I'm not able to install Wubi installer in my PC. When installing Wubi in my Windows 7, "Could not retrieve the required disk image files" appears
Windows installer for Ubuntu 14.04 LTS onwards
Printer "Filter failed" Upgraded to 18.04 from 16.04. I have a workplace printer connected through appsocket which stopped working.  Printer status is Idle-Filter failed.  Printing queue instantly goes to "stopped".  Right clicking on the printer shows "option finishings has value 3 and cannot be changed". I can't find any info on this error except one pdf to ignore the error.  The printer model Ricoh MP 2555 worked previously with the Ricoh MP C2800 driver. Now it works with neither 2800 or 2555.  The IP address of the printer pings fine. When I try and detect the printer on the network using IP address and I ask it to use the Ricoh MP 2555 driver, it asks for an additional driver which opens Ubuntu software (which never helps) and fails.  I tried changing drivers from "" by providing the ppd file. It still doesn't help. var/log/cups/error.log doesn't tell much, or I don't get it.  Hope someone knows about this error or some kind of a generic solution. How do you rename root? Not that it's a very good idea to change it, but for fun. According to  post, there are still some problems even after changing entries in /etc/passwd, /etc/shadow, and /etc/sudoers. Any suggestions? Short Question:  Why can we manipulate a read-only file in Vim using : + w + q + ! even without being an administrator?  Long Question:  I have a text file (myFile.txt) which is read-only for everyone:  navid@navid-ThinkPad-T530:~/ubuntuTest$ ls -l myFile.txt  -r--r--r-- 1 navid navid 26 Aug 22 21:21 myFile.txt   I can open it with Vim without having admin privileges:  navid@navid-ThinkPad-T530:~/ubuntuTest$ vi myFile.txt    I modify it and press: Esc + : + w + q + Enter and I see this error message:  E45: 'readonly' option is set (add ! to override)   So far, everything makes sense.  But when I press: Esc + : + w + q + ! + Enter, Vim saves the changes.  I'm using Ubuntu 16.04 and VIM 7.4. Proof for alternative definition of the derivative I read somewhere recently that you can define the derivative as follows:  $$f'(x) = \lim_{h, k \to 0^+} \frac{f(x +h) - f(x - k)}{h + k}$$   I have been trying to prove this for about 2 hours, and can't seem to get it done. How should I proceed?  Edit: Assume $f$ is differentiable for all $x \in (x - \delta, x + \delta)$ for some $\delta &gt; 0$. As far as I understand, whatever can be done using DeclareMathOperator can also be achieved using newcommand, but not the other way around. If this is the case, what are the circumstances where DeclareMathOperator is the better choice? When should I take solely newcommand?  I found a question regarding , and I wonder what other aspects should be taken into consideration when it comes to choosing which method to use when defining math operators. What's the difference between declaring a variable "id" and "NSObject *"? In Objective-C, what's the difference between declaring a variable id versus declaring it NSObject *? Help Text not showing on I have a table inside of a pageblocksection and then inside of that I have an  that I am trying to utilize the default help text for but it's not showing up.  &lt;apex:pageBlockSection columns="1"&gt;   &lt;apex:outputPanel&gt;     &lt;table&gt; width="100%"&gt;       &lt;tr&gt;         &lt;td&gt;           &lt;apex:pageBlockSectionItem helpText="test text"&gt;             &lt;apex:inputCheckbox value="{!searchBySKU}" /&gt;             &lt;apex:outputLabel value="Search for this SKU or text in the SKU name" /&gt;           &lt;/apex:pageBlockSectionItem&gt;         &lt;/td&gt;       &lt;/tr&gt;     &lt;/table&gt;   &lt;/apex:outputPanel&gt; &lt;/apex:pageBlockSection&gt;   Any ideas why this doesn't work as I expect?  EDIT:  So, I just did some more testing and it creates the text if it's a direct child of the pageBlockSection. Is there any way to get around this restriction without going the fully custom route to do so? Attaching towel rail to drywall I was wondering what the proper LaTeX code would be to display something like this:    You don't have to include the mathematical symbols, what is important is the structure. Shifting -5 V to +5 V signal to 0 to +5 V for ADC I want to convert the  output voltage of an ECG (-5 to +5) to 0 - +5 volt for ADC. Should i use Op amp ? What is my problem in this picture? I simulated it in Proteus ... but when input voltage is higher than 4 V or lower than -4 V Vout gives an unexpected value.   Below is another simulink that have same problem ...    My idea to make this level of voltage is (Vin +10)/2 that give the range 0-5 V. ImportError: No module named dbus I was trying to update my Python and messed up my whole system.   I am currently now able to start my Software Centre. I tried Googling multiple fixes but nothing helped. My Software Centre can't start.   When I try starting it up, this error shows:  astephen@localhost:/usr/bin$ ./software-centerGtk-Message: Failed to load module "gtk-vector-screenshot" Traceback (most recent call last): File "./software-center", line 36, in &lt;module&gt; from softwarecenter.utils import ( File "/usr/share/software-center/softwarecenter/utils.py", line 19, in &lt;module&gt; import dbus ImportError: No module named dbus   I tried reinstalling dbus using:  apt-get install --reinstall dbus   But it did not help.  astephen@localhost:/usr/bin$ sudo apt-get install --reinstall dbusReading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not      upgraded. Need to get 0 B/231 kB of archives. After this operation, 0 B of additional disk space will be used. (Reading database ... 676272 files and directories currently installed.) Preparing to unpack .../dbus_1.6.18-0ubuntu4.3_amd64.deb ... Unpacking dbus (1.6.18-0ubuntu4.3) over (1.6.18-0ubuntu4.3) ... Processing triggers for ureadahead (0.100.0-16) ... Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Setting up dbus (1.6.18-0ubuntu4.3) ... Show badges in user profile in iOS app When viewing a user's profile from the iOS app, it would be nice to be able to see what badges they have, instead of just the counts. WPF textblock binding with List does anyone know if there is a simple way to bind a textblock to a List. What I've done so far is create a listview and bind it to the List and then I have a template within the listview that uses a single textblock.  what I'd really like to do is just bind the List to a textblock and have it display all the lines.  In Winforms there was a "Lines" property that I could just throw the List into, but I'm not seeing it on the WPF textblock, or TextBox.  Any ideas?  did I miss something simple?  Here's the code  &lt;UserControl x:Class="QSTClient.Infrastructure.Library.Views.WorkItemLogView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"          Width="500" Height="400"&gt; &lt;StackPanel&gt;     &lt;ListView ItemsSource="{Binding Path=Logs}" &gt;         &lt;ListView.View&gt;             &lt;GridView&gt;                 &lt;GridViewColumn Header="Log Message"&gt;                     &lt;GridViewColumn.CellTemplate&gt;                         &lt;DataTemplate&gt;                             &lt;TextBlock Text="{Binding}"/&gt;                         &lt;/DataTemplate&gt;                     &lt;/GridViewColumn.CellTemplate&gt;                 &lt;/GridViewColumn&gt;             &lt;/GridView&gt;         &lt;/ListView.View&gt;     &lt;/ListView&gt; &lt;/StackPanel&gt;     and the WorkItem Class  public class WorkItem {     public string Name { get; set; }     public string Description { get; set; }     public string CurrentLog { get; private set; }     public string CurrentStatus { get; private set; }     public WorkItemStatus Status { get; set; }     public ThreadSafeObservableCollection&lt;string&gt; Logs{get;private set;}   I'm using Prism to create the control and put it into a WindowRegion          WorkItemLogView newView = container.Resolve&lt;WorkItemLogView&gt;();         newView.DataContext = workItem;         regionManager.Regions["ShellWindowRegion"].Add(newView);   thanks I've installed Ubuntu 13.04 two times on my PC. Each on a different partition. I would like to delete the one which I'm not using. How would I do that? How can I get Gnome3 to remember my session? I am running Gnome3, but I had the same problem with Unity, on Ubuntu 12.04.  I have a fairly elaborate setup I enjoy using day-to-day. A LibreOffice spreadsheet with everyone's extension numbers; a window with reference data I use regularly; two mulit-tabbed Konsole/Terminal windows with several remote systems sessions, firefox with a set of open tabs, and so on. But whenever I log out, when I return, I must set up everything from scratch. I remember the good 'ol days, when I rebooted, I'd re-log in, and all my windows came back up in the same places as they were when I logged out, and my Konsole/Term would come up with the same remote logins as before.... I'd have to re -setup  some of my programs, but that's better than having to move every win into place, and resize them, etc.  How do I get this functionality back? What are the answers for these basic quetions? Get complete stats of process started/terminated during login of user account When I login, I notice many process quickly start and terminate in task manager. But it happens very fast and I cannot save details about them (like process name, command line, CPU usage,..)  How can I collect stats about them so I can view them later Date Formatting C# The feeling of always wanting newer possessions? I am looking for a word that describes the emotion or feeling of an intrinsic want of a new and better possession. Covetous or envious seem a bit too focused on the other other person's possession of the desired object whereas I am looking for something that is defined by the internal thoughts we have when seeing an advertisement for the latest iPhone or life-changing new service.    but I am wondering if there is a word with less emphasis on the second entity? Otherwise, would I covet new things from Amazon or Apple? Can I be envious of corporations?  For example, I just bought a new car and now, looking at my slightly out of date television, I feel the need to upgrade my T.V. with a newer, shiny one from Amazon. Would I be coveting that T.V. which Amazon sells?     I saw the ad for the latest iPhone, the iPhone 3000, and feel that my current phone is inadequate. I am a(n) ______ person, since I always desire something better than what I currently possess. If I was a caveman with a sharpened stick, I'd want your sharper, pointier stick.   I feel like there is probably some niche German word for exactly this, but I'm unsure it exists in English. Thanks! Improving our spatial data by calculating "Close to Coastline", "Close to Park", "Close to Stadium" etc A quick background for context is maybe helpful for this.  Essentially we have "vacation rentals" and I would like to add additional data to them automatically. We create booking websites for customers who have very niche sites, for example,    "Pet Friendly" rentals.  "Olympic Cottages" "Surfing Adventure Lettings".    Quite often each of our customers always ask the same questions,   "It would be awesome if we could plot the distance and sort properties based on their relative distance from XYZ".   Usually XYZ is something like a list of dog friendly beaches, or cycle tracks, or wine vinyards. So esesntially points of interests which are easily definable. In those cases, we've always just asked the customer to provide a list of the lat/lngs of every possible "point of interest" that they would like us to calculate distance from".  More recently we've been asked to include "Close to Coastline".   What I want is to come up with a standard way of automating this. My ideas so far are to create a shapefile. For example, let's say we wanted to do "Close to Coastline", we could use something like     At this point, I'm somewhat stuck in knowing how would be most efficient to calculate the distance from the edge of the coastline.   I'm thinking about being able to just create/add a shapefile per "concept" that the customer wants us to use for their product. But then do not know the process/tools available to me to know distance from each edge, or vector point.