After upgrade from 16.04 to 18.04 there are different APT repositories disabled.  I see this via app "Stacer".  I can't delete this, and I can't find this when I check in folder:  ls /etc/apt/sources.list.d  So I am not sure how to delete.   I found also from google chrome, even if I never installed it.. pretty strange?  Check this:    The other question suggest to remove from Softare center, but in 18.04 I can't find it. And from source.list directory, the disabled APT is not there.
Please let me know how to remove certain repositories in Ubuntu 11.04. I am getting the following errors while updating.  sudo apt-get update  Err http://ppa.launchpad.net natty/main Sources                                      404  Not Found Err http://ppa.launchpad.net natty/main i386 Packages                                404  Not Found ......  E: Some index files failed to download. They have been ignored, or old ones used instead.
"To shoot out of cannon into sparrows" In Russian we have idiom/saying "To shoot out of cannon into sparrows" (literal translation) which is used to convey an idea of applying too drastic measures to small problems. I believe there should be some native-English equivalents to this saying. Can you share if there are any? Why we usually do not exceed ARMA(5,5) models in practice? Is there any mathematical justification for this? Random spawn location despite sleeping in a bed I am trying to make Minecraft harder, and one of the ways I wish to do this is to have a "pseudo-hardcore" mode where dying spawns you in a random location rather than completely locking you out of the world.  I intend to do this by setting the spawn radius to be very high.  However, I also want to make this "bed-proof" - that is, if someone places a bed and sleeps in it, I want the player to still be spawned in a random location, regardless of their personal spawn point.  How do I do this? Command blocks are fine, but data packs are not preferred. Car accident, put in park or neutral? What are the powers shown by the Rings of Power? Complicated FOR loop nesting. Having trouble cleaning up legacy code execute drush command from devel/php drupal Can any one please tell me how can I execute drush command from devel/php?  I can execute PHP codes from devel/php. But I don't know how can I execute drush command from devel/php. (As we know "devel/php" URL coming from devel module).  I have written some custom drush command for cron purpose. I can able to run those commands from command line.  &gt; drush my-cmd or drush cc all or drush status , etc ... I can run it through command line.   Expecting some function as mentioned below to run from devel/php  some_function("drush cc all"); Show the post's comments on the "Suggested Edits" review interface What is "summoning sickness" and how does it affect my creatures? Note: this is intended to be a canonical question about summoning sickness.  "Summoning sickness", broadly, is the rule that stops you from attacking or paying {T} costs with a creature that you just played. But how exactly does it work? How does it interact with other rules and effects?  For example, if I'm trying to figure out how a creature is affected:   Does the status matter (tapped/untapped, face down/face up, etc.)? What if it came into play, but I didn't cast it? What if it's a token? What if it was on the battlefield when my turn started, but it wasn't a creature? What if it stops being a creature? What if it's a creature and also another card type? What if it's a double-faced card that just transformed? What if it changes control? What if it's a copy of another creature? Which of the creature's activated abilities can I use? Are any of its other abilities affected? Can I tap the creature to pay a cost that is not a {T} cost?   (These examples are primarily taken from questions about summoning sickness that have already been asked on the site) Analogy: "as if" vs. "as though" This is something that confuses me from time to time. When making an analogy in literature, is it better to use the phrase "as if" or "as though", or is it completely a style thing?  E.g.      She looked frazzled, as if she had just gotten off of a roller coaster.   or     She looked frazzled, as though she had just gotten off of a roller coaster. Vertical component of moving weight at a 45 degree angle Here's an easier one. I use the leg press machine at the gym so I don't have to worrying about hurting myself while lifting heavier weight.  The weight glides on a track that looks to be 45 degrees.  What's the equation to figure out how much weight I would be able to squat normally.  IE the vertical component of moving 400lbs at a 45 degree angle. 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? Changing units of measurement in a simple regression model When I boot in GRUB2 and press c, I have access to GRUB shell.  How to change the keyboard layout (language) of this GRUB shell?  Note that I'm booting an Ubuntu VM inside Virtualbox. Attempt to de-reference a null object: Trigger There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was:      Apex trigger updatequotestatus caused an unexpected exception, contact your administrator: updatequotestatus: execution of AfterInsert caused by: System.NullPointerException: Attempt to de-reference a null object: Trigger.updatequotestatus line 5, column 1.   Error Occured at Line:     if((t.what.getsobjecttype() == quote__c.sobjecttype) &amp;&amp; (t.subject.substring(0,5) == 'Email')  trigger updatequotestatus on task (after insert, after update){     Set&lt;Id&gt; quoteIds = new Set&lt;Id&gt;();     List&lt;quote__c&gt; quotes = new List&lt;quote__c&gt;();      for(task t:trigger.new){         if(t.whatId!=null){             if((t.what.getsobjecttype() == quote__c.sobjecttype) &amp;&amp; (t.subject.substring(0,5) == 'Email')){                 quoteIds.add(t.whatId);             }         }     }      for(quote__c q:[select StageName__c from quote__c where Id IN : quoteIds]){         quote__c qt = new quote__c();         qt.Id = q.Id;         qt.StageName__c = 'Proposal Sent';         quotes.add(qt);     }      if(quotes.size()&gt;0){         update quotes;     } } Generalized Euler sum $\sum_{n=1}^\infty \frac{H_n}{n^q}$ I found the following formula   $$\sum_{n=1}^\infty \frac{H_n}{n^q}= \left(1+\frac{q}{2} \right)\zeta(q+1)-\frac{1}{2}\sum_{k=1}^{q-2}\zeta(k+1)\zeta(q-k)$$  and it is cited that Euler proved the formula above , but how ?  Do there exist other proofs ?  Can we have a general formula for the alternating form   $$\sum_{n=1}^\infty (-1)^{n+1}\frac{H_n}{n^q}$$ I noticed that when I had a helium filled, latex balloon inside of my car, it moved forward in the cabin as I accelerated forward. The faster I accelerated forward, the faster the balloon went from the back of the car to the front of the car. The balloon didn't have a string.  This became a game with my 4 year old as we drove home. We figured out where the balloon would go based on how fast I accelerated, turned corners etc.  I expected that it would act a lot like the water in a cup does, but it was the total opposite it seemed.  What forces caused this behavior?  I assumed it has something to do with the fluid dynamics in the closed cabin, but I can't figure it out. On the existence of a continuous bijection $f\colon [0,1]\to [0,1]\times [0,1]$ Let $f$ be a continuous function on $[0,1]$ such that $f([0,1])=[0,1]\times[0,1].$ Then show that $f$ is not one-one.  Hints will be appreciated. Limit of $(\cos1/n)^{n^2}$ when $n\to\infty$ I've been trying to solve this limit: $$\lim_{n\to \infty} \left(\cos\left(\frac{1}{n}\right)\right)^{n^2}$$ I solved it using l'hopital but I have to try in another way. I tried to make the expression:  $$ \lim_{n \to \infty}\exp\left(n^2\ln\left(\cos\left(\frac{1}{n}\right)\right)\right)$$  but it didn't work out for me... Repeat String - Javascript