I am trying to access the CSV file's data using the Java and Apache commons CSV library.  I am stucked in a problem.  The problem is: "To Display the data of particular row if "Name" Header is equal to the "rahul". when I run the code nothing is printed out there."  The data in exportdata.csv file is :   Name,Food,Phone rahul,Rice,9876416884  ram,Egg,8437123456 rohit,Burger,9814125755 amit,chicken,8568934464   And my code is :  public class csvexample {   public void readfile()  {     FileResource fr=new FileResource();     CSVParser parser=fr.getCSVParser();     for(CSVRecord record : parser)     {          String str=record.get("Name");         System.out.println(str);          if(str=="rahul")         {         System.out.print(record.get("Name") + "    ");         System.out.print(record.get("Phone") + "    ");         System.out.println(record.get("Food"));         }               } }   I think that the error is in the line if(str=="rahul") , I have checked that the program is not treating the str and "rahul" same when str="rahul" in First iteration of for loop.
I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?
Since Newton's law of gravitation can be gotten out of Einstein's field equatons as an approximation, I was wondering whether the same applies for the electromagnetic force being the exchange of photons. Is there an equation governing the force from the exchange of photons? Are there any links which would show how the Coulomb force comes out of the equations for photon exchange? I know that my question is somewhat similar to the one posted here , but it doesn't really have an answer to my question specifically. I was just chatting on the Ask Different chat - and the reputation numbers for me and the others chatting don't seem to match any other reputation count I can see on the sites here.  Is there some calculation being made? These numbers are the highest of any other combined reputation I have seen. For me - I'm listed over 10k - but no other aggregate reputation counter I can see is above 8k.  Perhaps I'm unaware how reputation is calculated, but the people there suggested a bug report in case this isn't intended.  (after three lines of text are drawn - a number shows beneath our icons in the left hand side) How can I save application settings in a Windows Forms application? When I boot my Windows 8 laptop (see details below), it displays this message:  Recovery  Your PC needs to be repaired  A required device isn't connected or can't be accessed.  Error code: 0xc0000225  [ A text saying I should use recovery tools on my installation media to fix the issue. ]  Press Enter to try again  Press F8 for Start-up Settings  Press Esc for UEFI Firmware Settings   If I press Enter or F8, the central part of the message changes to:  The application or operating system couldn't be loaded because a required file is missing or contains errors.  File: \Windows\system32\winload.efi  Error code: 0xc0000225   I don't have a recovery disk and I have owned this computer for a year with no problems. All I did prior to this error was unistall avast and restart. I can only access UEFI Firmware Settings and have no clue what to do from there. PLEASE HELP! Compiling documents online I have heard rumors that you can compile documents online, and more specifically that Google has a free online compiler, but I have never been able to find any. Is there a way to compile documents online, so that I can write and compile documents even if I don't have a TeX distribution installed on my computer? Updating entities in response to collisions - should this be in the collision-detection class or in the entity-updater class? Windows 10 ver 1607: File Explorer long paths not working? I updated to the Windows 10 home anniversary edition version 1607 and set LongPathsEnabled to 1 with regedit.exe but the File Explorer doesn't seem to work with long paths still. If you select a long path file and try to rename it, no option will be available. I restarted the computer after making the changes and update.   Is there any way to enable renaming in the File Explorer in the new updated version? Did I miss a step somewhere? Total width of element (including padding and border) in jQuery As in the subject, how can one get the total width of an element, including its border and padding, using jQuery?  I've got the jQuery dimensions plugin, and running .width() on my 760px-wide, 10px padding DIV returns 760.  Perhaps I'm doing something wrong, but if my element manifests itself as 780 pixels wide and Firebug tells me that there's 10px padding on it, but calling .width() only gives 760, I'd be hard pressed to see how.  Thanks for any suggestions. How to make a press proof with crop marks and color bars? A standard proof for press needs crop marks and color bars as below    With the package crop, the crop marks can be easily added.  But how about the color bar ?  Is there a way or a package to make it ?  An example is   \documentclass[b5paper,10pt]{article} \usepackage[utf8]{inputenc} \usepackage[cross,a4,center,info,axes]{crop}  \title{Test} \author{User} \begin{document} \maketitle \section{Fox} The quick brown fox jumps over a lazy dog. \end{document} What is time dilation really? Please will someone explain what time dilation really is and how it occurs? There are lots of questions and answers going into how to calculate time dilation, but none that give an intuitive feel for how it happens. Can I get back my saved data? Can my spouse receive an emergency UK visa to visit a funeral? I'm a British national. My grandmother just passed. My wife is Chinese. In general it's a major pain to get my wife a visa to visit the UK, we have never been before.  Is there any way to get an emergency visa to attend the funeral?  What sort of documents would we need? How to install Blender from the official website I installed Blender from official Ubuntu repository but its version is always behind the version available from the official Blender website.  I'm aware that I can launch the program within the downloaded folder, but i want to replace the install version with a new version downloaded from the website?   It must be present in the unity launcher.  I'm also aware of the available PPA's that are available, however I just want to install Blender manually.  Thanks in advance I have been wondering about the differences between model paramters and model hyperparameters, as well as what their categorization means for a learning problem.  Is the distinction between model parameters and hyperparameters only about reducing the complexity of the problem or are there implications for the 'model quality' to be considered?  Let's consider an example from (1, Eq. 2.43), a linear expansion of basis functions   $$f_\theta(x) = \sum_{m=1}^{M} \theta_m h_m(x), $$  where $h_m\:\forall m=1,...,M$ is some function of $x$, $\theta=[\theta_1,...,\theta_M]^\intercal$ is a vector of the parameters of the model and $M$ is the number of basis functions.   In my understanding, we would consider $\theta$ to contain the parameters of the model, while $M$ is a .  To quote the Wikipedia article of hyperparameter that I linked above:     In machine learning, a hyperparameter is a parameter whose value is   set before the learning process begins. By contrast, the values of   other parameters are derived via training.   It makes sense treating the values in $\theta$ as parameters that should be learned from the data, similar to the coefficients in a linear model - it is surely far more reliable  and  specifying them manually would be quite annoying, although it's not impossible. But what about $M$? It surely is easier to pick some integer value for it. But would it really be terrible to determine $M$ based on the data, too? Probably not, as that is what we would do if we search a grid of possible values for the best performing one.   Let's consider the above basis expansion model and choose Gaussian kernel functions to serve as basis functions. As the Kernel itself has parameters too  this makes the problem a bit more complicated.  $$f_\theta(x) = \sum_{m=1}^{M}\theta_m K_{\lambda_m}(\mu_m,x), $$ with $\mu_1,...,\mu_m$ being the location of the kernels and $\lambda_1,...,\lambda_m$ their scales/bandwidths.  Friedman et al. write in (1, p. 36)        "In general we would like the data to dictate them as well. Including   these as parameters changes the regression problem from a   straightforward linear problem to a combinatorially hard nonlinear   problem. In practice, shortcuts such as greedy algorithms or two stage processes are used."   I see that if we were to treat $M$, $\theta_1 ... \theta_M$, $\mu_1 ... \mu_M$ and $\lambda_1 ... \lambda_M$, as model parameters, this problem would be really complex, especially with the choice of $M$ determining the number of the other parameters. But what if we simplify the model definition - let us for example use the same scale/bandwidth for each kernel, that gives us only one parameter $\lambda$. Furthermore, let's say we specify $\mu_1 ... \mu_M$ based on some heuristic, which would mean we treat it as a hyperparameter.  This gives us   $$f_{\theta,\lambda}(x) = \sum_{m=1}^{M}\theta_m K_\lambda(\mu_m,x), $$  Besides increased complexity of the involved optimization problem, does treating $\lambda$ as a parameter rather than a hyperparameter have other negative or undesired effects?      (1) Friedman, Jerome, Trevor Hastie, and Robert Tibshirani. The   elements of statistical learning. Vol. 1. No. 10. New York: Springer   series in statistics, 2001. HTTP GET request in JavaScript? I need to do an  request in JavaScript. What's the best way to do that?  I need to do this in a Mac OS X dashcode widget. A feature of C++ is the ability to create unnamed (anonymous) namespaces, like so:  namespace {     int cannotAccessOutsideThisFile() { ... } } // namespace   You would think that such a feature would be useless -- since you can't specify the name of the namespace, it's impossible to access anything within it from outside. But these unnamed namespaces are accessible within the file they're created in, as if you had an implicit using-clause to them.  My question is, why or when would this be preferable to using static functions? Or are they essentially two ways of doing the exact same thing? Causes of hexagonal shape of Saturn's jet stream NASA has just shown a more detailed picture of the hexagonal vortex/storm on Saturn:           Is that theoretically understood what is the cause behind this eye-catching nontrivial, regular yet not circular, shape? If so, what is the cause? I expect some explanation in terms of "nonlinear equations" of "mathematical physics" and "solitons".  P.S. (added a day after this question and the first answer was posted): On  where I posted the same question, people came up with some articles and phrases like "Rossby waves" and "resonance of latitude-dependence Coriolis frequency". Correct position of "only" Which is grammatically correct?  I can only do so much in this time.  or  I can do only so much in this time. I use ps -ef | grep catalina | grep -v grep to print the tomcat process running on the system:  kshitiz   7099     1  0 May11 ?        00:02:29 /usr/lib/jvm/jdk1.8.0/bin/java -agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:38156 -Dcatalina.base=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1 -Dcatalina.home=/opt/tomcat-7.0.42 -Dwtp.deploy=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1/wtpwebapps -Djava.endorsed.dirs=/opt/tomcat-7.0.42/endorsed -Dfile.encoding=UTF-8 -classpath /opt/tomcat-7.0.42/bin/bootstrap.jar:/opt/tomcat-7.0.42/bin/tomcat-juli.jar:/usr/lib/jvm/jdk1.8.0/lib/tools.jar org.apache.catalina.startup.Bootstrap start   Then I use ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}' to extract the process id:  7099   But when I alias the whole command alias tomcat_id="ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}'" and use it via alias, it prints the whole text and awk doesn't seem to work.  type tomcat_id gives:  tomcat_id is aliased to `ps -ef | grep catalina | grep -v grep | awk -F' ' '{print }'' I can buy Dell Latitude E7270 through my employer. It will come with Windows, but I would like to install Ubuntu (most likely 14.04). This model does not appear on the list of certified hardware, however. Does anyone know whether I should anticipate any problems with his laptop? Thanks!