I have an iron door on the first floor (to the outside) of my tower. I tried to put a switch on both sides of the door so it can be opened from the inside and the outside. My problem is that because the switch has an "On" and "Off" if I open the door from the outside I need to turn "On" the switch on the inside, go back outside and turn "Off" that switch, just to run back inside and turn "Off" the inside switch to finally get the door to close. This is a giant pain in the rear when I have mobs chasing me to the door.   Is there any way to use switches to open and close the door no matter their position? Or would it be easier to use a button and just run through the door and have it close behind me automatically?
In order to protect a portal in the nether I have an obsidian room with an iron door, which works off a switch in the room. The problem is that if I leave the room and someone else on the server closes the door from the inside I can't get back to that portal.  Powering red stone on the outside of the door doesn't seem to work, as the switch inside is already powering it, so I'm guessing something like an XOR gate will be the solution, however I am finding it difficult to see how to make this work in practice.
Is there a service that I can use to check if my machine will be able to run a certain game? Is reusing old code for a new assignment considered self plagiarism? How to protect yourself if you consider it to be, and a group partner does not? I am taking a graduate machine learning course and am working with another student in the class on a final project. In his undergraduate studies, the other student wrote code that accomplished a similar task, and mentioned in our previous meeting that we would be able to leverage much of this code for our current project if we wanted to. I responded that I believe it would constitute textbook cheating and self-plagiarism, but the other student disagrees and believes that re-using the code would not constitute self-plagiarism because he himself wrote it, and it would be redundant to re-write what he had already done.  Now, the course instructors have made it clear that we are not allowed to use any external libraries to perform certain classes of algorithms for this project. This students' prior code would fall under this category of prohibited tools, but he claims that it doesn't qualify because he wrote the code himself (so it is not an "external library"). I believe this is hyperbole, but he disagrees. It is also worth mentioning that this code is licensed under an , though it is not widely used at all.  It has gotten to the point where I am uncomfortable going forward with the project by re-using his old code, and he does not want to do work on the project that he considers to be redundant. My worry is that if it turns out we're not allowed to reuse the code, then using it could cause us to fail the course and severely negatively affect our reputations. Even if we don't get caught, I personally feel that it would be unethical to copy-paste old code and present it as though it's fresh code for this current project.  I am unsure of how to proceed. I have tried reaching out to the professor of the course some time ago (she has been traveling for some conferences recently and will be for a while) but I have not heard back from her. Additionally, the course TAs have been unwilling to weigh-in on the situation.  I have the following questions:   Is the above situation usually considered to be self plagiarism? Why or why not? Is the above act typically allowed in an academic setting? Assuming you are in my position, and consider re-using the code to be cheating and/or unethical, what is the best way to proceed; both in terms of how to make progress on the project, how to compromise with my group mate, and how to protect myself if my group mate refuses to budge. If I remove Minecraft sound files from .minecraft/assets/objects, will Minecraft be unable to play them? In Minecraft, there are a lot of cool sounds. I decided to find there location and move them to my desktop. I have Ubuntu, and if when I remove them from that folder will Minecraft be unable to play them or is it smart enough to figure out that they are gone and download them again. Before minecraft was installed, it had to download the files. I even moved my favorite song (creative 6) from the sounds. The sounds are not labeled and have seemingly random names like b0b12118a97ddd733a50e9382e91a21652568641 and how will I know what to call them that will be recognized without digging through the index if Minecraft fails to download them? Or do I not have to worry because it will download them again upon launch?  Note: Why does it not label them and call them random names? Configure long table caption $IS \mid JS$ implies that $I\mid J$ where $I$ and $J$ are ideals of a number ring contained in another number ring $S$ customize of autoref How can I group numerical data into naturally forming "brackets"? (e.g. income) The following describes what I'm trying to accomplish, but it's possible an alternative problem statement can describe my goal:  I want to    divide the following numbers into groups where the variances of the numbers within each group are not too large, and the differences between the averages of groups are not too small  compare the distribution obtained in the end with the "perfect" ones and see how "different" it is from being perfect.     Layman's explanation of goal  , and determine the "income brackets" each population is in.  The income bracket is supposed to be self-adjusting based on the input data.  My goal is to ultimately measure or calculate the difference between the income brackets.  I assume there will be many brackets, and want to see how far "apart" each tier is.  Here is a sample of hourly income for a sample set of a population of 20, and a total income of 3587:  Population= 10                   pop=2   population=5              population =3 10, 11,13,14,14,14,14,14,15,20,  40,50  ,90,91,92,93,94      999,999,900    How can I use mathematical concepts to group, sort and analyze data that acts like income distribution over a given population?  At the end of the calculation, I want to determine tiered income distribution, where a perfect distribution would look (something) like this   (each person makes $10 more per hour than the previous; total is 3587) 89, 99, 109, 119, 129, 139, 149, 159, 169, 179, 189, 199, 209, 219, 229, 239, 249, 259, 269, 279   or this:   (evenly distributed groups of people make the same per hour)  (gaps between income groups is consistent and not "too far") (income total is 3587) 99 99 99   129 129 129   159 159 159   199 199 199  229 229 229  269 269 269    Question  How should I analyze the population groups, and measure the gap in a way that will tell me how much is needed to make it more like the last two model sets listed above? SF novel -- the only human on a space station full of aliens Some things I remember:   Pretty sure the author was female The novel had won some award or other The title was one word (I think) and it started with "I" (I think) It would have come out in the mid to late 90s or early 2000s It was a paperback or trade paperback, in English.  The book was originally written in English as far as I know. The cover, if I remember correctly, had an orangish background.   The plot involved a sole human representative to what was effectively an alien "United Nations" type of organization.  There were myriad types of aliens, many of whom were completely biologically incompatible.  Even the ones that could live in the same conditions generally found each other either repugnant or incomprehensible.  The main character ended up feeling incredibly lonely and was "set up" with a superficially similar humanoid female, but found their pheromones were incompatible and it was still difficult to communicate. What is the difference between 32-bit and 64-bit Ubuntu? I've heard the 64-bit platform performs better and can detect more than 4GB of RAM. Also, while some apps haven't ported to 64-bit yet, ia32-libs lets a 64-bit machine run them.  If so, why not promote 64-bit over 32-bit? Carry over long sequence of missing values with Postgres I have a table like this:  create table foo (foo_label text, foo_price int, foo_date date);  insert into foo (           values           ('aaa', 100,  '2017-01-01'),           ('aaa', NULL, '2017-02-01'),           ('aaa', NULL, '2017-03-01'),           ('aaa', NULL, '2017-04-01'),           ('aaa', 140,  '2017-05-01'),           ('aaa', NULL, '2017-06-01'),           ('aaa', 180,  '2017-07-01')         );   As you can see a few values on the foo_price column are missing.  What I need is that missing values get filled up with the "previous" available value in this way:   foo_label | fixed_foo_price | foo_date -----------+-----------------+------------  aaa       | 100             | 2017-01-01  aaa       | 100             | 2017-02-01  aaa       | 100             | 2017-03-01  aaa       | 100             | 2017-04-01  aaa       | 140             | 2017-05-01  aaa       | 140             | 2017-06-01  aaa       | 180             | 2017-07-01   My attempt:  select      foo_label,      (case when foo_price is null then previous_foo_price else foo_price end) as fixed_foo_price,     foo_date from (   select        foo_label,        lag(foo_price) OVER (PARTITION BY foo_label order by foo_date::date) as previous_foo_price,        foo_price,       foo_date       from foo ) T;   As you can see from here:    It doesn't fill completely the '100' series.  Any idea how can I get the wanted result? Statistics and causal inference? In his 1984 paper , Paul Holland raised one of the most fundamental questions in statistics:     What can a statistical model say about   causation?   This led to his motto:     NO CAUSATION WITHOUT MANIPULATION   which emphasized the importance of restrictions around experiments that consider causation.  Andrew Gelman makes :     "To find out what happens when you change something, it is necessary to change it."...There are things you learn from perturbing a system that you'll never find out from any amount of passive observation.   His ideas are summarized in .  What considerations should be made when making a causal inference from a statistical model? Eigenvalues of Householder matrix What would be the eigenvalues for a Householder matrix defined as: $H = I - 2 u u^T$? Can someone explain it  to me intuitively or with a simple proof? Windows 7 won't boot after installing Ubuntu 11 Iterating through columns in table using ModelBuilder? I am unable to find any info on how to use ModelBuilder to run a certain spatial analysis function on each column in a table.  I have a table to sample locations and at each location there are a series of measures (e.g. temperature, flow rate, number of certain species).  For each of those attributes (columns in the table), I was to run the IDW function from the surface tools.  This would be easy if I had each attribute in a separate shp/feature class, but not very efficient.  I tried Iterate Feature Selection, but was unable to pass the field name as the Z value in the IDW function.  This is for ArcGIS 10.1 (Basic and Spatial Analyst license) If I am shooting the 8-ball for a win, and my opponent has a ball near the pocket I'm aiming for, can I call something like "8-ball off the 2 ball into the corner pocket"?  I thought this was allowed, but a friend says this is an automatic loss and that the 8-ball must never touch another ball before going into the pocket.  Various pool rules aren't clear for me on this scenario. At the end of the game, how are medals awarded?   As a secondary, what is the relation between bronze silver and gold medals, and how much experience do they reward? Why aren't people voting for questions? While at least some answers from every question seem to have been up-voted as a "helpful" answer:   about 49% of questions have score of 0 or 1. another 21% of questions have a score of 2.   Most questions seem to have an answer or two with score +5. Is it that we have a lot of fluff questions and not useful ones? Or perhaps it just seems more natural to vote for answers than questions? If we want the most useful info on Stack Overflow to filter to the top, how can this disparity be fixed?  I think this may cause real problems for people getting the badges which require +25 or +100 votes on questions.    I like a lot of the feedback I'm seeing. Two problems are highlighted:   The work flow doesn't promote voting for questions the way it promotes voting for answers. One solution: when a user answers a question, the system should invite them to vote for the question.  If someone cares enough to answer a question, then they care enough to vote for it as well. Users with less than 15 reputation cannot vote for questions or answers. Is this warranted?  Maybe these users could provisionally vote for questions and answers and those ratings would only take effect when the user reaches 15 reputation?   All I ask is this. As you browse Stack Overflow, when you see a good question: vote for it.  If everyone does, then this problem will disappear. Are  and the  really the same thing?  Not too long ago, Susskind and Bousso uploaded the article "" with the thesis that the many-worlds interpretation and the multiverse of eternal inflation are one and the same thing. The parallel worlds of one are exactly the same thing as the parallel worlds of the other.   First, they claim decoherence can't happen over a complete description of the future light-cone of the measurement. Then, they apply that principle to eternal inflation. Without decoherence, superpositions of nucleating bubbles and metastable vacua can't decohere. According to the anthropic principle, most bubbles have no conscious observers, but an exponentially small minority do. Apply black hole complementarity to causal horizons.  Then, somehow, in a way I can't follow, they combine causal diamond worlds into a global multiverse.  Then they claim decoherence is reversible.  My head is spinning. What are your opinions on this paper? Let $G$ be a non abelian group of order $p^3$, with $p$ prime.  I'm proving that $Z(G)$ (its center) is of order $p$. I already know how to do it by saying that its order can't be $p^3$, nor 1, and if it's $p^2$ then $G/Z(G)$ is cyclic then G is abelian, Abs!  But I've been reading another way of proving it and the author supposes that $|Z(G)|=p^2$. Then, she says: "$\exists\ x$ outside the center of $G$, of order $p$." Could someone give me a hint? Thanks! Too long in Primary Fermentation? What's the maximum amount of time for primary fermentation, assuming the beer is going straight to bottles next? Will it over ferment and then fail to carbonate, if left too long in a carboy?