Just = only a short time after that I had just arrived home last night when I remembered that I had left my keys in the office   I had arrived home last night, and only a short time after that, I remembered that I had left my keys in the office      These two have the same meaning, right?
The word that always gets me mixed up : JUST I had just arrived at the hotel, checked in and gotten into my room. Just as I was about to unpack, I noticed that one of my bags was missing. At first I thought I had left it back at the airport, but it turned out that I had left it on the taxi.  Here, what's the meaning and role of "just"?  Why do you guys input the word "just" here?  What exactly does the word do grammatically?   Could you help me?
Joining attributes of polygons and points by location in QGIS I have two shapefiles....   points containing a number field 'response_time' a polygon grid of square polygons containing fields including 'PNTCNT' with the number of points per polygon, calculated already using the tool 'points in polygon'   There are between 0 and 600 points within the bounds of each polygon in the grid.  I want to add fields to the polygon grid for the mean, min and max response times within each polygon, in addition to the PNTCNT field already there.  I have tried the 'Join attributes by location' tool, making the polygon layer the target and the points the join layer, and vice versa. I've selected 'take summary of interesting features'.  But I can't get the result I want. All I end up with is the polygon grid again but with an extra field 'COUNT' which replicates (or duplicates) the 'PNTCNT' field. No min, max and mean of values from the points layer.  What am I doing wrong? Is there a better way to do this? I have tried this using QGIS 1.7 and 1.8. How to model this odd-shaped distribution (almost a reverse-J) There are no book recommendations for Astrophysics here. I will write my own answer, but I am also interested in what are others' views on the question (I will NOT mark my own answer as the best one). Converting a system command to python for file search and delete How to obtain and use the .bbl file in my tex document for ArXiv submission? I am submitting my first article to ArXiv and in the instructions they specify I have to include the .bbl file. Their instructions are:  "We do not run BibTeX in the auto-TeXing procedure. If you use it, include in your submission the .bbl file that BibTeX produces on your own machine; otherwise your references will not come out correctly. We do not run BibTeX because the .bib database files can be quite large, and the only thing necessary to resolve the references for a given paper is the .bbl file. The name of the .bbl file must match the name of the main .tex file for the system to process the references correctly."  My knowledge of LaTeX is basic, and I have not heard of .bbl file before. I am using TeXmaker. I have my tex file and my bib file. So what do I exactly do to obtain the .bbf file correctly and submit the article?  Thanks a lot! Linear regression best polynomial (or better approach to use)? Any ideas on other polynomials I could successfully use for applying regression? My goal is a solution that has fit error strictly based on the noise. Is this possible since it is a bell-like curve? The tails can be long, short or non-existent. Am I looking for the impossible? Please note it has been a while since I have plunged this far into linear regression.   Anyway, my data points do not fit the $ax+bx^2+c$ polynomial well enough. I would like a replacement for this polynomial to apply regression (or different approach). In the following example, each point misses the fit curve by $20\%$ of the $Y$ range on average (of the data points). I looked at splines, but I do not know how to apply the regression since they look piece-wise.   Example $Y$ values (evenly spaced in $X$). It looks kind of like a bell curve. I would be applying 5 to 50 data points to determine the polynomial coefficients. Ultimately, I am interested in the best $X$ location for the peak based on the data points.     X      Y -40    -21142.1111111111 -30    -21330.1111111111 -20    -12036.1111111111 -10      7255.3888888889   0     32474.8888888889  10     32474.8888888889  20      9060.8888888889  30    -11628.1111111111  40    -15129.6111111111 Economics.SE's favicon is missing in action The existence of the empty set is an axiom of ZFC or not? I found in the Wolfram MathWorld page of the  that this is one of the Zermelo-Fraenkel Axioms, however on the page about these  I read that it is an axiom that can be deduced from the Axiom of Subsets and the Axiom of Foundation (or Axiom of Regularity), so, the existence of the Empty Set is an axiom of ZFC or not? Do mankind and manmade activities/constructions have any effect on the rotation of the Earth? We walk or ride on our vehicles to our destinations daily. Does our movement have any effect on the rotation of the earth according to Newton's law? What will be the effect if we move all the peoples along with their vehicles at their maximum velocity in one line in one direction along the equator? How much effect will it make? Showing $d(x,y) = \frac{|x-y|}{1+|x-y|}$ is a distance. Show that $(\mathbb{N}, d)$ is a metric space   with $$d(x,y) = \frac{|x-y|}{1+|x-y|}$$   My attempt:   let $x,y \in \mathbb{N}$,  1) $d(x,y) = 0 \implies |x-y| = 0 \iff x = y$  2) $d(x,y) = d(y,x)$  3) show for $z \in \mathbb{N}$, $d(x,z) \leq d(x,y) + d(y,z)$  Using the triangle ineuqality I managed to get:  $$d(x,z) \leq \frac{|x-y|}{1+|x-y| - |y-z|} + \frac{|y - z|}{1 + |x-y| - |y-z|}$$  but i assume here I must use the fact that $x,y,z \in \mathbb{N}$ but I'm not sure how.  Any hints please:  edit: improvements on solution - Using fact that $|x-y|$ is a metric we have that $$d(x,y) \leq \frac{|x-y|}{1+|x-y| + |y-z|} + \frac{|y - z|}{1 + |x-y| + |y-z|}$$ (Since $|x-z| \leq |x-y| + |y-z|$) Is this correct? From there I can use the fact that $$\frac{1}{1+|x-y|+|y-z|} \leq \frac{1}{1+|x-y|} $$ and $$\frac{1}{1+|x-y|+|y-z|} \leq \frac{1}{1+|y-z|}$$ to conclude? When should you use WP_Query vs query_posts() vs get_posts()? It seems like half the tutorials in the  and around the blogosphere use  and half use . They all do similar things, so when should I use one over the others? Difference in meaning of "frustrated at" and "frustrated with" What is the difference in meaning of "frustrated at" and "frustrated with" used in sentences like     He is frustrated with me   or      He is frustrated at me   When is each of these sentences above are used? To me, using Present Perfect form means the event can occur again. So, saying      someone has died   may not be grammatically correct.  Also, I noticed (it might be just coincidence):     passed away   is used more often than     has passed away   Is using Present Perfect correct here? bibtex and genitive / possessive 's: the proper way to obtain "Kuran's (1989) model" Is there an automatic way to attach a genitive apostrophe or " ' s " to an author's name?  Currently I use:  \citeauthor{kuran1989}'s \citeyear{kuran1989}   But since this comes up regularily I'd like to know whether there's a general solution. I have often heard people say "x of his" or "x of mine". But since his and mine point out ownership, isn't using "of" here doubles that ownership? Wouldn't it be more appropriate to say "x of him" or "x of them" etc.?  Example:     I was a good friend of your dad's. He told me all about you` Some time ago, we announced that . This has gone well and we're extremely thankful to everyone for their support and feedback. Because it has been successful so far, we're going to be extending the program to the majority of our graduated sites. Well, we've pretty much already done that, but there are quite a few sites that have ads enabled, yet still display nothing. The thing is, we don't really have an abundance of clients offering products that a  would find relevant, but Amazon has stand mixers, a selection of super fine chinois, deliciously sharp cutlery and enough cast iron to fill the Gulf Of Mexico with . Beginning as early as this week (week of 5 February 2018), our ad team is going to be hand selecting affiliate ads to be displayed on select sites. The use of inventory will of course depend on the availability of relevant ads to display which means:  Some sites might see very few, if any ads. Some topics simply don't come remotely close to orbiting anything worth advertising. Furthermore, while graduated, some sites simply don't have enough activity for ads to make sense.  Since these are hand-selected, it could take a while for ads to appear initially.  These would of course yield to inventory from clients if clients had products that were relevant to any given topic.   Nothing changes when it comes to the . If you're used to occasionally seeing a community promotion ad, you'll just notice that you'll also occasionally see an ad for something that is likely to be of interest to someone interested in the topic that your site covers. In fact, to be clear, this is simply a continuation of the announcement we made in November of 2016. We just wanted folks to know that we're going to be continuing the program where there's good potential to show relevant advertisements, even if we don't have clients lined up with a demand for it. Where can I give feedback about a certain ad on [site]? Open a meta post on your per-site meta and let us know. Please remember, the bulk of advertisements are an effort to get something small back from folks that hit the sites through search engines and are extremely unlikely to ever become contributors. Their soufflé stopped falling, and we'll probably never see them again. Maybe we can get a few bucks once they realized that copper ions help egg whites stiffen properly and buy a bowl or a proper bloom whisk. However, you're the experts on these topics and we're very likely going to listen to you. What sites, specifically? Are any sites exempt? If you're a former Stack Exchange 1.0 site and / or subsequently joined the network under a special charter, nothing changes - don't panic :) For the rest, we're just extending what we're currently doing with ads on graduated sites to also include those where there's an opportunity to make sensible use of affiliate ads. If a site has less than 15k (average) daily visits, or fewer than roughly 50k combined total posts - it might not yet be time to invest in selecting ads to be shown there. But, part of this exercise is also seeing what works best. I don't really have feedback, just some suggestions Ads aren't just an opportunity to sell stuff, they're an opportunity to really show people that we understand a given topic. That, of course, makes suggestions from people that do that stuff every day quite valuable. Post on your per-site meta and our community / ad critters will take a look. Questions? Comments? Kvetches? Let us know in an answer or comment below. If anything about the plan changes, we'll update this post to let folks know. Obviously, most beers are carbonated with carbon dioxide, while some stouts/porters are "carbonated" with nitrogen.  I was curious if there has been any notable experimentation with other gasses to "carbonate" beer. If nitrogen can introduce a "creamy" texture to a beer, I would think that other gasses would also be able to introduce their own characteristics on beer. If any of these experiments have done, what characteristics do these other gases impart?  I'm sure cost would be an issue for certain gasses that would prohibit its use in beer, but for purposes of this question, cost is irrelevant.  As an aside, what is the correct term to use, as opposed to "carbonate", for a question of this nature? Often I have a question, in a specific area (say Math SE or English SE) that is appropriate for the child meta of that site.   Then I realize it is not particular to the meta for that site but for Meta for all sites (like this question itself; I wanted a link to Meta Stack Exchange from meta.english, but realized no meta sites had such a link).  Wouldn't it be nice to have a link in all meta sites to Meta? TTY doesn't wait for password I upgraded from 16.04 to 18.04. When I press Ctrl+Alt+F3 I get the terminal which prompts for the username. When I type my username and press Enter, it doesn't wait for my password (its as if I pressed Enter without entering anything). Even if I enter something, the text shown in plaintext and then it keeps on saying my password is wrong. After few times, the screen is cleared and it prompts for my username again and the same loop goes on. It's been more than a month since I have started using . It has these users with user names in the format of "user-random number". I have observed them in some of the stack activities, most of the time asking questions.   Does the moderators create them for their own purpose. If yes what purpose do they serve?   I mean a user is free to have any user name. But it's just a hunch that such users are actually moderators. I may be wrong; just need some clarification.