Now we only need to understand whether or not $$\sum_{k=0}^{\infty} (e^{(k+1)}-e^{(k)})\left(\prod_{\ell=0}^{k} e^{(\ell)}\right)^{-1}$$ converges.


What is $\int_{-\pi}^\pi \cos(nx)\cos(mx)\,dx$?

I'm pretty sure that there's a theorem that says that the Fourier coefficients of a sum of $\cos(nx)$ and $\sin(nx)$ 's are the coefficients of the sum itself.   I tried to prove that in the specific case of $f(x) = \sum_{n=1}^{\infty}\frac{\cos(nx)}{n^2}$. In calculating the Fourier coefficients I got to calculating  $\cos(nx)\cdot\cos(mx)$, but I'm now stuck. Any tips would be appreciated!


How can I color some text green in SO questions?

(For code that is for Ruby on Rails questions on SO)  I have some output in my terminal.  When things work I get a green status line, e..g  Using /Users/durrantm/.rvm/gems/ruby-1.9.3-p125 with gemset dmworkflow   I would like to be able to show that in SO in green, which is the way is appear in the terminal.  This would also be useful for manual red/green coloring of passing/failing tests that people would want to colorize to be easier to read.


When I try to install apache2, I get:  $ sudo apt install apache2 Reading package lists... Done Building dependency tree        Reading state information... Done The following additional packages will be installed:   apache2-data apache2-utils Suggested packages:   apache2-doc apache2-suexec-pristine | apache2-suexec-custom The following NEW packages will be installed:   apache2 apache2-data apache2-utils 0 upgraded, 3 newly installed, 0 to remove and 48 not upgraded. 1 not fully installed or removed. Need to get 339 kB of archives. After this operation, 1,760 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 apache2-utils amd64 2.4.29-1ubuntu4.11 [83.9 kB] Get:2 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 apache2-data all 2.4.29-1ubuntu4.11 [160 kB] Get:3 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 apache2 amd64 2.4.29-1ubuntu4.11 [95.1 kB] Fetched 339 kB in 8s (40.2 kB/s)                                                                     W: APT had planned for dpkg to do more than it reported back (0 vs 19).    Affected packages: apache2-data:amd64 apache2-utils:amd64 apache2:amd64 phpmyadmin:amd64   i think this is the problem  W: APT had planned for dpkg to do more than it reported back (0 vs 19).    Affected packages: apache2-data:amd64 apache2-utils:amd64 apache2:amd64 phpmyadmin:amd64


Read text from a PDF stored in S3 (Python)

I'm trying to read text from a pdf stored in S3. Is there a way to read text from the stream, rather than creating a PDF locally and then converting it.  import boto3 as boto from boto3.session import Session  session = Session(     aws_access_key_id=AWS_ACCESS_KEY_ID,     aws_secret_access_key=AWS_SECRET_ACCESS_KEY )  s3 = session.resource('s3')  obj = s3.Object('my-bucket', 'file.pdf')  text = obj.get()['Body'].read()  print(text)   I've read that this returns a binary string, <botocore.response.StreamingBody object at 0x10d5a0fd0>. But not sure how to get the text from that.  I'm also new-ish to Python.  How do I read this as text so I can parse that text?


Relation between rank and number of distinct eigenvalues

$3 \times 3$ matrix B has eigenvalues 0, 1 and 2. Find the rank of B.  I understand that $0$ being an eigenvalue implies that rank of B is less than 3.  The solution is  (right at the top).  It says that rank of B is 2 because the number of distinct non zero eigenvalues is 2.  This  says that the only information that the rank gives is the about the eigenvalue $0$ and its corresponding eigenvectors.  What am I missing?    Edit  What I am really looking for is an explicit answer to this:      "Is the rank of a matrix equal to the number of distinct non zero eigenvalues of that matrix?"  Yes/No/Yes for some special cases


Register new dynamically created element with existing function, in javascript

I have created a new html element, and inserted it onto a node. However it doesn't have any listeners registered on the class name 'edit-expense-category' because of this. My code for registering this class name on page load is as follows:   $(".edit-expense-category").click(function () {    // function related stuff });   What I'd like to know is once I have another element created dynamically using the class name above, how do I register this element with a listener as well?


Best way to import analog video tape to Mac?

I want to transfer my family's analog video tape collection to digital form on my Mac (mid-2014 MacBook Pro).  Unlike the asker in , my goal is not to identify an inexpensive solution but rather to preserve video and audio quality.  I would prefer to do it myself because besides being naturally hands-on I can't risk these being lost/damaged/not-returned if sent out.  Details  Details of my particular situation follow, but please feel free to provide answers, background, and further considerations useful to future readers with similar but possibly varying needs.   Our working     which has  through which I can still play... Our 20     which are 10 to 15 years old.   How can I best preserve the content of these tapes?   What device and/or software should I use to transfer and convert the videos into digital format? What target video file format should I choose to preserve quality and maximize flexibility?  Electronic-only files are fine with me -- I don't particularly need or want to burn to DVD or Blu-ray.


How to recover my pc or accidentally deleted username

In my Windows 7 Ultimate 64-bit, I was deleting unused usernames in Advanced Profile management window (I could not remember the exact name but there were three buttons: Add, Remove, Properties) which others have created temporarily.   Since I was using shortcut key for Remove button I didn't stop pressing the shortcut key while my username also came to selection and got deleted, furthermore I pressed the OK button for the confirmation dialog box. So tried to recover in the hope of it will be recovered, I create the username account with same username by Computer->Right Click->Manage->Local Users and Groups->Users.  When I restart I realized I no longer have administrator rights. So whenever I try to do administrator things (My password accepts on login, but not when I try to change password in control panel) it asks username and password with administrator privilege.  I am using Dell GX620 PC. I've disabled DVD/USB for standard users. So now I even not able to insert DVD to reinstall the OS.  So How can I retrieve my username or format the OS in this situation?


Conneted normal space having more that one point is uncountable

A connected normal space having more that one point is uncountable.   As I apply Uryshon Lemma to resolve this fact. Thanks.


What's wrong with this : $$e^{i\pi} = -1$$ $$\therefore e^{2i\pi} = 1$$ $$\therefore \log \left( e^{2i\pi} \right ) = \log(1) = 0$$ $$\therefore 2i\pi = 0$$


Lowest volume is still too loud—how can I make it even lower?

The lowest volume I can get by pressing the volume keys is still too loud when I'm wearing headphones. How can I make it even lower?   I have a Mac Mini 2011 (5,1) running Mountain Lion.


Why is binary cross entropy (or log loss) used in autoencoders for non-binary data

I am working on an autoencoder for non-binary data ranging in [0,1] and while I was exploring existing solutions I noticed that many people (e.g., the , ) use binary cross-entropy as the loss function in this scenario. While the autoencoder works, it produces slightly blurry reconstructions, which, among many reasons, might be because binary cross-entropy for non-binary data penalizes errors towards 0 and 1 more than errors towards 0.5 (as ).  For example, give the true value is 0.2, and autoencoder A predicts 0.1 while autoencoder 2 predicts 0.3. The loss for A would be  −(0.2 * log(0.1) + (1−0.2) * log(1−0.2)) = .27752801  while the loss for B would be  −(0.2 * log(0.3) + (1−0.2) * log(1−0.3)) = .228497317  Hence, the B is considered to be a better reconstruction than A; if I got everything correct. But this does not exactly make sense to me as I am not sure why asymmetric is preferred over other symmetric loss functions like MSE.  In  Hugo Larochelle argues that the minimum will still be at the point of perfect reconstruction, but the loss will never be zero (which makes sense). This is further explained in , which proves why the minimum of binary cross-entropy for non-binary values that are in [0,1] is given when the prediction equals the true value.  So, my question is: Why is binary cross-entropy used for non-binary values in [0,1] and why is the asymmetric loss is acceptable compared to other symmetric loss functions like MSE, MAE, etc.? Does it have a better loss landscape, i.e., is it convex while others are not, or are there other reasons?


I want to save paper when I print my LaTeX file. That's why I want to hide all my code, inserted wtih lstinputlisting{}  I already know how to exclude tables and images or math but the lstinputlisting{} is a problem.   Hope someone can help me  \usepackage{comment} \excludecomment{figure} \let\endfigure\relax \excludecomment{table} \let\endtable\relax \excludecomment{align*} \let\endalign\relax \excludecomment{lstlisting} \let\endlstlisting\relax   edit: added lstlisting


The airline allowed us to travel to our destination without checking our visas. Who is at fault for the incurred expenses?

OK, I will try and stick to the facts to explain this whole situation. I would really appreciate everyone's comments:   Me (Irish passport) my wife (Filipino passport) and 2 year old twins (Irish passports) all live in the UK. My wife has residence here. We are flying from Manchester to Doha. We're Planning to stay 3 weeks. As my wife had a UK residence stamp & EEA Family permit visa, we called the UK home office to just verify if she could travel to Qatar without a Visa. They informed us (recorded conversation) that my wife had the same entitlement to me as long as she was traveling with me. I understand now, that our calls should have been straight to the Qatar embassy in London to Verify. We just took it from the UK Home Office as being correct. We arrive at Manchester Airport. We asked the Qatar Airways check in staff to verify my wife's passport to confirm she is entitled to entry in the state of Qatar. Check-in staff confirmed everyone is OK with my wife's passport as we board our 8 hour flight to Doha with our 2 year old twins. We get to Doha and my wife is refused entry at immigration as they say she requires a visa. Calls are made by Qatar airways to Manchester Airport - Qatar airways admit full responsibility for allowing us to travel when we should not have been allowed to travel. We have to re-book flights at Doha - Qatar Airways just changed our return flight to get us back on the next available flight.  We had to pay to enter a lounge in Doha airport with our own money, just so we can give our children some rest and food. We return to Manchester 8 hours later. The twins' double buggy is missing (still missing to date). I understand my wife didn't have the correct Visa, as we were given false information by the UK home office. But, they should not have allowed us to board a plane with those checks being done. If I had known at Manchester airport, I could have made the journey myself with 1 of my children, and I could have processed the Visa for my wife at our hotel in Doha. But, because were not noticed and all allowed to board, I was never given this option. Are Qatar Airways at fault? Should all our flights be re-instated? Are we entitled to compensation? Should they reimburse our expenses?   This is currently being reviewed by the airline. It would be good to get comments and peoples thoughts.


Why is iptable necessary if i can trust my server installation?

I'm trying to get i bit more into security's best practices for my personal knowledge.  Actually i'm not able to understand the necessity of configuring a Firewall like iptable if i can trust my server's setup.  In my actual state of mind, this can be explained this way: If i know that only:   A web server listening on port 80 A ssh server listening on port 22 An api server listening on port 8080   are running on my server, any incoming trafic on my (only) ethernet adapter eth0 that does not use port 80, 22 or 8080 will get lost because there is no process listening on those ports.    This mean nothing consuming the incoming packets, so they are simply droped.  With that in mind, i do not understand the necessity of configuring iptable to accept only tcp traffic on port 80, 22 and 8080.  This was all before i watch this great video:   The video present how to setup an iptable config to do exactly that: Only accept incoming traffic on port 80, 22 and 8080 and drop all others input packets.  I guess that there is a reason to do that, but i can't actually find it.  Can you explain why is this iptable configuration is needed ?  Is there differences between a packet drop by iptable and a packet not 'consumed' by any application running on the server?  Thanks a lot.


Ring of rational-coefficient power series defining entire functions

I'm wondering if anyone has come across the following ring before. Let $R$ be the ring of complex power series $f=\sum_{n \ge 0} a_n t^n$ such that   $a_n \in \mathbb{Q} \: \: \forall \: n$ The function $f: \mathbb{C} \rightarrow \mathbb{C}$ is entire   Any information about it would be welcome but in order to keep the question specific, I'll list a few things I would like to know in particular.   Is $R$ a unique factorisation domain? Are there any elements of $R$ which are known to be prime/irreducible but are not associates of polynomials? If an element $f \in R$ is prime/irreducible, must all its zeroes (in $\mathbb{C}$) be simple? Is every $\alpha \in \mathbb{C}$ a root of some nonzero $f \in R$ ?


I have a problem with PHP. I have a form with input named text. If I send a word with accenture letters like "coupè", the $_POST['text'] return me "coupÃƒÂ¨" also utf8_encode($text).  How is possible? The Db is utf-8 bin.


Oracle: Combine multiple results in a subquery into a single comma-separated value

I'm trying to convert a single-columned subquery into a command-separated VARCHAR-typed list of values.  This is identical to , but for Oracle rather than SQL Server or MySQL.


Execution order of event receivers and workflow on a list

Is it possible to know beforehand whether event receivers on a list will always execute before any workflows associated with that list?


Product of degree of two field extensions of prime degree

Let $L/K$ be a field extension. Let be $\alpha, \beta \in \mathbb{C}$, such that $[\mathbb{Q}(\alpha):\mathbb{Q}] = p$, and $[\mathbb{Q}(\beta):\mathbb{Q}] = q$, for some prime numbers $p$ and $q$. Assume $p \neq q$. Prove that:  $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,[\mathbb{Q}(\alpha,\beta):Q] = [\mathbb{Q}(\alpha):\mathbb{Q}] \cdot [\mathbb{Q}(\beta):\mathbb{Q}]$  I have no idea how to proceed on this, besides proving that the left hand side is $pq$.


How to change font for the integral symbol

I'm looking how to change the integral symbol.  For example:  \documentclass{article} \begin{document} \[\int_a^b f(x) \mathrm{d} dx\] \end{document}   I want to only change the font of \int to get a \rm\int like \mathrm{d} or can I  define a new \rmint using other package, for example arev?  \documentclass{article}  %define a new command for \rm font of int  \begin{document} \[\rmint_a^b \] \end{document}   to get the style of \int is      I have get \rmoint and \rmint by  \DeclareMathSymbol{\rmintop}{\mathop}{rmlargesymbols}{82} \DeclareMathSymbol{\rmointop}{\mathop}{rmlargesymbols}{72}   but I can not get all of integrals as follows:


Count number of rows with conditions met in two columns

I have some Excel columns that look like this.  1774    David                    Not Upheld 1770    James                    Upheld 1771    David                    Upheld 1772    Sam                      Upheld 1768    Arthur                   Not Upheld 1769    James                    Upheld   How can I write an Excel formula for: count the number of rows with 'James' in column B, and 'Upheld' in column C?  I know how to do each of these conditions individually (using COUNTIF), but I'm not sure of the best way to combine them.  Thanks!


SyntaxError: invalid syntax "url = ("https://etherscan.io/address/%s"address)

This is my code for print: "url = ("https://etherscan.io/address/%s"address)" and i got SyntaxError: invalid syntax  My Python version is 3.7 and i'm new to python I think %s is the problem, i'm not what replacement of that in Python 3.7


How to configure axis on pgfplots? Similar for this.  \documentclass{article} \usepackage{tikz,pgfplots} \pagestyle{empty} \begin{document} \begin{tikzpicture}[>=latex] %x axis \draw[->] (-5,0) -- (5,0) node[below] {$x$}; \foreach \x in {-4,...,-1,1,2,...,4} \draw[shift={(\x,0)}] (0pt,2pt) -- (0pt,-2pt) node[below] {\footnotesize $\x$}; %y axis \draw[->] (0,-5) -- (0,5) node[left] {$y$}; \foreach \y in {-4,...,-1,1,2,...,4} \draw[shift={(0,\y)}] (2pt,0pt) -- (-2pt,0pt) node[left] {\footnotesize $\y$}; \node[below left] at (0,0) {\footnotesize $0$}; \end{tikzpicture} \end{document}


In Game of Thrones/A Song of Ice and Fire, bastards have the last names such as Snow, Sand, Flowers, Hill, Pyke, Rivers, Stone, Storm, Waters.  In the event that they are never legitimized what happens when these bastard children become adults? Do they and their offspring forevermore hold these last names or as they grow up do they invent a name for themselves? Would that even be allowed?  Edit Pt2: What happens to unacknowledged bastards? Do they get to make up names too?


Asymptotically unbiased estimator vs consistent estimator

I'm wondering if there is a difference between an asymptotically unbiased estimator and a consistent estimator.   For asymptotically unbiased estimators, the expected value of the estimator converges to the parameter, while for a consistent estimator, the estimator converges in probability to the parameter.   These sound nearly identical, but I believe that being consistent might actually be stronger than being asymptotically unbiased, since being consistent, i.e. converging in probability, implies that not only will the estimates be roughly centered around the true value, but will also be getting closer to it as n increases.   Can someone confirm or refute this claim?


Windows 10 upgrade from Windows 7 broke GRUB

I've looked at other answers regarding this issue but none of them had the same configuration I have so this is new although related to other posts.  I had a dual boot Windows 7 and Ubuntu. What was a bit different than typical is that I had 2 physically separate HDs. The first one had GRUB and Ubuntu, the second one had Windows 7 only. The advantage I had with this setup is that I could physically remove the Ubuntu hard drive and then Windows 7 would boot up normally none the wiser that it used to be booted from GRUB.  After doing a Windows 10 upgrade, things changed. GRUB with Ubuntu hard drive in place still works but if I pull out Ubuntu hard drive, now Windows 10 boot fails with the message GRUB recovery command prompt.  So somehow the Windows 10 upgrade did something to the boot record of the Windows hard drive. I had thought that when I installed GRUB on the Ubuntu hard drive that it only affected Ubuntu hard drive and not the Windows 7 boot disk. Maybe that wasn't true and what was there got corrupted by Windows 10 upgrade.    So now the Windows hard drive has some aspects of GRUB on it that are now corrupted.  Suggestions on how to fix the Windows 10 boot?


Are there any artifically intelligent Starfleet ships?

We know the computer on Starfleet ships has very advanced AI to interact with the crew, but also it can produce very complex simulations in the holodeck with person-to-AI interaction.  So did Starfleet ever design a fully AI vessel for research / combat?  (I would prefer canon-only answers.)


I am trying to find the possible topologies on $X=\{ a,b \}$.   $\varnothing ,\{ a,b \}$ $\varnothing ,\{ a \},\{ a,b \}$ $\varnothing ,\{ b \},\{ a,b \}$ $\varnothing ,\{ a \},\{ b \},\{ a,b \}$   First off, a topology $\tau $ on a set $X$ consists of subsets of $X$ following the properties:   The empty set $\varnothing$ and the space $X$ are both sets in the topology. The union of any collection of sets in $\tau$ is contained in $\tau$. The intersection of any finitely many sets in $\tau$ is also contained in $\tau$   All four I think are actual topologies. Am I correct?


Surprisingly it seems no one asked this before.   Not long ago I asked a question on the site, and in a comment I was asked "what version of jQuery are you using?". The answer is obviously less than 15 characters. So I had to do something like this "I am using version 1.9.1" instead of just "1.9.1".  I see this a lot, so why not allow shorter comments?   I guess the idea is to force people to give more thorough comments and not just small quirks, but I think it reasonable to allow users with a ceratin amount of reputation to give shorter comments, because sometimes it just makes more sense and you don't really need 15 characters


Wasn't Strange tempting fate by telling Stark this?

Since these plot points are fairly important for Avengers: Endgame I'm going to put them all in spoiler paragraphs.  The Avengers are able to       bring back all of the characters who were snapped in the last film, including Doctor Strange. Stark finds Strange in the final battle and asks him about what he saw in Avengers: Infinity War when he saw 1 successful outcome in 14,000,605 and whether they were living in that reality. Strange says that if he were to tell Stark whether they were in that successful version or not then it could not come to pass (or words to that effect).   Later on, at a pivotal moment,       Strange turns to Stark and indicates the number one to him. This prompts Stark to sacrifice himself. However, didn't this violate the very rule which Strange had outlined just a few moments before? Didn't telling Stark that by taking on Thanos he could realise Strange's vision mean that, by Strange's own logic, that Stark should have failed?   So was Strange talking nonsense when he said that      he couldn't let Stark in on the secret? Or is there some other explanation for what happened that I've missed?


C: Why does converting an int to float output 0.000?

I have been working on this quiz:   and don´t understand why casting an int to a float would output 0.000000      #include <stdio.h>     int main()     {             int i = 10;             void *p = &i;             printf("%f\n", *(float*)p);             return 0;     }   Expected output: 10.000000  Actual output: 0.000000  Thank you very much for your help!


When did the 5-foot square/hex become the standard unit of measurement in Dungeons & Dragons?

I was playing with  the other day and noticed a lack of a five-foot-unit of measurement. There are inches, feet, yards, meters and then fathoms (apparently, six feet). This tool seems fairly old, but the  says it was published in 2006.  At any rate, my question is as follows - when did the five foot square/hex become the standard unit of measurement in Dungeons and Dragons? Or, has it always been that? Call me a sucker for accuracy, but I've considered switching to meters more times than just for AutoREALM measurements.


Sequences of arithmetic and geometric mean

I am assuming my teacher wants us to conclude they converge by being bounded and monotone, since part (i) is to show that $a_n$ is monotone increasing and $b_n$ is monotone decreasing.  I am confused though because I have never worked with a sequence defined with... another sequence.


What size breaker and wire do I need to run 2 GFCI receptacles and a flood light on exterior of my house?

Is it OK to use a 15amp breaker and a 14ga wire (14/2 copper) to run 2 GFCI receptacles and a flood light on the exterior of my home? The voltage is 120.  The 2 receptacles are rated at 15amps and won't be carrying a continuous load very often. Might plug a George foreman grill into it every now and then, maybe some party lights. And an occasional power tool (hedge trimmers, weed eater, etc.). I believe the flood lights are 75w a piece.  Should I go with a 20amp/12ga wire instead?  Update**  It is a new circuit so I think I will go with the 20A/12ga just to be safe and I will check the code requirements for having receptacles on the same circuits as lights!  Lets just it is OK to have both receptacles and lights on the same circuit. Is this an acceptable way to wire it? Using a junction box to divert wire towards the outlets and a separate wire to control the flood light with a switch on the same circuit? Pardon my drawing!


“is” vs. “are” in a question involving a collective noun

Is it “What tools is your team using for collaboration?” or “What tools are your team using for collaboration?”?  My normal tactic would be to rephrase the question as a statement and consider “Your team is using these tools for collaboration” vs. “Your team are using these tools for collaboration”, which seems to suggest that “is” is correct here, but something seems awkward about that.


the basemap of QuickMapService changed when exported from print composer layout?

I was trying to export the layout, which was supposed to be like this:    However, the exported image became untidy and unclear because of many secondary information were added, such as those tiny road names or county names.    How do I print the image as it appears in print composer layout?  The basemap is Bing Map from plugin `QuickMapService’.


What is the evolutionary advantage to a lifespan limit?

How/Why  Do Koi have a lifespan of hundreds of years? Do humans have a lifespan of decades? Do dogs have such a short lifespan?  Within these questions I pose further questions.  How does size relate to lifespan. Elephants?  If dogs were to evolve independent of humans (at this point) would they rule the world?


Windows Virtual PC says CPU is not compatible with x64 mode, but Virtual PC is run in a 64 bits OS system

I'm trying to install a WindowsXP 64 bits in Windows Virtual PC. Windows Virtual PC complains:     Attempting to load an x64 operating system, however this CPU is not   compatible with x64 mode. Please install a 32-bit x86 operating   system.   But the whole thing is running under a Windows 7 Enterprise 64 bits. How can this be? What coult it be the problem?


How to sort keys of a dictionnary posted in url?

I have this dict posted in request.POST:  <QueryDict: {u'csrfmiddlewaretoken': [u'fhvpUorGAl7LMv4JIJRd0WOEHPkKn6iN'], u'actor_1': [u'first_actor'], u'actor_5': [u'second_actor'], u'actor_55': [u'third_actor'], u'actor_2': [u'fourth_actor']}>   i want to sort it by the keys to have  <QueryDict: {u'actor_1': [u'first_actor'], u'actor_2': [u'fourth_actor'], u'actor_5': [u'second_actor'], u'actor_55': [u'third_actor'], u'csrfmiddlewaretoken': [u'fhvpUorGAl7LMv4JIJRd0WOEHPkKn6iN']}>   Is there a way to sort keys (not values) of a dictionnary ?


flipping card with increasing probability

In an online game you can buy cards which has a 5% probability to be rare cards. If you don't have the rare card for more than 20 times, the chance of next purchase will increase by 5%, repeat until it becomes 100%. If you have the rare card the probability will reset to default.  Question: what's the chance of having m rare cards in n attempts?  Is there any way to avoid listing possible permutations directly?


I do wonder, due to the peculiarities of the Common Travel Area between Ireland and the UK, if the following hypothetical scenario is possible:  A non-EU citizen flies Boston-Dublin-London with airside transit in Dublin. Will this non-EU citizen undergo an immigration check for the UK at any point? As airside transits, by nature, do not have immigration checks and the final flight (Dublin-London) does not have an immigration check upon arriving into the UK.  This scenario is completely hypothetical, but I just wonder if this happens in real life or not? Thanks


I deleted a licensed application, an sh10.dll file, a $200 program, by mistake and I can't get it back, I can't locate it at all. Resetting to prior date did not work. I called the company and they want to charge me again! I have Windows XP, an older version.  Help!


Quick add on requirement in our project.  A field in our DB to hold a phone number is set to only allow 10 characters.  So, if I get passed "(913)-444-5555" or anything else, is there a quick way to run a string through some kind of special replace function that I can pass it a set of characters to allow?  Regex?


How should I write the command variable to get the expected behavior?  #!/bin/bash  function f ( ) {     echo "$2" } command="f --option=\"One Two Three\" --another_option=\"Four Five Six\"" $command  f --option="One Two Three" --another_option="Four Five Six"   First calling is wrong, second - right  $> ./test.sh  Two --another_option=Four Five Six


Prove that if every subsequence converges to $a \in \mathbb{R}$ then the sequence converges to $a$

This question has been asked. For example: . I am interested in a different way of proving this statement.   A subsequence $(b_k)$ of a sequence $(a_n)$ is  $ b_k = a_{n_k}$ such that $n_k < n_{k+1}$.   (1) With this definition choosing $k = n_k, k = 1,2,3,...$ results in $b_1 = a_1, b_2 = a_2, ..., b_k = a_k$. So by this definition any sequence $a_n$ contains itself as a sub-sequence.   Now if every subsequence $b_k$ converges to $a$, so does the specific subsequence $b_k$ when $k = n_k$. From (1), if every $(b_k)$ converges to $a$ we can choose $k = n_k$, which leads to $(b_k) = (a_k)$ and $(a_k)\rightarrow a$.   Is this proof valid?


I stumbled upon  an intriguing behaviour of a list of string lists in Python 3.7.3. I define the lists of lists as below, and  update an element:      s = [['']*2]*2     s[1][1] =  'why?'     print(s)   It prints:  [['', ''], ['', '']] [['', 'why?'], ['', 'why?']]   I cannot figure out why is not updated the right element. A first thought was to define s = [['    ']*2]*2, with 4 spaces = len('why?'), as elements, but the wrong update persists. Redefining the list s explicitly, and performing the same update as above, I get the right result:      s = [['', ''], ['', '']]     s[1][1]= 'why?'     print(s)   [['', ''], ['', 'why?']]   I'm  working with such lists as lists of  tooltips associated to  large  heatmaps. I can avoid this issue converting the list of n-spaces lists to a np.array, but I'd like to know why the above odd update occurs. Thanks!


Replacing rubber spring/cup under Tab key cap

To make a long question short: What's the proper way to replace a rubber spring (inverted cup-like thing) under a keycap, specifically the Tab key on a unibody design MacBook Pro or Air?    Details: I just bought a used MacBook Pro (so it's out of warranty), and noticed the Tab key felt spongy. Also, after first opening up the laptop, the key seemed to be stuck down until I tapped it a few times.  I had a replacement rubber spring from my old MacBook, so I tore the one off the new laptop and put that one in its place, without gluing it down or anything. Right away after that I noticed that pressing Caps Lock would sometimes trigger a tab; maybe one time in seven or eight presses. Worried I had shorted something, I shut down, repositioned the spring, and booted back up, and things seemed normal again.  Satisfied with the way the Tab key was now behaving, I decided to superglue the spring as instructed :  Squeeze a small amount of super glue onto a sheet of paper. Then dip the edge of the rubber cup into the super glue. Then place the rubber cup in its place. Let it dry. You want to have the minimum amount of glue on your cup, just enough to make the cup stick while installing the hinges onto your keyboard.   I let the glue dry for a few seconds before putting the key cap back on, and while I was waiting I pressed on the spring a few times to make sure it was still springy. Unfortunately, I got way more glue on the spring than I had intended, and it oozed out a little. I also later realized the spring was displaced a little from where the original one had been (as evidenced by the still-visible metal circle under it).  When that was done and I booted back up, I found the key to be better than before, but it still seemed to require a little more pressure than other keys, and it didn't make the same clicky sound when I hit it. I decided to live with that. However, when I opened the laptop again this morning, I found that the Tab key, although it still works, moves up and down very slowly; it takes a second or two to pop back up after I press it. There really isn't any tactile feedback to speak of, so it's worse than when I started. Tapping it quickly a few times didn't cause it to release, the way it used to.  I'm about to order a new rubber spring and hinge kit (and maybe a key cap). How should I install the new spring to make the Tab key act like new again? Is there a specific way I should clean off the old rubber and super glue?


PC automatically booting into windows 10 in dual boot

I have both windows 10 and ubuntu 16 installed on my system.   Lately the system is automatically booting to windows. To boot to ubuntu, I first have to pause startup by pressing escape and then boot into ubuntu.  I know that I have to change the boot order to Ubuntu  but am not able to do so and the grub customiser helps to change only the boot order in grub menu to the best of my knowledge.  What should I do? I am unable to find any way to change the boot order in bios


Processing a single file as both input and output throughout pipes

Good evening,  I would like to filter a file's content with some piped commands and then write the result back to the same file. I know, I can't do that the way I wrote it. Hold on …  This is the piece of bash script I have.  grep '^[a-zA-Z.:]' "$filepath" \     | sed -r '/^(rm|cd)/d' \     | uniq -u \     > "$filepath"   So I thought I could succeed in, using process substitution instead. I then wrote:  grep '^[a-zA-Z.:]' < <(cat "$filepath") | …   This did not solve anything either. I expected process substitution to « save » my input file content somewhere, like in a temporary file. It seams I haven't understood process substitution either.  I read threads about "inplace" edition but these articles highlighted special options of some binaries like sed -i or sort -o but I need a general solution (I mean it has to suit any piped commands).  So first, why 'pipes standard way' cannot do this, what's happening underneath ? :/ And how should I solve my issue ? Could someone please explain me what is this all about ?  Thank you.


Can't draw Plain mono amp with Circuitikz

I want to draw a "plain mono amp" in my circuitikz schematic, but I keep getting this error :  Package pgfkeys Error: I do not know the key '/tikz/plain mono amp' and I am going to ignore it. Perhaps you misspelled it.  I triple checked the manual, this key is supposed to exist, and I don't get what I am actually doing wrong. I am using Overleaf by the way, which should have the latest package of Circuitikz. Here is an example of what is not working : \documentclass{article} \usepackage{circuitikz} \begin{document} \begin{circuitikz}  \draw (0,0) node[plain mono amp]{}; \end{circuitikz} \end{document}


Disable a specific WiFi network from automatically connecting to in Android

I have several WiFi networks setup on my android device. I want most of them to automatically connect, but one specifically I don't want to automatically connect to. I want to manually connect to it only.  I don't want to forget it because I don't want to lose the settings for it.


Why does the nature always prefer low energy and maximum entropy?  I've just learned electrostatics and I still have no idea why like charges repel each other.  I don't quite understand why U has to be minimum. Can someone explain?


Program displaying array class name while using getter method

I just want to scan and display array using getter and setter method.It works fine in setter but when i am trying to call getter method instead of displaying array elements it display array class name. how can i display array elements using getter method??      public class ArrayElements {      private int[] arrayElements;      public int[] getArrayElements() {         return this.arrayElements;     }      public void setArrayElements(int[] arrayElements) {         this.arrayElements = arrayElements;     } }   public class BubbleSort {      public static void main(String[] args) {         Scanner scanner = new Scanner(System.in);         ArrayElements arrayElements = new ArrayElements();         int[] element = new int[5];         System.out.println("Enter Elements :");         for (int i = 0; i < element.length; i++) {             element[i] = scanner.nextInt();         }         arrayElements.setArrayElements(element);         System.out.println(arrayElements.getArrayElements());     }  }   Enter Elements : 10 20 0 45 56  [I@299a06ac


How to search skype chat history for linux beta version

How can I search within skype chat history?  I tried CTRL+F but nothing happens.


What is $E(e^{rX^2})$ when $X~N(0,\sigma^2)$?

This is part of a homework problem. I think I've got it right, but it isn't fitting into the next step, so wanted to check this one. Question: What is $E(e^{rX^2})$ when $X$ is $N(0,\sigma^2)$? My answer: $E(e^{rX^2})=\int_{-\infty}^{\infty}{\frac{1}{\sqrt{2\pi\sigma^2}}e^{-\frac{1}{2}\frac{x^2}{\sigma^2}}}e^{rx^2}dx=\frac{1}{\sqrt{2\pi\sigma^2}}\int_{-\infty}^{\infty}{e^{-x^2(\frac{1}{2\sigma^2}-r)}}dx$ The term inside the integral is just the main part of the formula for a cdf for a normal distribution with standard deviation $\gamma$ where $\frac{1}{2\gamma^2}=\frac{1}{2\sigma^2}-r=\frac{1-2r\sigma^2}{2\sigma^2}$ so it has area $\frac{\sqrt{2\pi\sigma^2}}{\sqrt{1-2r\sigma^2}}$ So, overall: $E(e^{rX^2})=\frac{1}{\sqrt{2\pi\sigma^2}}\frac{\sqrt{2\pi\sigma^2}}{\sqrt{1-2r\sigma^2}}=\frac{1}{\sqrt{1-2r\sigma^2}}$ Is this right?


Should I flag/down-vote "Draft Answers"?

I've been finding "answers" that are slapped together and submitted, with the sometimes explicit intention of "I'm going to edit this".  e.g.   This seems silly, and I think ought to be discouraged.  Is the proper response "oh, how annoying", commenting, down-voting, flagging?  I'm heistant on the last two becuase sometimes they are edited (sometimes within the 5min grace) and become good answers, and then there's an unnecessary dv or flag.


could somebody explain how orthographic scale is calculated in Blender? I am trying to match an orthographic view that I get from another software with that of Blender, but I am not able. Camera gets in the correct position but the zoom level is wrong.  Thanks, byte


$H_1(\mathbb{C}/\Lambda, \mathbb{Z})$ → $\Lambda$ via the map $f:\gamma \mapsto \int_\gamma dz$ is surjective?

Let fix an arbitraly lattice of $\mathbb{C}$ and call it Λ. How to prove $H_1(\mathbb{C}/\Lambda, \mathbb{Z})$ is isomorphic to the lattice $\Lambda$ via the map $f:\gamma \mapsto \int_\gamma dz$ ? If once the map $f$ is proved to be surjective, I finish the proof. I already proved this map is well defined, hom, inj. For arbitrary $nω1＋mω2$ from $Λ$, what is the original image of $f$? Thank you for your help.


I ran sp_Blitzfirst, and it threw back CXPACKET and CLR_SEMAPHORE waits as the top waits for my SQL server.   I know how to fix CXPACKET waits, but how do I go about fixing CLR_semaphore waits?


Tensor product of monoids and arbitrary algebraic structures

Question. Do you know a specific example which demonstrates that the tensor product of monoids (as defined below) is not associative?    Let $C$ be the category of algebraic structures of a fixed type, and let us denote by $|~|$ the underlying functor $C \to \mathsf{Set}$. For $M,N \in C$ we have a functor $\mathrm{BiHom}(M,N;-) : C \to \mathsf{Set}$ which sends an object $K \in C$ to the set of bihomomorphisms $M \times N \to K$, i.e. maps $|M| \times |N| \to |K|$ which are homomorphisms in each variable when the other one is fixed. Then one can show as usual that $\mathrm{BiHom}(M,N;-)$ is representable and call the universal bihomomorphism $M \times N \to M \otimes N$ the tensor product of $M,N$. This is a straight forward generalization of the well-known case $C=\mathsf{Mod}(R)$ for a commutative ring $R$.  Actually, this is a special case of a more general tensor product in concrete categories, studied in the paper "Tensor products and bimorphisms", Canad. Math. Bull. 19 (1976) 385-401, by B. Banaschewski and E. Nelson.   Here are some examples: For $C=\mathsf{Set}$, the tensor product equals the usual cartesian product. This is also true for $C=\mathsf{Set}_*$. For $C=\mathsf{Grp}$, we get $G \otimes H \cong G^{\mathsf{ab}} \otimes_{\mathbb{Z}} H^{\mathsf{ab}}$, using the . (This differs from the "tensor product of groups" studied in the literature). The case $C=\mathsf{CMon}$ is very similar to the well-known case $C=\mathsf{Ab}$ and is spelled out ; namely, we have internal homs and therefore a hom-tensor-adjunction. The same is true for $C=\mathsf{Mod}(\Lambda)$ for a commutative algebraic monad $\Lambda$, see , Section 5.3.  Note that the tensor product is commutative, and that it commutes with filtered colimits in each variable. However, the case $C=\mathsf{Grp}$ shows that it does not have to commute with coproducts. In particular, tensoring with some object is no left adjoint. Also, the free object on one generator is not a unit in general:  Let us consider $C=\mathsf{Mon}$. Then, we have  $\mathbb{N} \otimes M = M / \{ (mn)^p = m^p n^p \}_{m,n \in M, p \in \mathbb{N}}$  The usual proof of the associativity of the tensor product breaks down: There is a map $\beta : M \times (N \otimes K) \to (M \otimes N) \otimes K$ mapping $(m, n \otimes k) \mapsto (m \otimes n) \otimes k$, which is a homomorphism in the second variable. But what about the first variable? The equation $\beta(mm',t) = \beta(m,t) \beta(m',t)$ is clear if $t \in N \otimes K$ is a pure tensor. But for $t=(n \otimes k) (n' \otimes k')$ we end up with the unlikely equation  $((m \otimes n) \otimes k) ((m' \otimes n) \otimes k) ((m \otimes n') \otimes k') ((m' \otimes n') \otimes k')$ $=((m \otimes n) \otimes k)  ((m \otimes n') \otimes k') ((m' \otimes n) \otimes k) ((m' \otimes n') \otimes k')$


How to protect from spoofed SYN flood on a Linux machine?

I have a server (2 x E2620, 32 GB RAM, Debian 6 Linux us-fw 2.6.32-5-amd64 #1 SMP Mon Feb 25 00:26:11 UTC 2013 x86_64 GNU/Linux, 10G Intel Ethernet Card). It has an Nginx proxy server inside. Idea is to use it as a frontend against DDoS attacks. Currently, if faced to a 500kpps spoofed SYN flood, it becomes almost unresponsive. I've already tried syncookies and various sysctl parameters. Even if a half-open connection timeout is 1 second, it is enough to fill up any buffers. Any ideas how to harden it against spoofed syn floods? Maybe, some hardcore configs or fw rules?


How do you describe the following set: $\bigcap_{i=0}^{\infty}(\frac{-1}{i}, \frac{1}{i})$

I've been stuck on this question since last night and the problem I'm having is  I just don't know how to set out the answer or if I answered it correctly.  Question  Describe the following set, and prove your answer correct. (Here brackets denote intervals on $\mathbb{R}$.)  $\bigcap_{i=0}^{\infty}(\frac{-1}{i}, \frac{1}{i})$  Working  As I said I don't know how to set it out, so my answer is simply:  $() \cap (-1, 1) \cap (\frac{-1}{2}, \frac{1}{2}) \cap (\frac{-1}{3}, \frac{1}{3}) \cap ... \cap (\frac{-1}{k}, \frac{1}{k}) \cap ...$  and as for the actual working, I just kind of used my head and it seems like there isn't any working, and it says to prove my answer correct so I don't know what to do for it.  Thanks, any help is greatly appreciated! :)


Example of pairwise but not mutually independent

Give an example of a probability space (Ω,Pr) and pairwise independent events A, B, and C which are not mutually independent.  This is my understanding of what pairwise independent events are: Events $A_1, A_2,..., A_k$ are pairwise independent if for all i,j, $A_i $ and $A_j$ are independent: $Pr(A_i\cap A_j) = Pr(A_i)Pr(A_j)$  Events $A_1, A_2,..., A_k$ are mutually independent if for all $I\subset 1,2,...,k, Pr(\bigcap ._{i\subset I} A_i) = \prod\limits_{i\subset I} Pr(A_i) $ so $ Pr(A_1)\cap Pr(A_2) ... Pr(A_k) = Pr(A_1)Pr(A_2)...Pr(A_k)$


Why is oil a better lubricant than water?

How come mineral oil is a better lubricant than water, even though water has a lower viscosity?    When two surfaces slide over each other with a gap filled with a fluid, the different layers of the fluid are dragged at different speeds. The very top layer touching the top metal surface will have the same speed as the surface itself, while the bottommost layer is stationary. The speed in the layers between is distributed linearly and there exist friction forces between those layers that slow the movement. Those frictional forces should be reduces however, if a fluid with a lower viscosity is chosen.   How come this is not so?   Does it have to do with water's polarity, so that it sticks to surfaces in a different way than oil?


Need an app that tells about file & folder sizes

I need an app that tells about file & folder sizes, like what is the biggest file and/or folder on my hard disk, sort this detail from biggest file and/or folder to the smallest & vice versa, also able to tell me about this detail based on the folder that I have chosen.


font looks thinner in adobe/acrobat reader

Why do fonts look thinner in adobe and different and richer in sumatra pdf.  Sumatra   Adobe   Adobe reader settings:


Find the functions for which the area of the triangle made by tangent at a point is independent of the point

Question: Find the functions for which the area of the triangle made by the two axis and the tangent any point on the function is independent of the coordinate of the point.  Now I approached the problem like this. Let the function be $f (x) $. Hence the slope of the tangent at a point $(h,f (h)) $ is $f'(h)$. Hence the equation of the tangent at that point is \begin{align*} y-f (h)=f'(h)(x-h)& \implies -xf'(h)+y=f (h)-hf'(h)\\ & \implies \frac{x}{\dfrac{hf'(h)-f (h)}{f'(h)}}+\frac{y}{f (h)-hf'(h)}=1 \end{align*} Hence he intercepts of the tangent are $\left(\dfrac{hf'(h)-f (h)}{f'(h)},0\right) $, $ \left(0, f (h)-hf'(h)\right) $. Hence the area of the triangle is $$\frac{1}{2}\cdot\dfrac{ f (h)-hf'(h)}{f'(h)}\times( f (h)-hf'(h))=\dfrac{( f (h)-hf'(h))^2}{2f'(h)}$$ According to the question $\dfrac{( f (h)-hf'(h))^2}{2f'(h)}$ is independent of $h $ and $f(h) $. Which means it is constant (Let $k $). Hence we have to solve the differential equation $$\dfrac{( f (h)-hf'(h))^2}{2f'(h)}=k$$ Now I cant move further. Also am I going in the correct way?


I got a dataset made out of tweets and I need to classify them into topics. For topic modelling with LDA I have cleaned out the dataset (removing stopwords, mentions, symbols, etc). Do I need to remove also retweets in order not to influence the LDA? If so, how should I finally classify all tweets since I could not use per-document-per-topic probability?


A short while ago I had posted about adding a comma to the value once it reached a certain number (1000).   At the moment, the value is going up $11 every second, although I would like to implement a change so that it goes up $11.43 every second.   For example: 0, $11.43, $22.86 ... and then when it reaches $1000 it should have the comma ($1,024.56). You should get the drift.  Here is my jsFiddle:   var millisecs = 1000; setInterval(function() {     var $badge = $('#badge');     var num = parseInt($badge.text().replace(',', ''))+11;     $badge.text(num.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",")); }, millisecs);   Any help will be much appreciated.  Cheers


Proving $x_{n+1}=\sqrt{\alpha +x_n}, x_0=\sqrt \alpha, \alpha>0$ converges.

Picking up from where ...  I have my own take on this proof. I started by showing, by induction, that the sequence is monotonically increasing, and then, also by induction, I showed that the sequence is bounded above by $ x_n<1+\sqrt{a}$. (I can include this if need be) But I want to know if this sequence actually converges to $1+\sqrt{a}$. I know that this sequence is bounded above by this, but I don't know if it is the lease upper bound. Would anyone have any intuition as to prove that, or even where to begin?  Thanks in advance.


Why aren’t remotely-controlled robots used in Star Trek?

While watching Star Trek Into Darkness, the following two scenes looked funny to me.   In the opening scene, Spock almost dies while trying to save a native population from death by volcano. His death is only averted by exposing the population to the sight of the Enterprise, which might or might not be a worse problem, depending on your perspective. Some time later, McCoy and Dr. Marcus go open a torpedo they know little about, with a very real risk of instant death apparently hanging over their heads.   What I find funny is that these are the kind of tasks that could be easily delegated to a remotely-controlled robot. Bomb-disposal units in the present day never send a person to examine a suspicious device if they can use a robot instead. Why do the enterprise crew not make use of this option? Given how stupendously advanced their technology is, you would think they could have a few mechanical gizmos with a radio link to the bridge, so that they could perform this kind of tasks without putting lives at risk.


On a Samsung Galaxy S4 Google Play Edition running 4.4 and non-rooted (I'd prefer not to root a device used for professional development purposes)  Having stored some ebooks on my external SDcard, I decided that I wanted to add some audio as well (as my internal device storage is quite full.)  As far as I can tell not one app (nor adb) can perform any write operations to the external SDcard's root directory.  The one exception that I've found is that my ubuntu computer, can create and rename directories inside /storage/extSdCard/Android/data/ even though none of my apps can.  Is there a workaround for this that doesn't involve rooting the device?


Do the Sith have a sense of humor, do they laugh?

I know that this question is similar to asking whether "Dementors" in Harry Potter can laugh or smile, but still, in the canon do the Sith ever laugh, maybe at least smile? Do they understand jokes and do they have a sense of humor?


How to stitch planar images? (pixel exact, no bluring, no deformation)

i have a sets of images A  Each image (a_i) is a slice of an huge computer generated map-image M_A.  Each image a_j in A overlaps with at least one other image a_k in A. There is no distortion, blur or color difference they overlap pixel perfect and are completely planar.   i need to stitch them together = map M_A. After that i need to find the difference between M_A and an other map-image M_B (gimp)   the last part is no problem: I can put them in 2 layers in Gimp an set one to 'Differece'  the tricky part is the lossless stitching  so:   How do i stitch the overlapping images together without blurring or deformation?   i tried Hugin () - i like it - but it seems it is all about inexact images (taken by Cameras). It forced me to choose a focal length. And after 3h of computation i ended up with a projection of planar objects on a sphere, witch were then projected back to a plane for rendering...


I have installed apache2  mysql php5 in my Computer. Files which are in var/www/html directory run properly. I want to run my Files from my home directory.


Get rid of the power and accessibility options on Windows 8 logon screen

I'm using Windows 8 and I find the power button and the accessibility options very annoying. It's a computer that is in a public place surrounded with kids and they keep on changing the accessibility options and turn off the computer.  Is there a way to remove those two features from the logon screen and make it available for authenticated users only?


What do off-diagonals in density matrix represent?

I am having trouble understanding what off diagonal elememts of a density matrix represent. I know that it tells you the coherence but i dont undetstand why. Like in case of diagonal elements it tells you the probability of finding the system in some state because the diagonal terms are the product of the complex number (associated with the state) times its conjugate which gives the probability, but i dot understand the logic behind saying off-diagonal terms tell us coherence


Which variables should I typecast when doing math operations in C/C++?

For example, when I'm dividing two ints and want a float returned, I superstitiously write something like this:  int a = 2, b = 3; float c = (float)a / (float)b;   If I do not cast a and b to floats, it'll do integer division and return an int.  Similarly, if I want to multiply a signed 8-bit number with an unsigned 8-bit number, I will cast them to signed 16-bit numbers before multiplying for fear of overflow:  u8 a = 255; s8 b = -127; s16 = (s16)a * (s16)b;   How exactly does the compiler behave in these situations when not casting at all or when only casting one of the variables? Do I really need to explicitly cast all of the variables, or just the one on the left, or the one on the right?


Can't find the first/non added value in my generic BinaryTree

im trying to create my own BinaryTree class and i also got a JUnit-Class which outputs the tests for the non added value and the first added value as a Nullpointer..  The Nullpointer occurs in my BinaryTree class at the while-loop, which doesnt make sense to me, as i've got the following lines of code to check it:   if(key.compareTo(current.key) == 0) {            return current.value;       }       return null;   }   The first added value should be checked first (at least i think)  Here is my code:  public class BinaryTree<K extends Comparable<K>, V>{      int count = 0;   //Please don't add any further attributes.   private K key;   private V value;   private BinaryTree<K,V> left, right;   private BinaryTree<K,V> root;   /**    * Constructor creates new BinaryTree instance, initially without child nodes.    */   // Done!!   public BinaryTree(K key, V value){       this.value = value;       this.key = key;       left = null;       right = null;   }    /**    * Stores a key-value pair in the tree.    * If the key has already been stored, then the current value for this key    * is replaced by the new value.    */   public void put(K key, V value) {       BinaryTree<K,V> newNode = new BinaryTree<K,V>(key, value);         if (root == null) {           root = newNode;           root.value = value;           root.key = key;           count += 1;           return;         }         BinaryTree<K,V> current = root;         BinaryTree<K,V> parent;           while (true) {             parent = current;             if (key.compareTo(current.key) == -1) {               current = current.left;               if (current == null) {                 parent.left = newNode;                 count += 1;                 return;               }             } else {               current = current.right;               if (current == null) {                 parent.right = newNode;                 count += 1;                 return;               }             }           }       }     /**    * Returns the value object stored with the given key.    * Returns null if the key is unknown.    */   public V get(K key) {       BinaryTree<K,V> current = root;        while(key.compareTo(current.key) != 0) {            if(key.compareTo(current.key) < 0) {             current = current.left;             } else if(key.compareTo(current.key) > 0) {             current = current.right;                      }        }       if(key.compareTo(current.key) == 0) {            return current.value;       }       return null;   } }


Area of intersection of 4 quadrants present in a square

If I were to draw 4 quadrants of circle inside a square, with each right angle being the angle between the arms of the quadrants, what will be the area of intersection.   Now I've tried this a few times and there's no way to find the area of the inner squarish figure which occurs twice in the intersection.   Finally, a preemptive apology, I am just a 15-year old who is a semi-Maths enthusiast who is unaware of proper terminologies.  The diagram (pardon, sire for 'tis drawn by me):


Printing excess decimal places in python

I run the following code: numero = 80.12 a = int(numero) b = abs(numero) - abs(int(numero)) print(a,b)  And as a result I get... 80, 0.12000000000000455  I don't know what could be the problem of printing excess of decimal places.


I own a 18-55 kit lens for my Nikon D3300. i plan to sell it and buy a 35mm 1.8 prime lens. will it worth. i think there is no much difference in focal range of the both


How do i destroy a specific boundary when inseting

I'm following Blender Gurus tutorial where he instructs to click B during an Inset in order to dissolve a border, but when I click B nothing happens.


How to check if a binary is 32 or 64 bit on Windows?

Is there an easy way to check if a binary is 32 or 64 bit on Windows? I need to check before I move the program to a 32bit machine and experience a spectacular failure.


Was "the mother of all" a common expression before Saddam Hussein used it?

The  popular idiomatic expression  (something) means:         an extreme example of something. Donny's car crash was the mother of all crashes. Hundreds will travel to Stonehenge, the mother of all places to celebrate the longest day of the year.      From: Cambridge Dictionary of American Idioms   It appears that it was originated during a famous speech by the president of Iraq in 1991:  :         Calque from Arabic; popularized in 1991 after its use by Saddam Hussein, then president of Iraq, in reference to the Gulf War as ام المعارك (umm al-ma‘ārik, “mother of battles”).      From: Wiktionary   shows earlier usages  but was the phrase commonly used before 1991, and if not, what alternative idiomatic expression, if any,  was used to convey the same concept?


I noticed that the most recent update of ubuntu offers to install systemd components. I hesitate to allow this update for I had very nasty experience of doing this in debian-testing when services weren't starting and I had no network.  Is it possible to keep the current init system (upstart?) and somehow, on a permanet basis, ignore the offer to install systemd?


Why are there no maps of lands east of Westeros in The Game of Thrones?

The Dothraki come from a land (Essos) that is east of Westeros, and separated by the Narrow Sea. But the map given in the book (A Game of Thrones) doesn't show anything beyond Dragonstone. Is there a reason for this?


If two resistors (5 Ohms & 10 Ohms) are connected in parallel, current will flow through both resistors. Then, assume a parallel circuit (5 Ohms & 0 Ohms), why does current flows to the path with 0 Ohms only and not through both of the paths?


If I want to highlight some words of following frame:  \begin{frame} \frametitle{Paragraphs of Text} Sed iaculis dapibus gravida. Morbi sed tortor erat, nec interdum arcu. Sed id lorem       lectus. Quisque viverra augue id sem ornare non aliquam nibh tristique. Aenean in ligula nisl. Nulla sed tellus ipsum. Donec vestibulum ligula non lorem vulputate fermentum accumsan neque mollis.\\~\\  Sed diam enim, sagittis nec condimentum sit amet, ullamcorper sit amet libero. Aliquam vel dui orci, a porta odio. Nullam id suscipit ipsum. Aenean lobortis commodo sem, ut commodo leo gravida vitae. Pellentesque vehicula ante iaculis arcu pretium rutrum eget sit amet purus. Integer ornare nulla quis neque ultrices lobortis. Vestibulum ultrices tincidunt libero, quis commodo erat ullamcorper id. \end{frame}   what should I do?


How do I simulate a parallel (LPT) Printer with a USB Printer?

I have some legacy software that only prints on printers connected via an LPT port. The machine I need to use, however, doesn't have a parallel port. Plus my printer is a USB device.  How do I trick my computer into thinking my usb printer is hooked up to the lpt port?  Further, this is for an office. I'll have admin rights when implementing the work around, but I'm shooting for a solution that works while a 'regular' user is logged after everything is set up.


Does Maximum Likelihood Estimation always yield the same result as Maximum a Posteriori with uniform prior?


How do I install and use a minecraft mod on ubuntu 18.04.1?  On the internet I have found many descriptions on how to do it (e.g.  and ) but either these instructions are out of date or do not work.   The mod to install is Lucky Blocks which seem to work only for version 1.12. Therefore I already installed a minecraft forge server version 1.12.   But now what? The instruction says to place the mod file (its a zip) into the mod folder. But neither in the client (in ~/.minecraft) nor in the folder where I downloaded the forge version (~/.minecraftForge12) does such a folder exist. So create one? Where? Client or server? And then what to do exactly to use this mod?   I also want other users to be able to join this mod minecraft server from the outside. Do they have to install something? What? Where?   Here are the steps I did:   Installed forge server 12.2 on computer1 Created mods folder inside the forge server 12.2 on computer1 Copied the mod zip file into the mods folder inside the forge server 12.2 on computer1 Launching normal minecraft client. There is no mods to select from.


"Treats of the place where Oliver Twist was born"

What does the word treats mean in this context? I don't think it means entertainment, food, drink etc.. Maybe it is an old usage of this word? Does it mean influencing factors or something like that?  This is the first part of the title of the first chapter of the novel "Oliver Twist" by Charles Dickens. The whole title reads:     Treats of the Place Where Oliver Twist was Born and of the Circumstances Attending His Birth


bash script pass parameters to iterative for loop

I'm writing a bash script to download a BUNCH of data files from a source. The data files all have a numeric portion of their filename to identify their segment, like so: Filename_blahblah_000000 or Filename_blahblah_000024, etc.  I want to open multiple threads, so I can pull these segments in parallel (there are roughly 4200 of them).   Here's my question: Is there any way I can pass input parameters that I can invoke in a for loop? Sample code is below.  Here's the code in "brute force" format. This particular example would pull 3 files: File 000000, file 000001 and file 000002, called as follows:  sr/bin/env bash (initial non-related stuff)  for i in {0..2} do     filenum="00000$i"      ...blahblahblah  done   And here's the result:  % ./data_download-19-x.sh <-- This is the code entered into the command line  Downloading file /blah/file_000000... (stuff happens) Downloading file /blah/file_000001... (stuff happens) Downloading file /blah/file_000002... (stuff happens) (done, everybody happy)   However, I want to be able to pass in the start and end parameters, so the code now looks like this:  #!/usr/bin/env bash (initial non-related stuff)  start=$1 end=$2  for i in {@start..@end} <-- I KNOW THIS IS WHERE THE WRONGNESS IS do     filenum="00000$i"      ...blahblahblah  done   Except now, the end result looks like this:  % ./data_download-19-x.sh 0 2 <-- Notice the 2 input parameters  Downloading file /blah/file{0..2}  Error: Program failed. Exception: File not found   It's interpreting the iterative parameter as the literal string {0..2} instead of processing $start and $end as numbers.   So is there a sneaky way to make bash interpret the values of $start and $end as the bounds of this for loop, or do I have to make a bunch of different files with the bounds hard-coded into them and execute them that way?


I have an object containing multiple models with several IK.  One model has fcurves (euler rotation only) which gives motor to linked IK models.  What I need is bake/convert all IK animations into FCurves.  Is it possible?


Save command output as environment variables

If the command my_command has this output:  VAR1=some_value VAR2=other_value   is it possible to call my_command from a shell script so that both VAR1 and VAR2 are saved as environment variables?  I tried the following ways, and none of them works:  #!/bin/bash source my_command export `my_command`   However if I manually enter  export `my_command`   in a terminal console, then both variables are saved.


How to prevent NullPointerException in Java when referencing object in array which works fine when referenced directly

lblPt1.setIcon(bd.pt1.getImage());   works while  lblPt1.setIcon(bd.pts[0].getImage());   throws a NullPointerException   pts[] is an array containing "Point" objects pt1 through pt24.  I would like to handle it with this for loop where pointLbls[] is an array of JLabels:  for (int i = 0; i < 24; i++)         pointLbls[i].setIcon(bd.pts[i].getImage());   I have determined that it is the object that is null, not its associated image. What am I doing wrong? I am rather new to programming.


Removing all E mails from a gmail (all mail) account

I have read all the current responses, and still do not see an answer, but I too have a desire to remove ALL E mails in the category of "all mail". How do I do this???


I recently organized my modules in /sites/all/modules in 4 differents subfolders: contrib, custom, patches, migration. It works very well, but after using the update manager, the new updated modules appears in /sites/all/modules instead of /sites/all/modules/contrib, so I have to move it manually to contrib. How can I set the default module location to /sites/all/modules/contrib ?  Thanks.


How do I install build-essential without an Internet connection?

I can't install it. Qhen I am installing build-essential_11.4build1_amd64.deb getting error of wrong architecture still I am using amd turion 64 and then i am trying to install build-essential_11.4build1_i386.deb getting error of Dependency is not satisfiable:g++(>=4:4.3.1)   I don't have an internet connection in ubuntu that's why I have downloaded from windows so what to do now?


tabular input by columns (i.e. transpose a table)

I would like to be able to transpose a tabular(x) table like in the following example. It is not necessary to be completely automated, but I don't want to change the data order, which is a painful and stupid. By "not completely automated" I mean that e.g. the headers can be done seperately etc.  Let's see the MWE:  \documentclass{article}  \usepackage{booktabs} \def\Midrule{\midrule[\heavyrulewidth]}  \begin{document}  \centering  \begin{tabular}{*6c}\toprule \bfseries Name & Alice & Bob & Chuck & Dave & Eve\\\Midrule \bfseries Sex & Female & Male & Male & Male & Female\\\midrule \bfseries Age & 18 & 19 & 20 & 21 & 22\\\bottomrule \end{tabular}  \bigskip  Which I want to look like  \bigskip  \begin{tabular}{*3c}\toprule \bfseries Name & \bfseries Sex & \bfseries Age\\\Midrule Alice & Female & 18\\\midrule Bob & Male & 19\\\midrule Chuck & Male & 20\\\midrule Dave & Male & 21\\\midrule Eve & Female & 22\\\bottomrule \end{tabular}   \end{document}     Note: I know that , but I would like to get it without expl3 (mostly because people would might use my code quite often have an old LaTeX installed and I cannot be convincing them to change this).


Creating a large amount of convex polygons using existing coordinates

I downloaded the georeferenced event dataset (top left) from this website:  It consists of coordinates of violent conflicts which differ in time and space. My aim is to connect the coordinates of one country during the same time (say a month) in a way that it forms a convex area. In other words, I want to create a polygon by connection only the outer coordinates with each other. I want to do this for every country for each time period; therefore, only an automatised process will do.  If you would like to see a picture, you can have a look at the code book of the top right(!) dataset. In case you wonder why I don't simply download the top right dataset: The data is only available until 2010, but I need it until 2014.  I work with the trial version of ArcGIS Pro 1.3  I have worked with ArcGIS before, but this is a few years ago and I used it for quite basic procedures.


Maven - Always download the latest version of dependency or plugin

In the pom.xml, I always specify the <version> of the dependency or plugin I am using.  Is there a way to tell Maven I always want the latest version downloaded without explicitly updating the version number every time?


Is there any problems with driving a single 5mm LEDs off of a single or parallel 18650 batteries?

I want to drive one or two small (5 or 10 mm) white LEDs in parallel using one or multiple 18650 3.7vV Li-ion cells. The main reason I want to use the 18650's is, I already have them, they are rechargeable and have a pretty good mAh rating.    Is this as simple as putting a resister and a switch and I'm done? What about when the battery is drained and can only output 2.x volts? Will the light simply not light at that point and we charge the batteries?


After upgrading to 13.10 I'm unable to use Dash. Nothing appears when I type something, I don't see any icons or shortcuts.   Resetting unity does not help, the command is unavailable.  What should I do?


The FAQ says:     Each room has owners, who can change various room settings and transfer ownership to other users.   And:     There are not a lot of responsibilites connected to room ownership, just a few extra permissions: The owner can add and remove RSS feeds being posted into the room, change room name and description, and similar things.   So what is the full extent of their powers?  Plus, besides revoking ownership, do moderators have any more chat room powers than a room owner?


Postgresql POSTGIS not using index field while having GIST index on geometry field

I have around 2M rows on my PostgreSQL table with GIST index on geo_point field but while I try to use ST_Distance or ST_DWithin it is not using the index instead it is doing Parallel Seq Indexed Field: CREATE INDEX rental_properties_geo_point_idx ON rental_properties USING gist(geo_point);  Initial Query: with ST_Distance EXPLAIN SELECT id FROM rental_properties WHERE ST_Distance(ST_Transform(rental_properties.geo_point, 26986), ST_Transform(ST_SetSRID(ST_MakePoint(-115.74181,46.394012), 4326), 26986)) / 1000 < 5 AND rental_properties.published = true  AND rental_properties.usd_price IS NOT NULL  AND rental_properties.usd_price != 0  ORDER BY distance ASC,  rental_properties.review_score DESC, rental_properties.number_of_review DESC LIMIT 12  Explain: ->  Parallel Seq Scan on rental_properties  (cost=0.00..23188911.68 rows=197196 width=1016)       Filter: (published AND (usd_price IS NOT NULL) AND (usd_price <> '0'::numeric) AND ((st_distance(st_transform(geo_point, 26986), '01010000206A6900004204EC0D715A47C1D41445CDFFE54041'::geometry) / '1000'::double precision) < '5'::double precision))  Then I converted it to ST_DWithin as per the suggestion   like below but still, it is not using the Spatial Index Converted Query: with ST_DWithin EXPLAIN SELECT id FROM rental_properties WHERE  ST_DWithin(ST_Transform(rental_properties.geo_point, 26986),             ST_Transform(ST_SetSRID(ST_MakePoint(-80.08713,26.237396), 4326), 26986), 5000::double precision) AND rental_properties.published = true  AND rental_properties.usd_price IS NOT NULL  AND rental_properties.usd_price != 0  ORDER BY ST_DWithin(ST_Transform(rental_properties.geo_point, 26986),             ST_Transform(ST_SetSRID(ST_MakePoint(-80.08713,26.237396), 4326), 26986), 5000::double precision) ASC,  rental_properties.review_score DESC, rental_properties.number_of_review DESC LIMIT 12  Explain: ->  Parallel Seq Scan on rental_properties  (cost=0.00..17763977.78 rows=59 width=1009)       Filter: (published AND (usd_price IS NOT NULL) AND (usd_price <> '0'::numeric) AND st_dwithin(st_transform(geo_point, 26986), '01010000206A690000899A6DDC3A0025C1AE1388EB44622AC1'::geometry, '5000'::double precision))  Another one suggested  to convert it from geometry to geography. So my basic question is how to do a radius search to utilize the index instead of Seq scan.


How much hosting service is enough for hobby site?

I've decided that it's time to get my own domain where I can nonprofessionally communicate on the web. More or less, I would like to set up a blog on a similar level as Coding Horror, and would probably use something easy like Wordpress.  I've set up many a site with generic, cheap web hosts and been disappointed. I am willing to spend a little money but am still very budget-conscious about the features I buy into.  The option that I've most closely been looking at is VPS from a2hosting, for example. They offer "128 MB Dedicated RAM (256 MB Burstable), 10 GB Disk Space, and 100 GB Monthly Data Transfer", with SSH access, for about . Being a UNIX-capable person, I believe that it's important to have root access to some (virtual) server that runs your site. Also, I think that doing this is wise because while all sorts of vanilla hosting services have claims of unlimited traffic, they don't guarantee that a certain amount of RAM will be allocated to your site, or that you will have your own php process. Since it'll be a blog, I don't expect to push many GBs. But in case I did have popular content, I don't want to be embarrassed by the server going down because of low processor allocation.  But I'm second guessing myself, so my concerns are as follows:   Certainly a vanilla web host might set me up with Wordpress and "unlimited" traffic  for about half that price. Is it really worth having SSH/root access, or are the 5-minute Wordpress setups okay? (in other words, are my trust issues unwarranted?) Am I looking at a good web host provider? Will they scale if I grow popular? Is the "dedicated" RAM (only 128mb, but it's something) a real point of value relative to vanilla web hosting? I would have to sign up for an extended contract to get a good rate. Do you think that 10gb storage/100gb traffic will be a lot smaller than it is now in three years?   Remember that I really don't have huge requirements, just want a good-looking site. Thanks.


I'd like to combine the shell bar and the top bar on my desktop for all applications.   I have noted on the screenshot below what I mean by shell bar and top bar.


in some (very rare) cases, it might be desirable to have the type area, particularly the text width, be different on even and odd pages. Let's say we're typesetting a textbook that's supposed to have small illustrations or annotations in the margin of the odd pages -- so we'd need a narrower type area on these. Like this:   Here's an attempt at a solution I came up with. It isn't as smart as I thought it was. I thought we might just combine everyshi and an \ifthispageodd test to change the typearea at every shipout. Obviously, that's not how it works:  \documentclass[paper=a5,pagesize,10pt,DIV=12,twoside=true]{scrreprt} \usepackage{everyshi,blindtext} \EveryShipout{% \ifthispageodd{\areaset{6cm}{12cm}}{\areaset{9cm}{12cm}}}  \begin{document} \Blinddocument \end{document}   this results in:  ! Bad space factor (0). <recently read> \@savsf   l.7 \Blinddocument   Is there a way to improve this? Or something entirely different?


Problem when trying to start Windows from grub boot menu in 18.04

I have a problem when starting Windows using grub (Ubuntu 18.04). The boot screen is messed up. When starting Windows directly [by selecting Windows Boot Manager from UEFI? It doesn't appear in the video.] everything is normal.  I tried changing the resolution in grub from lowest to higher and nothing changed. I have uploaded a video that shows what is happening.


So I'm doing the undo and redo functions using a stack object, but when I try to undo adding a friend to the array list I'm getting this error:  Exception in thread "main" java.lang.NullPointerException     at main.main(main.java:256)   Here's the line where the error occurs in the main:  else if("friend".equals(temp.getAction())) //add friend {     int newFriendUserIndex = facebook.findUser(temp.getUser2());     user.defriend(facebook.getUser(newFriendUserIndex));//Error is here      MyStackObject undo = new MyStackObject(user.toString(), "deFriend", temp.getUser2());     facebook.redoList.push(undo); }   MyStackObject Class  import java.util.*; import java.io.Serializable;  public class MyStackObject implements Serializable {     private String user1 = null;     private String action = null;     private String user2 = null;     private String like = null;     private FacebookUser user;      public MyStackObject(String user1, String action, String user2)     {         this.user1 = user1;         this.action = action;         this.user2 = user2;     }      public MyStackObject(String user1, String like)     {         this.user1 = user1;         this.like = like;     }      public MyStackObject(FacebookUser user, String action)     {         this.user = user;         this.user1 = user.toString();         this.action = action;     }      public FacebookUser getUser()      {         return user;     }      public void setUser(FacebookUser user)      {         this.user = user;     }      public String getUser1()      {         return user1;     }      public void setUser1(String user1)      {         this.user1 = user1;     }      public String getAction()      {         return action;     }      public void setAction(String action)      {         this.action = action;     }      public String getUser2()      {         return user2;     }      public void setUser2(String user2)      {         this.user2 = user2;     }      public String getLike()      {         return like;     }      public void setLike(String like)      {         this.like = like;     }   }   MyStack Class  //EXPLANATION:  public class MyStack implements Serializable {     private java.util.ArrayList<MyStackObject> undoList = new java.util.ArrayList<MyStackObject>();      public MyStack()     {      }        public MyStackObject peek()        {         return undoList.get(getSize() - 1);       }        public int getSize()        {         return undoList.size();       }       public void push(MyStackObject temp)        {         undoList.add(temp);       }        public MyStackObject pop()        {         MyStackObject temp = undoList.get(getSize() - 1);         undoList.remove(getSize() - 1);         return temp;       }        public boolean isEmpty()        {         return undoList.isEmpty();       }  }   Ah well other thing I found as null is this for the undo option:  case 12://Undo                     if(facebook.undoList.isEmpty() && facebook.redoList.isEmpty())                     {                         System.out.println("\n\tNo recent actions have been done yet!");                     }                     else                     {                         MyStackObject temp = null;                         int secondMenu = undoMenu();                         String userName;                         String password;                         boolean match = false;                         boolean quit2 = false;                         Scanner input2 = new Scanner(System.in);                         FacebookUser user = null;   but I'm not sure what to change it too.


ubuntu 16.04 nautilus there is no clickable area in a folder because the folder is full of files

I cannot click on the folder area when the folder is full of files, and thus I cannot right click to open the context menu and for example "launch terminal".    In other words, no matter where I try to click on with right click, it selects the file or folder, and not the current folder itself.  This might be a minor inconvenience but surely it is not meant to be this way? There were some older questions where the answer seemed to be to use specific shortcuts but this is complete nonsense, as I want to open the context menu, not to memorize specific keyboard shortcuts.


What are the relativistic arguments for existence of space?

One of the interpretation of special relativity states that the time is an illusion and does not really exist. This interpretation promoted Einstein himself in his condolence letter after the death of his friend Michelle Besso(but let's set aside if he actually meant this emotional letter seriously). This interpretation takes into account the determinism that the theory contains. Relativity, contrary to the quantum mechanics, is purely deterministic.  However, I would like to know if there are actually any reasons why to suppose the "nonexistence" of time. Why to chose time from the four dimensions that relativity describes? The theory does not explicitly state we should choose the time dimension to be non-existent, the same can be told about space. Yes, relativity brought to life the problem with definition of simultaneity in time, but the relativity of simultaneity in space is much more trivial and older than the time one.   Also, if we choose to accept that the universe is deterministic and expanding, then the apparent freedom of movement is just as big of an illusion as the one of our perception of time. Because if the universe is deterministic, you have actually no freedom in movement through space - you are predestined to move as you move. If we choose to accept the expansion of the universe, we can also say that we are continuously moving "forwards" in space, let's say from a point our particles were at the moment of the big bang. And probably the point is even out of our reach now thanks to the rapid expansion in the first few moments after the big bang.  Is it only our experience from other fields, like the said thermodynamics, that dictates to choose the interpretation in which we treat time as being "non-existent"? Or are there actual reasons within the relativity itself that the time should be treated as such? Or the apparent empirical observation(irrelevant if time should be an illusion and contradicted in the quantum field theory in which we can interpret antiparticles as particles moving backwards in time and the problem of not enough backwards-time-travelling elements of our world gets transformed into the baryon asymmetry problem) that everything moves forwards in time?


I need to add to add the following characteristics to this form but I'm stuck. any help would b greatly appreciated. Thanks      One or more word characters   Exactly one at-sign  One or more word characters  Exactly one period  Two or more characters that are a-z, A-Z, 0-9, period, or hyphen  <!DOCTYPE html>   <html>   <head>   <script>     function validateForm()     {       var x=document.forms["myForm"]["email"].value;       var atpos=x.indexOf("@");       var dotpos=x.lastIndexOf(".");       if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)       {          alert("Not a valid e-mail address");          return false;       }     }   </script> </head>  <body>   <form name="myForm" action="demo_form.asp" onsubmit="return validateForm();" method="post">     Email: <input type="text" name="email">     <input type="submit" value="Submit">   </form> </body>


Draw lines between points from two layers in QGIS

In QGIS 3.10.4 on Mac, I have two multipoint shapefiles: one is "Start" points, and the other is "To" points. Each layer has "x" and "y" coordinate columns in the attribute table. "Start" points only have "location_name" (string) as IDs, and "To" points have ID numbers as IDs. I also merged the two layers, so I have a layer that has both sets of points if needed. My goal is to draw lines between each "start" point and each "to" point. Many plugins in other answers cannot be found now. I'm wondering how can I do so? The points look like the picture below, red dots are Start points, and blue ones are Tos.


Is this a bed bug? Found this on the pillow as I was putting my daughter to sleep

My husband found this small (~4mm long) insect on a pillow while putting my daughter to sleep in our New Jersey (USA) suburb home. We checked our daughter's and our own mattress as well as the rug, but we found no mark or other bugs. No one has recorded any bites. We had bedbugs years ago in another home in another city, but have not seen evidence previously in this home. We moved in about 2 months ago at the end of September. We have not travelled recently due to Covid. We are petrified and will call someone first thing in the morning but need to know


A counter-example for continues functions on Metric spaces

Give a function $f : X \to Y$ such that $(X,d)$ and $(Y,p)$ are metric spaces, and $f$ is continues and one-to-one function and onto $Y$ but $f^{-1}$ is not continues ?  I know that compactness of $X$ must play a role here, because if $X$ is compact then there is no such counter-example, so $X$ must be no compact, but other than this i don't have a direction for the solution, please help.


How can Madara use Susanoo without any eyes?

Something that I am confused about Madara's powers.  When Madara used the Rinne Tensei to bring himself back to life, he did not have his eyes, but he had the First Hokage's face embedded into himself.  Even though he did not have his Sharingan or Rinnegan, he was able to use Susanoo.  Is there any explanation for these two anomalies?    His both eyes were closed at all times, and he had Rinnegan in both his eyes when he was brought back using Edo Tensei. Since his left eye had been destroyed when he was brought back to life using the Rinne Tensei, it is only natural that his right eye too was destroyed.


I have this line of HTML:  <li class="col-xs-6 col-sm-6 col-md-2 filter active" data-filter=".office">   And i want to check if the  ".filter" has class ".active", if it has active class then i need to get its data attribute. I tried like this, but it alerts undefined  if($(".filter").hasClass("active")) {      var activeFilter = $(this).attr("data-filter");     alert(activeFilter); }   What I'm doing wrong?


I just recently completed a neutral run where I experimented seeing how the story would go on if I only killed certain characters (it was my second run, my first run was True Pacifist) and I ended up choosing to kill Flowey instead of letting him live. I planned to start a Genocide run after resetting the game, but Flowey was gone when i did. Flowey is basically the base for each story in undertale (pacifist and genocide) so I know I can't progress any further without him being here. I really just want to start anew and, without Flowey, I dont think I can access True Resets anymore. It may be possible if I did a genocide route, but then I'd have to fight Sans, and that would take FOREVER.  Basically, I am wondering if I can erase all my progress somehow. I heard that True Resets don't erase everything entirely, so is there another way? Please respond, Undertale is the only game I have that's any fun and I don't want to have to buy another game.


I'm trying to add 3 days in a date, like this:  var dat = new Date(2014,9,16);   Thu Oct 16 2014 00:00:00 GMT-0300 (Hora oficial do Brasil)  dat.setDate(19);   Sat Oct 18 2014 23:00:00 GMT-0300 (Hora oficial do Brasil)  Why this not returns this Sat Oct 19 2014 23:00:00 GMT-0300 (Hora oficial do Brasil)?


Use a string variable in MFMailCopose Message

- (IBAction)sendButton:(id)sender {  NSString *locationFormatter = [NSString stringWithFormat:@"https://maps.google.com?saddr=Current+Location&daddr=%f,%f", self.locationManager.location.coordinate.latitude, self.locationManager.location.coordinate.longitude];  if ([MFMailComposeViewController canSendMail]){      MFMailComposeViewController *mailComposer = [[MFMailComposeViewController alloc]init];     mailComposer.mailComposeDelegate = self;     [mailComposer setSubject:@"Google Maps Directions"];     [mailComposer setToRecipients:@[@"castro.michael87@gmail.com"]];     [mailComposer setMessageBody:@"Google Maps Url:locationFormatter" isHTML:NO];      // Display Mail Composer     [self presentViewController:mailComposer animated:YES completion:nil]; }   How do I insert the locationFormatter string in the MessageBody? I was hoping this would work:  [mailComposer setMessageBody:@"%@",locationFormatter isHTML:NO];


How do I tell what version and edition of Windows is on the filesystem?

I am attempting to recover an old computer that won't boot and I'm not sure what version of Windows it is running. How do I tell simply by examining the file system?  I am fairly confident it is either Vista or Windows 7. There is a small chance it is Windows Server 2008.


How do I make a collection dissapear and reappear?

In my animation, I want the destructable object to replace the non destructable clone right before the impact frame, but I cant seem to keyframe the renderability of the collection, any way to fix this or to make a collection dissapear and reappear?