Every time I open a question I get this oh so funny 90s feel with scrollers and whatnots. In every question I need to click it off. The button seems to only work for the specific page I load; loading a different page shows the theme again.  Is this an attempt to keep people from using the site for a few days or how do I tell you "please never ever do anything like this if you want me to keep contributing here"? Yes I have no sense of humor if this is an attempt at that.  How do I turn off "time travel" (also known as "back to the future") mode off permanently, on all questions, and preferably network-wide?


What is it called when object A is accelerating at rate B, but rate B is also accelerating at rate C. What is it called? How does it work? How can I apply it?


How can I negate the return-value of a process?

I'm looking for a simple, but cross-platform negate-process that negates the value a process returns. It should map 0 to some value != 0 and any value != 0 to 0, i.e. the following command should return "yes, nonexistingpath doesn't exist":   ls nonexistingpath | negate && echo "yes, nonexistingpath doesn't exist."   The ! - operator is great but unfortunately not shell-independent.


According to PHB p. 194 you always score a critical hit on any attack roll.  Does this rule also apply to magical attacks, e.g. the  spell?


Still dealing with fancy tables, now I am trying to get one with multicolumn and multirow cells.  I can get multicolumn cells right, but I am still struggling with multirow ones.  MWE in Beamer:  \documentclass[xcolor={dvipsnames,table}]{beamer}  %%TABLE \usepackage{multirow} \newcommand*{\arraycolor}[1]{\protect\leavevmode\color{#1}} \newcolumntype{A}{>{\columncolor{red!20}}c} \newcolumntype{B}{>{\columncolor{blue!20}}c}  \mode<presentation> {     \usetheme[compress]{Singapore}     \usecolortheme{orchid} }  \begin{document}  \begin{frame}     \sffamily     \arrayrulecolor{white}     \arrayrulewidth=1pt     \renewcommand{\arraystretch}{1}     \rowcolors[\hline]{2}{.!50!White}{}     \resizebox{\linewidth}{!}{%         \begin{tabular}{A|A|A|A|A|B|B|B|A}             \rowcolor{.!50!Black}             \multicolumn{5}{A|}{\arraycolor{White}\bfseries 14 subjects} &             \multicolumn{3}{B|}{\arraycolor{White}\bfseries 10 subjects} &             \multirow{2}{*}{\arraycolor{White}\bfseries Control}\\             \rowcolor{.!50!Black}             \multicolumn{3}{A|}{\arraycolor{White} Surface} &             \multicolumn{2}{A|}{\arraycolor{White} Follicle} &             \multicolumn{3}{B|}{\arraycolor{White} Surface} & \\             No les & Non-inf & Inf & Non-inf & Inf & Cheek & Fh & Nose & Mock\\         \end{tabular}     }% \end{frame}   \end{document}   I need to make the "Control" cell span 2 rows properly, is it possible? Thanks!   EDIT!  I looked at the answers in the , but I still do not seem to get it right... I feel like it is almost there though.  Please check my updated MWE below:  \documentclass[xcolor={dvipsnames,table}]{beamer}  %%TABLE \usepackage{makecell, multirow} \renewcommand\theadfont{\arraycolor{White}\bfseries}  \newcommand*{\arraycolor}[1]{\protect\leavevmode\color{#1}} \newcolumntype{A}{>{\columncolor{red!20}}c} \newcolumntype{B}{>{\columncolor{blue!20}}c}  \mode<presentation> {     \usetheme[compress]{Singapore}     \usecolortheme{orchid} }  \begin{document}  \begin{frame}     \sffamily     \arrayrulecolor{white}     \arrayrulewidth=1pt     \renewcommand{\arraystretch}{1}     \rowcolors[\hline]{2}{.!50!White}{}     \resizebox{\linewidth}{!}{%         \begin{tabular}{A|A|A|A|A|B|B|B|A}             \rowcolor{.!50!Black}             \multicolumn{5}{A|}{\arraycolor{White}\bfseries 14 subjects} &             \multicolumn{3}{B|}{\arraycolor{White}\bfseries 10 subjects} & \\             \rowcolor{.!50!Black}             \multicolumn{3}{A|}{\arraycolor{White} Surface} &             \multicolumn{2}{A|}{\arraycolor{White} Follicle} &             \multicolumn{3}{B|}{\arraycolor{White} Surface} &             \multirow{-2}{*}{\thead{Control}}\\             No les & Non-inf & Inf & Non-inf & Inf & Cheek & Fh & Nose & Mock\\         \end{tabular}     }% \end{frame}   \end{document}   Which produces:


How to install Stock Android on Samsung Galaxy Ace 3 s7270

I was wondering if it is possible to install the official stock android operating system from google without the customization of the manufacturer like Touch Wiz on Samsung Galaxy Ace 3 s7270, is there a way to do this


I tried changing my sudoers.d file to remove authentication from my pc by typing %admin  ALL=(ALL) NOPASSWD:ALL without using visudo. However, after doing that anywhere where the sudo command is used, it says that the password that I've entered is incorrect. I tried correcting it, by logging with my username to virtual terminal and running sudo visudo and typing %<username> ALL=(ALL) ALL in vain.  How do I get sudo to recognize my password?


Reading of hex file in testbench : Verilog

I have converted an image file into hex file which has R,G,B and alpha values in multiple columns. For example :  3c 48 36 ff 1d 2b 19 ff 08 18 06 ff 08 17 05 ff 14 1f 0d ff 1b 22 11 ff 1a 1f 0e ff 1a 1b 0b ff 1d 1a 0b ff 20 1a 0b ff 23 1a 0c ff 23 1c 0d ff 24 1d 0e ff 24 1d 0e ff 21 1c 0d ff 23 1c 0d ff 1f 1a 0b ff 1e 19 0a ff 1c 19 0a ff 1e 1a 0b ff 20 1a 0b ff 24 18 0b ff 23 18 0a ff 21 18 0a ff  Now I want a way to read and store this data as a collection of 32 bits( i.e. 4bytes). If I do not know how bytes are present in the file (since file can be of any size), how can I achieve this?


no material are showing instead it takes a still color of the background in viewport

I didn't use blender for quite some time then I loaded a saved file and saw that there were no material. I checked the material properties and they were all there but the viewport couldn't display them. I created new things and no matter what there were no material in the viewport in rendered view or material preview mode instead I see weird behavior when I zoom in and out it's as if there's a black thing of the same shape as the object that isn't affected by the zoom. and in the material properties menu the small balls that display the color of the material left of the material name disappear.


Would you mind me / my opening the window?

Would you mind me opening the window?      Would you mind my opening the window?   Who uses which form, and why? Is this a difference in dialect? A difference between formal and informal grammar?


Assigning CRS to shapefile when it doesn't have one, in R?

I think that by using readOGR to import a shapefile renders worthless to put proj4string to the script since if any coords are available in the shapefile, it will be transported through the readOGR.   Therefore, proj4string is expedient only if we use another import function for example readShapeSpatial (for polygons, lines or points) or by using readOGR, but in the case that the shapefile does not contain the coordinates/projection:  When checking if the shapefile has projection information and if it has not, should I add proj4string although I have put readOGR?


What is the force of gravity, $F_g$, if the distance between two objects is $0$? Wouldn't that mean that the fraction: $m_1m_2/d^2$ is undefined? And in that case, how would you escape Earth's gravity field unless you had no mass?


Why can't I break or place blocks in Minecraft?

I was playing on a single player modded survival and I went to check the forums for help with one mod. When I got back on my game I couldn't mine or place blocks and I've tried switching to /gamemode 0 but this only happened in my modded survival. I can still place and break blocks in vanilla Minecraft.


Simple Java web service connecting to mySql not working

I decided to try to connect a java client to a mysql db running on wamp. Can anybody tell me why im getting this runtime problem?  My DBConnect() class  import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;  public class DbConnect {      private Connection conn;     private Statement statement;     private ResultSet resultset;      public DbConnect(){         try{             Class.forName("com.mysql.jdbc.Driver");             conn=DriverManager.getConnection("jdbc:mysql://xxx.xxx.xxx.xxx:3306/pk","root","");         }       catch (Exception e){             System.out.println("Error: " + e);         }     }      public String getData(){         String result ="";         try {             resultset = statement.executeQuery("select * from data_user");             while(resultset.next())             {                 result+=resultset.getString("userFirstName");             }         } catch (SQLException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }            return result;       }   My main() class  public class Main {      public static void main(String[] args) {         // TODO Auto-generated method stub         DbConnect conn = new DbConnect();         System.out.println(conn.getData());     }   My error at runtime     Error: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:   Communications link failure           The last packet sent successfully to the server was 0 milliseconds     ago. The driver has not received any packets from the server.     Exception in thread "main" java.lang.NullPointerException   at     DbConnect.getData(DbConnect.java:26)    at Main.main(Main.java:8) ERROR:     JDWP Unable to get JNI 1.2 environment, jvm->GetEnv() return code = -2     JDWP exit error AGENT_ERROR_NO_JNI_ENV(183):  [util.c:840]  }       Offending line      resultset = statement.executeQuery("select * from data_user");


Null pointer error in cucumber with Java

I'm new with Cucumber... I've been getting a NullPointer Exception when I try to run my code. The java version works fine though... Could someone please tell me where I'm going wrong?  public class Stepdefs {  protected WebDriver driver;   @Before     public void setup() {      DesiredCapabilities capabilities = DesiredCapabilities.firefox();         capabilities.setCapability("marionette", true);   System.setProperty("webdriver.gecko.driver","/Users/sajupt/Documents/geckodriver");         WebDriver driver;         driver = new FirefoxDriver();         driver.get("localhost");  }        @After         public void after() {             driver.quit();         }  @Given("^I am on the Preconditions Page$") public void i_am_on_the_preconditions_page() { }   @When("^I click on the continue button$") public void I_click_on_the_continue_button() {      driver.findElement(By.xpath(".//*[@id='root']/div/div/div/section/div[2]/div/section/form/section[2]/div[2]/div/div/button")).click();     WebElement continueButton = driver.findElement(By.className("RadioButton__button--2mnYd"));   continueButton.click();   This is the error Trace  [31mWhen [0m[31mI click on the continue button[0m           [90m#  Stepdefs.I_click_on_the_continue_button()[0m   [31mjava.lang.NullPointerException     at  skeleton.Stepdefs.I_click_on_the_continue_button(Stepdefs.java:71)     at ✽.When I click on the continue button(skeleton/belly.feature:5)   [0m [36mThen [0m[36mI should go to the registered owner page[0m [90m#  Stepdefs.i_should_go_to_the_registered_owner_page()[0m   [31mFailed scenarios:[0m [31mskeleton/belly.feature:3 [0m# Scenario: Accessing the Quotes page  1 Scenarios ([31m1 failed[0m) 3 Steps ([31m1 failed[0m, [36m1 skipped[0m, [32m1 passed[0m) 0m6.000s  java.lang.NullPointerException at skeleton.Stepdefs.I_click_on_the_continue_button(Stepdefs.java:71) at ✽.When I click on the continue button(skeleton/belly.feature:5)    java.lang.NullPointerException at skeleton.Stepdefs.I_click_on_the_continue_button(Stepdefs.java:71) at ✽.When I click on the continue button(skeleton/belly.feature:5)   Here is the feature file  Feature: Getting a Quote  Scenario: Accessing the Quotes Feature     Given I am on the Preconditions Page     When I click on the continue button     Then I should go to the registered owner page     When I click on the continue button     Then I should go to the Enter HSN TSN page     Then I should go to Select make page     When I select a make and click continue     Then I should go the Select model page     When I select a model and click continue     Then I should go the select fuel page     When I select the fuel and click on continue     Then I should go to the select Engine page     When I select the Engine and click on continue     Then I should go to the Registration page.     When I enter the year and click on continue      Then I should go to the Date of Birth page.


Some of my side ops show as being completed, with the tick mark, yet I can do them again whereas with others once they're done, then, that;s it , they're done.  Can someone explain this?


If T And T' be two Topology on a same set X and T is strictly finer than T' then "there exit no homeomorphism between them",is a correct statement?

We know lower topology on $\Bbb R$ and usual topology on $\Bbb R$ is not homeomorphic and one is finer than other..now is it true for all topological spaces on a same set where one is strictly finer than other.


Is there a way to write my Thesis in separate files for each chapter and then merge them into one main.tex at the end?

I am starting to write my materials and methods section of my thesis. My Supervisor would rather have one chapter at a time to an extent so I was wondering if it is possible to have separate documents for each chapter with identical preamble and bibtex files attached and then just link them all up in a single latex document.   In the main latex document I would then want to auto generate the ToC in the correct format, have references work across chapters and be able to have my title page etc in main.   Is this possible or should I just write it all as one document?


Adding mAh when wiring battery cells in series?

When combining battery cells in series, the voltages of the cells are added to get the voltage of the final circuit.  Do the mAh add up, or stay the same?  For example, suppose you have two 3.7V cells, each with 200 mAh capacity.  When connected in series, will the resulting battery will be a 7.4V, 200mAh battery?


Do I need a transit visa if I have 9 hours of layover at Delhi airport?

I have a valid US passport. I will fly Jet Airways to Delhi airport with 9 hours of layover to change to another Jet Airways Flight to Abu Dhabi. Do I need a transit visa?


When we say a function is smooth? Is there any difference between smooth function and continuous function? If they are the same, why sometimes we say f is smooth and sometimes f is continuous? Please help me. Thanks.


"Dostoyevsky is a Russian writer. He has written Crime and Punishment." - or is it "he wrote"?

Which of the two sentences would look more natural in this short text:     Dostoyevsky is a famous Russian writer. He has written Crime and Punishment.   or     Dostoyevsky is a famous Russian writer. He wrote Crime and Punishment.   There's no specific time expression in sentence 2, and "Crime and Punishment" is a widely-read novel, so we can say that the event "relates to the present" in some way. Still, could the use of Present Perfect be erroneous or infelicitous here, and why?


I use "Texmaker-3.5.2" with "basic-miktex-2.9.4757" on Windows 8.1 on my personal laptop (LenovoZ5070).  I checked Options\Configure Texmaker\Commands. It includes:  LATEX:     latex -interaction=nonstopmode %.tex  PDFLATEX:  pdflatex -synctex=1 -interaction=nonstopmode %.tex  XLATEX:    xelatex -synctex=1 -interaction=nonstopmode %.tex  You can see that my system contains "-synctex=1". However “click to jump to the line”  is not working! Please help me.


iPhone personal hotspot sharing Wi-Fi connection instead of 4G

I have an iPhone 5s and it's connected to a Wi-Fi network. I have a personal hotspot set up. I'm currently using this hotspot on my laptop and am just wondering if it is uses my phone's data or the Wi-Fi connection.


In the movie prisoners what does Alex mean he never came

When Alex Jones is imprisoned in the makeshift shower/bath torture area made by Keller Dover. He says during one scene “I’m not Alex.” But then he says “I waited but he never came” “ I just wanted to play but he never came” .... this part confuses me, who is Alex referring to when he says “he never came?” Is this is real dad? Another kid who was kidnapped? If anyone can help explain who is the “he never came” that would be awesome. Thanks


When we punch a wall our hand hurts...  Do we feel the pain due to the normal force exerted by the wall or due to the reaction force?


Let $X$ be a connected space, $f:X\to X$ continuous involution, $g:X\to\mathbb{R}$ continuous. Prove that $\exists$ $x\in X$ such that $g(x)=g(f(x))$.

This is a homework problem in an undergraduate topology class that I am ludicrously (and probably stupidly) stuck on. Any guidance would be appreciated:  Let X be a connected space, $f:X\to X$ a continuous involution (i.e. f is its own inverse), $g:X\to\mathbb{R}$ continuous. Prove that $\exists$ $x\in X$ such that $g(x)=g(f(x))$.  Here are the things I understand:  Some examples of $f$ include the identity map, $f(x)=-x$, $f(x)=\frac{1}{x}$ if $x\neq0$, etc. The result clearly holds if $f$ has a fixed point. I know any continuous involution in $\mathbb{R}^2$ has a fixed point, but we are on an arbitrary connected space, and I have no results I can use for such a thing. I can define a new continuous function $h:X\to\mathbb{R}$ so that $h(x)=g(f(x))-g(x)$. If this function has a zero, the result follows, but I don't know how to show it does. I could apply the intermediate value theorem since X is connected and $g:X\to\mathbb{R}$, but I again don't see how this would be helpful.  Thanks very much in advance!


What is the latest advice for using tex and providing a Word as output?

Despite many "older answers" I should like the latest advice. I love tex, and I use TeXstudio. Due to collaborators needing Word- I would like to know best way to convert or get an output in Word.


LSTM for time series forecasting bad performance

I am trying to design a neural network for time series forecasting using LSTM neurons.  I am stuck because the many different configurations that I tried so far are not performing well (actually they perform really really bad).  So I am starting to think that I'm missing something :).  This is the time series that I am using for training. I have a similar time series for testing (the training consists in 2016 data and test is 2017):   What I want is to take T steps of my time series and predict the following P steps, so I converted the problem in a multi-output regression problem in order to solve it using supervised learning: suppose I want to predict the series from time a+1 to time a+P, the features of my dataset are the steps from a-T to a, (by consequence my ys for training are the steps from a+1 to a+P)  As only preprocessing step, I applied different types of scaling (using scikitLearn:  stdscaler = StandardScaler() minmaxScaler = MinMaxScaler(feature_range=(-1, 1)) robustscaler = RobustScaler()   Sometimes I combined these methods, but I have always got bad results in term of network performance.  After preprocessing and reshaping, I designed the following network:  # create and fit the LSTM network model = Sequential()  model.add(LSTM(NODES_L1, return_sequences=True, input_shape=(1, SEQ_LEN), stateful=True, batch_size=BATCH_SIZE)) model.add(Activation(ACTIVATION_L1)) model.add(Dropout(DROPOUT_L1))  model.add(LSTM(NODES_L2, stateful=True)) model.add(Activation(ACTIVATION_L2)) model.add(Dropout(DROPOUT_L2))  model.add(Dense(OUTPUT_TIMESTEPS, activation='linear')) adam = Adam(lr=0.0001) model.compile(loss='mean_squared_error', optimizer=adam)  callbacks = [     EarlyStopping(monitor='val_loss', min_delta=0.00001, patience=5, verbose=0, mode='auto') ]  model.summary()  model.fit(     trainX,     trainY,     shuffle=False,     batch_size=BATCH_SIZE,     epochs=EPOCHS,     validation_data=(validX, validY),     verbose=2,     callbacks=callbacks)   Two LSTM layers and one dense at the end to predict the time steps. The validation loss and the loss are descending quite well; what I see when I train the network is the following output:  4s - loss: 3.8233 - val_loss: 0.6118 Epoch 2/100 3s - loss: 3.4985 - val_loss: 0.6668 Epoch 3/100 3s - loss: 3.1761 - val_loss: 0.6724 Epoch 4/100 3s - loss: 2.7586 - val_loss: 0.5258 Epoch 5/100 3s - loss: 2.3404 - val_loss: 0.3424 Epoch 6/100 3s - loss: 2.0137 - val_loss: 0.2554 Epoch 7/100 3s - loss: 1.7479 - val_loss: 0.1697 Epoch 8/100 3s - loss: 1.5935 - val_loss: 0.1564 Epoch 9/100 3s - loss: 1.3824 - val_loss: 0.1206 Epoch 10/100 3s - loss: 1.2645 - val_loss: 0.0699 Epoch 11/100 3s - loss: 1.1752 - val_loss: 0.0619 Epoch 12/100 3s - loss: 1.1283 - val_loss: 0.0711   And so on (until early stop kills everything).  After the training step, I try to do some predictions, here the results:     Not even close.  I tried to find the best hyperparamters with hyperopt, here the configuration I used (maybe I am wrong on the dimension of the network):  fspace = {         'SEQ_LEN': hp.choice('SEQ_LEN', range(5, 48)),         'NODES_L1': hp.choice('NODES_L1', range(1, 80)),         'NODES_L2': hp.choice('NODES_L2', range(1, 80)),         'DROPOUT_L1': hp.uniform('DROPOUT_L1', 0.05, 0.8),         'DROPOUT_L2': hp.uniform('DROPOUT_L2', 0.05, 0.8),         'BATCH_SIZE': hp.choice('BATCH_SIZE', range(25, 150)),         'ACTIVATION_L1': hp.choice('ACTIVATION_L1', ['relu', 'tanh']),         'ACTIVATION_L2': hp.choice('ACTIVATION_L2', ['relu', 'tanh']),         'EPOCHS': hp.choice('EPOCHS', range(15, 1000))     }   Where SEQ_LEN is the number of T timesteps used as features.  The question is: how can I improve my process? What I am doing wrong? I double checked my code and all data seems to be loaded correctly, so I think it's a methodological problem.  Thank you for any clue ;)


How not to have a face left over when extruding a face inwards?

Here's a screenshot showcasing my problem:     I found  on this issue, but for some reason, it's not working for me. I'm using the Inset tool, and setting the depth to a negative number.  Do I need edge loops first for that to work? There's no way for blender to create vertices at the right spot automatically?


A way to encourage/enforce constructive comments rather than anonymous down-votes. Please discuss

I believe this is different from other similar questions such as   My question is not about encouraging politeness, it is about providing a simple automated way to increase positive, constructive feedback.  My suggestion is that a down-vote could be required to have an associated comment so that the down-voter is identified.  You might object that this would encourage revenge voting. Not so IMO. The revenge voter would also have to provide sensible reasons for their down-votes. It would be obvious if someone was doing it vindictively.  Please discuss both the benefits and drawbacks of this idea.  Thank you.


Fuses - Are there any voltage conversion for the break-off

Anyone knows the very common glass fuses in electronics etc. But I am uncertaion about the breaking conditions.  Example: A fuse rated as 5A/250V, it is the breaking point. But I have seen such used in devices with a much lower voltage, like 12V or 24V.  The breaking of the fuse is based on a maximum energy generated as heat to melt the internal lead by Ohm'S law, aka P = UxI.  But this does not correlate with the current (A) at different voltages. In the example, the nominal is P = 5A*250V = 1.250, which used with a 24V case, would be (I = P/U) = 1.250/24 = 52A which is way beyond the rated 5A.  In other words: We have different currents at different voltages to generate the same energy, if we are to follow Ohm'S law and that the breaking requires the same energy in any case.  This is a little confusing, because it must be the current that are the dominator and the current is driven by the voltage, so the voltage is certainly a factor...


How can I calculate a point's coordinates given distances from three other known points?

I have a trilateration-related problem that I'm unsure how to solve mathematically. I can see a solution is possible through geometry, but I'm unsure how to solve the resulting equations.     Given three 2D points, find where to put a new point on the same plane. You know the exact distances from the new point to each existing point.   By drawing a picture, it is clear that this is attainable:    In this image, $P_1,P_2,P_3$ are the known points, and $P_4$ is the point we want to find coordinates for. The red lines denote known distances.  Given only two points, we can find 2 candidate positions (where the circles intersect), while the third given point limits us to our solution.  Using the properties of circles, I have come up with 3 equations and 2 unknowns. Let $P_i=[x_i,y_i]^T$ and $r_i=|P_i-P_4|$ for $i\in\{1,2,3,4\}$. Then my set of equations, expanded, is $$r_1^2 = (x_4 - x_1)^2 + (y_4 - y_1)^2\\ r_2^2 = (x_4 - x_2)^2 + (y_4 - y_2)^2\\ r_3^2 = (x_4 - x_3)^2 + (y_4 - y_3)^2$$ How can I calculate $x_4$ and $y_4$?    I FOUND THE ANSWER I WAS LOOKING FOR  (I'd answer my own question, but since it's closed as a duplicate all I can do is post it here)  So I was hoping to find a way to express this as a linear least-squares ($Ax=b$) type problem. I mentioned that in the comments, but not in this OP. Regardless, the link from @dxiv in the comments below helped me get to this solutions. Also worth mentioning, the question this is a duplicate of reaches the same conclusion (as it obviously should). It just stops short of the $Ax=b$ form.  In short, the approach is to combine the 3 quadratic equations to get 2 linear ones.  Given  $$\text{(1)  } r_1^2 = (x_4 - x_1)^2 + (y_4 - y_1)^2\\ \text{(2)  }r_2^2 = (x_4 - x_2)^2 + (y_4 - y_2)^2\\ \text{(3)  }r_3^2 = (x_4 - x_3)^2 + (y_4 - y_3)^2$$  we first expand each to  $r_i^2 = \hat{x}^2 + \hat{y}^2 - 2\hat{x}x_i - 2\hat{y}y_i + x_i^2 + y_i^2$  Then we subtract (2) from (1) and (3) from (1):  $$\text{(1)-(2)   }2\hat{x}(x_2 - x_1) + 2\hat{y}(y_2 - y_1) + (x_1^2 - x_2^2) + (y_1^2 - y_2^2) - (r_1^2 - r_2^2) = 0\\ \text{(1)-(3)   }2\hat{x}(x_3 - x_1) + 2\hat{y}(y_3 - y_1) + (x_1^2 - x_3^2) + (y_1^2 - y_3^2) - (r_1^2 - r_3^2) = 0$$  This is now able to be expressed as an least-squares problem, particularly as an $Ax=0$ (i.e. nullspace) problem if the distances $r_i$ are precise.  $\left[  \begin{matrix}   2(x_2 - x_1) & 2(y_2 - y_1) & (x_1^2 - x_2^2) + (y_1^2 - y_2^2) - (r_1^2 - r_2^2) \\   2(x_3 - x_1) & 2(y_3 - y_1) & (x_1^2 - x_3^2) + (y_1^2 - y_3^2) - (r_1^2 - r_3^2)  \end{matrix} \right] \left[ \begin{matrix} \hat{x} \\ \hat{y} \\ 1 \\ \end{matrix} \right] \left[ \begin{matrix} 0 \\ 0 \end{matrix} \right] $  Thus, in short, the solution for $\left[ \begin{matrix} \hat{x} \\ \hat{y} \end{matrix} \right]$ is found in the nullspace of the $A$ matrix.  If the distances $r_i$ have some uncertainty, this can be expressed as a linear least-squares minimization problem which is easily solvable using SVD.


Make voting activity on your posts available on site metas (what you would get from rep if metas had rep)

Child metas don't have rep, so there's no point in tracking a rep stat or reporting changes.  But one of the things rep updates do on main sites is to alert me when there's activity on older posts.  On metas, unless I revisit a question I'll never notice that there's been a bunch of voting (which might be accompanied by new comments that didn't ping me).  I'd like to know about that activity, not because of any ego reasons but because meta is where site policies get discussed and set and it's useful to know about changes in the community will.  A couple days ago I visited a meta post where, a few weeks ago, my answer had been voted down, and this time it was at the top.  Could we have something like the reputation-changes tab on meta?  I suspect that the data already exists, because I once  (and I see I'm not the only one).  If something akin to reputation is already being tracked internally on per-site metas, can we get it exposed?


How do muggles and wizards differ physiologically?

In "Fantastic Beasts and Where to Find Them", the main character () meets a muggle () who is bitten by a .      Thats definitely the Murtlap. You must be particularly susceptible.   Then Newt says:      See, you're a Muggle. So our physiologies are subtly different.   How do muggles and wizards differ? If the only difference is exposition to magical creatures then muggle borns should also have different physiologies. What about Squibs, do they share the same physiology as wizards or muggles?


How does brightness affect the color of light? For instance, the sun might be yellow because of the blue scattering when the light travels through the atmosphere - but if you look at it, it seems brighter and looks more white. So how does brightness affect the number of photons we perceive? Something must have an effect on the color because otherwise I cannot see why it would look white when not all photons are present.


Expected value of latent utility in logistic regression

I'm looking for an analytical expression for the expected value of the latent utility in a logistic regression.  Setup:  There are two choices indexed by $i \in \{0, 1\}$ with associated utilities $u_i = w_i + \epsilon_i$, with the $\epsilon_i$ i.i.d. Gumbel(0, 1), aka Type I Extreme Value with location 0 and scale 1. The $w_i$ are constants.  (Same setup as )  Let $Z \equiv \max\{u_0, u_1\}$, i.e. $Z$ is the utility you get when choosing the preferred alternative.  Question:  Is there a closed-form expression for the expected value of $Z$? If so, what is it, and how is it derived?  Additional Info:  If you know the answer, skip this section :-)  The $\epsilon_i$ have CDF $F(x) = e^{-e^{-x}}$ and expected value $\gamma \approx 0.5772$, the Euler–Mascheroni constant -- here I'm copying from , in case this is helpful to anyone reading this question.  I did some googling, and I found something saying $\mathbb{E}[Z] = \ln(\Sigma_i(e^{w_i})) +$ constant. Is this correct?  I wrote some R code to investigate, and it seems like $\mathbb{E}[Z] = \ln(\Sigma_i(e^{w_i})) + \gamma \approx \ln(\Sigma_i(e^{w_i})) + 0.5772$. Is this correct?  Here's the code:  # Binary choice # w_i + \epsilon_i with \epsilon_i ~ Gumbel # Is Emax{w_i + \epsilon_i} = log(sum(exp(w_i))) + \gamma?  rgumbel <- function(n) {   # Slower than Runuran, but avoids installing a new package   u <- runif(n)   return(-log(-log(u))) } library(Runuran)  # Gumbel rgumbel <- function(n) {   distribution <- udgumbel()   generator <- pinvd.new(distribution)   return(ur(generator, n)) }  gamma <- 0.57722 # Euler–Mascheroni constant GetError <- function(w=c(5, 10), n=100000) {   epsilon <- matrix(nrow=n, ncol=2, data=rgumbel(2*n))   utility <- pmax(epsilon[, 1] + w[1],                   epsilon[, 2] + w[2])   emax <- mean(utility)   emax.analytical <- log(sum(exp(w))) + gamma  # Correct?   return(emax - emax.analytical) }   The GetError function returns the difference between a sample mean and my candidate analytical expression. I played around and tended to see values very close to zero.  Here's my very feeble attempt at getting an analytical expression for $\mathbb{E}[Z]$:  $G(z) \equiv Pr[Z \leq z] = Pr[w_0 + \epsilon_0 \leq z] Pr[w_1 + \epsilon_1 \leq z | w_0 + \epsilon_0 \leq z]$  $G(z) = F(z - w_0) F(z - w_1) = e ^ {-e^{-z + w_0} -e^{-z + w_1}}$  $g(z) \equiv G^\prime(z) = e ^ {-e^{-z + w_0} -e^{-z + w_1}} (e^{-z + w_0} + e^{-z + w_1})$  $\mathbb{E}[Z] = \int z g(z) dz$  So, assuming there are no mistakes up to here, I need to calculate:  $\int z e ^ {-e^{-z + w_0} -e^{-z + w_1}} e^{-z + w_0} dz$ plus a similar second term, but I'm not sure how to deal with this integral.  Many thanks for any help,  Adrian


What should I write in the question body if the title already explains everything?


Using bash "&" operator with ";" delineator?

I'm trying to write a command that's a one-line for loop containing a command that uses the & operator to put the command in the background:   for dir in $(ls); do command $dir &; done   Where & tells BASH to run command in the background. Yet BASH returns   bash: syntax error near unexpected token `;'   What's going on here? How can I use & in conjunction with ;? I tried enclosing things in quotes, like do "command $dir &" or do command $dir "&" but those have unexpected results.


I have recently been promoted to associate professor with tenure. But I want to relocate to another institution of similar rating. Is it possible to get an offer with tenure from another institution in the US? How common/uncommon is it in the US? Advices on the procedure with respect to the US academia will be highly appreciated. The central part of my question is about the possibility for retaining the 'tenured' status at the mid-career move (e.g., how common it is and how to negotiate).


Running a later model laptop of the win7 generation now running nicely under 8.1. Now I'm re-paving it and need to ensure that current drivers are available to the next install as painlessly as is possible. I don't want to wade thru the vendor's site hoping to coax them to give me 8.1 stuff when they have me of record at win7.  Is there a single place to go to copy folders off to a USB?


How to split and extract multispectral imagery in QGIS (2.18)

I am looking for a way to split multiband images and extract all the bands at once- instead of subsetting one band at a time.   Is there any method in QGIS which could allow for this? I know there are split RGB band tools but I have 8 band files.


How do you represent ideas and concepts visually?

Are there any books (or articles, websites etc..) that talk about the subject of "translating" ideas and concepts into graphics? I would like to learn about this and get some new ideas to help me as a beginning graphic designer.  Thank you in advance for any useful resources you can provide me with.  Regards,


Send email using the GMail SMTP server from a PHP page

I am trying to send an email via GMail's SMTP server from a PHP page, but I get this error:     authentication failure [SMTP: SMTP server does no support authentication (code: 250, response: mx.google.com at your service, [98.117.99.235] SIZE 35651584 8BITMIME STARTTLS ENHANCEDSTATUSCODES PIPELINING)]   Can anyone help?  Here is my code:  <?php require_once "Mail.php";  $from = "Sandra Sender <sender@example.com>"; $to = "Ramona Recipient <ramona@microsoft.com>"; $subject = "Hi!"; $body = "Hi,\n\nHow are you?";  $host = "smtp.gmail.com"; $port = "587"; $username = "testtest@gmail.com"; $password = "testtest";  $headers = array ('From' => $from,   'To' => $to,   'Subject' => $subject); $smtp = Mail::factory('smtp',   array ('host' => $host,     'port' => $port,     'auth' => true,     'username' => $username,     'password' => $password));  $mail = $smtp->send($to, $headers, $body);  if (PEAR::isError($mail)) {   echo("
" . $mail->getMessage() . "
");  } else {   echo("
Message successfully sent!
");  } ?>


How to evaluate a candidate skills for purely manual testing

Is there any well-defined process to be followed in evaluating a candidate for manual testing?


Show that the set of all irrationals is not countable

The power set of $\mathbb{N}$, $\mathcal{P}(\mathbb{N})$, is not countable as well as the sets $\mathbb{R}$, and $\{0, 1\}^{\mathbb{N}}$ the set of all sequences which takes values 0 or 1. Use this to show that the set of all irrationals is not countable.   We have the set $\mathcal{E} = (\mathcal{E}_{n}) \in \{0, 1\}^{\mathbb{R}}$ defined by $\mathcal{E}_{n} = 1 - f(n)_{n}$, where $f(n)_{n}$ is the n-term in the sequence $f(n) \in \{ 0, 1\}^{\mathbb{N}}$  We can find a subset of $\mathbb{R}$ to show that $\mathbb{R}$ is not countable:  $$ C = \left \{ \sum_{n=0}^{\infty} \frac{\mathcal{E}_{n}}{3^n}; (\mathcal{E}_{n}) \in \{ 0, 1 \}^{\mathbb{R}} \right \} $$  $C$ is the Cantor triadic set. So, $C$ is a subset of $[0,1] \in \mathbb{R}$, and it is bijection with $\{ 0, 1\}^{\mathbb{N}}$. Hence $\mathbb{R}$ is not countable. Since $\mathbb{R}$ is not countable and $\mathbb{Q}$ is countable, then $\mathbb{R}$ \ $\mathbb{Q}$ is the set of all irrationals and it's not countable since the union of two countable sets is countable.  Now, I'm looking for other solutions to prove it, please comment on


Consider the following HTML:
     aaaa     bbbb     cccc     dddd     eeee
   How can I use JQuery to match the [aaaa, cccc, eeee] elements? I've attempted  $('div > :not(span)')  $('div:not(span)')  $('div').not('span')   But they all returned an empty array.


Determining functions from specifications...

my high school teacher asked this question today, and I am struggling to find an answer that will work. The question is outlined below:  Give an example of a cubic polynomial, defined on the open interval (-3,3), which reaches both its maximum and minimum values.


By a d-metric on a set $X$ we mean a function $d : X × X \to \mathbb{R}$ satisfying the following two properties:   $d(x,y)≥0$ for all $x, y∈X $ and $d(x,x)=0$ for all $x, y∈X.$   The $d$-ball of radius $r>0$ centered at $x$ is defined as $B_r(x)=\{y∈X:d(x,y) < r\} $  We'll say the topological space $(X,T)$ is d-metrizable if there is a d-metric $d$ on $X$ such that $U$ is in $T$ if and only if for all $x \in U$ there exists a $d$-ball centered at $x$ which is contained in $U$. (I.e., the family of $d$-balls is a basis for the topology $T$.)  How can I prove that d-metrizable spaces are sequential?  (A topological space $X$ is  means every sequentially open set is open, where $A \subseteq X$ is sequentially open if whenever a sequence $( x_n )_n$ converges to a point in $A$, then $x_n \in A$ for all but finitely many $n$.)


File Recovery software for ubuntu 13.10 32-bit

Just a mont ago I copied pdf files from windows mount 'C:\' to linux OS home folder.   But since I was new to Ubuntu.while resolving oerheating problem through installing drivers My Ubuntu turned blank screen. So now I have Installed Ubuntu 13.10-32-bit again with bumblebee project.I have solved over heating problem .But my pdf files are lost. I want good file recovery software for ubuntu which can scan windows mount sda3 and recover those file(2.3GB).  On linux partition 'C:\' drive Is shown with name '2EE8844CE88413ED' .


Use the definition of derivative to find $f'(x)$ for $f(x) = x^{1/2}$.

This is an analysis question so we use the definition that the derivative of a function is, $$\lim_{x\to c} \frac{f(x)-f(c)}{x-c}$$ But I'm not really sure if I should just continue to say that $x=c$ for now as the second $x$ perhaps as if $f(x) = \sqrt c$. Obviously if we leave $x$ as is, $(f(x)-f(x)) = 0$ and the lim is $0$, but this is obviously not the case since $f'(x) = \frac{1}{2}\sqrt x$


What happens when FILE parameter is not given in grep ls folder1 folder2 new.txt new.cpp folder3 # -> folder 3 has all .cpp files with main grep -rl -e "int main" new.cpp folder3/one.cpp folder3/two.cpp  From   If no FILE is given, recursive searches examine the working directory  But if i removed -r it doesn't give any output and still running like infinite loop grep -l -e "int main"   From man pages it;s already recursive if there's no FILE parameter but if -r is removed nothing's happening. I'm a beginner what am i missing?


To avoid spending time on the internet I decidet to block several time wasting web sites I added rule redirecting several pages to localhost changine file     C:\Windows\System32\drivers\etc\hosts   I added following line     127.0.0.1 joemonster.org   But great idea could be redirect it to more valuable site like . The problem is that duolingo is listening on port 443.  Hosts files aren't for redirecting port but only for resolving addresses. How can I redirect joemonster to duolingo?


There are a variety of different forms of CAPTCHA and other strategies in order to prevent spam. To briefly list a few:   Simple math or word questions. Obfuscated text. JavaScript-based CAPTCHAs. Image CAPTCHAs. Honeypots. Audio CAPTCHAs. Rule-based filtering like Akismet. Gradual increase in privileges based on trust. Community moderation like StackExchange. Spam disincentives like nofollow attributes to links. Incentives for posting good content. Admin moderation. IP whitelists and blacklists. Public shaming and disgrace.   Each one of these approaches has obstacles to overcome due to accessibility issues, technical limitations, time restrictions, conversion problems, or size of community. The systems that I've seen working best are a combination of several of the above techniques. However, I can't help but feel as if we're missing something important when it comes to combating spam.  I know that it may be too much to wish for a single one-size-fits-all solution, but perhaps spam prevention could be approached from a different angle. I suspect that there may be more to explore in terms of the way the user interface influences human behavior.  I find that having constraints often triggers creativity, so given the following constraints, can we come up with any new tools to add to our arsenal against spam from a user interface perspective?   It must be accessible. It must be non-disruptive and transparent to the end user. It cannot detract or distract from the primary purpose of the page. It must be automated or require very little moderation on a large scale. It cannot be a 3rd-party service.


Can a real function $f$ on $[0,1]\cap\mathbb{Q}$ be differentiable?

can a real function $f$ on $[0,1]\cap\mathbb{Q}$ be differentiable?  if so, and if the derivative of $f$ is zero, then is $f$ is a constant function?


Can't give myself NOPASSWD privelege for chmod/chown

I'm trying to set my local computer (which has Linux Mint 13 Maya) so that I can chmod & chown  any file with my regular max user account.  Following this page,    I've done the following:  #edit the /etc/sudoers file via `visudo`  sudo visudo  #in the file, added these lines: Cmnd_Alias NOPASS_CMNDS = /bin/chmod, /bin/chown max ALL=(ALL) NOPASSWD: NOPASS_CMNDS   Then saved. (I got the locations for chmod and chown using which)  So, my visudo file now looks like this:  # # This file MUST be edited with the 'visudo' command as root. # # Please consider adding local content in /etc/sudoers.d/ instead of # directly modifying this file. # # See the man page for details on how to write a sudoers file. # Defaults        env_reset Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"  # Host alias specification  # User alias specification  # Cmnd alias specification  # User privilege specification root    ALL=(ALL:ALL) ALL  Cmnd_Alias NOPASS_CMNDS = /bin/chmod, /bin/chown max ALL=(ALL) NOPASSWD: NOPASS_CMNDS  # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL  # Allow members of group sudo to execute any command %sudo   ALL=(ALL:ALL) ALL  # See sudoers(5) for more information on "#include" directives:  #includedir /etc/sudoers.d   This is the output from sudo -l  $ sudo -l Matching 'Defaults' entries for max on this host:     env_reset, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin  User max may run the following commands on this host:     (ALL) NOPASSWD: /bin/chmod, /bin/chown     (ALL : ALL) ALL   I then open a new shell tab and try to sudo chmod a file which is owned by a different user & group, and it asks me for a password:  $ ls -l  tmp/0000000001 -rw------- 1 www-data www-data 19245781 Sep 10 16:59 tmp/0000000001  $ sudo chmod +w tmp/0000000001 [sudo] password for max:   Am I missing something here?  I don't know if I've done it wrong or have misunderstood what I was actually trying to change.  Do I need to reboot, or reload/restart something to see the change?


Just got Ubuntu mini 18.04 and I'm planning on making it specially designed for hacking & pentesting. I've got the basics such as nmap and some custom scripts but I'm wondering how to get the god of hacking tools - metasploit. Please don't just say "just use kali or blackarch" because I want this to be custom. All help will be appreciated.


Are the shift operators (>) arithmetic or logical in C?

In C, are the shift operators (<<, >>) arithmetic or logical?


Issue in File exporter while trying to export the documents

I am trying to export the contents from a salesforce org using file exporter.  I have installed Data loader 21.  After running the file exporter.bat: 2 folders created: 1. CSVs 2. Exported content CSVs folder has 4 files: ContentVersion.FileType.csv,ContentVersion.FirstPublishLocationId.csv,ContentVersion.Title &ContentVersion.VersionData.  In the exported content all the files are exported but the size is 0.  In the file exporter console window i see the msg:  "A duplicate file name exists , or the file cannot be found"  Now the issue is I am all the files but the size is o for all files.  Can anyone faces similar issue, can anyone suggest any solutions. Appreciate your help and support on this.


Executing QGIS tools in Python from Linux Shell

I would like to execute a Python script which uses QGIS Processing tools. On Ubuntu 20.x I installed qgis, qgis-common, python3-qgis and python3-qgis-common. My objective is to execute the tool  from shell within a python script. The following lines are working well within the QGIS-GUI Python Console from qgis.core import processing from qgis.core import * processing.run("qgis:explodehstorefield", {      'INPUT' : '/home/myacc/geodata.gpkg|layername=points',     'FIELD' : 'other_tags',      'EXPECTED_FIELDS' : '',      'OUTPUT' : 'ogr:dbname=\'/home/myacc/geodata_explode.gpkg\' table=\"points\" (geom)' })  My problem is, that processing.run is not recognized outsite the QGIS-GUI Python console. I tried to create a pre-build script from the modeller, but there is the same problem.


How can i create points per 10 and 100 meters for several lines with ArcPy?

I have 10 lines and i want to generate points per 10 and 100 meters for each one of them. In ArcGis there is the tool construct points(COGO) but is not scriptable. Is there any suggestion? Also i don't want to be saved in memory but in Hard disc, also i don't have the points i want to create them, with a loop, for several lines (10).


I need remove a the first N nodes of a XML inside of a String.      $xml = new SimpleXMLElement($xmlString, LIBXML_NOCDATA);      $node = $nodes->xpath("/data/event");     $total_nodes = count($node);      $delete_n_rows = $total_nodes-$N;      for($i=0; $i<$delete_n_rows; $i++){         if ( ! empty($node)) {            unset($node[i]);         }     }   But that code does not work on this xml inside of the String.  <data profile='color'><scale mode='month' today='February 2010'><x> <column><![CDATA[Monday]]></column> <column><![CDATA[Tuesday]]></column> <column><![CDATA[Wednesday]]></column> <column><![CDATA[Thursday]]></column> <column><![CDATA[Friday]]></column> <column><![CDATA[Saturday]]></column> <column><![CDATA[Sunday]]></column></x> <row height='224'><![CDATA[01|02|03|04|05|06|07]]></row> <row height='224'><![CDATA[08|09|10|11|12|13|14]]></row> <row height='224'><![CDATA[15|16|17|18|19|20|21]]></row> <row height='310'><![CDATA[22|23|24|25|26|27|28]]></row></scale>  <event week='4' day='3' type='event_clear' x='300' y='672' width='93.52554744525547'                     height='13' len='1'><![CDATA[• 06:00 Wicked]]></event> <event week='4' day='3' type='event_clear' x='300' y='696' width='93.52554744525547' height='13' len='1'><![CDATA[• 07:00 Ben Hur Live]]></event> <event week='4' day='3' type='event_clear' x='300' y='720' width='93.52554744525547' height='13' len='1'><![CDATA[• 07:00 Giselle]]></event> <event week='4' day='3' type='event_clear' x='300' y='744' width='93.52554744525547' height='13' len='1'><![CDATA[• 08:00 Billy Connolly]]></event> <event week='4' day='3' type='event_clear' x='300' y='768' width='93.52554744525547' height='13' len='1'><![CDATA[• 09:00 Giselle]]></event> <event week='4' day='3' type='event_clear' x='300' y='792' width='93.52554744525547' height='13' len='1'><![CDATA[• 10:00 Legally Blonde The Musical1]]></event> <event week='4' day='3' type='event_clear' x='300' y='816' width='93.52554744525547' height='13' len='1'><![CDATA[• 12:00 Giselle]]></event> <event week='4' day='3' type='event_clear' x='300' y='840' width='93.52554744525547' height='13' len='1'><![CDATA[• 12:00 Legally Blonde The Musical2]]></event> <event week='4' day='3' type='event_clear' x='300' y='864' width='93.52554744525547' height='13' len='1'><![CDATA[• 13:00 Legally Blonde The Musical3]]></event> <event week='4' day='3' type='event_clear' x='300' y='888' width='93.52554744525547' height='13' len='1'><![CDATA[• 14:00 Wicked]]></event> <event week='4' day='3' type='event_clear' x='300' y='912' width='93.52554744525547' height='13' len='1'><![CDATA[• 16:00 Billy Connolly]]></event> <event week='4' day='3' type='event_clear' x='300' y='936' width='93.52554744525547' height='13' len='1'><![CDATA[• 22:00 Jersey Boys]]></event></data>   As you see, I'm trying with SimpleXMLElement, but I will happy with any other solution too.


Is "with" or "by" the correct word in the phrase: Replaced ________ a new printer

English is my second language. Which of the following is correct?   Replaced with a new printer.  Replaced by a new printer.


"On a page" or "in a page" for a web page

Which is the correct usage:     Something on a page   OR     Something in a page   By page, I mean a web page, not a physical book page.


Query regarding a transformation of continuous random variables question

I have a query related to a transformation of variables question; the images of which I have attached here.  I have solved the question almost, but there seems to be a problem with the distribution that I have derived in the last line of the solution.  I would greatly appreciate any kind of help. Thanks in advance.  N.B.: In the question, $U$ should follow $N(\mu = 0, \sigma^2 = \frac{1}{4} = 0.25)$.


Show that a Set is dense in $(C[0,1],|| \cdot| |_\infty)$

I have to show that the set: $$M :=\{f\in C[0,1]:\exists L \gt 0 \: \forall x,y \in [0,1] \space \space \space |f(x)-f(y)| \leq L|x-y| \} $$ is dense in $(C[0,1],|| \cdot|  |_\infty)$  Any ideas?  Thanks in advance.


I'm trying to analyze my data using mlogit. I get singularity issues. I am very new to statistical modelling. Help appreciated!

The csv for the dataframe is . Basically the column Mode represents the transportation choice available for the user to go to the airport, Choice represents the user's choice, and all the other columns depict the variables affecting the choice. I am posting some code below. the mFormula function just segregates the variables into 3 parts separated by a '|' i.e   alternative dependent w generic coefficients | individual specific w alternative specific coefficients | alternative dependent w alternative specific coefficients  I tried two formulas with the mFormula function one of which outputs the coefficients(f1) but doesn't model the variables for the utility function as it should(f).  library(mlogit)  path=""  a<-read.table(path,sep=",", header=TRUE)   Ta<-mlogit.data(a,shape="long",alt.var="Mode",choice="Choice")    f <- mFormula(Choice ~ CostPersonal+CostTrainBus+CostCarpool+CostTaxi+CostSharedTaxi+CostCS+CostSCS+DistSYR+DistNYC+DistALB+DistEWR+SafteyPersonal+SafteyTrainBus+SafteyCarpool+SafteyTaxi+SafteySharedTaxi+SafteyCS+SafteySCS+PrivacyPersonal+PrivacyTrainBus+PrivacyCarpool+PrivacyTaxi+PrivacySharedTaxi+PrivacyCS+PrivacySCS+ConviniencePersonal+ConvinienceTrainBus+ConvinienceCarpool+ConvinienceTaxi+ ConvinienceSharedTaxi+ConvinienceCS+ConvinienceSCS+payUticaSYR+payUticaALB+flightsYear+daysBreturn+incomeB+familySize+ageB|Airport+TimePersonal+TimeTrainBus+TimeCarpool+TimeTaxi+TimeSharedTaxi+TimeCS+TimeSCS+luggage+ownVehicle+shuttleMaxPersonsB)  f1<- mFormula(Choice ~ 1| +0+CostPersonal+CostTrainBus+CostCarpool+CostTaxi+CostSharedTaxi+CostCS+CostSCS+Airport+DistSYR+DistNYC+DistALB+SafteyPersonal+SafteyTrainBus+SafteyCarpool+SafteyTaxi+SafteySharedTaxi+PrivacyPersonal+PrivacyTrainBus+PrivacyCarpool+PrivacyTaxi+PrivacySharedTaxi+ConviniencePersonal+ConvinienceTrainBus+ConvinienceCarpool+ConvinienceTaxi+ConvinienceSharedTaxi+TimePersonal+TimeTrainBus+TimeCarpool+TimeTaxi+TimeSharedTaxi+flightsYear+daysBreturn+luggage+ownVehicle+incomeB+familySize+ageB+shuttleMaxPersonsB+payUticaSYR+payUticaALB)   ml.a<-mlogit(f,Ta)#does not output coefficients ml.a<-mlogit(f1,Ta)#does output coefficients summary(ml.a)`  The error is:  Error in solve.default(H, g[!fixed]) :    Lapack routine dgesv: system is exactly singular: U[3,3] = 0   although mlogit with f1 does output the coefficients with a   Likelihood: -2.2039e-07   Clearly I don't understand which variables should and should not be included and co-relation between which ones is causing the issue.


$(2,x)$ is not a principal ideal of the ring $\mathbb{Z}[x]$

Let $R=\mathbb{Z}[x]$ be a ring of integers with usual addition and multiplication. Consider $$I:=(2,x):=\Big\{2\alpha(x)+x\beta(x)\ :\ \alpha(x),\beta(x)\in \mathbb{Z}[x]\Big\}.$$ I have to prove that the above one is ideal but not a principal ideal.   I have proved that    $(I,+)$ is a group and  $\forall f(x)\in \mathbb{Z}[x],\ \forall\  (2\alpha(x)+x\beta(x))=g(x)\in I, f(x)g(x) \in I,g(x),f(x)\in I.$   But I am unable to prove that it is not a principal ideal.


Why do some decks run only one of a card?

, for example, has 1x , 1x , and 1x . Since it's a 60 card deck the odds of drawing any one of them is 1/60. ie. quite slim. So why do they include cards they likely won't be drawing? Why not run 4x of each card? Gives you less versatility, I suppose, but what good is versatility if you don't draw the cards you need?


Residue at $z=0$ for the complex function $8z^2\sin(\frac{1}{z})$

I'm just learning calculating residue please help.


What would you call someone who plays hero in situations?

Example: You have a costumer you have been working with who purchases something then your coworker later says they purchased because of something they did (like discrediting you). Or another example would be, they are asked a simple question and then make it seem that the person who asked the question was freaking out and that they calmed them down even though the person was not freaking out at all? I thought self righteous may be right but now I am not sure.


How much does NASCAR affect the rotation of the Earth?

Many of us will be familiar with , in which someone spins counterclockwise to slow down the rotation of the earth and make the night longer.  The mass of an individual human is not all that much compared to the earth, so the gesture is poetic but futile. On the other hand, the mass of forty 3,300 pound cars driving counterclockwise is quite a lot more considerable.  How much does an individual NASCAR race affect the rotation of the earth? How much time does an individual NASCAR race remove from (or add to) the length of a day on our planet?  Let's assume we're operating on the 's not-quite-oval outer track , with 200 laps of a 2.5 mile track made by forty cars weighing exactly 3,300 pounds each. The race lasts approximately three hours.


How do you get the logical xor of two variables in Python?

How do you get the  of two variables in Python?  For example, I have two variables that I expect to be strings. I want to test that only one of them contains a True value (is not None or the empty string):  str1 = raw_input("Enter string one:") str2 = raw_input("Enter string two:") if logical_xor(str1, str2):     print "ok" else:     print "bad"   The ^ operator seems to be bitwise, and not defined on all objects:  >>> 1 ^ 1 0 >>> 2 ^ 1 3 >>> "abc" ^ "" Traceback (most recent call last):   File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for ^: 'str' and 'str'


I'm new to number theory and was wondering if someone could help me with this proof.  Prove: The product of any three consecutive integers is divisible by $6$.   So far I have $\cfrac{x(x+1)(x+2)}{6}$; How would I go about proving this? Should I replace $x$ with $k$ and then $k$ with $k+1$ and see if the statement is true?


Getting OS major, minor, and build versions for Windows 8.1 and up in Delphi 2007

I have seen in a few questions/answers on how to detect the OS version of Win 8.1 and 10.0 using VerifyVersionInfo (since GetVersionEx no longer works without manifesting), but this only allows me to check if the OS is a version you pass to the function. It does not return this info to me. For example, with GetVersionEx it would tell me the major, minor, and build versions, but with VerifyVersionInfo I have to essentially ask "Is the OS version 6.3 or greater?" or "Is the OS version 10.0 or greater?" since GetVersionEx now returns 6.2 for the OS version even if it is actually 6.3 or 10.0.  This is fine in that I can easily add this check to my code, but I now have no way of getting the build version since VerifyVersionInfo does not tell me this. Is it possible to still get the build version by some other means?  Here is what I am doing now to determine if the OS is 8.1 or 10.0:  function IsWindowsVersionOrGreater(wMajorVersion, wMinorVersion, wServicePackMajor: Word): Boolean; var   osvi: OSVersionInfoEX;   dwlConditionMask: Int64; begin   FillChar(osvi, sizeof(osvi), 0);   osvi.dwOSVersionInfoSize := SizeOf(osvi);   osvi.dwMajorVersion := wMajorVersion;   osvi.dwMinorVersion := wMinorVersion;   osvi.wServicePackMajor := wServicePackMajor;   dwlConditionMask := VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL);   dwlConditionMask := VerSetConditionMask(dwlConditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);   dwlConditionMask := VerSetConditionMask(dwlConditionMask, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);   Result := VerifyVersionInfo(osvi, VER_MAJORVERSION or VER_MINORVERSION or VER_SERVICEPACKMAJOR, dwlConditionMask); end;  function IsWindows8Point1OrGreater: Boolean; begin   Result := IsWindowsVersionOrGreater(HIBYTE(WIN32_WINNT_WINBLUE), LOBYTE(WIN32_WINNT_WINBLUE), 0); end;  function IsWindows10OrGreater: Boolean; begin   Result := IsWindowsVersionOrGreater(HIBYTE(WIN32_WINNT_WIN10), LOBYTE(WIN32_WINNT_WIN10), 0); end;  function GetWinVersion: string; var   osVerInfo: TOSVersionInfo;   majorVersion, minorVersion: Integer; begin   Result := '?.?';   osVerInfo.dwOSVersionInfoSize := SizeOf(TOSVersionInfo) ;   if GetVersionEx(osVerInfo) then   begin     minorVersion := osVerInfo.dwMinorVersion;     majorVersion := osVerInfo.dwMajorVersion;      if (majorVersion = 6) and (minorVersion = 2) then     begin       if IsWindows10OrGreater() then              // 8.1+ does not report correct version.         Result := '10.0'                          // NOTE: NO BUILD NUMBER       else if IsWindows8Point1OrGreater() then         Result := '6.3'       else                                        // This 6.2 is actually Win 8         result:=inttostr(majorVersion)+'.'+inttostr(minorVersion)+'.'+inttostr(osVerInfo.dwBuildNumber);     end     else       result:=inttostr(majorVersion)+'.'+inttostr(minorVersion)+'.'+inttostr(osVerInfo.dwBuildNumber);     end;  end;   EDIT: As suggested by David, the solution was to use WMI. This works with Win 8.1 and Win 10 and does not need you to keep an updated manifest with each new version of Windows.  function  GetWinVersion8AndUp(): String; const   WbemUser            ='';   WbemPassword        ='';   WbemComputer        ='localhost';   wbemFlagForwardOnly = $00000020; var   FSWbemLocator : OLEVariant;   FWMIService   : OLEVariant;   FWbemObjectSet: OLEVariant;   FWbemObject   : OLEVariant;   oEnum         : IEnumvariant;   iValue        : LongWord; begin;   Result := '';    try   try     FSWbemLocator := CreateOleObject('WbemScripting.SWbemLocator');     FWMIService   := FSWbemLocator.ConnectServer(WbemComputer, 'root\CIMV2', WbemUser, WbemPassword);     FWbemObjectSet:= FWMIService.ExecQuery('SELECT * FROM Win32_OperatingSystem','WQL',wbemFlagForwardOnly);     oEnum         := IUnknown(FWbemObjectSet._NewEnum) as IEnumVariant;     while oEnum.Next(1, FWbemObject, iValue) = 0 do     begin       Result := Format('%s',[String(FWbemObject.Version)]);        FWbemObject:=Unassigned;     end;   except   end;   finally   end; end;


In the entire universe, who else can lift Thor's hammer?

Who else can lift 's hammer?   Thor's hammer is so heavy, I heard only Thor can move or handle it.


Postfix still trying to send spam despite closing open relay

I have a small server at home, which has postfix installed.  It's only use is to return the results of cronjobs and email out externally for a few other scripts.  I use my ISP's mail server as a relay host.  It recently came to my attention that the mail server was acting as an open relay.  I fixed that problem by closing incoming port 25 on the router and reconfiguring postfix to only accept outcoming mail from the server.  I have checked with nmap externally from the LAN and tried various open relay tools and everything seems fine.  The problem is that I am still getting mail trying to be sent.  I have temporarily set the relay host to 127.0.0.3 (non-existent) to stop things being sent out and have set up iptable firewall rules on my server to prevent outbound port 25, so nothing is actually going out.  I thought the queues might still be full so I did:  sudo postsuper -d ALL deferred sudo postsuper -d ALL   But the mail keeps on coming in with the following log messages:     Dec  1 12:04:56 server postfix/pickup[3267]: E18411FA4: uid=33 from=   Dec  1 12:04:56 server postfix/cleanup[3274]: E18411FA4: message-id=<20111201120456.E18411FA4@server>   Dec  1 12:04:56 server postfix/qmgr[3268]: E18411FA4: from=, size=15619, nrcpt=1 (queue active)   Dec  1 12:04:57 server postfix/error[3304]: E18411FA4: to=, relay=none, delay=0.17, delays=0.1/0/0/0.08, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to 127.0.0.3[127.0.0.3]:25: Connection timed out)   So the question I have are:   How to determine where the incoming mail is coming from? i.e. which program on the server or from which other ip-address. What other ways can I debug this problem? Do you think I've been hacked and my server is compromised?


Cross-referencing issue with subcaption in beamer

Thank you in advance and support that provides this website for the tex users. I am a new member of the tex society almost a year now and I can say that most of my answers related to my problems have been answered previously here. Your work is really impressing taken in consideration that people are sharing knowledge for free.  Recently I came across with a problem that I think it is a bug of the system. I was trying to create a beamer presentation and by using \usepackage{subcaption} and \begin{subfigure} environment. While I was trying to use the \label and \ref points to my subfigure(s) I noticed that only the first \label was operating correctly as 1a. Unfortunately the rest are coming up as ??. I assume this is because the \ref points are located before the \label, but in this case all of them should not be operating correctly all should fail.  I was not able to find an answer relative to my question no matter how much I searched for. Maybe it is a bug of the system. I was just hopping that you could provide more information and maybe a solution to overcome this problem.  More information and the testing code can be found here: .  \documentclass[xcolor=pdftex,dvipsnames,table]{beamer} \usepackage[english]{babel} \usepackage{hyperref} \usepackage{cleveref} \usepackage{caption} \usepackage{subcaption}  \mode<presentation> \setbeamertemplate{caption}[numbered]  \begin{document} \begin{frame}  \begin{columns}[t]  \begin{column}[T]{5cm}  \begin{itemize}  \item<+-| alert@+> 1~\autoref{1}  \item<+-| alert@+> 2~\autoref{2} etc  \end{itemize}  \end{column}  \begin{column}[T]{5cm}  \begin{figure}  \only<1>{\begin{subfigure}[b]{1.0\linewidth}           \caption{sub caption 1}           \label{1}           \includegraphics[width=7.0cm,height=5cm]{fig 1}           \end{subfigure} }  \only<2>{\begin{subfigure}[b]{1.0\linewidth}           \caption{sub caption 2}           \label{2}           \includegraphics[width=5.5cm,height=5cm]{fig 2}           \end{subfigure} } \caption{main}  \protect\label{3}  \end{figure}  \end{column}  \end{columns}  \end{frame} \end{document}


Mapping k-means cluster centers and origins (measuring k-means accuracy)

Say I generate a dataset $X$: the first $i$ samples follow $x_i\sim N(\mu_1,\Sigma_1^2)$, the next j samples follow $N(\mu_2,\Sigma_2^2)$ and the last $l$ samples from $N(\mu_3,\Sigma_3^2)$. Naturally, I denote the clusters $(1,2,3)$ by the order of creation.  When using kmeans(X,3)$clusters I get the predicted assignment of the samples, but here lies the problem: kmeans might enumerate the clusters differently, for example set $N(\mu_2,\Sigma_2^2)$ as cluster#3 and vice versa. In this situation, I cannot compare the 'original' cluster assignment (say $(1,1,2,2,2,3,3,3,3,3)$) with the predicted one (say $(1,1,3,3,3,2,2,2,2,2)$). this will result with only 20% accuracy, even though the actual accuracy is 100%.  Any ideas of how to map the centroids or measure the accuracy of the kmeans performance?


Unlike Windows, you cannot maximize a window in Mac with a click of the button. The little green (+) button next to the red and yellow buttons at the left of the windows does some strange stuff sometimes when you click it and doesn't do the expected operations.  How would you fully maximize a window on a Mac?


How force affect the objects that we apply on?

Why do things get accelerated rather than do a moving at constant speed when we apply a force on them? How my force affect the object at atomic level? Does it increase the kinetic energy of atoms ? If it does, why ı can't observe the same event when ı heat them(cus both of these increase the kinetic energy)?


Saudi transit visa for more than 12hrs layover

I am travelling from Mumbai to Vienna and my layover in Saudi is 10hr 45 min and when I return from Vienna my layover in Saudi is 1hr 45min. Should I apply for a Saudi transit visa?


How can I find the version of Ubuntu that is installed?

I installed some version of Ubuntu on my VMware, but I don't know what version exactly it is. How can I find it out?


php var_dump() does not show non-english character

I am now working on Japanese projects. When I use var_dump() the japanese characters are not show correctly in browser. But English characters are showing correctly. How can I fix this problem. The following is portion of my var_dump() result,      'id' => int 71680   'customer_id' => int 16161   'amount' => string '1' (length=1)   'second_customer_id' => null   'second_amount' => null   'customer_name' => string 'é£›çŸ¥å’Œã€€å•“ä¸€' (length=18)   'second_customer_name' => null   'payment_flag' => string 'æŽ›' (length=3)   'payment_flag_id' => int 2   'order_id' => int 9108   'article_name' => string 'ç¥å£‡' (length=6)   'article_id' => int 1000001   'sales_price' => string '200000.0' (length=8)   'discount' => int 0   'ceremony_cooking_category_id' => null   'payment_date' => string '2014/12/05' (length=10)   'payment_hour' => string '0' (length=1)   'payment_min' => string '0' (length=1)   'hall_id' => null   'hall_name' => null   'hall_address' => null   'hall_tel' => null   'stock_date' => null   'stock_confirm_emps_name' => null   'check_date' => null   'check_emps_name' => null   'note' => string 'memo 333' (length=8)   'label' => string 'label 333' (length=9)


nginx / ssl: Always redirect to one of two https subdomains

My webserver supports the following two subdomains:       I want to create my nginx config so that:   $request_uri => $request_uri $request_uri => $request_uri Every other subdomain independent of http or https => $request_uri   I could not find any solution online that solves this problem. Can anybody help me out with the correct nginx config.


what's the difference between $SL(2,C)$ and $PSL(2,C)$?

Am I missing something? what's the difference between $SL(2,C)$ (matrices 2x2 complex coefficients and determinant 1) and $PSL(2,C)$ which is isomorphic to $PGL(2,C)$ (matrices of complex coefficients with determinant 1)? Are $PSL(2,C)$ and $SL(2,C)$ the same?


How can I disable the tooltip showing up on my dock items on hover?


Why are these formulas for the variance equal?

I am trying to understand why the simple bootstrap procedure does not work, but for now I would like to know why we can we write $s^2_n = \frac{1}{n} \sum^n_{i = 1} X^2_i - (\bar{X}_n)^2$ ?  This is a part of a paper by Liu and Singh (1992) Moving blocks jackknifes and bootstrap capture weak dependence.


What is the importance of 3rd axiom of dedekind's cut?  a Dedekind cut is a partition of a totally ordered set into two non-empty parts (A and B), such that A is closed downwards (meaning that for all a in A, x ≤ a implies that x is in A as well) and B is closed upwards, and A contains no greatest element.(From Wikipedia)  what is importance of statement "A contains no greatest element"?? Please explain in intuitive way.  Also my reasoning is that if you don't know what is greatest number in A how can you calculate Least Upper Bound for A which is required for completeness of R.


How to install multiple versions of the same software?

I manage phone systems for multiple clients. Each system uses the same administrator software, but it runs on different versions depending on what version of firmware is installed on the system controller.   The software is downloaded directly from the system controller so it's the right version. For example, if the controller runs on version 5.0.2, you have to run version 5.0.2 of the administrator software. You can't administrate a 5.0.2 controller with a later versions of administrator software.   Bottom line, you have to have the right version of software to log into the controller. The software is not executable on its own, you have to install it. So every time I want to log into a different controller, I have to reinstall the right software.   Any way to get around this?   I'm running Windows 7 Enterprise x86.


How do you start ubuntu unity 3D with the dash open? This is so that I can get things done fast. I would like to log in to my desktop with a full-screen dash without having to click the Ubuntu dash button.


Proving inequality on functions $x-\frac{x^2}{2}<\ln(1+x)<x-\frac{x^2}{2(1+x)}$

To prove: $$x-\frac{x^2}{2}<\ln(1+x)<x-\frac{x^2}{2(1+x)},\quad\forall x>0$$  I have used Taylor series expansion at 0 for both the inequalites. The greater than by expanding $\ln(1+x)$ and the less than by expanding $\int \ln(1+x)\,dx$ at 0.   Is there a cleaner / more elegant way of achieving the same?


Why doesn't a query on data.stackexchange.com show the most recent data?

I have  query: SELECT * from Posts WHERE OwnerUserId = 2545680  I've used my OwnerUserId. Why doesn't it show the most recent questions I asked?


How to rename different UV maps in blender 2.74

In every tutorial i've seen, there is a Name field under the "UV Maps" section of the Data for an object.  The latest tutorial i've seen said simply it was version 2.7.  I am using Cycles renderer.  However I have no Name field, nothing in right click, and nothing I could see in the UVs menu seems to have anything to do with naming it.    How can I rename my multiple UV maps?  Edit:  I didn't think to ask about renaming vertex groups because it wasn't obvious to me that they would have anything in common.


What is the difference between Register and volatile? when to use use which one ? what is the meaning to volatile register variable?

What is the difference between Register and volatile? when to use which one? what is the meaning of volatile register variable?  register int a;  volatile int a;


Is the electric force a vector or a vector field?

The electric force (Coulomb's law) on a point charge $Q_2$ due to $Q_2$: \begin{gather*} \mathbf{F}_{12}=\frac{Q_1Q_2}{4\pi\epsilon_0}\frac{\mathbf{r}_2-\mathbf{r}_1}{|\mathbf{r}_2-\mathbf{r}_1|^3} \end{gather*}  The seperation vector between the charges is $\mathbf{r}_{12}=\mathbf{r}_2-\mathbf{r}_1=(x_2-x_1)\hat{\textbf{i}}+(y_2-y_1)\hat{\textbf{j}}=(z_2-z_1)\hat{\textbf{k}} $.  Does this mean that the force is a vector field or just a vector?   Is the force a function of $\mathbf{r}_{12}$, so $\mathbf{F}_{12}=\mathbf{F}_{12}(\mathbf{r}_{12})$?


Insert result of a parallellized select query into a table, in Postgresql

According to ,      "Even when it is in general possible for parallel query plans to be   generated, the planner will not generate them for a given query if any   of the following are true:       The query writes any data or locks any database rows. If a query contains a data-modifying operation either at the top level or within   a CTE, no parallel plans for that query will be generated. This is a   limitation of the current implementation which could be lifted in a   future release."   Indeed, when I try to insert result of a parallel SELECT query into a table (either by SELECT.. INTO either by WITH..SELECT..INTO, the query is not executed as parallel query.  My question is: Is there any way to trick the Postgresql so that a SELECT query is executed as parallel query and then its result inserted into a table?


I had Windows 8 installed on my laptop. I then installed Ubuntu 12.04 along on separate partition. After a few days I mistakenly deleted the Ubuntu partition. Now I every time I start my laptop it don't show boot options (F2 & F12). It just gets stuck at a screen showing   unknown file name  grub rescue>   It's not booting either into Windows nor into Ubuntu.


Auto-rotate only for YouTube app, disabled otherwise

I find auto-rotate really annoying so I generally have it turned off.    Unfortunately, when I'm playing a YouTube video, it's equally annoying when I try to tilt the screen and then remember I have it turned off  :)   I would like a way to have auto-rotate working as usual when a YouTube video is playing, otherwise disabled.    Is that possible? I would like it all handled automatically, I'm not really interested in apps or widgets where I have to toggle a setting manually.  P.S. My phone is a Galaxy Nexus.


Avoiding the second leg of an international flight - different rates for a return ticket?

Possible Duplicate:          I am in the process of booking a flight from LAX - ZUR. I found a flight for approx. 1100 USD. However, if I book that flight and then continue, after a 5 hour layover, onward to SVO, The flight is approx. half of the initial price, and the first leg of the second flight is the exact same flight as the first booking. Assuming I travel light and do not check any baggage, are there any potential issues with this? Seems like a hell of a way to save a good chunk of change.


Riemann Rearrangement Associative property

I found that if the series $\sum {a_n}$ convergences conditionally, there exists the convergent rearrangement series $\sum {b_n}$.  For example, Let rearrangement of $$\sum {(-1)^{n+1} \frac{1}{n}} = ln2$$ is  $$ 1 - \frac{1}{2} - \frac{1}4 + \frac{1}3 - \frac{1}6 - \frac{1}8 + \cdots $$  Can I roughly associate some terms like this?  $$ \left( \frac{1}1 - \frac{1}2 - \frac{1}4 \right) + \left(  \frac{1}3 - \frac{1}6 - \frac{1}8 \right ) + \cdots $$  so, the normal term is  $$ \frac{1}{2n - 1} - \frac{1}{4n-2} - \frac{1}{4n} $$  like this?  If I calculate like this, the result is $\frac{1}{2} ln2$  But, can I assure that the associative property is valid for this rearranged series? I even don't know this series converges or diverges. Would you please give me the right, strict and reliable answer?  I want to show the possibility of associative property in this rearranged series. Because normally, the associative property is invalid in infinite series. Is it OK to associate some terms if the original form is convergent conditionally?


Suppose $a, b, c\in\mathbb R^+$ are such that $$(1 + a + b + c)\left(1+\frac1a+\frac1b+\frac1c\right)= 16$$ Then prove $a + b + c = 3$.  I tried to solve this by trial and error, put $a=b=c=1$. But I want to know how to solve it mathematically.


Compiling the following MWE with lualatex with makeindex, my index renders with no hyperlinks for page numbers:   %!TEX encoding = UTF-8 Unicode %!TEX program = lualatex \documentclass[11pt,a4paper,fleqn,pdftex]{report} \usepackage[utf8]{luainputenc}  \usepackage[latin,english]{babel} \usepackage[unicode=true,colorlinks=true]{hyperref} \usepackage{imakeidx} \makeindex  \begin{document}     Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas at quam libero. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. \index{Donec} nulla diam, dignissim sed ligula et, mattis efficitur augue. Ut vel rutrum lacus. Nulla sed lorem vel lacus convallis pharetra. Phasellus fermentum arcu eget magna placerat, sit amet egestas enim viverra. Integer eu ex mollis nisi ultrices congue sed eget nunc. Duis sed ipsum eu ligula hendrerit placerat.      Etiam vitae massa in magna \index{hendrerit} pharetra. Vestibulum lectus purus, rutrum at sollicitudin eu, dignissim quis diam. Suspendisse potenti. Vestibulum commodo justo vitae pretium fermentum. Donec ornare pulvinar ligula non ultrices. Nullam at rutrum nunc, a volutpat metus. Aliquam id velit varius massa feugiat malesuada congue at dolor. Interdum et malesuada fames ac ante ipsum primis in faucibus. Nunc quis magna nisi. \index{Vestibulum} efficitur justo turpis, eget ultricies sem iaculis in. Nulla sit amet urna lorem. Sed magna elit, fringilla in augue sit amet, pellentesque semper nunc. Mauris enim urna, dictum vel nisi vehicula, congue euismod ligula.       Morbi consectetur efficitur purus, vel vestibulum risus hendrerit nec. Curabitur mattis dolor eget lorem imperdiet, id maximus massa porttitor. Vivamus sit amet urna ut est fringilla porta ac sed leo. Nunc ac lectus ullamcorper, accumsan dolor dictum, tincidunt quam. Praesent condimentum ultricies magna, at placerat neque molestie sit amet. Vivamus a nisl et sapien imperdiet finibus eget vitae nulla. Curabitur semper sem non leo elementum, vitae lobortis massa cursus. Pellentesque sodales rutrum tempus.      In ut purus elementum, scelerisque mauris pellentesque, pretium nisl. Sed eget luctus nisl, eu accumsan nisl. Phasellus purus erat, blandit nec odio a, rutrum ultrices mauris. Proin interdum justo eget mollis volutpat. Donec tellus diam, scelerisque sit amet laoreet eget, tristique ac magna. Aliquam posuere commodo nulla, sit amet vehicula sapien efficitur eu. Maecenas vel elit facilisis, aliquet elit sit amet, euismod augue. Donec ac risus porttitor, vulputate ex ut, finibus ipsum. Pellentesque aliquam ac nisi sit amet luctus. Mauris cursus facilisis egestas. Cras \index{vulputate} nunc purus, id dictum mi tincidunt vel. Morbi finibus tortor mauris, a sagittis justo luctus ut. In lobortis felis vel lorem mollis cursus. Curabitur sit amet iaculis purus. Proin ac dolor non nibh ultricies facilisis.      Nulla consectetur eget sapien in pulvinar. Mauris sollicitudin ornare lorem, ut auctor magna imperdiet nec. Donec et nibh ipsum. Curabitur a tortor condimentum turpis pretium ornare. Vivamus quis feugiat nisl. Curabitur at rutrum lorem, sit amet consequat neque. Duis \index{convallis} a ipsum sit amet sodales. Sed eleifend feugiat aliquam. Morbi efficitur est odio, vel sagittis mi condimentum sed. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Maecenas vulputate dapibus leo vel ornare. In fermentum libero nulla, vitae faucibus quam scelerisque venenatis. \printindex \end{document}   Looking at the .idx file, the list items are showing as \item ABCDE, ## instead of \item ABCDE, \hyperpage{##}.   Are there some package clashes in my preamble?  If that could matter, texindy returns ERROR: Opening file "./FILE.ind" failed! for the same file.


Why doesn't exposure change when changing focal length?

With a Canon 550D camera and a Tamron 18-270 mm zoom lens, I tried to fix shutter time, aperture (f/8.0 to cover all zoom range), and ISO, so the exposure meter read 0.0 with 18 mm focal length and while focusing on a uniform white wall.  Then I changed to 270 mm focal length, but the exposure reading did not change significantly (only to -0.7).  However, I had expected exposure to change, since only (18 mm / 270 mm) ** 2 = 1/225 of the wall is now covered in compare the coverage when focal length is 18 mm, thus only 1/225 of the light gets to the sensor after the change of focal length.  Why does exposure not change when narrowing the field of view with change of focal length?


Can we theoretically balance a perfectly symmetrical pencil on its one-atom tip?

I was asked by an undergrad student about this question. I think if we were to take away air molecules around the pencil and cool it to absolute zero, that pencil would theoretically balance.  Am I correct?  .


Java if or statement not working as expected

The or statement in the first line of my if statement is not working as i would expect it to, any suggestions?  if(answer == "deposit" || "Deposit"){         System.out.println("How much would you like to deposit?");         final int deposit = console.readInt();         account.deposit(deposit);         System.out.println( "This leaves you with $" + formatter.format(account.getBalance()) + " in your account");     }else if(answer == "Check Balance"){         System.out.println( "You have $" + formatter.format(account.getBalance()) + " in your account");     }else if(answer == "Withdraw"){         System.out.println("How much would you like to take out?");         final int with = console.readInt();         account.withdraw(with);         System.out.println( "This leaves you with $" + formatter.format(account.getBalance()) + " in your account");     }else{         System.out.println("You didn't enter a correct term, please try again.");     }


demostrate Jensen's inequality (i think)

Please any help is very good. I was trying to start with the definition of expected value but I don't know how to finish.


I need to return my computer to the company after our mass lay off. I want to remove everything. I care nothing about any files. Just need it ALL removed. Please advise me, as I am obviously a novice. Thank you in advance!!


How to make subsections not appear in the text?

I have the following preamble and I want the subsection not to be visible in the text.  Instead of Chapter 1 "Blah Blah" I only want "Blah Blah to be visible. With this code I did it bu the subsections are still visible in the text. e.g. 2.5 "blah blah".  How can I also remove 2.5 ??  \documentclass[a4paper,12pt]{book} \usepackage{titlesec}  \titleformat{\chapter}[display]{\normalfont\huge\bfseries}{}{20pt}{\Huge}  \let\cleardoublepage\clearpage \usepackage[english,greek]{babel} \usepackage[utf8x]{inputenc} \usepackage{blindtext} \usepackage[pdftex]{graphicx} \usepackage[skip=2pt, font=small, labelformat = empty]{caption}  \newcommand{\gr}{\selectlanguage{greek}} \newcommand{\en}{\selectlanguage{english}} \usepackage{wrapfig} \usepackage[paperwidth=17cm, paperheight=24cm]{geometry}   \usepackage[onehalfspacing]{setspace} \usepackage{textcomp} \useshorthands{;} \defineshorthand{;}{?} \usepackage{fancyhdr} \fancyhf{} \fancyhead[LE]{\nouppercase{\leftmark}} \fancyhead[RO]{\nouppercase{\rightmark}} \fancyfoot[LE,RO]{\thepage} \pagestyle{fancy}  \renewcommand{\chaptermark}[1]{ \markboth{#1}{} } \renewcommand{\sectionmark}[1]{ \markright{#1}{} }


Why does changing the number of protons cause such a fundamental change in an element?

When we change the number of electrons in an atom of an element, it constitutes an ion. When we change the number of neutrons of an element it constitutes an isotope. But when we change the number of protons of an element, the change is so drastic that it constitutes a whole new element.  Why is it so?


Cannot open zip created with shell script

I try to make a backup script, but when i create a zip with the script, and use cd myzip it sais that it dosnt exitst even when i can see it on the server with FileZilla.  This is my script:  TIME=BACKUPMC-`date +%d-%m-%Y-%H:%M`.zip DEST="/home/daixhosting/d1" zip -r $TIME /home/daixhosting/d1   Does someone know what the cause can be?


Why is the range of signed char -127 to 127 in C++11?

I was reading through The C++ Programing language 4th Edition by Bjarne Stroustrup and i was not able to fully understand the following paragraph mentioned in Page 141.     Each character has an integer value in the character set used by the  implementation. For example,   the value of 'b' is 98 in the ASCII character set. Here is a loop that outputs the the integer value   of any character you care to input:   void intval() {     for (char c; cin >> c; )         cout << "the value of '" << c << "' is " << int{c} << '\n'; }      The notation int{c} gives the integer value for a character c (‘‘the int we can construct from c’’).   The possibility of converting a char to an integer raises the question: is a char signed or unsigned?   The 256 values represented by an 8-bit byte can be interpreted as the values 0 to 255 or as the values −127 to 127. No, not −128 to 127 as one might expect: the C++ standard leaves open the possibility of one’s-complement hardware and that eliminates one value; thus, a use of −128 is nonportable.   Unfortunately, the choice of signed or unsigned for a plain char is implementation defined.   C++ provides two types for which the answer is definite: signed char, which can hold at least the values −127 to 127, and unsigned char, which can hold at least the values 0 to 255.   What is the possibility of one's complement hardware that c++ standard leaves? Is it to avoid the same representation of +128 and -128 in 8 bit?


\href and \includegraphics not making hyperlinks in XeLaTeX

I need to make hyperlink on a image. For that, I setup as follows.  \href{http://stackexchange.com/users/1170155/thekojueffect?tab=accounts}{\includegraphics[height=11pt]{stackexchange.png}}   The graphics is shown but the hyperlink is not created.  But when I add text like  \href{http://stackexchange.com/users/1170155/thekojueffect?tab=accounts}{\includegraphics[height=11pt]{stackexchange.png}~StackExchange}   The hyperlink is created on the text "StackExchange" but I don't want to have text.  How can I create hyperlink on a graphics?  Any hacks/ideas?  I'm using Ubuntu and xelatex -version gives  XeTeX 3.1415926-2.4-0.9998 (TeX Live 2012/Debian) kpathsea version 6.1.0 Copyright 2012 SIL International and Jonathan Kew. There is NO warranty.  Redistribution of this software is covered by the terms of both the XeTeX copyright and the Lesser GNU General Public License. For more information about these matters, see the file named COPYING and the XeTeX source. Primary author of XeTeX: Jonathan Kew. Compiled with ICU version 49.1 [with modifications for XeTeX] Compiled with zlib version 1.2.7; using 1.2.7 Compiled with FreeType2 version 2.4.10; using 2.4.11 Compiled with fontconfig version 2.10.1; using 2.10.2 Compiled with libpng version 1.2.49; using 1.2.49 Compiled with poppler version 0.20.5


I'm having trouble aligning an image with text.  I want my image on the left, and the text inline on the right, centered vertically to the image.
                        555-1212
   Right now, the text hugs the top of the container.  How can I center it vertically to the middle of the container?


I need help with the following problem:  Let $n$ and $m$ be positive integers.   Prove that  $$\frac{\gcd(n,m)}{n}{n \choose m}$$  is an integer.


Is a black hole really connecting two parallel universes?

What is beyond the point of singularity in a black hole and universe expands in all the three $x$, $y$ and $z$ axis?  So how can one thing be on top of another when we don't know where the end point of the things is?  And how does a black hole connect two parallel universes?  And if there is another universe then is there another milky way, solar system and Earth?  And how does a black hole connect them?


How to Unmount WIndows Partition Disk Permantely

I have dual OS (Windows 8 and Ubuntu), when I using Ubuntu, Windows partition Disks are automatically mounted in Explorer. I need to unmount permanently on every boot or permanently. I tried this in Gparted but when reboot it again mounted. Kindly Share your views.


I have tried to open a .accdb file on libreoffice and a few other ms access clones, but without any success. I saw some questions asked almost 10 years ago proposed installing something, but I am not sure if that is a safe or relevant option anymore.


Traceless multipole moments vs non-traceless moments

There are two different possibilities to define the electric quadrupole tensor:  On the one hand, one can define \begin{align}Q_{kl} = \int \rho(\mathbf r') \cdot r'_k \, r'_l  d^3r',\end{align} while on the other hand most of the textbooks (for example Jackson) define \begin{align} Q_{kl} = \int \rho(\mathbf r') \cdot (3r'_k \, r'_l - (r')^2 \, \delta_{kl}) \cdot d^3r'.\end{align}  For all higher moments, these two definitions (traceless vs. nontraceless) are also possible. Is there any physical reason why one of the definitions should be preferred?


"It was from that moment where" vs. "it was from that moment when"

Now that I think about it, it was from   that moment where I started to have   doubts about him.   Would it be better to use the word "when" instead of "where," or are they both equally valid word choices? Is there any difference at all?


Linked server returned message "Query timeout expired."

We have two separate SQL Servers. On one server we have a data warehouse (DWH), on the other we have sales information database.  Now on the DWH server there is an ETL job that collects the information from the sales server. The job runs daily after midnight. The DWH collects the information via linked server from the sales database.  Now, the most time the ETL job runs without any problems. But sometimes it fails because of query timeout. We have found out, that there is a specific pattern: The failure happens every 11th day. So on the 11th day the ETL job fails to collect information.   The following error occurs:     SQLNCLI11 for linked server “my linked server” returned message “Query timeout expired.”   Note: The job fails usually 10 minutes after start.  We have searched everything and could not found out what this issue causes. Also we know that the amount of data is every time, almost the same. Also there is no any scheduled job that runs all 11 days or something.  The remote query timeout on the linked server is set to 0.  Our next step will be, to turn off the antivirus programm on the sales server, to check if this causes the problem.  Does anyone have any clue or idea, where i can search further to find the problem?


How to create split tar archive in multiple stages to save space?

I have a very large folder that I am trying to create a tar archive of. The issue is I don't have enough extra free space to store the entire archive so I want to create say 100-200GB chunks of the archive at a time and transfer those individually to cloud storage. I need to be able to control when new chunks are created so my HDD doesn't fill up but all of the commands i've found to create split tarballs always create it all at once, in the same directory. The closest solution I found was from  but all the responses base the archives on number of files, not size which is important for my use case as my file sizes are unevenly distributed.


I have made a bootable USB. I have made 100s of them before. I have a dual boot pc, Kali and Ubuntu.   I want to reinstall Kali from USB (alongside my UBUNTU), but the computer will not boot to USB anymore. Burning ISO to DVD is really absurd.  Why can't I boot to USB anymore?


Checking existence and syncing data with millions of rows

I am developing sms based service platform. In India, we have two different types of routes to send sms - promo & trans. Sms sent via promo route has to be checked against nationally maintained database (DND), which currently holds 231450000 mobile numbers.  My question is   What is the efficient way to store this data (DND). What is the efficient way to check, whether the number exists within these numbers or not. Twice in a week, a delta dump of these numbers (DND) is provided by telecom authority. How to sync the dump with existing db. Should I use mysql to store this data, which will consist of mobile numbers, or any other in-memory storage?   EDIT:   Each row of data consists of mobile number alongwith few preferences like area code, user preference etc The data dump provided twice a week contains only additions / deletions and not the whole data. Lookup frequency can be very large. Actually every SMS sent from the platform has to first make a lookup against the data (DND). So if the platform is handling 100 sms per second, it has to make 100 lookups per second against this data. The lookup simply checks existence of a particular mobile number against the data(DND) in database. The new delta data dump (additions / deletions), has to be synced in few hours only, as the dump is provided by telecom authority in the day and the same has to go live by midnight 00:00 hours. So the total time to sync data will be around 3 hours.   Sample DND dump    Sample of DND dump provided. Here A under Opstype means record has to be added, while as D means record has to be deleted.


Since updating to iOS 11, I've lost the ability to surface apps from the swipe-down Spotlight search field. This was my preferred method of launching apps as it was quite a lot more convenient than swiping through endless pages of icons.  I found a couple of references (, ) pointing out that this behavior has been changed in iOS 11. Users are now forced to enable Search & Siri Suggestions for EACH app (found under Settings > Siri & Search)    If you do not do this, then the only way to surface an app via Spotlight is to type out the FULL APP NAME verbatim. Yes, that's C-a-l-c-u-l-a-t-o-r.  Not enough, apparently...    That last R — convenient!    Also, search does not yield the same result as past versions. Now, content from within the apps is also displayed. For example, if Evernote has its Siri function enabled, not only will the app itself show up in Spotlight, but also any notes inside Evernote that contain your search term. This is unwanted and potentially hazardous to privacy.  There seems to be no way to disable this or revert its behavior. I am posting this as a warning as well as a plea to any Apple engineers who might stumble onto this post. Apple, please fix this broken feature.


Low-Poly 3D Models are exporting but materials aren't

I'm planning on making a short animation so I kept all the models, props and assets separated in folders. Problem is, when I try to append each object into one scene, their colors (Basic colored Materials) is excluded. I've also noticed the same problem when I open those files (FBX format) in Mixed Reality Viewer, and all I get is a plain object    compared to what I am expecting that was rendered in blender (see image below);    I'm EXTREMELY worried that I have to apply UV mapped textures to every model I made for this to work properly especially for the future since I need to be exporting these models as well in UNITY. Any workaround on this or on how I may be able to fix this problem without applying uv map? Note: I tried baking but it didn't work for me :(


What are the differences between new and +new in javascript something like this?  var myVar = new function()   and   var myVar = +new function()


sortexpression gridview order desc doesn't work

hi have a gridview with sortexpression setted in columns. If i click on column title the table is ordered by asc, if  i click another time on title column the table doesn't change.  I want that on second click the table is ordered by desc.  How can i do it?  thanks


Hello guys I'm actually new to Terminal and Python. Just started following a Python tuturial on my Ubuntu and I've reached a part where it asks me to save a .py file and open it in Terminal.  Only when I try to type on Terminal $ python egotrip.py I get $: command not found Then I try to type it in python and I get   File "", line 1     python egotrip.py                  ^ SyntaxError: invalid syntax  But I mean all names are correct :(  Then I gave also tried /home/anacah/Desktop/python/egotrip.py And I get   Traceback (most recent call last):   File "", line 1, in  NameError: name 'home' is not defined  What am I doing wrong? :(  can someone please help?


The task is to calculate:                             $128! \pmod{257}$ I know that I'm supposed to use Wilson's theorem but I don't know how to apply it here.  [Reopen note: we already have answers (e.g. ) showing how to use Wilson's theorem to deduce $\,128!^2\equiv -1\equiv 16^2\pmod{\!257}\,$ so what remains is proving whether $\,128!\equiv 16\,$ or $\,128!\equiv -16\pmod{\!257}\ $ -- Bill D.]


Find the cardinality of the set $~\{t \in[0,3 \pi]: x(t)=0\}$

Question: Let $~x:[0,3 \pi] \rightarrow \mathbb{R}~$ be a non-zero solution of the ODE $$x^{\prime \prime}(t)+e^{t^{2}} x(t)=0~,~~\text{for}~~~t \in[0,3 \pi]~.$$ Then the cardinality of the set $~\{t \in[0,3 \pi]: x(t)=0\} \text { is }~$ $(1)~~$ equal to $1$ $(2)~~$ greater than or equal to $2$ $(3)~~$ equal to $2$ $(4)~~$  greater than or equal to $3$ Note: I edit this question and recommend to reopen this question because I think it is different from the proposed question. Note that I have an answer of the editor question.


How to change enumerate steps from 1 to 10

I have an enumerate environment  \begin{enumerate}[font={\bfseries}, label={\arabic*}, wide=0pt, labelindent=1em, leftmargin=*]     \item \end{enumerate}   where \arabic counts in steps of 1 (1, 2, 3, 4 etc) I know, I could just put a 0 behind \arabic*, but I would like to know if there is any functionality to change the counter steps of enumerate


I was given the proposition, ∃x,y ∈ R, x is irrational and y is irrational and x+y is rational To prove this, I first converted it into an if statement since it would make it easier to prove. I got, If -(∃x,y ∈ R, if X and y are irrational then X + y is irrational). From what I know, if I prove that the statement inside the brackets is false, by negating it, it would prove that the original proposition is true. However, I can't think of a way to prove this. Can someone help me out?