I have my own webserver on my home PC. I also have a mail server too. I have been pointing my paid server to my mail server and I'm just wasting $15 a month for this, so how can I get my domain to point to my server without the paid webhost?

I have to a get a very simple data entry website up and running. This website will be accessed by only a few people at a time (at most), but usually only one person, and not very frequently - maybe a coupel hours at a time, not every day.  I really don't want to pay for hosting if I don't have to. I have AT&T U-Verse Internet Service.   How feasible is it for me to setup a simple Windows/IIS website on my home network that can be accessed publicly? What's the minimum Internet speed I would need? How can make sure that the IP Address for the public website is static, so I can setup my DNS and forget about it?  Any additional thoughts or suggestions on this type of setup would be greatly appreciated. If this is not feasible, or easy, I will likely just go with a hosting service, and I already have one picked out, so I don't need any suggestions for this.


I have a CSV file that has about 20 columns and 50 rows.  I am trying to overwrite the first row so I can change the labels for the columns. I tried to simply open the writer and write on the file from scratch, but it cleared the whole file under the first column then.  Any ideas would be very much appreciated!

I want to loop over the contents of a text file and do a search and replace on some lines and write the result back to the file. I could first load the whole file in memory and then write it back, but that probably is not the best way to do it.  What is the best way to do this, within the following code?  f = open(file) for line in f:     if line.contains('foo'):         newline = line.replace('foo', 'bar')         # how to write this newline back to the file


I want download link of sofwares to download them with a download manager.  Could you please help to find download link of any Linux software?

I have multiple Ubuntu machines at home and a pretty slow internet connection, and sometimes multiple machines need to be updated at once (especially during new Ubuntu releases.)  Is there a way where only one of my machines needs to download the packages, and the other machines can use the first machine to get the debs?  Does it involve setting up my own local mirror?  Or a proxy server?  Or can it be made simpler?


Evaluate $$\sum_{n=0}^{\infty} \frac{n^3}{3^n}.$$  I started my using casework, listing out some terms when plugging values in. $0, \frac{1}{3}, \frac{8}{9}, 1.$ I noticed that there is no common ratio involved in these terms. I'm not sure if I can do any partial fraction decomposition here either. I'm not sure if it telescopes.

friends.  The question is:   Find the value of $ \sum_{n=1}^{\infty} \frac{n^3}{3^n} $. I know this sum converges and that it's value is $ \frac{33}{8} $, however, I can't seem to find it.  I've tried doing $3S-S$ to try and find a pattern, tried using different subtractions, all to no avail.  Any help would be gladly accepted.  Thanks in advance, Pedro


Consider the following LaTeX code:  \documentclass{article} \usepackage{unicode-math} \begin{document} Hello, world! \end{document}   When this code is run with lualatex, it aborts with the following error message:  LaTeX Warning: You have requested, on input line 26, version                `2018/02/21' of package expl3,                but only version                `2017/12/16 L3 programming layer (loader) '                is available.   ! Package xparse Error: Support package l3kernel too old.  See the xparse package documentation for explanation.   If the 2nd line (\usepackage{unicode-math}) is deleted, lualatex compiles the file successfully.  Adding the command \listfiles at the beginning of the file and recompiling, the lines starting with Package: inside the log file are:  Package: expl3 2017/12/16 L3 programming layer (loader)  Package: unicode-math 2018/02/02 vv0.8l Unicode maths in XeLaTeX and LuaLaTeX   My TeX Live Utility does not list any updates to these two packages.

After the latest TeX Live updates I keep getting these errors:  LaTeX Warning: You have requested, on input line 26, version            `2018/02/21' of package expl3,            but only version            `2017/12/16 L3 programming layer (loader) '            is available.   ! Package xparse Error: Support package l3kernel too old.   Any help appreciated.  Solution (from Christian's comment): restore l3packages to the previous version.


I'm playing Minecraft in Survival, and no hostile mobs are spawning! This has been happening for the past week or so. I also tried Creative mode (superflat) and mobs are spawning there.  What would cause mobs to stop spawning in Survival?  Details:   Minecraft 1.7.2 Using Rei's mini map mod Windows Vista Created a new super flat world (creative) and mobs spawn

I have just updated to Minecraft 1.7.4 and now all of a sudden there are barely any mobs spawning.  I checked to make sure that I was in normal difficult and I saw 1 creeper but that is all.  Also I tried different difficulties. Another thing - mobs seem to to spawn normally in the nether and all other mobs except aggressive mobs spawn like they should.  Please if you know how to fix this, please help!


My sister and nephews are coming to the USA to visit me for almost 90 days, and we would like my older nephew (6 years old) be able to go to school. We would like him to interact with other children and learn basic stuff. I am not sure if he could assist to any public or private school while they are visiting us. They are coming from Spain with the ESTA visa. Any information would be much appreciated.  Thank you.

I am British, currently staying in the USA for 6 weeks on an ESTA Visa Waiver. I am living with a local family and whilst here my child (9 years old) has been attending a private (non-state) school with the children of the local family.  Today somebody told me that by having my child attend a private school I may be in violation of the terms of the ESTA Visa Waiver.  I have found nothing about this at   Where can I find official documentation / online advice about this?


I want a document of a Refresh plan for in saleforce . Can someone share, let me know what exactly would need to be in there.   Please let me know the checklist what all should this document have

What steps should be taken after a sandbox refresh to avoid filling up the sandbox storage, sending emails, or outbound messages?   I'm looking for steps to take such as disable scheduled Apex jobs, disable outbound messages, disable analytic snapshots etc.


I want to combine the \equation* command and the \split command into a single macro.  This is what I want to do:  \def\beqn{\begin{equation*} \begin{split}} \def\eeqn{\end{split} \end{equation*}}  \beqn x_1 &=x_0+h\cdot f(t_0,x_0) \\ &=1+(0.1)(2x_0^2+x_0-1) \\ &=1+(0.1)(2+1-1)=1.2 \eeqn   But when I compile I get this error:  Runaway argument? x_1 &=x_0+h\cdot f(t_0,x_0) \\ &=1+(0.1)(2x_0^2+x_0-1) \\ &=1+(0.1)(2\ETC. ! Paragraph ended before \split was complete. <to be read again>                     \par    The problem seems to be with the \end{split}.  If I write the macro with the \end{split} left out and typed out before \eeqn, it works just fine.  Does anyone know  what's going on here?

When I use \def to redefine \end{split}, there is an error.  \documentclass{article} \usepackage{amsmath}  \begin{document} \def\be{\begin{equation}} \def\ee{\end{equation}} \def\bs{\begin{split}} \def\es{\end{split}}  \be     \bs         a\\         b     \es \ee  \end{document}   The error is:      Runaway argument?      a\ b \es \ee       ! Paragraph ended before \split was complete.   However, if I don't use \def\es{\end{split}} and just modify the code to be  \documentclass{article} \usepackage{amsmath}  \begin{document} \def\be{\begin{equation}} \def\ee{\end{equation}} \def\bs{\begin{split}} \def\es{\end{split}}  \be     \bs         a\\         b     \end{split} \ee  \end{document}   it's OK. What's the problem? Thank you!


I want to run a program (WhatPulse) when I login to my Win 8 account. The developers recommend to run it with admin privileges because that will "improve input accuracy". The problem running it as admin at startup/login usually requires a manual confirmation that this is OK. So I'm looking for a way to circumvent that.   In brief: the program (WhatPulse) should start automatically with elevated privileges when I login.  Disclaimer: I know that there are many very questions here but non of them quite solved my particular issue which is a combines several issues discussed in other questions (just for clarification):   The program should automatically run with admin rights It should do so when the user logs in It should circumvent the UAC prompt that usually shows up when running a program as admin This is on Win 8.1

Is there any way to configure application that requires administrator privilages (elevation) so it's automatically started with elevated privileges and does not request elevation on every startup?  For example, I have Riva Tuner that always starts with Windows. And it always asks for elevation via UAC. I need Riva Tuner to silently start with elevated privileges and without any message from user account control (without disabling it).


In my impression, this is very very common in the bible.   But how about scientific writing?

Since I first learned English, I have been holding this understanding that "and", as a conj. but unlike "but",  can only connect two clauses, not two sentences ended with periods.  But recently, I have seen so many prints, either in entertainment or in academia, where "And" is popularly used in the beginning of a sentence. It seems like the author is trying to connect the sentence just right before and the sentence following "And" in some intended meaning which I don't quite get.  I was wondering if I have been wrong all the time, or if there is a new trend that I fail to understand and accept? How to understand such usage of "and" in rigorous English grammar? If I am right, why it is used differently from "but" in terms of what I mentioned at the beginning of this post?


I am trying to understand the equivalence between the logistic function and the softmax function, when k = 2. My understanding is that the following code should output the same values. Where is my mistake?  def sigmoid(x):     x = np.asarray(x, dtype=np.float)     x = 1 / (1 + np.exp(-x))     return x  def softmax(x):     x = np.asarray(x)     x = np.exp(x)/np.sum(np.exp(x))     return x  x = .5 b1 = 1 b2 = -1 sigmoid(x*b1), sigmoid(x*b2), softmax([x*(b1-b2), x*(b2-b2)]) --- Output> 0.6224593312018546, 0.3775406687981454, array([0.73105858, 0.26894142])   Is it because I am assuming that the softmax optimization would find the same betas?

Is it correct to say that binary logistic regression is a special case of multinomial logistic regression when the outcome has 2 levels?


The usual ls command can display the size of files with the option -h and I am having a little doubt about it being display in  or .  For example :  $ ls -lha drwxr-xr-x 2 user group 4.0K Apr  2 21:49 .  drwxr-xr-x 5 user group 4.0K Apr  2 21:49 .. -rw-r--r-- 1 user group 129M Apr  2 21:49 2018-04-02T21:49:08.981976.hdf5   So, this leaves me with 2 questions :   Does ls -lha displayed the size in MB or MiB? Is it consistent across Unix-based operating systems and their own versions over time?   N.B.: Not only commercial Unix-based operating systems should be considered for this question.

[root@pdbosl02 daily]# ls -lrth total 12G -rw-r----- 1 oracle dba 3.8G Dec  7 20:43 BKPOSLPRD_jcns9p1f.F_bkp -rw-r----- 1 oracle dba 4.2G Dec  7 20:46 BKPOSLPRD_jdns9p1f.F_bkp -rw-r----- 1 oracle dba 3.0G Dec  7 20:51 BKPOSLPRD_jbns9p1f.F_bkp -rw-r----- 1 oracle dba 140M Dec  7 20:52 ALG_OSLPRD_jgns9rfr.alg -rw-r----- 1 oracle dba 189M Dec  7 20:52 ALG_OSLPRD_jfns9rfr.alg -rw-r----- 1 oracle dba 202M Dec  7 20:52 ALG_OSLPRD_jens9rfr.alg -rw-r----- 1 oracle dba  42M Dec  7 20:52 c-4249173797-20121207-00 -rw-r----- 1 oracle dba  41M Dec  7 20:52 ctrl_071223   I want to know about h in ls -lrth command.


Let $$f(x,y)=\left \{  \begin{array}{ll}   \frac{x^2+y^2}{sin(\sqrt{x^2+y^2})}  & \mbox{if } 0<||(x,y)||< \pi \\   0 & \mbox{if } x=(0,0)  \end{array} \right.$$  Determine if $f$ is differentiable at (0,0)  Im trying to use that if the partial derivatives exists and are continuous at (0,0) then f is differentiable at (0,0) but i can't conclude. I don't even know if I'm in the right way

Take the function  $$ \begin{cases}f(x,y)=(x^2+y^2)/\sin(\sqrt{x^2+y^2}) & \text{when } 0<\lvert (x,y)\rvert<\pi\\   0 & \text{when } (x,y)=(0,0) \end{cases}$$  I got that this function is differentiable at $(0,0)$. I calculated the partial derivatives at $(0,0)$ of which both were $0$ and trying to show the definition of differentiability is not satisfied but I keep getting that it is. Plz help.


I'm running Ubuntu 9.10 on my server. It works fine, it's just that over time (usually a couple of days) the memory usage just grows and grows until it invariably runs out and needs to be rebooted.  It's running Apache, Samba, ProFTPd, Postfix, Munin & Webmin.   Is there anything that can be done to free up the memory that it doesn't need anymore?

This is a  about how Unix operating systems report memory usage.   Similar Questions:                    I have production server that is running Debian 6.0.6 Squeeze  #uname -a  Linux debsrv 2.6.32-5-xen-amd64 #1 SMP Sun Sep 23 13:49:30 UTC 2012 x86_64 GNU/Linux   Every day cron executes backup script as root:  #crontab -e  0 5 * * * /root/sites_backup.sh > /dev/null 2>&1   #nano /root/sites_backup.sh  #!/bin/bash str=`date +%Y-%m-%d-%H-%M-%S` tar pzcf /home/backups/sites/mysite-$str.tar.gz /var/sites/mysite/public_html/www mysqldump -u mysite -pmypass mysite | gzip -9 > /home/backups/sites/mysite-$str.sql.gz cd /home/backups/sites/ sha512sum mysite-$str* > /home/backups/sites/mysite-$str.tar.gz.DIGESTS cd ~   Everything works perfectly, but I notice that Munin's memory graph shows increase of cache and buffers after backup.  Then I just download backup files and delete them. After deletion Munin's memory graph returns cache and buffers to the state that was before backup.  Here's Munin graph:  Externally hosted image was a dead link.


I have two .c files which I compile over a makefile.  foo.c:  void foo() {     printf("this is foo"); }   main.c:  #include  <stdio.h>  int main() {     printf("this is main\n");     foo(); }   the makefile looks like that:  all: main.o foo.o     gcc -o prog foo.o main.o  main.o: main.c     gcc -c main.c  foo.o: foo.c     gcc -c foo.c   So the question is: how can foo.c use printf() without me including stdio.h AND how can main.c use the method foo() without me including foo.c.  My guess/research is that the makefile works as a linker. But I dont have prove for that and want to understand how this works excactly.  Correct me if I misunderstood something.

Session transcript: > type lookma.c int main() {   printf("%s", "no stdio.h"); }  > cl lookma.c Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14.00.50727.762 for 80x86 Copyright (C) Microsoft Corporation.  All rights reserved.  lookma.c Microsoft (R) Incremental Linker Version 8.00.50727.762 Copyright (C) Microsoft Corporation.  All rights reserved.  /out:lookma.exe lookma.obj  > lookma no stdio.h


Let $R$ be a commutative ring and $S \subset R$ a non empty subset with $0_R \notin S$, and such that $s_1, s_2 \in S$ implies $s_1 \cdot s_2 \in S$. Let $I$ be an ideal of $R$ with $I \cap S = \emptyset$, and such that if $J$ is an ideal which contains $I$ then either $J = I$, or $J \cap S \neq \emptyset$.  I am wondering how to show that $a \cdot b \in I \Rightarrow a \in I$ or $b \in I$.

Let $S$ be a multiplicatively closed subset of a ring $R$, and let $I$ be an ideal of $R$ which is maximal among ideals disjoint from $S$. Show that $I$ is prime. If $R$ is an integral domain, explain briefly how one may construct a field $F$ together with a ring homomorphism $R\to F$. Deduce that if $R$ is an arbitrary ring, $I$ an ideal of $R$, and $S$ a multiplicatively closed subset disjoint from $I$, then there exists a ring homomorphism $f\colon R\to F$, where $F$ is a field, such that $f(x)=0$ for all $x\in I$ and $f(y)\neq 0$ for all $y\in S$.   [You may assume that if $T$ is a multiplicatively closed subset of a ring, and $0\notin T$, then there exists an ideal which is maximal among ideals disjoint from $T$.]  Here is a question I need to answer. For the first part I can show if $x, y$ are not in $I$ then nor does $xy$. The second part is just the field of fractions.   For the third part, I think I need to find an ideal $J$ containing $I$ such $J$ is prime, so that $R/J$ is an integral domain, and use the second part. To find $J$ prime, I think as suggested by the hint, I should go for a maximal ideal disjoint from $S$ containing $I$, but how can I do that?


I've been trying to install .deb chrome file (google-chrome-stable_current_amd.64.deb). It is saved in my Downloads, so I tried this command   sudo apt-get install ~/Downloads/google-chrome-stable_current_amd.64.deb    After reading the package list it responds:  E: Unsupported file /home/stockton/Downloads/google-chrome-stable_current_amd.64.deb given on command line   I don't know why it says E: file, I though Linux drives and files are not named after letters like Windows drives, for example 'C:' but idk I can still be wrong. I did have Windows 10 before I booted Ubuntu.  Any help will be great.

How do you install Google Chrome on Ubuntu?


I was wondering if there are any DDoS defences where a (any) router will block all packets (for any period of time) from the MAC address of its attacker. If so, under what circumstances would this occur?

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


I recently learned that in JavaSript, objects can be created by using function constructors to prevent repeating extra codes, and that there are two ways to add methods and properties to function constructors:  1.Directly typing them in the function constructors:  var Person = function(name, yearOfBirth, job){   this.name = name; // Parameters in the end   this.yearOfBirth = yearOfBirth;   this.job = job;   this.lastName = 'Smith'; }  var john = new Person('John', 1995, 'teacher')    2.Using inheritance to add the methods and properties to the prototype of the function constructors:  var Person = function(name, yearOfBirth, job){   this.name = name; // Parameters in the end   this.yearOfBirth = yearOfBirth;   this.job = job; }  Person.prototype.lastName = 'Smith';  var john = new Person('John', 1995, 'teacher')    What I don't fully understand is the difference between the two ways of adding methods and properties to function constructors. I know that unlike method1, method2 does not directly attach methods and properties to function constructors, but all the objects created by function constructors are still able to access it thanks to inheritance. Also, how could you pass different argument to the function with inheritance?  var Person = function(name, yearOfBirth, job){   this.name = name; // Parameters in the end   this.yearOfBirth = yearOfBirth;   this.job = job; }  Person.prototype.lastName = 'Smith'; **Person.prototype.isMarried= this.isMArried;**  var john = new Person('John', 1995, 'teacher', **true**);   Here, Person.prototype.isMarried= this.isMArried; and   var john = new Person('John', 1995, 'teacher', true); does not work

What's the difference between  var A = function () {     this.x = function () {         //do something     }; };   and  var A = function () { }; A.prototype.x = function () {     //do something };


I have thousands of files in a directory and need to remove a word if exist but not effect other documents without the word "draft" :   Currently ELC.Deeds.to.be.update-2014.draft.xls Rename to ELC.Deeds.to.be.updated-2014.xls  Currently AMC.Tax.time.envelope.client.listing.2013.draft.xls to AMC.Tax.time.envelope.client.listing.2013.xls  Other files like: AMC.Tax.time.envelope.client.listing.2014.xls would not need changing  So I would like to keep the file name and the extension just remove the word draft from any files that contain the word in the file name.  Any assistance would be great thanks.


I am working on a multivariate Gaussian distribution with mean $\mu \in \mathbb{R}^d$ and the variance-covariance $\Sigma \in S^{d\times d}$ where $S$ denotes the set of symmetric matrices.  When I am trying to maximize the log-likelihood of some observations (with respect to $\Sigma)$, I am basically trying to take the first-order conditions, and I need to derive the following:  $$\nabla_{\Sigma} \left( \mu^\top \Sigma^{-1}\mu \right)$$  This derivative is too complicated for me since $\Sigma$ is a matrix.  How can I solve these?

Prove that $$\nabla_{\mathrm X} \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) = - \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}$$   My proof is below. I am interested in other proofs.    My proof  Let   $$f (\mathrm X) := \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B)$$  Hence,  $$\begin{array}{rl} f (\mathrm X + h \mathrm V) &= \mbox{tr} (\mathrm A (\mathrm X + h \mathrm V)^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A (\mathrm X ( \mathrm I + h \mathrm X^{-1} \mathrm V))^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A ( \mathrm I + h \mathrm X^{-1} \mathrm V)^{-1} \mathrm X^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A ( \mathrm I - h \mathrm X^{-1} \mathrm V + O (h^2)) \mathrm X^{-1} \mathrm B)\\ &= \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) - h \, \mbox{tr} ( \mathrm A \mathrm X^{-1} \mathrm V \mathrm X^{-1} \mathrm B) + O (h^2)\\ &= f (\mathrm X) - h \, \mbox{tr} ( \mathrm X^{-1} \mathrm B \mathrm A \mathrm X^{-1} \mathrm V ) + O (h^2)\end{array}$$  Thus, the directional derivative of $f$ in the direction of $\mathrm V$ at $\mathrm X$ is  $$D_{\mathrm V} f (\mathrm X) = - \mbox{tr} ( \mathrm X^{-1} \mathrm B \mathrm A \mathrm X^{-1} \mathrm V ) = - \mbox{tr} ( (\mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top})^\top \mathrm V ) = - \langle \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}, \mathrm V \rangle$$  and, lastly,  $$\nabla_{\mathrm X} \mbox{tr} (\mathrm A \mathrm X^{-1} \mathrm B) = - \mathrm X^{-\top} \mathrm A^\top \mathrm B^\top \mathrm X^{-\top}$$


A logical argument has propositions or axioms which are assumed to be true.  It then has logical statements/manipulations which, if all valid, reach a logically valid conclusion.  If the argument is logically valid, then we can say that the conclusion is true if all the propositions are true. However, the logical validity of the argument says nothing whatsoever (and cannot) about the truth of the propositions.  They are simply accepted as true for the exercise of evaluating the logical validity of the argument.  It would seem to me that all a philosopher can truly do is determine if a philosophical or metaphysical school of thought is logically valid or not.  And adopt, or not, a given school based on your acceptance of the evidence for its propositions.  One can never get to the ultimate truth of any of its propositions, and therefore, can never address the ultimate truth of any of its conclusions.  One can only determine whether a given philosophical school of thought / logical framework / worldview is a logically valid paradigm with which to view the world - that is logically consistent within itself.  For example, as we perceive that the world is more complex than our mind - as we experience our minds - virtually all people accept that  is false based on their own personal experience of reality, but no one has been able to prove (nor do I believe anyone can prove) that solipsism is false.  It can be called "trivial", but not false.    This is illustrated by the conclusion of Dr. Kelly James Clark, in an Essay in which he argues - to the best of my understanding, that belief in God can simply be accepted as a propositional truth, without needing any evidence for it (emphasis added below). His reasoning ultimately is not that there is no evidence for the propositions of the existence of God, but that completely rational people using completely rational reasoning, just plain end up disagreeing on which philosophic system is correct, and no propositional belief can be fully proven.  Neither person is "wrong" from a philosophic standpoint.  All primary beliefs are based to some measure, on faith.     My point is not to make people skeptics. Rather it is my intention to   demonstrate the obvious truth that rational people rationally disagree. What people start with determines what people will end up with. What people reason from determines the kinds of inferences that it is rationally permissible for them to accept. There simply is no belief-neutral, obvious and simple foundation of beliefs to which to appeal in arguing for the existence of God.      (Dr. Kelly James Clark, )     So, what is the answer?  1. Is there any way to "prove" any given logically consistent epistemological system is true?  2. Or is Dr. Clark correct that there is no belief-neutral, obvious, and simple foundation we can base beliefs of propositional truths upon?

I don't understand philosophy very well, and so I am wondering whether you can "prove" anything in philosophy. It always seems you can go a layer down, and find another question, almost endlessly until you get to the question of "why/how/are we here?"  Can you prove, absolutely, and 100% that something is true, in the field of philosophy?


I made this diagram and the only thing I want are two parallel arrows that go from node A to B and vice versa by using pb-diagram package, so that I can label both arrows differently, because both nodes interact.

I have used the next code to get a commutative diagram:  \documentclass[10pt,a4paper]{article}  \usepackage[spanish]{babel} \usepackage{amsmath} \usepackage{tikz-cd}% diagramas  \begin{document}  %-----Diagrama------- \deactivatequoting \[ \begin{tikzpicture} \matrix(m)[matrix of math nodes, row sep=4em, column sep=3em, text height=1.5ex, text depth=0.25ex] { M   &   TN \\     &    N \\ }; \path[->] (m-1-1) edge node[auto] {$\psi\circ Y$} (m-1-2); \path[->] (m-1-1) edge node[left] {$\psi$} (m-2-2); \path[->] (m-1-2) edge node[right] {$\pi$} (m-2-2); \path[->] (m-2-2) edge node[left] {$Y$} (m-1-2); \end{tikzpicture} \] \activatequoting %-------------------  \end{document}   However, I would like two vertical parallel arrows and not a "leftrightarrow".  What is the solution?


In past communications with non-native English speakers, I occasionally see the use of two periods. Some examples:  Ok.. let's meet soon. Sounds good.. Thursday Meeting..  This seems to show up mostly in informal communication. It looks to be some kind of half-ellipsis. Where does this come from and what is the intended meaning?

I am sure that this wouldn't have much meaning, but still want to get acknowledged whether usage of double dots is formal.  I have observed people using double dots in business Emails. Usually while adding additional recipients to the thread. example:  Adding XYZ..  I would like to know the specific meaning of it.  In the world of music, placing double dots .. infront of   note is a shortcut, it signifies addition of its next level note.  EDIT: Does it specify an infinite Pause? Infinite .. I mean by unsure (not never ending).  In general case, if I use this .. in my statement what would it mean?


I getting the wrong result every time I run this program and I feel like an extra pair of eyes would be helpful at 4 in the morning. Can someone please help find where my curly braces or parentheses are off because I cannot find it for the life of me.  System.out.println("Please enter your guess") ;     userGuess = kbd.next() ;     if( userGuess != "a" || userGuess != "b" || userGuess != "c" ||          userGuess != "d" || userGuess != "e" || userGuess != "f" || userGuess != "g" ||         userGuess != "h" || userGuess != "i" || userGuess != "j" || userGuess != "k" ||         userGuess != "l" || userGuess != "m" || userGuess != "n" || userGuess != "o" ||          userGuess != "p" || userGuess != "q" || userGuess != "r" || userGuess != "s" ||          userGuess != "t" || userGuess != "u" || userGuess != "v" || userGuess != "w" ||          userGuess != "x" || userGuess != "y" || userGuess != "z" ||  userGuess!= "A" ||          userGuess != "B" || userGuess != "C" || userGuess != "D" || userGuess != "E" ||          userGuess != "F" || userGuess != "G" ||userGuess  != "H" || userGuess != "I" ||          userGuess != "J" || userGuess != "K" ||userGuess  != "L" || userGuess != "M" ||          userGuess != "N" || userGuess != "O" || userGuess != "P" || userGuess != "Q" ||          userGuess != "R" || userGuess != "S" || userGuess != "T" || userGuess != "U" ||          userGuess != "V" || userGuess != "W" || userGuess != "X" || userGuess != "Y" ||          userGuess != "Z" ) {         System.out.println("Invalid character, please enter your guess") ;     }userGuess = kbd.next() ;

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have successfully converted an existing app's database from SqlServer to Oracle. Everything works fine, but empty strings.  The app normally stores empty strings into the not null nvarchar2 fields which Oracle silently converts them to null and causes the following error:  ORA-01400: cannot insert NULL  Is there any workaround for this?  Note: I'm using Oracle Managed Driver ODP.NET + NHibernate Castle Active Record

I know that it does consider ' ' as NULL, but that doesn't do much to tell me why this is the case.  As I understand the SQL specifications, ' ' is not the same as NULL -- one is a valid datum, and the other is indicating the absence of that same information.  Feel free to speculate, but please indicate if that's the case.  If there's anyone from Oracle who can comment on it, that'd be fantastic!


I've read that in mechanical waves that it's(energy) is proportional to the amplitude squared but in electromagnetic waves it's only proportional to the amplitude, is that really true?

From multiple online sources I read that  $$E \propto A^2$$ but when I mentioned this in class, my teacher told me I was wrong and that it was directly proportional to amplitude instead.   As far as I know, every website I stumbled upon concerning this said that is the case. My teacher has a Ph.D and seems pretty experienced, so I don't see why he would make a mistake, are there cases where $E \propto A$?  I also saw this derivation:  $$\int_0^A {F(x)dx} = \int_0^A {kx dx} = \frac{1}{2} kA^2$$  located , does anyone mind explaining it in a bit more detail? I have a basic understanding of what an integral is but I'm not sure what the poster in the link was saying. I know there is , but it seems way too advanced for me (gave up once I saw partial derivatives, but I see that they're basically the same later on). The first one I linked seems like something I could understand.


I am sorry to be so troublesome and possibly infringing some rules, but could I once more invoke the help of other participants in order to solve my query on the Caldeira-Legget model, namely the introduction of a phase shift, better detailed in ?  Thank you very much. I am so keen to understand this point but got into a "loop" and cannot make sense of it any more...

I am trying to understand the . It considers the Lagrangian   $$L = \frac{1}{2} \left(\dot{Q}^2 - \left(\Omega^2-\Delta \Omega^2\right)Q^2\right) - Q \sum_{i} f_iq_i + \sum_{i}\frac{1}{2} \left(\dot{q}^2 - \omega_i^2q^2\right)$$   where $Q$ is the generalised coordinate of the macro variable (an oscillator with natural frequency $\Omega$), $q_i$ are variables related to an array of harmonic oscillators each with natural frequency $\omega_i$.The first term describes the potentail and kinetic energies related to the macro degree of freedom, the second term describes the coupling using constants $f_i$, the third again describes potential and kinetic energies of the array of oscillators,   $$\Delta \Omega^2 = -\sum_i \left( \frac{f_i}{\omega_i} \right)^2$$   is the ad hoc term my first question relates to. The explanation I found goes      the quantity is inserted to cancel the frequency shift    $$\Omega^2 \to \Omega^2 - \sum_{i} \left(\frac{f_i}{\omega_i}\right)^2$$    [...] the shift arises because a static Q displaces the bath oscillators so that $$f_i q_i = - \left(f_i^2 / \omega_i^2\right)Q$$    Substituing these values for the $f_i q_i$ into the potential terms shows that the effective potentail seen by $Q$ would have a "shifted" frequency.   I regretfully do not get it. I tried to get to the equation   $$f_i q_i = - \left(f_i^2 / \omega_i^2\right)Q$$   by considering the equation of motion in equilibrium, without success. Why would $\Omega$ be affected by the coupling? Also from the intuitive point of view, I fail to see how a "pre-load" would affect the natural frequency of a harmonic oscillator. Any hint would be so appreciated.


Prompt: You want to cut a rectangular pan of brownies, made up of n square-shaped brownies, but you can only make horizontal or vertical cuts.  Assuming you can only make one cut at a time, how many cuts will you need to split the pan into n individual brownies?  Use strong induction to prove your answer. I have no idea how to do this question but I assume it's using pigeonhole principle in the proof. Any help as to how I can solve this? I was thinking to start: The base case of 1 is either 1 slice horizontally or 1 slice vertically to get 2 brownies. Meaning your brownies created are determined by (number of cuts * 2). But I am not sure how to do a strong induction proof for this.

A carpenter has a rectangular board, $x$ feet long and $y$ feet wide, with total area $n = xy $square feet. The board is to be divided into n squares (each 1 foot x 1 foot) by successively cutting a rectangle into two smaller rectangles whose sides are each a whole number of feet. Using strong induction, show that exactly $n -1$ cuts are needed, no matter how the carpenter decides to perform the cuts.  Any help please? I was thinking of maybe trying to write down the possible number of arrangements he can do it but I think it is pointless since it states no matter how it is done.


Whenever a conductor is connected to a cell,what causes the conventional positivecharges inside it to move towards the lower potential level of cell.. My question is whether the charges experience a force due to electric field or all the positive charges in conductor gain higher potential energy and hence flow towards lower potential terminal of cell

This is a sort of a generalized question and not just referring to the flow of current. This includes fluids and many other such entities.  But why does this flow occur. For example if I consider current, then the definition of potential at any point is the work done by external agent in bringing a unit positive charge from infinity to that point. How can we deduce from this definition that the current will flow from higher to lower potential. In fluids, the fluid flows from higher point to lower point. Why so (referring, again to potential)?  Please avoid any analogies in answering the question.


i have done with the salesforce to Kafka already , i have some topics in KAFKA like Ptopic1 ,Ptopic2.  so the thing here is i want live data of some latitude and longitude that comes from MQTT. i am able to send it to the Kafka. why i chosen this because , even if my server down or something wrong, Kafka can hold my data and can be order, and later i can take back. i think my point is clear here.   one more thing here is i was able to directly connecting to MQtt on my Visual force page using some libraries and able to get data and able to plot this on my Visual force page.

I'll confess up front that my knowledge of event architecture is limited:  Can the cometd library that we can use to listen for Streaming API and Platform Events also be used to listen to external (i.e. non-Salesforce) event buses?  We're hoping to make Salesforce a subscriber to replace polling integrations through the REST API.


why the code adding the 3 to all the lists inside a list ? i tried this in python lists = [[]] * 3  print(lists)    print(lists[0])  lists[0].append(3)  print(lists)  output for this code is : [[], [], []] [] [[3], [3], [3]]  Thanks in advance

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


Find the $a < 0$ for which the inequalities $\hspace{0.5cm}2\sqrt{ax}<3a—x\hspace{0.5cm}$ and $\hspace{0.5cm}x-\sqrt{\frac{x}{a}}>\frac{6}{a}\hspace{0.5cm}$ have at least one solutions in common.  I really don't know how to start Please give me a hint Thanks in advance

Find the $a < 0$ for which the inequalities $\hspace{0.5cm}2\sqrt{ax}<3a—x\hspace{0.5cm}$ and $\hspace{0.5cm}x-\sqrt{\frac{x}{a}}>\frac{6}{a}\hspace{0.5cm}$ have at least one solutions in common.  I don't know how to begin Please give me a hint


How can we use grep to get line(s) containing a group of words, while the order of words is not important, although line(s) should contain all words mentioned in search?  I have done that with phasing the search (with piping, saving the outputs in temporary files, and searching again), but I'd like to know if I can do that in one attempt.  Here is a sample; I want to search in the lines below for lines containing sample, words, list:  it's a sample test file for a list of words. list of words without a specific order, it's a sample. line with no search keyword here. list the sample files. something completely different.   And get this result:  it's a sample test file for a list of words. list of words without a specific order, it's a sample.

I've been trying to find a way to filter a line that has the word "lemon" and "rice" in it. I know how to find "lemon"  or "rice"  but not the two of them. They don't need to be next to the other, just one the same line of text.


According to Heisenberg uncertainty principle, position and velocity cannot be measured accurately at the same time. What if we use 2 separate measuring instruments to measure position and velocity at the same time? One for measuring velocity and another one for measuring position. Would this solve the Heisenberg problem? I am sure there are smarter people who have thought of it, so I don't think it will work. May I ask why not?

My understanding is that an observer can measure the precise location of a particle so long as the corresponding uncertainty in momentum measurement is not an issue and vice-versa.    Say there is such an observer, interested in the precise position of a particular particle.  Now, consider a second, independent observer, unbeknownst to the first, who is trying to measure the exact momentum of the same particle without caring about the position.  As a thought experiment, we assume that the two observers are somehow able to access the same particle at the same time in some way without being aware of each other.  Can both observers get their desired results?


I want to solve following problem. I tried to solve it with "Cauchy integral formula" but I couldn't. How can I solve this?!   Suppose $p_0 > p_1 > p_2 > ... >p_n > 0$. Prove that all zeros of the polynomial $p(z) = \sum_{j=0}^n p_j z^j $ lie in the $\{|z| > 1\}$.   It's problem 1.1 in  "A Course in Complex Analysis and Riemann Surfaces(Wilhelm Schlag)".

Let $P(z)=a_0+a_1z+\cdots+a_nz^n$ be a polynomial whose coefficients satisfy $$0<a_0<a_1<\cdots<a_n.$$  I want to show that the roots of $P$ live in unit disc. The obvious idea is to use Rouche's theorem, but that doesn't quite work here, at least with the choice $f(z)=a_nz^n, g(z)=$ (the rest).  Any ideas?


I've just received a letter from Chase saying that my card has been upgraded to no longer have a credit limit, but a "credit access line" (which they can continue to "refer to credit access line [sic] as credit line or credit limit").  Several articles online mention this as a sneaky trap, but what exactly is the problem for someone who checks their spending regularly? Are charges over some limit incurring a higher interest? The only "danger" I've seen is that the card member might be spending more than if they had hit the limit, but I never hit the limit anyway.

My credit card just got "upgraded".  Tucked in among all the notes about new benefits I've got access to is this line:     Please note: Your credit line/credit limit will now be referred to as a Credit Access Line.   Does this change in terminology represent any change in how the credit card works?


While studying about the magnetic properties of matter, my book defines this vector as   $\vec{H}=\dfrac{\vec{B}}{\mu_0}-\vec{M}$  where $B$ is the magnetic field and $M$ is the intensity of magnetisation.  However it did not provide any definition of this new physical quantity whatsoever.

As per :  "The term (Magnetic Field) is used for two distinct but closely related fields denoted by the symbols $B$ and $H$, where $H$ is measured in units of amperes per meter in the SI. $B$ is measured in teslas in the SI."  So, the two are closely related. Why do we need two, then? Could just one be used? As I remember from the university, for vacuum the Maxwell's equations are written usually in terms of $B$, while for media in terms of $H$ (and $B=\mu H$).


I have an Asus K73S laptop with Windows 10 Home v.1809 (personal computer at home).  I never created a user account or password on it.  Windows apparently defaulted to a generic user account named User (located under the User directory as C:\User\User).    I am unable to do anything that requires elevated privileges.  Any attempt to launch a program that requires elevated privileges, or to launch an elevated command prompt, produces a dialog window asking for the administrator username and password, which doesn't work.  I researched how to get administrator privileges and found this article at Windows Central: .  It covers five approaches, which it describes as virtually every method available:   How to change user account type using Settings How to change user account type using Control Panel How to change user account type using User Accounts How to change user account type using Command Prompt How to change user account type using PowerShell   I tried followed every option.    I don't have the "Change account type" button described in the article. The same.  A window appeared asking me to enter a username and password as an administrator, which doesn't work.  The same as #3.  The same as #3.   I'm not an expert,can someone guide me to solve this problem?   Please,suggest any diagnostic that might be helpful.  Edit: This has been marked as a duplicate of .  That question does contain some methods not covered in the article (so apparently, the article was wrong about it covering every method available).    QGravity's answer was covered in the article.  Norbert Willhelm's answer re-enables a user account of a member of the Administrator group, which doesn't apply here.  The accepted answer may apply here, but I should clarify that by "not an expert", I mean I am a computer user and have almost no technical familiarity.  I also use Google Translate to converse here in English.  The accepted answer assumes a certain level of knowledge and familiarity, which I do not have.  While it's possible that this would be a solution, it requires meddling with things that seem unsafe for a total novice.

I accidentally disabled my admin account.  After I login to another account I found I can not get admin rights, because all admin accounts on my computer are disabled.  I clicked on 'run as administrator' but only see a smart card choice (all the admin accounts are disabled so no choice provided)    I don't want to re-install my OS, help!    Details:  I have account A on my computer.    I got a new computer so I want to give the old one to my mother.    Creating a new user account B for her and disable account A.    Logout and restart.    Successfully login B, now I found I could not get admin rights because no account choice is provided.    More informations about my machine:  OS is Windows 10 and my admin account is a Microsoft Account.  I have an arch-linux installed on my computer and dual-boot it using GRUB, so maybe I can not use safe mode.


I wanted to assign some specific actions when clicking on one of the images I have inserted in my Excel sheet. The problem is, I got 52 images (Poker cards for those wondering). So, my question is, is there any way to avoid writing code for 52 cases, and find a way like below:    Private Sub Image(x)_Click()    Call common_subroutine(x) End Sub   , instead of writing the same thing 52 times, one for each different image name? Since I use the same subroutine to do the work with a variable according to the case, the load of work won't be that big if there's no way to do it, but it surely bothers me whether this obviously silly way is the only one possible.

I have asked this question before, but admittedly in a terrible way, so I am asking this again. So here I am once more.    I am making a program in VBA Excel - or better, combining a certain worksheet with actions and parts of code to make something that works like a stand-alone program. Part of it involves the  binding of a number of images (tens of them) to a certain macro, on click.    I have created the said images through the "Developer"->"Design Mode" button. The images are named in the fashion: Image1, Image2, Image3... etc. What I want is, if, for example, I press Image1, the subroutine Action(1), is called. If I press Image100, I want the subroutine Action(100) to be called. Therefore, I want to call the Action Subroutine passing a value according to which image is clicked, in the example I gave you, according to its name.    With a quick search, the first way I found out to make this work was the one below:  Sub Image1_Click()      Call Action(1) End Sub   That was for a click on Image1. For a click on Image100, that would be:    Sub Image100_Click()      Call Action(100) End Sub     The downside of using solely this way is obvious: I would need to create as many on-click handlers as the images I have, even though the same routine is called every time and all that matters to get the value to be passed is the image name.    So, given the obvious order of my logic and of what I want to achieve, I would like you to provide me with a more clever way to create on-click events for all my images, without having to use so much redundant code and an obviously not-optimal logic.  NOTE:In case of confusion, the Action Subroutine IS the same for all images. Only the value passed changes.


I have a string that is in ALL caps originally and I want it to be title case:     THIS IS MY STRING WHY AM I YELLLING?   And I want it to be:     This Is My String Why Am I Yelling?   I can't use css text-transform:capitalize when the letters are in CAPS initially. So I know I have to use JS. I tried this, which works but I'm not sure it's very efficient:   $('.location').each(function () {      var upper = $(this).html();     var lower = upper.toLowerCase();     $(this).replaceWith(lower);   });   And now that my letters are actually lowercase, I use CSS text-transform:capitalize.   Is there a more efficient way to do this? (I'm already using jQuery on the site, so that's why I've used it above.)  Thanks!

Is there a simple way to convert a string to Title Case? E.g. john smith becomes John Smith. I'm not looking for something complicated like , just (hopefully) some kind of one- or two-liner.


import numpy as np  for _ in np.arange(0, 10, 0.01):     print(_)   Why are there outputs that suddenly have so many decimal places? Is it some kind of rounding off error? [I'm new to python and coding in general. I have snipped a picture for reference] :D

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Today I noticed in my inbox that I had been granted several privileges, for which I don't have the reputation necessary.  I still can't perform the functions allowed by the privileges, and my reputation has not increased.  I have a feeling this may be a bug, but I'm not sure.  Has this happened to anyone else?  The messages I received are as follows:     Congrats, you've gained the privilege – create wiki posts learn more   Congrats, you've gained the privilege – participate in meta learn more   Congrats, you've gained the privilege – vote up learn more   Congrats, you've gained the privilege – flag posts learn more   Congrats, you've gained the privilege – remove new user restrictions   learn more

On the main Stack Overflow site, I arrived and had a banner: "Congrats, you've gained the privilege – create wiki posts and 3 other privileges" This confuses me, because I only see two privileges listed at 100%. Is the banner just buggy?  Or is there a better place to see my privileges that the page linked to by that banner?


In Grimmet and Strizaker's Probability and Random Processes it states section 1.2  The power set of $\Omega$, which is written $\{0,1\}^{\Omega}$ and contains all subsets of $\Omega$....  It goes on to use this in an example as follows:  A die is thrown once. We can take $\Omega$ = $\{1,2,3,4,5,6\}$, $F = \{0,1\}^{\Omega}$  Here $F$ is the set of all subsets of the sample space $\Omega$ which are of interest. I don't understand this notation to specify that set. How does it generate/enumerate all the subsets of interest?

Let $ D = 2^\mathbb{N} $, i.e., D is the set of all sets of natural numbers.   What's the meaning of this definition? Intuitively, I would suggest that $ D = \{1,2,4,...\} $ but the explanation "set of all sets" leads me to the guess that this is wrong.


How do I approach this problem? I know the formula but do not how it had come. Could you please explain to me the procedure, with examples if possible.

I reading my textbook and I don't understand the concept of distributions or number of solutions to an equation.  It's explained that this problem is 1/4 types of sampling/distributions problems.  An example is provided to illustrate:     In how many ways can 4 identical jobs (indistinguishable balls) be distributed among 26 members (urns) without exclusion (since one member can do multiple jobs)?      A sample outcome might be:   $\text{_____________}$   |  A  |  B  |  C  |...|  Z  |    $\text{--------------------}$      $\text{_____________}$   |  o  | oo|    |   |    ||| o  |    $\text{_____________}$   |  A  |  B  |  C  |...  |  Z  |    $\text{--------------------}$      Thus, the question is reduced to, "How many $(26-1+4)$ letter words are there consisting of four circles and $(26-1)$ vertical lines?"  Therefore, the solution is:  $\binom{26-1+4}{4}$   I really don't understand why its $(26-1+4)$.  There's only 26 different spots or "urns" to place the 4 jobs.  Can someone please explain?    I looked through another text to try and understand and I found it explained as such:       There are $\binom{n+r-1}{r-1}$ distinct nonnegative integer valued vectors $(x_1,...,x_r$ satisfying the equation $(x_1 + ... + x_r = x_n$ for $x\ge0$. $\spadesuit$   How in the world are they deriving this?  For distinct positive integers I understand:  Assume I have 8 balls (n=8) and I have 3 urns (r=3): o^o^o^o^o^o^o^o, where o represents  a ball and ^ represents a place holder where an urn could be placed.  For this scenario:     There are $\binom{n-1}{r-1}$ distinct positive integer valued vectors $(x_1,...,x_n)$ satisfying the equation:  $x_1 + ... + x_n = n, x_i>0, i=1,..,r$ $\clubsuit$   It's clear that I could have this specific case ooo|ooo|oo.  Here the bar represents a divide for the urn and you see I have 3 sections.  So that case is clear.  Can anyone please explain this problem to me?  I don't understand the nonnegative integer case.   Also, people who post tend to be crazy smart and explain things very in a complicated manner.  I'd appreciate it if it could be explained in layman's terms as much as possible.   Thank you!!!


When i try to use the move i.e. Slide.move(1,0) i get the error:  non-static method move(int,int) cannot be referenced from a static context  This is my code at the moment, which i have no idea whats wrong.      public void move(int row, int col) {         char [][] temp= new char [cells.length][];          for (int i= 0; i< cells.length; i++) {             int destRow = (i+row)%cells.length;             temp[destRow] = new char [cells[i].length];             for (int j= 0; j < cells[i].length; j++)                 temp[destRow][(j+col)%cells[i].length] = cells[i][j];             }               cells= temp;         }      }

The very common beginner mistake is when you try to use a class property "statically" without making an instance of that class. It leaves you with the mentioned error message:     You can either make the non static method static or make an instance of that class to use its properties.   Why? I am not asking for solutions. I would be grateful to know what is the reason behind it. The very core reason!  private java.util.List<String> someMethod(){     /* Some Code */     return someList;             }  public static void main(String[] strArgs){                // The following statement causes the error. You know why..     java.util.List<String> someList = someMethod();          }


In one city, $N$ Petya, Vasya and Tolya hide from zombies in an underground bunker. But they have no connection with the outside world and they don’t know if the zombies remained in the city or left. They decided that someone needs to go out and find out the situation. they will throw a coin. Think about how to organize the tossing process so that they have an equal chance of being on the surface?   I tried to count the probabilities but nothing came of it . Please help to solve it.

Suppose that there are 3 players and 1 fair coin.  Devise a strategy such that we can have a clear winner. The coin can be tossed any number of times and the probability of winning for each candidate must be same.


I am trying to fetchAll() an array for rows in my database that are from a certain category.  <?php  require 'database.php';  $class = $_GET["class"]; $classes = $conn -> prepare("SELECT * FROM items WHERE class = $class"); $classes -> execute(); $all_items_from_class = $classes -> fetchAll(); ?>    On the previous page I want the user to click on a category and lead him to a page where it loads all items of that specific category, the URL will show something like website.com/category.php?class=bla and display all items from that specific class. After trying different foreach loops and not getting any results, I checked with a var_dump() to see what is wrong with the array $all_times_from_class and to my surprise it returns a completely empty array.  When I remove the WHERE from SELECT it returns the entire array of all items, but for some reason it does not with WHERE. I used $_GET in the same way in another .php file and it works fine there, but not when I try to $_GET the class. Why does it not return an array for that specific category? Does it not recognise what class to get from the URL, does it not work for VARCHARs in the database? I'm at a loss at the moment. The only fix I know would be to foreach() the entire database and run every row through an if.

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


Only my second question here so quite the noob, thanks for your expertise. I've been waiting for the automatic upgrade via Software Updater to Ubuntu Studio from 18.04, told it would be ready with the first point release July 23, then August 6, then the week after, then finally tried to do it manually only to be told: There is no development version of an LTS available. To upgrade to the latest non-LTS develoment release set Prompt=normal in /etc/update-manager/release-upgrades. Must I wait longer? til when exactly? or do I need to upgrade to an 'older' non-LTS version first? It seems my updates lately have been components of the new build, 'dummy' packages IIRC. I've been careful, upgrading only to LTS builds but I'm hitting a snag here. FWIW I'm on a Thinkpad X230. Some clarity would be much appreciated.

I want to use do-release-upgrade to upgrade from 18.04 to 20.04, but I can't do that do-release-upgrade Checking for a new Ubuntu release There is no development version of an LTS available.  It seems that  is used, and it still points to 18.04. Do you know when (or how?) can I upgrade to 20.04?


I'm trying to understand something about electricity. Is electricity being wasted when you use it?  I mean when you use an electrical appliance, you need to plug it into a socket right? So you create a circle, where electricity goes into your device and returns back into socket... So does any of electricity actually wasted by the device, or does it just go through the device?  Understand what I mean? What the difference between electricity traveling through power cables, or traveling through a TV or a washing machine?

All i know is electric current travels in a loop. So how / where in its way does electricity (electric energy) get wasted?  And what do we do on switching electric appliances off? If it's not electric current that is wasted then what is it?


Could you explain me simply why (3**2000 is 3**2000) is evaluated as False?

Why does the following behave unexpectedly in Python?  >>> a = 256 >>> b = 256 >>> a is b True           # This is an expected result >>> a = 257 >>> b = 257 >>> a is b False          # What happened here? Why is this False? >>> 257 is 257 True           # Yet the literal numbers compare properly   I am using Python 2.5.2. Trying some different versions of Python, it appears that Python 2.3.3 shows the above behaviour between 99 and 100.  Based on the above, I can hypothesize that Python is internally implemented such that "small" integers are stored in a different way than larger integers and the is operator can tell the difference. Why the leaky abstraction? What is a better way of comparing two arbitrary objects to see whether they are the same when I don't know in advance whether they are numbers or not?


How do I see the total amount of items I have in my SharePoint List? preferably on the view screen.

I have a lot of list views.  Each view is displayed having group by name such as pending, working, complete ,......  I need to count each item inside group.  I need camel query in c#  to count each group have once i pass parameter(siteurl,listname,viewname)


I've just returned from a trip.  One of the locations was very dark site. I took a photo with 4 minutes exposure for the foreground. The photo came out unusable. There are so many red, green, and white hot pixels. It's beyond photoshop clean up.  Is there a way to photograph such a dark foreground without getting hot pixels? I've heard that stacking multiple photos with lower (relatively) ISO + 30 sec shutter speed might work. How does that work and are there any other ways to prevent hot pixels other than using a film camera?

I discovered red/blue/white pixels on my night photographs tonight. Trying to confirm this, I took a black image with the lens on and indeed I saw a whole lot of them (I didn't count them but at least a good fifty on the whole picture).   I'm not exactly sure if they are hot pixels, stuck pixels or anything else.  I quickly gave a check to my last exported JPEG files (I get RAW out of the camera) and couldn't find anything. After a quick search, I've seen that Lightroom is caring about those pixels after RAW conversion.  I've read that, with Canon DSLRs, there is a software process that could take care of that directly on my camera. I don't know if I can use it without getting things even more messy.   My question is: Considering my crazy pixels are not visible on my pictures, should I get too emotional about them? My camera is under warranty but is it really worth it to return it to Canon? If it's only to receive it back 1 month later after Canon just used the very same menu to map out the pixels, it's a bit ridiculous. Could this be a sign that my camera has a bigger problem?  It seems related to shutter speed. When shooting a black image at 1/250s I get nothing. When shooting the same setup but 1s, I get a few of them. The more I increase the shutter speed, the more crazy pixels I get.


When we say a battery has voltage difference, can we deduce the difference in the number of electrons at the two terminals? What does it mean to say there exists a voltage difference?

I am a little unclear on what  actually is and I am trying to find out what the physical cause for voltage is. Is it the speed of the electrons through the conductor or is it an excess of electrons on the supply side of the conductor. I somewhat understand electromagnetic induction in transformers but I can't seem to figure what the voltage is physically.


Suppose $1 \leq p \leq \infty$ If $||f_n - f||_p \to 0$ then $f_n \to f $ in measure, and hence some subsequence converges to $f$ a.e. On the other hand, if $f_n \to f$ in measure and $|f_n| \leq g \in L^p$ for all $n$, then $||f_n -f||_p \to 0$  Here is how i prove the first part:  Suppose that $||f_n -f||_p \to 0$ Then $||f_n -f ||_p^p \to 0$, which is equivalent to $\int |f_n -f|^p \to 0$. Assume $1<p<\infty$ and let $\epsilon>0$ be given. Define the sets: $$E_{\epsilon}^n =\{ x | \ |f_n(x) -f(x) | \geq \epsilon\} =\{ x \ | \ |f_n(x) -f(x)|^p \geq \epsilon^p \}$$ then $$0\geq \epsilon^p m(E_{\epsilon}^n) = \int_{E_{\epsilon}^n} \epsilon^p \leq \int_{E_{\epsilon}^n} |f_n -f|^p \leq \int_E |f_n -f|^p \to 0$$ so that $m(E_{\epsilon}^n) \to 0$ Therefore $f_n \to f$ in measure  Can anyone show me how to prove the second part? Thanks

Given a sequence $f_n \in L^p$ and $g \in L^p$, with $|f_n| \leq g$, I am trying to show that $f_n \to f$ in measure implies $f_n \to f$ in $L^p$.  Firstly, I know that if $f_n \to f$ in measure, then there is a subsequence $f_{n_i}$ such that $f_{n_i} \to f$ almost everywhere. Then I can use the dominated convergence theorem to show that $\lVert f_{n_i} - f_p\rVert \to 0$.  Now I am trying to show that $\lVert f_n - f\rVert_p \to 0$. My idea is to assume that $\lVert f_n - f\rVert_p \nrightarrow 0$ and then show that this contradicts the fact that $\lVert f_{n_i} - f\rVert_p \to 0$, but I am not sure of the details. Can anyone help me finish the argument?


Question :  $x^4 + px^3 + qx^2 + px + 1 =0 $ has real roots. Then what is the minimum value of $ p^2 +q^2 $ .  How I started ?   I started by dividing the whole equation by $x^2$ then we get  $ (x + \frac{1}{x} ) ^2 + p (x + \frac{1}{x} ) + q - 2 = 0 $ Then put  $(x + \frac{1}{x} ) = t$. Then discriminant should be greater than equal to zero. But now the problem arises that $t$ does not belong to $(-2,2)$ , so taking care of that part leads to solving inequality which I am unable to do .  Have I started the right way?  One more thing to notice is that the sum of roots of the equation is equal to the sum of reciprocal of the roots .  How to proceed further ?

Question  What is the minimum possible value of $a^{2}+b^{2}$ so that the polynomial $x^{4}+ax^{3}+bx^{2}+ax+1=0$ has at least 1 root?  Attempt  I divided by $x^{2}$ and got $$x^{2}+\frac{1}{x^{2}}+2+a\left(x+\frac{1}{x}\right)+b-2=0$$ by letting $$x+\frac{1}{x}=X$$ the equation becomes: $$X^{2}+aX+(b-2)=0$$ $$\therefore X=\frac{-a\pm \sqrt{a^{2}-4b+8}}{2}$$ but I am not sure how to continue. If the polynomial has 1 root doesn't that is should be a double root? Are we counting multiplicity or not?


public class UtilityClass { public static String getDescribedObjects( List lstSObjectType ) {     // Globally desribe all the objects      Map<String, SObjectType> globalDescribe = Schema.getGlobalDescribe();      // Create a JSON string with object field labels and picklist values     String allObjJSON = '{';          // Iterate over the list of objects and describe each object       for( String sObjectType : lstSObjectType ) {                  if( allObjJSON != '{' )            allObjJSON += ', ';         allObjJSON += '"' + sObjectType + '": ';         DescribeSObjectResult describeResult = globalDescribe.get(sObjectType).getDescribe();         Map<String, Schema.SObjectField> desribedFields = describeResult.fields.getMap();         String objJSON = '{';                  for( String fieldName :  desribedFields.keySet() ) {                          // Descirbe the field              Schema.SObjectField field = desribedFields.get( fieldName );             Schema.DescribeFieldResult f = field.getDescribe();                  if( objJSON != '{' )                 objJSON += ', ';                 // Get the field label and append in the JSON string             objJSON += '"' + f.getName() + '": ' + '{ "label" : "' + f.getLabel() + '"';                          // if it's a picklist field then also add the picklist options             if( field.getDescribe().getType() == Schema.DisplayType.PICKLIST ){                                  List <Schema.PicklistEntry> picklistValues = field.getDescribe().getPickListValues();               List<String> pickListOptions = new List<String>();                 pickListOptions.add('{ "label": "--None--", "value": null }');                                  for (Schema.PicklistEntry pe : picklistValues) {                                           pickListOptions.add('{ "label": "' + pe.getLabel() + '", "value": "' + pe.getValue() + '" }');                                  }                                  System.debug( '>>>> ' + fieldName + '>>>> ' + String.join(pickListOptions, ', ') );                 objJSON += ', "picklistOptions": [' + String.join(pickListOptions, ', ') + ']';                }             objJSON += '}';         }         objJSON += '}';                  allObjJSON += objJSON;     }          // Close the object in the JSON String     allObjJSON += '}';          System.debug( ' JSON STRING : ' + allObjJSON );          return allObjJSON; }  }

How do I write a unit-test / test class for a trigger?  What are my options?   Inline with the trigger?  New Class?


I have basic tcp application written in C. It basically sends data to a tcp server. I have connected two PC's with cross cable. I send data from one, and successfully get this data from another one. I have built this mechanism to test If somehow connection broken by unhealty ways (ruptured cable etc.), I want to be informed as client. But things doesn't work as I wanted.If I manually stop tcpserver, client side is informed, but when I start program, connection establishes, data starts to flow, then I unplug the cable, and both sides behaves like nothing happened. Client still sends data with no error, and server still shows the client connected but data flow stops. After a few minutes, I plug cable again, the datas -which considered as sent but not sent- flushes suddenly then program continues normally. How can I detect a broken connection like this? Any help would be appreciated. Here is the code;  #include <arpa/inet.h> #include <stdio.h> #include <string.h> #include <sys/socket.h> #include <unistd.h>  int main() { const char* server_name = "192.168.5.2"; const int server_port = 30152;  struct sockaddr_in server_address; memset(&server_address, 0, sizeof(server_address)); server_address.sin_family = AF_INET;  // creates binary representation of server name // and stores it as sin_addr // http://beej.us/guide/bgnet/output/html/multipage/inet_ntopman.html inet_pton(AF_INET, server_name, &server_address.sin_addr);  // htons: port in network order format server_address.sin_port = htons(server_port);  // open a stream socket int sock; if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {     printf("could not create socket\n");     return 1; }  // TCP is connection oriented, a reliable connection // **must** be established before any data is exchanged if (connect(sock, (struct sockaddr*)&server_address,             sizeof(server_address)) < 0) {     printf("could not connect to server\n");     return 1; }  // send  // data that will be sent to the server const char* data_to_send = "HELLO THIS IS DATA!"; while(1) {     int err = send(sock, data_to_send, strlen(data_to_send), 0);      if(err==-1)     {         printf("ERROR \n");         break;     }     else     {         printf("sent  \n");         sleep(1);     }  } printf("EOP\n");  // close the socket close(sock); return 0; }

Let's say I'm running a simple server and have accept()ed a connection from a client.  What is the best way to tell when the client has disconnected? Normally, a client is supposed to send a close command, but what if it disconnects manually or loses network connection altogether? How can the server detect or handle this?


In trigonometry, how can there be angle thetas larger than 90 degrees, if sine and cosine only work for right triangles? I realize what we do is that we take the sine or cosine of the angle complementary to it. But then, how does that give the ratio between the opposite/adjacent and hypotenuse of the angle larger than 90 degrees? It doesn't! It only gives the ratio between the opposite/adjacent and hypotenuse of the angle complementary to it! Can someone please explain?

I have to write a paper about the unit circle and I'm trying to uncover some of its origins.   Also, when the trig functions were expanded to angles greater than $90^{\circ}$ and what was the rationale behind it? Also, why mirror the right triangle along the axis instead of just moving the base of the right triangle to the next axis $(+x\to+y\to-x\to-y\to+x)$?  I had no luck trying to find that online, and all the books that I looked into would jump right into the practical part of it.


I have two directories: /all/origins/ & /all/links/.  Everything in links/ points individually to something in origins/, but not everything in origins/ is linked in links/. (Squares, rectangles & categorical hierarchy, get it?) These are symlinks (ln -s), not hard links.  Everything in 1. links/ needs to be deleted, along with 2. the symlink destinations in origins/ (not knowing whether they are in origins/), and 3. the links/ directory itself.  What rm Unix command should I type to remove both the entire links/ directory AND any symlinked destinations symlinked to in origins/?  I'm looking for something maybe like: rm -R /all/links or rm -r --follow-all-ln /all/links.  If an rm command with parameters will not do the job, please say so explicitly as that is my preference and implicit in the title (can Unix & Linux do this via rm without a do loop?—only if that won't work, then please state so and explain what do loop.)

Say a is a symbolic link to b. I am looking for a simple command to remove both a and b at once that does not require me to know about b.


related   Is there a way to tell latex, via a macro or otherwise, to lower the subscript a little more, without changing or modifying the actual code itself after \begin{document}? But with a macro  or package, that I can put in the preamble which will affect this setting?  The above link has an answer to adjust the subscript level, but one has to edit each place in the code to do that, and actually modify the Latex itself, as shown   $\Pi_{\raisemath{2pt}{-}}$   I have a document that is auto-generated, and I'd like to add a macro or use package, in the preamble to globally change this setting. The reason is, when I have, as a MWE, something like this:  \documentclass[11pt]{article}% \usepackage{amsmath} \begin{document} \[ \{x_{N-1},x_n,x_1\} \] \end{document}   I find when the subscript is UpperCase, then it becomes very close to the same level as x which makes it little hard to read, as it looks like N is almost on same level as x.  I have many such cases. Here is the output    Again, I do not want to modify the Latex code after \begin{dociument} since it is autogenerated and will be overwritten each time.   Using TL 2015 on Linux.  Update: Thanks to comment below, I tried \usepackage[low-sup]{subdepth} which I did not know about, and it does lower the subscript a little. It looks better now. Here is side-by-side    MWE used for the above RHS:  \documentclass[11pt]{article}% \usepackage{amsmath} \usepackage[low-sup]{subdepth} \begin{document} \[ \{x_{N-1},x_n,x_1\} \] \end{document}

I am writing a script and got a formula with inverses, and I noticed that the subscripts have a different heigth.   This is the minimal working example:  \documentclass{scrbook} \begin{document} \[ \underline{h_1 h_1^{}  h_1^{-1}} \] \end{document}    after compiling this gives     The underline isn't really necessary but it makes it easier to see the difference, the -1 in the superscript is necessary, as only using 1 in the superscript gives the same heigth in the subscripts. I would like to have all subscripts on the same heigth. My only idea was with ^{}, but as the MWE shows it still gives a small difference. Is there another solution?


I am scratching my head on how to go about proving the statement that $F$ being a field implies $F[x_1,x_2]$ is not a principal ideal ring. I believe that the best method would be to initially assume for the sake of contradiction that $F[x_1,x_2]$ is a principal ideal ring. Then, given any ideal in $F[x_1,x_2]$, said ideal can be of the form of a cyclic group for a given element in $F[x_1,x_2].$ I can't seem to figure out an optimal path to move from here to solve this problem. Any suggestions?

Let $F$ be a field, and $F[x,y]$ be a ring of polynomials in two variables. Is $F[x,y]$ a Principal Ideal Domain?   Also show that $F[x,y]/(y^2-x)$ and $F[x,y]/(y^2-x^2)$ are not isomorphic for any field $F$.


Sorting methods in class file by access modifiers is good or wrong habit?  Which are another methods for structure of class file?

Is there an official C# guideline for the order of items in terms of class structure?  Does it go:   Public Fields Private Fields Properties Constructors Methods ?   I'm curious if there is a hard and fast rule about the order of items? I'm kind of all over the place. I want to stick with a particular standard so I can do it everywhere.  The real problem is my more complex properties end up looking a lot like methods and they feel out of place at the top before the constructor.  Any tips/suggestions?


My ISP has a 1TB cap on my usage and we nearly hit that cap or go over each month. I want to be able to see some data on this so I can see what is using the data and what the device/network is calling so much to use all that data. I know this is a complex question but been searching all over. I know I may need a new router to do so but want to be sure I am going in the right direction. I asked them for the usage and they told me it's private and cannot supply it.   Ideally I would like to see which services/domains and how much bytes they are using, but at a minimum see how much each device is using.   Currently Set-Up: Motorola Arris Surfboard (2014) Apple Airport Extrene (2013 maybe)

I noticed recently that my home external-facing router is showing that a lot of data has been downloaded in the last few days. Everything appears to be secured so I don't think it's anything malicious, and there are certainly activities on the network that will cause a lot of data to be pulled down (downloading digital games, for example).  I'd like to get a better understanding of what is using all of the data: either by device or by "service". By service, I mean a breakdown like: Netflix used 20Gb Xbox Live used 30Gb etc  What options are available for providing insight into data usage across the whole of the network? I'd consider inexpensive hardware or software.


I want to make a command block output a message in chat every half hour on my server. The purpose of this is to remind players to read the rules of the server.  Would plugins be necessary to do something like this?

I need a way for a command block to say things in chat when it is powered, or more preferably whenever someone spawns into the world.


After upgrading to Yosemite / Chrome updating (one of these two), I have difficulties to submit files via Google Chrome because the popup window for submitting is huge and lower buttons cannot be seen at all. The only way to operate that - double click on the file (I found that after some days!).  Look at the screenshot - it is the lower visible part of the popup window, but it is not a lower border of this window.     Is there any way to resize/move this window?

My chooser (file-picker dialog) goes under the dock so I can't see buttons. What can I do?


I found some LaTeX questions on  and . There is  completely dedicated to TeX and LaTeX.  I would like to migrate the questions, but I don't have the reputation points to do this:     Flag → Closing → Off-Topic → Migration   These are the questions:

I posted a question which was closed as off-topic and it seems like it could fit on another site in the network. How can I go about moving it there?   What is migration? When can a question be migrated, and who can migrate it? When should I consider migration, and when is it inappropriate? What causes a migration to be blocked and what happens after? What causes a migration to be rejected and what happens after? Anything else I should know about migration?


I'm trying to alias the type which is located in a class located in the base class's body.  Sample code:  #include <iostream> #include <typeinfo> #include <type_traits>   template <typename...Ts>     struct X;  template <typename T, typename...Ts>     struct X<T, Ts...> : X<Ts...> {     using base = X<Ts...>;      template <typename R, int I=0>         struct find     {         using type = base::template find<T, I+1>;     };      template <int I>         struct find<T, I>     {         using type = X;     }; }  template <>     struct X<> {};  int main() {     using type = X<int, float>;      std::cout << typeid(type::find<float>).name(); }   This produced an error error: expected a type for line:  using type = base::template find<T, I+1>;   What have I done wrong?

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


Based on the Star Wars movies, there seem to be quite a few Jedi who lose one or more appendage in light-saber battles. It seems like most Jedi are two-handed, but it's hard to know for sure. Is it common for a Jedi to have been injured in such a fashion, or are the Skywalkers particularly prone to premature truncation?

The Star Wars franchise is rife with dismemberments, particularly involving arms and hands.  User DVK had compiled a table of arm / hand removals via lightsaber from Episodes IV-VI in an answer to this question:         How many hands or arms have been cut off in the entirety of on-screen Star Wars, including The Force Awakens and The Clone Wars?  Limb removals count even if they were NOT cut off with a lightsaber.  Novels, comics, and other media do not count for the purposes of this question.  Since Star Wars Rebels is still ongoing, I am not including it.


While starting wireshark, I am getting following error:  sudo wireshark  This application failed to start because it could not find or load the Qt platform plugin "xcb".  Available platform plugins are: linuxfb, minimal, offscreen, xcb.  Reinstalling the application may fix the problem. Aborted (core dumped)   After installing xcb, still I get the same error.  I am using Ubuntu 16.04  Solutions from following links didn't worked for me:

I used to run wireshark on ubuntu 17.04 with  ~/$ sudo wireshark   but now (just after update to 17.10) when I write the same I get an error  ~/$ sudo wireshark      QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'     Invalid MIT-MAGIC-COOKIE-1 keyQXcbConnection: Could not connect to display :0


I've created a class with a few objects.   class SalesPerson {     String number;     String name;     double salesAmount; }    So now I need to copy some data from a text file to an array.   "sales.txt"  S0001 Alice 2000 S0002 Bob 3400 S0003 Cindy 1200 S0004 Dave 2600    Below is the shortened version of my code, assuming that the getName(s), setName(s) and constructors are created and the text file can be successfully read:   class ArrayImport {     public static void main(String args[]) throws FileNotFoundException {         String fileName = "sales.txt";         SalesPerson sp = new SalesPerson[4]; //Manually counted          //Read the file         Scanner sc = new Scanner(new FileReader(fileName));          //Copy data to array         int i = 0;         while (sc.hasNext()) {             sp[i].name = sc.nextLine(); //Error starts here             sp[i].number = sc.nextLine();             sp[i].salesAmount = Double.parseDouble(sc.nextLine());             i++;         }     } }   I get the error message "Exception in thread "main" java.lang.NullPointerException..." pointing to the line which I commented "Error starts here".    So I am guessing that this is not the way to assign a value to an object array, and if my guess is correct, what are the correct syntax?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I've got an older iMac running macOs Mojave. It is terribly slow and I am interested to see if we can improve the performance. Can you recommend steps to consider to improve the performance?   The performance issues I see impact the operating system and all applications. It's not specific to a single app.  When viewing the About modal:   MacOS Mojave Version 10.14.6 (18G103) iMac 27-inch, Late 2012 Processor: 3.2 Ghz Intel Core i5 Memory: 8 GB 1600 MHz DDR3 Graphics: NVIDIA GeForce GTX 675MX 1GB   Looking at the System Report, I see:   Status on Memory Slots is OK. Has 2 4GB 1600 DDR3 cards. Hard Drive: I have about 500GB of available storage on 1TB hard drive   Other than these basic stats, I'm not sure what would be relevant to help diagnose the performance issues on this machine. What information could I provide to help determine the issue? Thank you.

I bought a Mac (13", early 2011) almost 5 years ago. When I first got it, it was running under OS X 10.7 and it was pretty fast. I've being upgrading it ever since and it's now running under Mac OS X 10.11.  I guess it didn't totally survive the upgrades because, today, there's a lot of bugs, freezes, lags, "spinning beach ball" appearing,... for example, when I write something on a normal program/editor, the cursor freezes for a few seconds, then catches up to what I'm writting.  As you can guess, that's really annoying! I've been thinkning about upgrading the hardware but I don't know what to do: should I change the RAM to 8 GB - 1 333 MHz (currently my computer has 4 GB - 1 333 MHz)? Or should I upgrade to an SSD (which is pretty expensive and difficult to install)?  Thank you very much.


I'm currently playing a bit with X11.   I tried to display something from my Ubuntu PC on my Android tablet.  I installed and Xorg server in Android, set DISPLAY=<address> on the PC and ran xclock: this worked, the clock appeared in Android. If I run metacity & gimp, I get the GIMP GUI in the android machine. Is there a chance to get the Ubuntu desktop in Android? I wanted to run an X program in amazon EC2 Ubuntu and display the output on my local PC. Therefore I installed LXDE on the EC2 machine. But neither lxdm nor gnome-session work. Nothing happens.

When I was running Debian, I was able to start a remote session over x11 by just typing gnome-session  However, with Ubuntu 12.04, this only seems to result in my desktop and background being forwarded over x11 -- the top bar (where the clock is) and dock are both missing. I tried starting all of unity by executing unity, but that just resulted in a segfault.  How can I start a Unity 2D session over x11?  Edit: I prefer x11 as I need to tunnel the connection over 2 other servers. I would need to do a good amount of port forwarding within SSH to get any other connections back. Of course, if someone has any other suggestions, I'm willing to listen.


SO I have an assignment for one of my classes to create an Insurance Calculator that takes in some input for ones age, level of education, marriage status, and employment status and uses this to come up with an insurance payment. The default payment is set to 100 and if an individual is younger than 22 or older than 70, the insurance is increased by 25%. If the individual has a Bachelors, the cost is reduced by 10% (20% for masters), and if the individual is married it is further decreased by 20%. If their employment status is student, cost increases 10%, but if they are unemployed it decreases 5%.  I have a huge block of code and Ive been running through it for the last few days and I seem to be stuck on my conditionals.  Currently running in two classes, one for the Individual.Class and one for the user inputs.  Individual.java:   public class Individual {     private int age;     private String ed_stat;     private String mar_stat;     private String emp_stat;     private double default_Payment = 100;      public Individual(int suns, String edu, String mar, String employ, double payments) {         this.age = suns;         this.ed_stat = edu;         this.mar_stat = mar;         this.emp_stat = employ;         this.defaultPayment = payments;     }      public int getAge() {         return this.age;     }      public String getEdu() {         return this.ed_stat;     }      public String getMar() {         return this.mar_stat;     }      public String getEmploy() {         return this.emp_stat;     }      public double getPay(){         if (22 < age > 70) {             default_Payment = default_Payment + (default_Payment * .25);         }         if (ed_stat == "Bachelor's") {             default_Payment = default_Payment - (default_Payment * .10);         }         if (ed_stat == "Master's") {             default_Payment = default_Payment - (default_Payment * .20);         }         if (mar_stat == "yes") {             default_Payment = default_Payment - (default_Payment * .20);         }         if (emp_stat == "Student") {             default_Payment = default_Payment + (default_Payment * .10);         }         if (emp_stat == "Unemployed") {             default_Payment = default_Payment - (default_Payment * .05);         }         return this.default_Payment;     }      public void setAge(int suns) {         this.age = suns;     }      public void setEdu(String edu) {         this.ed_stat = edu;     }      public void setMar(String mar) {         this.mar_stat = mar;     }      public void setEmploy(String employ) {         this.emp_stat = employ;     }      public void setPayment(double payments) {         this.default_Payment = payments;      }     public String toString() {         return String("Age: " + age() + ", Education : " + ed_stat + ", Marital Status: " + mar_stat + ", Employment Status: " + emp_stat + ", Payment: " + default_Payment);        } }   And the InsuranceCalculator.java  import java.util.Scanner; public class InsuranceCalculator {     public static void main(String[] args) {     double insurance = 100;     Scanner scan = new Scanner(System.in);      System.out.println("Please enter your age: ");     int years = scan.nextInt();      System.out.println("Please enter your education level as High School, Bachelor's, or Master's");     String edu = scan.next();      System.out.println("Are you married? Yes or No");     String mar = scan.next();      System.out.println("Please indicate your employment status as Unemployed, Student, or Employed");     String employ = scan.next();      Individual me = new Individual(years, edu, mar, employ, insurance);     System.out.println(me.toString());  }   Note that I have errors in the Individual.java and I can't tell how the Calculator class will run once I fix the Individual.java.  Any help is greatly appreciated, I will be working on my own as well and will update as I solve

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Solve in $\mathbb{R^{3}}$ the following system :      $$\begin{cases}x+y+xy=19\\y+z+yz=11\\x+z+xz=14\end{cases}$$   My try but I think not complete :   The system equivalent :   $$\begin{cases}(x+1)(y+1)=20\\(y+1)(z+1)=12\\(x+1)(z+1)=15\end{cases}$$  Then from first equation we have :  $$x+1=\frac{20}{y+1}$$  So third equation give :   $$z+1=3\frac{y+1}{4}$$  Second equation $\implies $   $(y+1)^{2}=16$ then $y=3,-5$   This mean $x=\frac{17}{3}$ or $x=-6$ also $z=3$ or $z=-3$   I'm correct or no ??

Solve the following equation system:  $$x+y+xy=19$$ $$y+z+yz=11$$ $$z+x+zx=14$$  I've tried substituting, adding, subtracting, multiplying... Nothing works. Could anyone drop me a few hints without actually solving it? Thanks!


Actually we have an ESX Server running with 32gb Ram ( 2 pairs of 8gb ), and in need of more memory we purchased more 64gb ram ( 2 pairs of 1600hmz 32gb).  My question is, since this server is exclusive for serving VM's, could i mix 1300mhz and 1600mhz ?  the server we are using is an   Thanks in advance.

I currently have 2x1GG 1333MHz DDR3 strips. I plan to purchase a further 2x4GG 1600Mhz strips. Will I be able to use both sets of RAM in my PC together? Will they both be limited to 1333Mhz?   Old RAM: Corsair cm3x1024-1333c9dhx New RAM:  Motherboard:


In Java, non-primitive data types are passed by reference. So, this means whatever change is made to that object will be global. In the code below, a Test object is passed to a static function changeValue() to change the value of its attribute. So, from my knowledge the object is passed by reference, so the output should be:  test1 : Fuzzy   test2 : Billboard  But, the output is:  test1 : Fuzzy   test2 : Wuzzy  What am I missing here? class Test {         private String value; // instance variable          public void setValue(String value) { // setter function         this.value = value;     }          public String getValue() { // getter function         return value;     }          public static void changeValue(Test test, String value) { //Function to change the value of an object         test = new Test();         test.setValue(value);     }          public static void main(String args[]) {         // Object creation         Test test1 = new Test();         Test test2 = new Test();                  // Setting value         test1.setValue("Fuzzy");         test2.setValue("Wuzzy");                  // Changing value of test2         Test.changeValue(test2, "Billboard");                  // Printing values of the objects         System.out.println("test1 : " + test1.getValue());         System.out.println("test2 : " + test2.getValue());     }  }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


The wikipedia.org article on  provides an example of multiplying $83$ and $206$ in $\mathbb{F}_{2^8}$ with $x^8+x^4+x^3+x+1$ as the reducing polynomial (in fact it is the reducing polynomial for AES). Quoting it:  Multiplying $83$ and $206$, whilst ignoring the carries, yields $16,254$ or (in binary) 11111101111110.  The reducing polynomial is then converted to binary (100011011), shifted forward to match the length of the number being reduced (eg. multiplied by a power of two) and then XOR'd (subtracted) against the number to be reduced. It seems like it's supposed to do this until the number being reduced is less than the reducing polynomial (in binary).  Here's the example wikipedia gives:        11111101111110 (mod) 100011011      ^100011011             1110000011110       ^100011011             110110101110        ^100011011             10101110110         ^100011011             0100011010           ^100011011              00000001   My question is...  why is the last XOR done? 0100011010 is less than 100011011..

I am trying to understand how to calculate the modular reduction of Rijndael's finite field.  The example on  page says that {53} • {CA} = {01}, because (11111101111110 mod 100011011) = {3F7E mod 11B} = {01} = 1.  I am able to get to the point where I have 3F7E mod 11B, but cant seem to figure out how the reduction works.        11111101111110 (mod) 100011011      ^100011011             1110000011110       ^100011011             110110101110        ^100011011             10101110110         ^100011011             0100011010            ^100011011 <-- here, right shifted two places?             00000001   From this example, why does it right shift two places at one point?  I also found an example that 0x1b*0xaa equals 0x8c. Trying to solve this myself I get to the point: 0xE0E mod 0x11B   111000001110 ^100011011   11011010110  ^100011011    1010111010   ^100011011     010001100    ^100011011      10010111   This makes it 0x97


I read a source code of class address_v4 in boost library and there are several constructors declared with BOOST_ASIO_DECL (defined as inline)  /// Construct an address from raw bytes. BOOST_ASIO_DECL explicit address_v4(const bytes_type& bytes);  /// Construct an address from a unsigned long in host byte order. BOOST_ASIO_DECL explicit address_v4(unsigned long addr);   (from here )  # define BOOST_ASIO_DECL inline   (from here )  So, what the purpose of specifing "inline" for c++ constructor ? Is it the same meaning as for functions or it has a different meaning ?

VC++ makes functions which are implemented within the class declaration inline functions.  If I declare a class Foo as follows, then are the CONSTRUCTOR and DESTRUCTOR inline functions?  class Foo  {     int* p; public:     Foo() { p = new char[0x00100000]; }     ~Foo() { delete [] p; } };  {     Foo f;     (f); }


I have seen an example of functions that are weakly convergent but not strongly convergent in $L^2([0,2\pi])$, which is $f_k(x) = \sin(kx)$, but I'm unsure that this example works in $L^2(\Bbb R^n)$, mostly because I don't even think $\sin(x)$ is in $L^2(\Bbb R^n)$. Try as I might, I can't think of an example that works over all $\Bbb R^n$, with the exception of maybe $\sin(kx)\cdot \chi_{[0, 2\pi]}$, but I'm hoping to find a function that is substantially different from this example.

Let $f_n (x) = \sqrt n 1_{[0,1/n ] } (x) \in L^2 (\mathbb R)$. Does $f_n$ converges weakly to $0$ in $L^2$?  I tried to prove it by using Hölder's inequality or the Lebesgue differentiation theorem, but neither seems to work. I also can't find a counter example. Any help is appreciated.


App Version: 1.0.85 Device Manufacturer: motorola Device Model: MotoG3   OS Version: 6.0.1 (35)    Earlier it used to show feeds on various stack exchange site.. But now only an annoying disoriented random single post is shown..   I've cleared the data.. Reinstalled the app.. Still no change  Screenshot:

I have subscribed to many sites, but have no feed. I checked online, and I gathered this is not how it should normally look.    Buggy layout with empty feed    Fixed after having activity (e.g. reputation change, badge, etc)   Phone: HTC Desire 526G+ Android: 4.4.2 SE app: 1.0.77


I've been looking for a simple starter solution for monitoring my [currently] single server hosted solution. Other than Nagios and similar, are there other good (simple) solutions people are using?

This is a  about Monitoring Software. Also Related:   I need to monitor my servers; what do I need to consider when deciding on a monitoring solution?