How do I rotate a camera around the Y axis of the object it's looking at?
Orbiting a specific point - Orbiting Camera
Where did object dimensions go in 2.8? Are spells learned from feats considered to be associated with your class? The multiclassing spellcasting rules (PHB p. 164, or ) state:  Each spell you know and prepare is associated with one of your classes, and you use the spellcasting ability of that class when you cast the spell.  According to the above, every spell you know or prepare should be associated with a class.  However, for spells learned from feats like Drow High Magic or Wood Elf Magic are these actually associated with a class? If so, what class? If not, is the PHB statement above wrong/outdated? Are the spells learned in these feats (and others like it) associated with something else (like your race, in these cases)?  For reference, the  racial feat (XGtE p. 74) states:  You learn more of the magic typical of dark elves. You learn the detect magic spell and can cast it at will, without expending a spell slot. You also learn levitate and dispel magic, each of which you can cast once without expending a spell slot. You regain the ability to cast those two spells in this way when you finish a long rest. Charisma is your spellcasting ability for all three spells.  The  racial feat (XGtE p. 75) states:  You learn the magic of the primeval woods, which are revered and protected by your people. You learn one druid cantrip of your choice. You also learn the longstrider and pass without trace spells, each of which you can cast once without expending a spell slot. You regain the ability to cast these two spells in this way when you finish a long rest. Wisdom is your spellcasting ability for all three spells.  In regards to the third and fourth questions, the fact that the PHB quote says &quot;use the spellcasting ability of that class when you cast the spell&quot; and the fact that the feats specify what ability the spell uses in these examples (independent of class) suggests to me that they are not associated with class. Disable output buffering Is output buffering enabled by default in Python's interpreter for sys.stdout?  If the answer is positive, what are all the ways to disable it?  Suggestions so far:   Use the -u command line switch Wrap sys.stdout in an object that flushes after every write Set PYTHONUNBUFFERED env var sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)   Is there any other way to set some global flag in sys/sys.stdout programmatically during execution? What is the use of the yield keyword in Python? What does it do? For example, I'm trying to understand this code1: def _get_child_candidates(self, distance, min_dist, max_dist):     if self._leftchild and distance - max_dist &lt; self._median:         yield self._leftchild     if self._rightchild and distance + max_dist &gt;= self._median:         yield self._rightchild    And this is the caller: result, candidates = [], [self] while candidates:     node = candidates.pop()     distance = node._get_dist(obj)     if distance &lt;= max_dist and distance &gt;= min_dist:         result.extend(node._values)     candidates.extend(node._get_child_candidates(distance, min_dist, max_dist)) return result  What happens when the method _get_child_candidates is called? Is a list returned? A single element? Is it called again? When will subsequent calls stop?   1. This piece of code was written by Jochen Schulz (jrschulz), who made a great Python library for metric spaces. This is the link to the complete source: [Module mspace][1]. How to tail multiple files using tail -0f in Linux/AIX Is it okay to board only the second flight of a return ticket? The return ticket is much cheaper than buying one way I was browsing flight price at Singapore Airlines website, and a one-way flight from SIN to SFO cost this much:    That's quite expensive. I tried browsing around and found that a return flight from SFO to SIN and back to SFO cost much cheaper:    It's really weird because the second ticket includes the exact same flight that cost 1900+, but it's almost half the price. The reason for this counter-intuitive situation is explained in the answers this question   If I am located in Singapore and my intention is to fly one-way to SFO, is it safe to book the flight in the second picture and only board SFO-SIN leg? Will they deny me because I miss the SIN-SFO flight? Proof of continuity of Thomae Function at irrationals. In :  $$ \begin{align} t(x) = \begin{cases} 0 &amp; \text{if $x$ is irrational}\\ \frac{1}{n} &amp; \text{if $x = \frac{m}{n}$ where $\gcd(m,n) = 1$} \end{cases} \end{align} $$  I can prove the discontinuity at rational $b$ by taking a sequence of irrationals $x_n$ which converge to $b$.   But while going through an argument for continuity at irrationals.  I found this in a book.      On the other hand if $b$ is an irrational number and $\epsilon &gt; 0$   then there is a     natural number $n_0$ such that $1/n_0 &lt; \epsilon$.   There are only finite number of rationals with denominator less than   $n_0$ in the interval $(b-1,b+1)$. Hence we can find a $\delta &gt; 0$   such that $\delta$ neighbourhood of $b$ contains no rational with   denominator less than $n_0$.   I understand the rest of the proof. But I am unable to prove the emphasized text. Although I find it intuitive. A concrete example of involution in group theory I am reading the textbook "Introduction to Modern Algebra, Joyce 2017" and in the Cyclic groups and subgroups section, there is a following sentence about involution.     An involution $a$ is an element of a group which is its own inverse, $a^{-1} = a$. Clearly, the order of an involution $a$ is $2$ unless $a = 1$, in which case the order of $a$ is $1$.    I was trying to come up with a concrete example, but I am having difficulties. Maybe when $a = \frac{1}{2}, \frac{1}{2}^2 = 1$? I also searched the  for a concrete example, but wasn't able to find anything.  Can someone provide an example with numbers for me please? I want to understand why the author writes "clearly" that the order of an involution $a$ is $2$. Thank you revoking apex managed sharing permission I'm using apex managed sharing to grant permissions very similar to how it is done in this example trigger:   However, I also need the ability to revoke or delete this access and having it revert to private. The reason for this is my understanding is that there are only two access options for managed sharing access 'read' or 'edit' with no 3rd option of 'none' or 'private'.  Reference:   I've tried adding the shares to a list and deleting the list and I'm getting the error: DELETE_FAILED, cannot delete owner or rule share rows,   I also noticed there is a field on the share object 'isDeleted' this field however is not writable.  Does anyone have experience revoking or deleting these permissions once they've been created?  Thanks! Cardinality of quotient ring $\mathbb{Z_6}[X]/(2X+4)$ I saw this movie a while back. I don't remember how it starts, but from where I remember watching it, it may have not been too far from the start. Apparently, Earth has been conquered by some alien empire or something and humanity are basically cavemen being used as slaves. From what I remember, the main antagonist alien is seen taking one of the slaves to a room where a machine is used on him to make him smart; this is apparently a big no-no so the main antagonist and his sidekick have to keep it quiet. The idea was that by making one of the slaves smart, it could increase the work output of the others. Apparently the antagonist is using the slaves on Earth to gather gold bullion  which is apparently still very valuable to the aliens but he's doing it illegally (not the slave labor; that's apparently ok). The protagonist who had the machine used on him becomes the intermediary between the slaves and the aliens and begins teaching the other slaves. I remember him teaching them mathematics and I remember him saying that it was universally accepted (I think he may have been referring to algebra or trigonometry). At some point he becomes aware that they are slaves and organizes a plan to free not only his fellow slaves but the Earth. Some escape and find an old museum which has old flight simulators, and shows that humanity wasn't always a slave race and that it may have been modern times in which Earth was invaded (i.e. no lasers or starships). I think they also find Fort Knox as there is a huge collection of gold bricks and weapons. The protagonist comes up with a plan to destroy some sort of teleporter the aliens use to transport stuff to and from Earth, however that alone wont be enough as they could fight back, which will be bad for humanity, which is still undeveloped. So the plan also includes using the teleporter before destroying it to to transport and detonate a nuclear warhead on the alien home world which apparently cripples any attempt to immediately send a fleet but also as a show of strength. After executing their plan, the main antagonist is captured by the humans and as an insult is locked in a cage surrounded by the gold he sought. If I recall correctly the place is set to detonate as to destroy the precocious gold and that will be used against the aliens should they mobilize a fleet in the future (i.e. attack us and we destroy Earth's supply of gold). The antagonist's side kick for some reason I remember as a big black man from whom the antagonist had removed his hand at some point and also apparently the antagonist was cruel to him. After the antagonist is locked up, he is trying to appeal to his sidekick's loyalty, however the sidekick takes the humans' side, I'm also getting an image that apart from treating him kindly the sidekick's missing hand was restored. Where do Orc babies come from? I've not seen/read any female Orcs mentioned in the movies or in the books. In one of the movies, an Uruk-hai is momentarily shown emerging from a giant, grown-Orc sized flesh packet. So are they created with spells, or do they follow the Standard Reproductive Model. I have just started studying implication in mathematics. So, you'll probably have an idea of where my confusion lies right from the get go.  In the truth table, where $A \implies B$ we obtain this result:  A   B   T/F ___________ T | T | T T | F | F F | T | T F | F | T   Now, my confusion here is regarding why $A\implies B$ given A is false, and B true. The others I understand. The first and last one are obvious, the second one implies, to me anyway, that given A implies B, the truth of B rests upon the truth of A, B is false, A is True, which cannot be, thus not B given A is false.  Now... then, why is B true despite the fact that A is false? Or rather, why is the statement B given not A, True. The truth of B is implied from the truth of A, but A is a false statement. So it's very contradictory that this may be, and in fact, if you go through a real life example, you would find that the third statement seems to be false.  Say $A$ is the statement that it is dark outside, and $B$ the statement that the sun is not on our side of the earth. If it is not dark outside, than stating that the sun is on the other side of the planet must be wrong (in my example i'm going to claim that the sun is the only light source).  Side note:  I just had a thought, if A is false, does that mean you can conclude... mmm, whatever? I mean, B is implied via the truth of A, if A is false, B is NOT implied, but then B could be EITHER true or false, I suppose. Is this correct?  However, would that not mean that A does not imply anything when false. Would that not set the 3rd and 4th statement to be undefined? longtabu and color compatibility The no. of all possible matrices of order $3\times 3$ with each entry $0$ and $1$ and $ -1$. Comment textbox placeholder appears to be incomplete The placeholder text on Stack Overflow is:     Use comments to ask for more information or suggest improvements. Avoid comments like    So, what kind of comments should be avoided? I seem to recall that it was only      Use comments to ask for more information or suggest improvements.   before.  Screenshot:    I notice the same on Meta. Tested in latest Chrome and Firefox versions on OS X. I am writing a doctoral thesis and I am using  to set the references in APA (American Psychological Association) format. Mostly this has worked perfectly fine, but I would like to suppress the author initials from the compiled version (in-text, not in the end references section). This happens because there are multiple authors with the same name e.g.,     Smith and Jones (1992) or Wells and Smith (1901)    are typeset in-text as:      I. Smith and Jones (1992) or Wells and D. Smith (1901).   Although it may be correct to have the initial in-text in APA format, in reality I am using BPS (British Psychological Society) format, which uses an adapted APA format (and you guessed it, they don't like the initial in text). Thus in-text should look like the first example above (without initial) but looks like the second (with).  To clarify: Any ideas on how to suppress the initial in-text in apacite?  Thanks.  ps. I understand that I could do it with a different bibtex style, but my question pertains to apacite. Brace expansion not working in a script Gravitational waves and time Two questions.  It is said that time can only go slower in gravity fields and if you move faster.  I have heard that when a gravitational wave pass earth then the space/time vibrate and time change for an instance.  But a wave is often with a top and a valley.  They have now atomic clocks that might be able to detect time variations, placed in satellites around the sun and "quantum entangled". "Using Atomic Clocks to Detect Gravitational Waves"   So what if we could compare time ticks between clocks in space at "absolute frame of reference" where time has its maximum universal speed as time in deep space between Galaxy Filaments.  Will we only detect that time ticks slower for an instance when the gravational wave pass?  1. Or will we detect that time tick slower AND faster than normal time also, as compared to zero gravity time and no movement time in "absolute frame of reference"?  2. Can time go let's say 10 times faster by theory/mathematics, by a extreme theoretical gravitational wave, than time in "absolute frame of reference time"? Does any test actually prove causation?