The larger $R^2$ the better?
Is $R^2$ useful or dangerous?
Why are these pistons pushing? I've lately become hooked into building computers in Minecraft and today I decided to build a giant hard drive. I've built HDDs before, but not at the scale I'm currently attempting, and I anticipated problems. As I was wiring some pistons, they activated and pushed forward oddly. As far as I can tell, there's nothing powering them.    I thought at first that it might be the redstone torches (top left of above pic) but they aren't powered.   Here's a top view of the same pistons. I also thought the line of redstone above  them might be the problem (middle of above pic), but when I destroy it, the pistons stay extended.  Is there a reason why my pistons are extending? If so, is there a way to get them to power (when I want them to) without disturbing the pistons above? I can't seem to get Python to import a module in a subfolder. I get the error when I try to create an instance of the class from the imported module, but the import itself succeeds. Here is my directory structure:  Server     -server.py     -Models         --user.py   Here's the contents of server.py:  from sys import path from os import getcwd path.append(getcwd() + "\\models") #Yes, i'm on windows print path import user  u=user.User() #error on this line   And user.py:  class User(Entity):     using_options(tablename='users')      username = Field(String(15))     password = Field(String(64))     email    = Field(String(50))     status   = Field(Integer)     created  = Field(DateTime)   The error is: AttributeError: 'module' object has no attribute 'User' Proving $6^n - 1$ is always divisible by $5$ by induction I'm trying to prove the following, but can't seem to understand it. Can somebody help?     Prove $6^n - 1$ is always divisible by $5$ for $n \geq 1$.   What I've done:  Base Case: $n = 1$: $6^1 - 1 = 5$, which is divisible by $5$ so TRUE.  Assume true for $n = k$, where $k \geq 1$: $6^k - 1 = 5P$.  Should be true for $n = k + 1$  $6^{k + 1} - 1 = 5Q$  $= 6 \cdot 6^k - 1$  However, I am unsure on where to go from here. Flagged emails keep returning and won't synchronize between Apple Mail and Gmail I've had this problem before and can't recall how I managed to fix it last time. I use Apple Mail to access my Gmail and normally flagged emails show up correctly. Starred emails in Gmail equate to flagged emails in Apple Mail and I can unflag an email in either Gmail or Apple Mail and it works.  But now I've got four emails that I can't unflag. They're not flagged in Gmail at all (although they used to be). When I see them in the Flagged folder in Apple Mail, they don't even have flag icons next to them but they're still counted in the number showing next to "Flagged". If I manually re-flag them and then unflag them, they disappear from the Flagged box. But then if I click into Inbox and then back into Flagged they show up again.  Any ideas about how to make these guys disappear for good?! I have been trying to install the latest version of java-8. However, I found out that the  due to changes in the java licence.  How should I update my java to 8.0_201 or 8.0_211 now?  Thanks! MacVim -- how to make Ctrl+A go to beginning of line, Ctrl+E to the end of the line I'm trying to switch to MacVim as my main editor, and I'm liking it so far, except for one issue:  I got really used to the Mac shortcuts control-A to go to the beginning of a line, and control-E to go to the end of a line.  However, these two don't work in MacVim (control-A does something weird -- it seems to increase the last number in a line by 1 or something, and control-E seems to scroll down the screen by one line).  Any way to make these two shortcuts go to the beginning of a line / end of a line respectively instead? launch sms application with an intent How to SEO a Single-Page website I am creating a new website for a client, and I think a single page website / layout will be pretty neat. There is not that much detailed content, it is a company that imports a lot of products from different companies. So it will be a bit of a showcase of the different types of products / equipment you can order. Of the whole catalog only maybe 10 products are actually shown.  Now I have the basic structure with sections and links like:      #home / #products / #equipment / #services / #contact.    Now from what I understand is that Google does not index links containing #, so there will be no problem of duplicate content, everything will be indexed as the frontpage.  Now what I want to optimize is searching. This company is agent of some product in the country, meaning only they have the permission to import and sell that product. This means  that when somebody searches for product x, this website pops up as the first hit.  Now can I make it that they will be automatically brought to the #products part of the website directly from google.  I was thinking of something like having google index the different sections as different pages. Is something like that possible? How do I disable notifications in my personal profile for activity on pages I am an admin of? I'm an admin of several pages on Facebook (for technical stuff like RSS imports, etc.), but neither do I contribute content nor do I care about their content.  Still, as an admin, I get notifications (upper left hand, the globe icon) about activity (someone liked this, someone posted that) on those pages in my personal (!) profile .  Does anyone have the same issue? Is there any way to explicitly disable notifications for certain pages?  (This behavior seems to be new, by the way; I'm only seeing those notifications for a few weeks now.) How can I install Sun/Oracle's proprietary Java JDK 6/7/8 or JRE? I want to install Oracle's JRE and to update to the latest version with the Software Updater when they released. Is there a Ubuntu package that is provided by Canonical or Oracle?  Before release Java 7, I followed  to install Java 6.  But it doesn't work for Java 7. There is no package sun-java7-xxx. How can you install Java 7? Can i install ubuntu on meizu mx4 android edition like ubuntu edition with iso recovery in this page "  " How to achieve this smudge effect in photoshop? Increasing the Size of Beamer Footer I work in Beamer extensively (specifically the Madrid theme). Sometimes, my "title" is quite long. Beamer puts this title at the bottom, but when it's too long it cuts it off. I'd really like to know how to increase the size of the bottom middle rectangular footer.    Here's the code (sorry for all of the packages and commands):  \documentclass[t]{beamer} %Add "mathserif" to script math lettering. "t" places all text to start at the top of each slide \usetheme{Madrid}  %Packages  \usepackage{amsmath} %Math mode \usepackage{amssymb} %Math mode \usepackage{commath} \usepackage{graphicx} %Including pictures \usepackage{color} %Define colours \usepackage{setspace} %Enables double-spacing/variable spacing \usepackage{pgfplots} %Draw graphs \usepackage{upgreek} %Insert theta symbol as unitalicized  \usepackage[version=3]{mhchem} %Chemistry equation mode \ce{} \usepackage[export]{adjustbox} %Place black borders around images \usepackage{scrextend} %Used to change font size \usepackage{caption} %Used to utilize * in caption function \usepackage{subfig} %Used to place figures side-by-side with sub-captions \usepackage{siunitx} %SI Units (+ scientific notation) \usepackage{cancel} \usepackage{fancybox} %\usepackage{enumitem} %Making lists %\usepackage[english]{babel} %Lists with letters  %Erases Beamer Navigation Symbols on the bottom left \setbeamertemplate{navigation symbols}{}  %\setbeamertemplate{footline}{} \captionsetup[subfigure]{labelformat=empty}  %Defined Colours \definecolor{orangered}{RGB}{255,69,0} \definecolor{darkgreen}{RGB}{0,100,0}  \definecolor{firebrick}{RGB}{178, 34, 34} \definecolor{navy}{RGB}{0,0,128} \definecolor{lightsteelblue}{RGB}{176,196,222} \definecolor{steelblue}{RGB}{70,130,180} \definecolor{darkslateblue}{RGB}{72, 61, 139} \definecolor{forestgreen}{RGB}{34, 139, 34} \definecolor{Gold}{RGB}{218,165,32}  %Defined Colour Theme and List Sizing \setbeamercolor{structure}{fg = Gold} \setbeamertemplate{navigation symbols}{}  \setbeamerfont*{itemize/enumerate body}{size=\normalsize} \setbeamerfont*{itemize/enumerate subbody}{parent=itemize/enumerate body} \setbeamerfont*{itemize/enumerate subsubbody}{parent=itemize/enumerate body}  %Opening Title Page \title{Chapter 7 - Absolute Value and Reciprocal Functions} \subtitle{Section 7.3 - Absolute Value Equations} \date{}  \begin{document}     %Slide 1     \maketitle \end{document} Set active image node with python There's any way to change it directly by Python, or there's any way to set by Python what node image is the active to display in viewport (Textured) and bake? I am testing the new  &lt;lightning:datatable&gt;, it is really good, and is a good replacement for most of my use cases which today I use a custom list component that I have developed.  I am getting data from my server through apex method, to populate it into the &lt;lightning:datatable&gt; component. I can bind the returned list directly to the data attribute and if the column names are same as the field names, all data is bound correctly.  The problem occurs when I get data from a parent record. For example - I want the Account name of my contact.  This example can show the problem:  Component Markup    &lt;aura:handler name="init" value="{!this}" action="{!c.doInit}"/&gt;  &lt;aura:attribute name="mydata" type="Object"/&gt; &lt;aura:attribute name="mycolumns" type="List"/&gt; &lt;aura:attribute name="sortedBy" type="String"/&gt; &lt;aura:attribute name="sortedDirection" type="String"/&gt;  &lt;lightning:datatable data="{! v.mydata }"                      columns="{! v.mycolumns }"                      keyField="Id"                      onrowselection="{! c.getSelectedName }"                      onsort="{!c.updateColumnSorting}"                      sortedBy="{!v.sortedBy}"                      sortedDirection="{!v.sortedDirection}"                      hideCheckboxColumn="{!false}" /&gt;        Component Controller  ({     doInit: function (component, event, helper) {         component.set('v.mycolumns', [                     {label: 'Id', fieldName: 'Id', type: 'id', sortable:"true"},                     {label: 'First Name', fieldName: 'FirstName', type: 'text', sortable:"true"},                     {label: 'Last Name', fieldName: 'LastName', type: 'text', sortable:"true"},                     {label: 'First Name Hebrew', fieldName: 'First_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Last Name Hebrew', fieldName: 'Last_name_Hebrew__c', type: 'text', sortable:"true"},                     {label: 'Account', fieldName: 'Account.Name', type: 'text', sortable:"true"},                     {label: 'Email', fieldName: 'Email', type: 'email', sortable:"true"},                     {label: 'Phone', fieldName: 'Phone', type: 'phone', sortable:"true"}                 ]);          var action = component.get("c.getRecordsFromDb");         action.setParams({             sObjectName: "Contact",             commaDelimitedFieldNames: "Id,FirstName,LastName,First_name_Hebrew__c,Last_name_Hebrew__c,Account.Name,Email,Phone",             filter: ""         });         action.setCallback(this, function(response){             var state = response.getState();             if (component.isValid() &amp;&amp; state === "SUCCESS") {                 var data = response.getReturnValue();                  component.set("v.mydata", data);             }         });         $A.enqueueAction(action);     } })   APEX Aura Enabled Method  @AuraEnabled public static List&lt;sObject&gt; getRecordsFromDb(String sObjectName,         String commaDelimitedFieldNames,         String filter) {      system.debug('\n\n\n\ngetRecordsFromDb sObjectName: ' + sObjectName + ', commaDelimitedFieldNames: ' + commaDelimitedFieldNames + ', filter: ' + filter + '\n\n\n\n');      // create a dynamic soql to get the value of the field     String sql = 'SELECT ' + commaDelimitedFieldNames + ' FROM ' + sObjectName;      if (!String.isBlank(filter))         sql += ' WHERE ' + filter;      system.debug('\n\n\n\ngetRecordsFromDb sql: ' + sql + '\n\n\n\n');     List&lt;sObject&gt; records = Database.query(sql);     system.debug('\n\n\n\ngetRecordsFromDb: ' + records + '\n\n\n\n');      return records; }   The problem is with the Account.Name field - the &lt;lightning:datatable&gt; component does not display the column data.   I know that the data is returned ok, and I know that in the object that is returned, the Account is contained like an object (probably this is the problem):    Is there a good way to show parent record data with this component? I've tried to render my scene but there's an object that won't show up. I've checked the camera, I've checked the visibility, it isn't hidden and it's showing in the viewport. I feel like I've opened every setting and have achieved nothing. I’m trying to render a book with a cover, flipping pages and stacks of pages. I have no idea how to fix the fact that the book cover doesn’t render. If I create a plane and select both the book cover and the plane and join them with Ctrl+J, the render contains a book cover but it doesn’t turn as it’s rigged to do so because it’s now linked to the plane and loses all the animated properties. As soon as I unjoin them the book cover stops rendering and everything appears as you see it there, a book with binding, pages, but no cover. For the life of me I cannot figure out what’s going on. There's a link to the file here: How to iterate through array combinations with constant sum efficiently? How to check if a string starts with a specified string? How to remove GNOME Shell from Ubuntu 20.04 LTS to install other desktop environment from scratch? Send mail without MFMailComposeViewController