if(txtValueUIT.getText()==null || txtValueDolar.getText()==null || txtValueUIT.equals("") || txtValueDolar.equals("")) JOptionPane.showMessageDialog(null, "You have not entered both values", "Error", JOptionPane.ERROR_MESSAGE);   What I try to do is to show the Error Message when the JTextFfields are empty or null.  I am using if and it shows no bugs but when testing it it simply won't show the message when it is supposed to do it.  *It seems it doesn't perform any action at all because the code that follows in that method, when there is a value missing in those JtextFields, won't be processed. *  The code that follows is a setText to another component using as parameters Strings that get the Text from the JTextFields  By the way:  if(e.getSource() == btnRefresh) //I added the button with an action listener refreshValues(); //this contains the code with the JOptionPane
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?
"Install VMware Tools" greyed out after installing ubuntu 15.04 on vmware player 7.1 "Install VMware Tools" greyed out after installing Ubuntu 15.04 on VMware Player 7.1. I tried checking "No proxy" instead of default "Windows proxy settings" at "File->Preferences->Software updates-> Connection Settings". This did not work either. Is there a way to install VMware Tools? Evaluating and negotiating a start-up package I've been offered an academic position, and am now in the fortunate, but unfamiliar position of negotiating the offer.  I've seen a few blogs/comments/posts on this process.  However, I have no real idea how to evaluate the offer that's been made.  Coming from the position of a postdoc, the package seems impressive (given that, as a postdoc, my "package" consists of a very modest salary and health benefits).  However, I also realize the importance of maximizing (within reason) my initial offer, as this sets the baseline for, at least, the first few years of my faculty career and could provide support that would prove very important in the initial year or so while I'm trying to obtain grant funding.  In particular, I'm looking for two types of information.  First, what types of startup packages are standard for tenure-track assistant professors of Computer Science at a public RU/VH (i.e. Research) university?  This is just to give me some point of comparison.  Second, what types of changes are reasonable to negotiate?  Can I ask for more summer salary support while still conveying to them my desire to obtain grant funding as quickly as possible?  The offer already includes a reduced teaching load for the first few years --- is it also reasonable to ask for an extra semester off prior to a tenure review?  I understand these are fairly broad questions, but any input or suggestions would be very helpful.  I'm definitely interested in the job; I really liked the department and think it's a great opportunity.  I don't want to alienate anyone by pushing too hard, but at the same time, I want to make sure that I make every reasonable effort to maximize my chances for academic success, which includes maximizing my available resources by negotiating the best startup package I can. What is the simplest way to generate a dodecahedron? I've been thinking of animating some dice and while most are easy to make, I'm having some trouble figuring out a way to generate a regular dodecahedron. I could hand build it but it would be potentially uneven. Would using the base of a 5 sided cylinder and then some variation on spin be the best option or is there a better way? Possessive 's for things Does the Planck scale imply that spacetime is discrete? On a quantum scale the smallest unit is the , which is a discrete measure.  There several question that come to mind:   Does that mean that particles can only live in a discrete grid-like structure,  i.e. have to "magically" jump from one pocket to the next? But where are they in between? Does that even give rise to the old paradox that movement as such is impossible (e.g. )? Does the same hold true  for time (i.e. that it is discrete) - with all the ensuing paradoxes? Mathematically does it mean that you have to use difference equations instead of differential equations? (And sums instead of integrals?) From the point of view of the space metric do you have to use a discrete metric (e.g. the ) instead of good old Pythagoras?   Thank you for giving me some answers and/or references where I can turn to.  Update: I just saw this call for papers - it seems to be quite a topic after all: Is Reality Digital or Analog? FQXi Essay Contest, 2011. , , . One can find some pretty amazing papers over there. Issue with particles in blender donut tutorial I have been recently doing the blender donut tutorial and ran into a problem regarding the sprinkle particles. The particles (hair) keep appearing on the underside of the icing. As seen in the image below, most of the hair particles only come out from the bottom of the icing. I tried to readjust the normals but I realised the normals were already correct. (Blue colour donut in image) Someone suggested following through the weight painting part of the tutorial. However, the sprinkles still remain on the underside of the icing. What is the actual problem and how do I solve this?  Particle settings below  Edit: @moonboots Thanks the hair particle problem has been solved. How do I prevent the submersion of the sprinkle particles? Error: "To run a ssis package outside of sql server data tools you must install [send successful email] of Integration Services or higher." NOTE that the title of this qusetion is a verbatim error message specific to this user. The error message illustrates a bug in the dtexec application, which substitutes a user variable into the error message string. In this case, the standard message Standard E dition is replaced with send successful email.  The 'standard' error message would be :  Description: To run a SSIS package outside of Business Intelligence Development Studio you must install Standard Edition of Integration Services or higher.    Version SSIS 2012. Package was originally 2005 ver. Package on file system.  DB Engine / Agent on Host 1, SSIS on Host 2.  Execution from Host 2 runs successfully. Execution from Host 1 gives the error in the question subject. Saw , but engine and agent are installed on Host 1. Has anyone seen this? Google returns no results when searching on the exact error (subject line is exact, wording is odd in the error message).  Thank you! Travel to Ireland (Dublin) with U.K. Visitor visa If $a \cdot a = 1$ then $a = 1$ or $a = -1$ How do I reference the only element in a singleton set? You can turn any element $n$ into a singleton set by adding braces, $\{n\}$. Is there an inverse to this operation, such that if I know the set is a singleton set I can easily reference its element?  For example, say I have the set $A = \{5,6,7,8\}$, and then some process that iteratively eliminates all but one element of $A$, and then I want to see what 10 plus the resulting element is, how could I write that?  The only way I can think of is by referencing the first element by its index, e.g., $10 + A_1$. Is there another way to do it though? In my case the elements of $A$ are already indices, so I would have to index an index, like $10 + x_{A_1}$. Which is not the worst thing in the world, I was just wondering if there is a better way. PhD Student : Publish Paper with Wife? Should I delete my own questions with answers? I don't know much about this,  But I've some of the questions on which some user has answered (not helpful answer) also but I want to delete those questions, but whenever I go to delete that question. It is prompting with     What does it mean? Can someone tell me what would be the action taken by Stack Exchange if I delete more questions? Let $z \in\Bbb{C}^{\times}$ such that $|z^3+\frac{1}{z^3}|\leq 2$. Prove that $|z+\frac{1}{z}|\leq 2$. Problem :  Let $z \in\Bbb{C}^{\times}$ such that $|z^3+\frac{1}{z^3}|\leq 2$. Prove that $|z+\frac{1}{z}|\leq 2$.  My approach : Since : $(a^3+b^3)=(a+b)^3-3ab(a+b)$ $\Rightarrow z^3+\frac{1}{z^3}=(z+\frac{1}{z})^3-3(z+\frac{1}{z})$ Now I don't know further about this problem whether or not this will help here. Please guide to solve this problem will be of great help, thanks. If $A$ and $B$ are compact subsets of $\mathbb R$, then so is $\frac{A}B$. Given compact $A,B \subseteq \mathbb{R}$ with $\alpha := \inf(B) &gt; 0$, define $$\frac{A}B := \left\{\frac{x}y : x \in A  \text{ and } y \in B\right\}.$$ Show that $\frac{A}{B}$ is compact.  I am thinking of using the following result given in a previous exercice but I don't know how to proceed.     $K \subset \mathbb R^n$ is compact if and only if for all $\{x_{n}\}$ such that $\{x_{n} : n\in \{1,2,\dotsc\}\}\subset K$, there exists a convergent subsequence $\{{x_{\phi(n)}}\}$ that converges to a limit $l \in K$.   When does the infimum come into place? If $S_n$ has cyclic subgroups of these orders or not? This question was asked in my quiz and I am having difficulties in solving it .  Question : For a positive integer $n$ , let $S_n$ denote permutation group on $n$ symbols. Choose correct statements from below. (a) For a positive integer $n$ and for every $m$ with $1\leq m \leq n , S_n $ has a cyclic subgroup of order $m$; (b) For every positive integer $n$ and for every $m$ with $n&lt;m &lt;n!$, $S_n$ has a cyclic subgroup of order $m$; (c) There exists positive integers $n$ and $m$ with $n&lt;m&lt;n!$ such that $S_n$ has a cyclic subgroup of order $m$; (d) For every positive integer $n$ and for every group $G$ of order $n$, $G$ is isomorphic to a subgroup of order $S_n$ .  Attempt: (a) is true as I can choose an element of length $m$ which will generate cyclic subgroup of order $m$. (b) Choose $n=4$ and $m=19$ to contradict (b). (c) I dont know if there can be found any such case and if yes how to do so . (d) I dont know about it . kindly tell. Answer:   A,C,D are true Reclassifying raster layer with certain colors for value ranges in QGIS? I'm using QGIS. I want a raster layer with 6 different colors each color representing a certain value range (e.g. -1 to 0 red, 0 to 0.2 orange).  In the layer style menu I can only approximate colors. What category does the 'the recent perfect' belong to? A scholar has said that there are 4 usages of the present past tense:   The Universal sense of the Perfect, used to indicate that a state of affairs prevailed throughout some interval stretching from the past into the present       I've known Max since 1960.  The Existential sense of the Perfect, used to indicate the existence of past events     I have read Principial Mathematica five times.  The Stative/Resultative sense of the Perfect, used to indicate that the direct effect of a past event still continues     I can't come to your party tonight - I've caught the flu.  The Hot News sense of the Perfect, used to report hot news     Malcolm X has just been assassinated.    To what category does the recent past belong? Understanding dummy (manual or automated) variable creation in GLM If a factor variable (e.g. gender with levels M and F) is used in the glm formula, dummy variable(s) are created, and can be found in the glm model summary along with their associated coefficients (e.g. genderM)  If, instead of relying on R to split up the factor in this way, the factor is encoded in a series of numeric 0/1 variables (e.g. genderM (1 for M, 0 for F), genderF (1 for F, 0 for M) and these variables are then used as numeric variables in the glm formula, would the coefficient result be any different?  Basically the question is: does R use a different coefficient calculation when working with factor variables versus numeric variables?  Follow-up question (possibly answered by the above): besides just the efficiency of letting R create dummy variables, is there any problem with re-coding factors as a series of numeric 0,1 variables and using those in the model instead? How can I search tags on StackOverflow Careers? I am attempting to search jobs by tag on StackOverflow Careers. On SO, this is done using square brackets, but that is simply doing a keyword search, and I still get results that don't have the tag I am looking for.  For example, when I search for the keyword "android", I get this:        which is the same as when I search for the keyword "[android]":        Is there a format I can use to search jobs by tag? If not, I believe this would be a nice feature (seems intuitive for the Stack Exchange invite-only job site). I know I need to have (although I don't know why) a GROUP BY clause on the end of a SQL query that uses any aggregate functions like count, sum, avg, etc:  SELECT count(userID), userName FROM users GROUP BY userName   When else would GROUP BY be useful, and what are the performance ramifications?