I started my Ubuntu 15.10 and am unable to open the software updater app. I keep getting the following error  SystemError: E:Malformed line 55 in source list /etc/apt/sources.list (dist parse)   I tried purging the app and reinstalling, but still get the same error. Any suggestions?
I have unistalled and reinstalled the Ubuntu Software Center as per info I found in a similar thread and I got the same response about line 91 or something like that.  I just tried to upload a screen shot but since I'm new it won't allow me to.  I also can not figure out how to cut and paste anything so I have to hand type what the error screen says, both when I attempt to open the software center and nothing happens, when I try to enter commands into the terminal to uninstall, reinstall, whatever I get the same following:  COULD NOT INTITIALIZE THE PACKAGE INFORMATION An unresolvable problem occured while initializing the package information Please report t:his bug against the 'update-manager' package and include the following error message: 'E: Malformed line 91 in source list/etc/apt/sources.list (dist parse)  E: The list of sources could not be read.,  E: The package list of status file could not be parsed or opened.   How do I report bugs?  What can be done about this.  I have searched and everything everyone says to do leads me back to the same line error message.  So, I don't know how to get to line 91 in the source list; to tell you what it says. Sorry, I'm really new to this. That is what I need is to find out how to get there and fix what it says. I would really like to NOT have to re partition my hard drive and start from scratch, so I'm really looking forward to getting this problem solved. I need to be able to install new software.
Is it appropriate to use a question mark at the end of a compound sentence where the first independent clause is a question but the second is a statement? For example:     Do you want attribution for that quotation, because I'm definitely sharing it and want to know if I should give you credit?   or      Do you want attribution for that quotation, because I'm definitely sharing it and want to know if I should give you credit.   I suppose this could work, but it's a little niche, as the second clause might not always be appropriate for a parenthetical.     Do you want attribution for that quotation (because I'm definitely sharing it and want to know if I should give you credit)? Python import coding style I've discovered a new pattern.  Is this pattern well known or what is the opinion about it?  Basically, I have a hard time scrubbing up and down source files to figure out what module imports are available and so forth, so now, instead of  import foo from bar.baz import quux  def myFunction():     foo.this.that(quux)   I move all my imports into the function where they're actually used., like this:  def myFunction():     import foo     from bar.baz import quux      foo.this.that(quux)   This does a few things.  First, I rarely accidentally pollute my modules with the contents of other modules.  I could set the __all__ variable for the module, but then I'd have to update it as the module evolves, and that doesn't help the namespace pollution for code that actually lives in the module.  Second, I rarely end up with a litany of imports at the top of my modules, half or more of which I no longer need because I've refactored it.  Finally, I find this pattern MUCH easier to read, since every referenced name is right there in the function body. For regression problem, I have seen people use "coefficient of determination" (a.k.a R squared)  to perform model selection, e.g., finding the appropriate penalty coefficient for regularization.   However, it is also common to use "mean squared error" or "root mean squared error" as a measure of regression accuracy.  So what is the main difference between these two? Could they be used interchangeably for "regularization" and "regression" tasks?  And what are the main usage of each in practice, such as in machine learning, data mining tasks? How can I get useful error messages in PHP? Prove $f $ is identically zero if $f(0)=0$ and $|f'(x)|\le|f(x)|$ I want to see what nodes exist under a certain domain from within the domain. Short of querying every valid IP address within that domain, is there a way to get all records/map the network? how to change landscape mode Let $G$ be a group of order $56$. (We do NOT assume the Sylow-$7$ subgroup to be normal.) Then either the Sylow-$2$ subgroup is normal or the Sylow-$7$ subgroup is normal. How to prove?  My idea: consider the case $n_2=7,n_7=8$. Then the number of elements in all Sylow $2$ -subgroups and Sylow $7$-subgroups is at most exactly $(7-1)*8+(2-1)*7+1=56$. This cannot give a contradiction. We need to prove that $G$ is simple. Then $|G||(8!/2)$. To prove $G$ simple, we need to prove there does not exist normal subgroups of order $2$ and order $4$. But I do not know how to prove. What are the options for managing multiple Ubuntu installations together and keeping them in same state Recently I got in charge of managing 2 computer labs (currently 35 workstations, could double in a month or two) in university with total control over software stack as long as I install a bunch of commonly used scientific software (Mathematica and friends).  I plan to use Ubuntu for various reasons.   Installing Ubuntu and managing updates etc by hand is certainly an option, But I want to know if there is a more efficient way to do this stuff in and a more "Don't Repeat Yourself" manner?  Tasks   Ubuntu installation Installation (duplication) of same software stack and configuration over each workstation Keeping them updated How to ensure that all traffic goes through VPN connection once it has been started? I connect to the internet through a VPN provider along with other precautions in order to ensure privacy (against traffic analysis by agencies of a repressive government). I currently use  to configure and establish the VPN connection. Tunnelblick does not allow automatically connecting to the provider at or before login so I need to connect manually each time, and sometimes the connection is lost.  I need any and all traffic to go through the VPN connection at all times; whenever the VPN isn't connectable for whatever reason, I want the fallback to be no connection. I need to ensure   that OS X does not connect to the internet on my regular internet connection, or at all, during boot (until the login screen, for time synchronization and other possible "call home" stuff etc.). What services, if any, try to do this, and how can I practically analyze and change what's going on with networking during boot? Is there a way to connect to VPN earlier than right after login? that if my VPN connection is temporarily lost, applications do not continue to communicate over my regular unencrypted connection.    I basically want the system to act as if the network connection is lost altogether if the VPN connection fails, but currently they just continue to work as if nothing happened. What can I do to my system so that once a VPN is established, all traffic can only flow through that connection and no traffic can flow if the connection drops? I have read a lot about the SB-800/SB-900 but I am on a low budget (around ~120$). Is there an external flash that I can have to start learning to use it? I do not need TTL compatibility so it can be an older model. I have a Nikon D5000. Extension “RANDR” missing on xvfb My system:  $lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 14.04.3 LTS Release:        14.04 Codename:       trusty   Xvfb:  $ dpkg -s xvfb Package: xvfb Status: install ok installed Priority: optional Section: x11 Installed-Size: 2140 Maintainer: Ubuntu X-SWAT &lt;ubuntu-x@lists.ubuntu.com&gt; Architecture: amd64 Multi-Arch: foreign Source: xorg-server Version: 2:1.15.1-0ubuntu2.7 Provides: xserver   Current problem:  Xvfb do not support RANDR extension, even if I add the flag:  +extension RANDR   If I run xdpyinfo, RANDR is not on the list. It's a missing feature or a bug. I found a reference here with a patch:   And looks like that in other distros like debian, there is already a testing build of Xvfb with support:   I am trying to run a program throught Xvfb, and it returns the following error:  Xlib:  extension "RANDR" missing on display ":99".   The program works if I run it via ssh/command line. The problem appears to be the the lack of support for "RANDR" in xvfb.  My question is: what is the easiest way to get xvfb with "RANDR" support in my system? How to get speech output from entered text by using command-line?  Also facility to change speech rate, pitch, volume etc using simple command. Why does "kill -9 0" end my console session? I just wonder why kill -9 0 ends my tty console session?   What exactly is PID 0, it is not listed on a ps aux? At what pressure will be particles in a medium be unable to form a sound wave when disturbed? How can this pressure be described mathematically?  My guess is that this would correspond to the point at which the restoring force due to pressure is unable to create a transverse wave and the disturbed particles travel infinitely far away before the hypothetical wave reaches it's amplitude. But I have no idea how you would even begin to start finding a quantitative value for this point. Can a willing lycanthrope be True Polymorphed? Can a lycanthrope or other shapeshifter be willingly affected by the spell True Polymorph? I know that it can be affected by regular Polymorph, but the text for the enhanced version seems to differ. ML estimate of exponential distribution (with censored data) In Survival Analysis, you assume the survival time of a r.v. $X_i$ to be exponentially distributed. Considering now that I have $x_1,\dots,x_n$ "outcomes" of i.i.d r.v.'s $X_i$. Only some proportion of these outcomes are in fact "fully realized", i.e. the remaining observations are still "alive".   If I wanted to perform a ML estimate for the rate parameter $\lambda$ of the distribution, how can I utilize the non-realized observations in a coherent/appropriate manner? I believe they still contain useful information for the estimation.   Could someone guide me to literature on this topic? I am sure it exists. I am however having trouble finding good keywords/search terms for the topic. How do I generate the upper triangular indices from a list? Are \( and \) preferable to dollar signs for math mode? Along the lines of , what reasons are there (if any) to favor \( ... \) over $ ... $? Dilemma: Present Perfect Or Perfect Continuous?