Is it legal to have 2 flights in the air at the same time with the same flight #?
Can two different planes share the same flight number?
Having briefly looked at Haskell recently, what would be a brief, succinct, practical explanation as to what a monad essentially is?  I have found most explanations I've come across to be fairly inaccessible and lacking in practical detail. iCloud Disassociation for a Mac Computer I had a Mid-2012 MacBook Pro that recently stopped booting. I narrowed this down based on troubleshooting of the boot device to likely the SATA/hard drive connector/cable no longer working for whatever reason.  I have decided to sell the system. I'd like to know if I remove the hard drive (or in this case, an after-market SSD I've installed) from the system, will there be any other data (i.e. iCloud data) stored on the system on any other chip that I can reset in any way? I plan to reset the SMC/NVRAM before I sell the system off of to someone else.  Additionally, if I remove the hard drive, is the system still associated to iCloud (specifically Find My Mac) or any other service? If so, how do I disassociate it? The system will no longer boot even if I put in my boot device.  Thanks! I am trying to do kriging by gstat package through R.   Here is my Code:  krg&lt;-krige(var ~ 1,data,grid,model=vgm,nmax=30)   But each time I recive this warning:  1: In predict.gstat(g, newdata = newdata, block = block,  ... :    Warning: Covariance matrix (nearly) singular at location [1,4501,0]: skipping...   and when I try to plot it by spplot this error appears:  Error in seq.default(zrng[1], zrng[2], length.out = cuts + 2) :    'from' cannot be NA, NaN or infinite In addition: Warning messages: 1: In asMethod(object) :   complete map seems to be NA's -- no selection was made 2: In min(x) : no non-missing arguments to min; returning Inf 3: In max(x) : no non-missing arguments to max; returning -Inf   Here is the full code: You can download my data through this link:  and here is my full code:  library(gstat)                                          library(sp) library(raster)  coordinates(Mydata) &lt;- ~East + North proj4string(Mydata) &lt;- CRS("+proj=utm +zone=10+datum=WGS84") ext &lt;- as(extent(Mydata), "SpatialPolygons") r &lt;- rasterToPoints(raster(ext), spatial = TRUE) proj4string(r) &lt;- proj4string(Mydata)  v1 &lt;- variogram(cpue_female ~ 1, Mydata) vgm_mod_omni &lt;- vgm(psill = 0.0003, model = "Mat", range = 50000, nugget = 33, kappa = 0.5) G1 &lt;- krige(cpue_female ~ 1, Mydata, r, vgm_mod_omni, nmax = 30) gridded(G1) &lt;- TRUE spplot(G1) How does a circular lens produce rectangular shots? Cycles not rendering image or movie clip used as background in the viewport I am trying to make a pirate ship and am trying to attach rope to the sails. my rope is made using a path, and soft body physics. I can not find a way to attach my rope to the sail. and I can not use pinned vertices because this is not a cloth modifier. Oneboxing is a handy feature in chat for quickly previewing links, but the list of supported sites is very small, and occasionally boxes for sites such as Wikipedia can break and fetch any image/text.  Instead of having to request additional sites to be added to the onebox list (, , , , , and of course ), we could let the sites themselves handle the oneboxing with some &lt;meta&gt; tags, such as:  &lt;meta name="onebox-title" content="The Onebox Title"/&gt; &lt;meta name="onebox-image" content="/image.png"/&gt; &lt;meta name="onebox-summary" content="This is the summary for a site's onebox"/&gt;   Then when a link is placed on its own in chat, the oneboxing spider would look for these tags and, if they are found, show the appropriate data.  Support for these tags would certainly be bad (for lack of any real better term) at first, though most users of SO chat could easily add it to their personal / company's sites (should they be in such a position) and writing friendly suggestions to other sites to implement them isn't exactly a gargantuan effort.  This would also present an opportunity for currently oneboxed sites to set in stone what should be shown, such as each Wikipedia article setting the main image to be oneboxed instead of SO's spider picking one willy-nilly.  Finally, sites implementing these tags would lay the foundation for other sites and services to develop similar features to the onebox, without having to write per-site scrapers. Existence in ZF of a set with countable power set Is it consistent with ZF for there to exist a set $S$ such that the power set $P(S)$ is countable? If so, what is the weakest form of the axiom of choice needed to prove that no such set exists? Should form 'Continue' button be disabled if validation is incomplete? In forms we often see the 'continue' button inactive until all the required fields are complete:         &ndash; Wireframes created with   Is this actually a help to the user, or a hindrance?  I imagine the Pro for this is that it's a visual indicator to the user that they haven't finished filling in the form or dealing with errors (because even with inline validation a user won't be informed if they've never actually interacted with a field so won't show any errors for those at that point).  But then the main Con for this (which I've also seen borne out in usability testing) is that users will be confused why they can't click the button.  Is the pattern of disabling the Continue button until validation is complete actually providing a negative user experience? I have a log file being written by another process which I want to watch for changes. Each time a change occurs I'd like to read the new data in to do some processing on it.  What's the best way to do this? I was hoping there'd be some sort of hook from the PyWin32 library. I've found the win32file.FindNextChangeNotification function but have no idea how to ask it to watch a specific file.  If anyone's done anything like this I'd be really grateful to hear how...  [Edit] I should have mentioned that I was after a solution that doesn't require polling.  [Edit] Curses! It seems this doesn't work over a mapped network drive. I'm guessing windows doesn't 'hear' any updates to the file the way it does on a local disk. Creating label in QGIS? I am using QGIS 2.18.16 on Windows 10.    What I want is a label to appear within the boundaries of a polygon.    I select a layer, then select command Layer>Labelling, and I get:    From here, I can change "No Labels" to "Show labels for this layer".  But I can't actually create label text.  I find a clue in a prior question:    “Labelling polygon using QGIS?”    The answer was:  The layer you are trying to label must have at least one attribute field populated with data. You can then turn on labelling in Layer Properties and select which attribute field to use for your labels.  I can enter command Layer>Open Attribute Table, and what I get is:    If I need something in the attribute table in order to apply a label, how do I accomplish that? I am trying to send an email using a Visualforce template and I want that template to include an icon. Is this possible? Is there a term for switching syllables of words? Primary question: A common speaking mistake is to exchange syllables of words, saying "It's trace rhyme!" instead of saying "It's race time!", or pronouncing "kickin' chackatory" instead of "chicken cacciatore." Is there an existing name in poetry, linguistics, or English studies for switching syllables of (quasi-)consecutive words? I am not especially interested in the case when switching syllables results in interpretable homonyms or portmanteaus, like in the first example.  Secondary question: if not, what would you call it?  Tertiary question: is there somewhere a (playful?) taxonomy of fruitful or unfruitful lingual aberrations? How do I connect to a MSSQL database using Perl's DBI module in Windows? How do I connect to a MSSQL database using Perl's DBI module in Windows? How do I login to the Gamecenter on PewDiePie's Tuber Simulator, if you have not done it when they asked? Crick’s Central Dogma — Counter Cases bash regex with quotes? The following code  number=1 if [[ $number =~ [0-9] ]] then   echo matched fi   works. If I try to use quotes in the regex, however, it stops:  number=1 if [[ $number =~ "[0-9]" ]] then   echo matched fi   I tried "\[0-9\]", too. What am I missing?  Funnily enough,  suggests this should work.  Bash version 3.2.39. Override a method via ObjC Category and call the default implementation? Accumulation Points for $S = \{(-1)^n + \frac1n \mid n \in \mathbb{N}\}$ I was recently asked to find the accumulation points of the set $$S = \{(-1)^n + \frac{1}{n} \mid n \in \mathbb{N}\}$$  I answered that the accumulation points are $\{-1,1\}$, because despite the fact that $\frac{1}{n}$ diverges, we can still use $\frac{1}{n}$ to find an element arbitrarily close to either $1$ or $-1$, i.e. to show that there is an element in an arbitrarily small neighborhood of $1$ or $-1$. (No proof was required for this question --- this is my intuition.)  Am I right at all? How to do joins in LINQ on multiple fields in single join I need to do a LINQ2DataSet query that does a join on more than one field (as  var result = from x in entity join y in entity2         on x.field1 = y.field1  and            x.field2 = y.field2   I have yet found a suitable solution (I can add the extra constraints to a where clause, but this is far from a suitable solution, or use  solution, but that assumes an equijoin).  Is it possible in LINQ to join on multiple fields in a single join?  EDIT  var result = from x in entity              join y in entity2              on new { x.field1, x.field2 } equals new { y.field1, y.field2 }   is the solution I referenced as assuming an equijoin above.  Further EDIT  To answer criticism that my original example was an equijoin, I do acknowledge that, My current requirement is for an equijoin and I have already employed the solution I referenced above.  I am, however, trying to understand what possibilities and best practices I have / should employ with LINQ. I am going to need to do a Date range query join with a table ID soon, and was just pre-empting that issue, It looks like I shall have to add the date range in the where clause.  Thanks, as always, for all suggestions and comments given