Why does Jupyter display of floating-point values differ from Python console?
Is floating point math broken?
Is a switches voltage and current rating a hard limit? Chat flag notification, but no flag It appears  is back. Upon refreshing any chat page (even when dumping the cache and hard reloading), a chat flag notification is displayed, but there is no chat flag. Cannot install Oracle JDK via apt in Ubuntu 16.04 I created a new Ubuntu 16.04.3 VM and am attempting to install JDK 9. Unfortunately, the latest version of the JDK apt installer, 9.0.1-1~webupd8~0, is failing to download the binaries and I suspect that the reason is because   I carried out the typical steps for installation:    add-apt-repository ppa:webupd8team/java apt-get update &amp;&amp; apt-get install oracle-java9-installer   I am then prompted with the following error message:  Downloading Oracle Java 9... --2018-01-16 15:15:07--  http://download.oracle.com/otn-pub/java/jdk/9.0.1+11/jdk-9.0.1_linux-x64_bin.tar.gz Resolving download.oracle.com (download.oracle.com)... 23.200.70.136 Connecting to download.oracle.com (download.oracle.com)|23.200.70.136|:80... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://edelivery.oracle.com/otn-pub/java/jdk/9.0.1+11/jdk-9.0.1_linux-x64_bin.tar.gz [following] --2018-01-16 15:15:11--  https://edelivery.oracle.com/otn-pub/java/jdk/9.0.1+11/jdk-9.0.1_linux-x64_bin.tar.gz Resolving edelivery.oracle.com (edelivery.oracle.com)... 23.35.226.115, 2600:1404:21:49d::2d3e, 2600:1404:21:493::2d3e Connecting to edelivery.oracle.com (edelivery.oracle.com)|23.35.226.115|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: http://download.oracle.com/otn-pub/java/jdk/9.0.1+11/jdk-9.0.1_linux-x64_bin.tar.gz?AuthParam=1516137431_0e89d10b30203a572ea858768475ef74 [following] --2018-01-16 15:15:11--  http://download.oracle.com/otn-pub/java/jdk/9.0.1+11/jdk-9.0.1_linux-x64_bin.tar.gz?AuthParam=1516137431_0e89d10b30203a572ea858768475ef74 Connecting to download.oracle.com (download.oracle.com)|23.200.70.136|:80... connected. HTTP request sent, awaiting response... 404 Not Found 2018-01-16 15:15:11 ERROR 404: Not Found.  download failed Oracle JDK 9 is NOT installed. dpkg: error processing package oracle-java9-installer (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  oracle-java9-installer E: Sub-process /usr/bin/dpkg returned an error code (1)   I found , but it does not appear that the  works for JDK 9.0.4+11. I've updated the SHA checksums (), set the major version to 9.0.4, and set the minor version to 11, but I'm still not having success.  What steps need to be carried out to get the JDK apt installer to work until the WebUpd8 team is able to update the PPA? I remember very little but enough... I know that there were 3 worlds, a real one, a mid-world kind of with a teleporter, and the world with all the creatures. The first episode was in the desert and there was a good monster that saved the main guys from a bad one. Before he saved them he said every end is a beginning and every beginning is an end.   Please help me; I've tried everything. I saw it on , I think it was not Japanese. I live in Croatia, so I saw it there. It was aimed at kids, but not younger kids. The main characters were human, around 15 years old. The teleporter was in the middle of a big structure. It was a 6 piece tp, so every circle was one, and it was shaped like a star. There were robots working there; they carried food and other things.  I remember that all the creatures thought that the humans are evil, all but the one, the "lord" of all of them. And yes, the main character got to the world by some sort of a device that he found and it belonged to another kid who lost it and they were able to transform in the creatures from the world by it. When they are in the "other world", their body stays in the real world and acts normally but their soul gets transported to the mid-world I need to build a probabilistic cellular automaton for simulating land-use changes and am wondering how to implement this in a GIS. I understand that Markov chains are a way of doing this, and IDRISI has some sort of module for Markov chains, but I have no access to IDRISI.  that, with raster data, this can, in theory, be done with any GIS that can do raster algebra. Presumably this means that it can even be done in ArcGIS, and I think I've figured out how to build cellular automata in ModelBuilder (once I know with certainty how to make iteration work there).  Still, I can find next to no practical advice on this. Once I have two datasets, one showing the land use at a certain point in time (time A) and the other at a later time (time B), I imagine doing the following (correct me if I'm wrong):   If there are (for example) 3 types of land use, then there are 9 possible things that can happen to a cell from time A to time B; thus, reclassify each dataset such that each land use is represented by a different number (for example, 9, 11, and 14 at time A and 3, 4, and 5 at time B); Divide one raster by the other, obtaining a raster with 9 possible cell values. Determine the percentage of cells in the new raster that has each of the 9 values (I forgot, how does one do this in ArcGIS?); those will be the probabilities of each type of change (or lack thereof) in land use.   What I cannot figure out, though, is how to apply these probabilities during the next iteration. Finally, I wonder if there is a way of making an external factor (say, proximity to roads) influence the spatial distribution (not the overall likelihood) of change in my model.  Can anyone recommend where to find information on how to do this in ArcGIS? On my Windows machine, my main hard drive has the letter C: and the name "Local disk".   To list the drive letters in Java on Windows, the File object has the static listRoots() method. But I can't find a way to acquire the drive names (as opposed to the drive letters) on Windows.  Has anyone tried this before? Should flour be thrown out past its expiry date? We just got a new laptop (ASUS) though we did have a mac.  We are trying to log onto Mojang to download Minecraft and it keeps saying, "The username and password are not recognized."   We have done all the usual procedures; we have reset the password, we are using the email, not the username to sign in, and it looks like the minecraft login servers are working etc. etc.  We quit Minecraft on the old computer and shut off that computer thinking that was the issue.   Still, we can't get onto Mojang.  We are accessing mincraft through firefox and trying to download it to the new computer but we can't get into the account to do that!  What in the world could be the issue? Editing photo dimensions in large batches If I had the time, I would go through each and every photo to make sure that the dimensions and quality are pixel perfect. However, I'm in a time crunch, and need to make the couple hundred photos that are 4320 x 3240 into 950x630.   now I could- 1. Upload them into WordPress, uses native image reducing components and J query go from there. 2. Go through each and every photo, reduce file size, and proportion and bring it to Yahoo's PNG processing script.  However, maybe I'm missing a choice or alternative workflow that would allow for processing all of these photos in a clear manner without losing quality or perspectives. Any workflow suggestions? Let $A$, $B$ be two reduced $k$-algebras. Then if an element of the form $$\sum a_{i}\otimes b_{j}$$ is nilpotent, we can compose it with any $k$-homomorphism $f$ from $A$ to $k$ to get a homomorphism from $A\otimes B$ to $B$. This map's image is $$\sum f(a_{i})\otimes b_{j}$$must be nilpotent as well. So if we assume $b_{j}$ is linearly independent in the first place, we may reason that $f(a_{i})=0$. This showed that $a_{i}$ are in the Jacobson radical of $A$. However, we only know $\mathrm{Nil}(A)=0$, and it is not clear to me how to pass from the Jacobson radical to the nilradical without using some commutative algebra machinery.   Here is what I think that might work. If $A$ is of finite type, then by Nullstellensatz we can assert the above is true. But if $A$ is not of finite type, then I can write $A=k[x_{1},...,x_{n}][X]$, where $n$ is the transcendence degree of $k(A)$ and $k[X]$ is finite over $k$. Then I should be able to pass from $k[X]$ to $A$ by inductive argument on the transcendental degree of $k(A)$, since prime ideals are maximal in a UFD (I am working with $k[x]$ by introducing $[x]$).   The proof I have for the case of finite type is not satisfying. Given $I\subset k[X]$, using Nullstellensatz one can show that $$I_{X}V_{X}[I]=\sqrt{I}$$ where $V_{X}[I]$ is the set of all points in $X$ on which $I$ vanishes, and $I_{X}(V_{X}[I])$ be the ideal in $k[X]$ which vanishes on $V_{X}[I]$. Granting this, let $I=(a_{i})$, then we want to show $I=0$, which is $V_{X}[I]=X$. This follows since if $U\subset W$, then $V_{X}[U]\supset V_{X}[W]$. Since $V_{X}[I]\supset V_{X}[m_{x}]$ for all maximal ideal corresponding to points, it must be $X$. This proof is unnecessarily winding by using the ideal-variety correspondence. Ideally I should be able to construct a pure algebraic proof.   The thing not clear to me is whether the above strategy really works. Namely I am not sure if I can really induct on the transcendental degree of $k(A)$. To make matters simple assume we showed the statement holds for $A$ with transdental degree $&lt;n$. For $A$ with transdental degree $n$ we can thus write it as $k[A'][x]$. Then any maximal ideal $m'$ of $k[A'][x]$ must correspond to a maximal ideal $m=m'\cap k[A']$ in $k[A']$. But it seems not possible to show that any prime ideal is maximal. Indeed considering the simple example of $k[x,y]$, where $(x)$ is a prime ideal but not maximal since $k[x,y]/(x)=k[y]$ is not a field. The problem is in the inducting process the base ring is not neccessarily a field, and so this strategy cannot work.   I am thinking maybe I can show $m'=m[f(x)]$ with $f(x)$ some irreducible polynomial in $k[A'][x]$. Because we know $k[A'][x]$ is noetherian by Hilbert's basis theorem, so in particular $m'$ must have a finite generating set. And we can reduce the number of irreducible polynomial to 1 since $m'$ is a maximal ideal. But I still do not know how to use this to finish the proof. Why is the inclusion of the tensor product of the duals into the dual of the tensor product not an isomorphism? Let $V$ and $W$ be vector spaces (say over the reals). There is a linear injection $V^* \otimes W^* \to (V \otimes W)^*$ which sends $\sum_i f_i \otimes g_i \in V^* \otimes W^*$ to the unique functional in $(V \otimes W)^*$ sending $v \otimes w \mapsto \sum_i f_i(v) \cdot g_i(w)$ for all $(v,w) \in V \times W$. In the finite dimensional case it is easy to see this is an isomorphism by comparing dimensions on both sides. I'm aware that this is not an isomorphism in the infinite-dimensional case (see Relation with the dual space in the  on tensor products) but I must admit that I'm not sure why. Cardinal arithmetic does not seem help here and, even if it did, I would be much happier to see an explicit example of a functional in $(V \otimes W)^*$ outside the range of this map. I'm having trouble cooking one up myself.  Added: Let me elaborate on my comment about cardinal arithmetic. Suppose that $X$ and $Y$ are infinite dimensional vector spaces over a field $k$. I'm confident that $\dim (X \otimes Y) = \dim X \cdot \dim Y$ holds. It is clear that $|X^*| = |k|^{\dim X}$ since we may identify a functional on $X$ with a function from a basis for $X$ to $k$. Also I think I've convinced myself that if $\dim X \geq |k|$ then in fact $|X| = \dim X$ ie. the cardinality and dimension of a vector space agree when the dimension is larger than the cardinality of the ground field. Consequently, assuming say that $|k| \leq \dim X \leq \dim Y$ it seems we have $$ \dim(X \otimes Y)^* = |k|^{ \dim X \cdot \dim Y} = |k|^{ \dim Y} = \dim Y^* = \dim X^* \cdot \dim Y^* = \dim (X^* \otimes Y^*)$$  which implies that in fact $(X \otimes Y)^*$ and $X^* \otimes Y^*$ are isomorphic but, rather frustratingly, the obvious map does not do the job. Did I make a mistake here? If not, is it generally true (ie without making assumptions about $|k|$) that there exists some isomorphism $(X \otimes Y)^* \to X^* \otimes Y^*$? How to change a default application in Ice Cream Sandwich? I used the ADWLauncher EX by default while having Gingerbread 2.3.6.  Today I have manually updated my Nexus S to Ice Cream Sandwich 4.0.3, and I wanted to give the new default launcher a shot, but I cannot find anymore where to select / forget the default application for an action.  I've turned the settings of my phone inside out, googled and crawled the forums, but without success. If anybody can tell me how to change a default application in ICS, I'd be grateful!      Yeah, I never thought I'd want to see that Complete action using... window again! :D How to show that $f'(x)<2f(x)$ This is question B4 in 1999 Putnam Exam. I would appreciate if somebody could help me with this.      Let $f(x),f'(x),f''(x),f'''(x)&gt;0$ , $f'''(x)$ is a continuous function and $f'''(x)&lt;f(x)$ on $\mathbb{R}$. Then show that   $$f'(x)&lt;2f(x),~ \forall x\in \mathbb{R}.$$ I am asking this question because I've always had the impression that manuscripts submitted to a journal in my field (theoretical linguistics) take an insanely long time to get published, and sometimes I get the impression that this is because, most of the time, nobody other than the author cares about getting things done within a reasonable amount of time. Some examples from personal experience follow.   For the last paper I submitted before getting my PhD, I had to wait nine months from the submission date to get reviews back from the referees. Last week I got a review request from a journal I had never reviewed for previously. The review deadline is March 15 (almost four months). In early October, I submitted a manuscript to a journal that I know asks reviewers to return reviews within 6 weeks. I checked the status of the manuscript online and it still says "with editor". Earlier this year, I was about to start writing a review when my wife went into labor. By the time we came back from the hospital, I had forgotten about the review, so I missed the deadline. The editor didn't contact me to ask about the review until two months after the deadline. Late in 2013, I was asked to write a survey chapter for a handbook. The expected publication date of the handbook is summer 2016.   All of this is not me being unlucky with editors and referees. In private conversations through the years, many colleagues have confirmed that it is virtually unheard of to get reviews back within 3 months of submission; 5 or 6 months seems to be a good average, but in some cases it can take longer (see my first point above). In general, everybody seems to have accepted that the submission-to-printed-journal process is going to take a bare minimum of one year, and that's assuming that the manuscript is accepted without revisions. If revisions are required, two years is not out of the question. Also, it's not like our papers are ridiculously long. I've reviewed about 100 papers so far, and the longest one was about 50 single-space pages; 30-35 single-spaced pages is closer to average.  I remember that, when I was a postdoc, my astrophysics housemate mentioned that in his field the entire submission-to-printed-journal process took only three or four months. I really can't see a good reason why theoretical linguistics shouldn't operate on similar timeframes, other than the fact that everybody seems to have grown used to things taking way longer than they really need to. What are the wait times in other fields? How do you manage to get things done quickly? Please tutor the usage of patchcmd and xpatch I understand that the  package provides a command \patchcommand that can be used to add material at the beginning and/or end of the replacement text of an existing macro. It works for macros with any number of normal arguments but has limitations for macros with optional arguments.   was introduced to take care of the above limitations as well as provide some additional functionality.   Now, when I try to comprehend the usage of the above packages by reading the user documentations (, ), I get the feeling that they move to implementation details a little too quickly compared to other package documentations. There are not enough explanations or examples.  I also tried to grasp the concepts by reading the  and more or less understood whatever is presented there. However, that is not enough.  So, do you think we can ask for a complete tutorial on the usage of patchcmd and xpatch? Explaining the usage of the relevant commands like \patchcmd, \pretocmd and \apptocmd as well as, \xpatchcmd, \xpretocmd and \xapptocmd with sufficient examples should suffice. Suppose we define the following relationship of ordering between propositions in PROP: $$ \phi &lt; \psi := (\models \phi \rightarrow \psi \land \lnot(\models \psi \rightarrow \phi) ) $$ Show that if exists $\phi$ and $\psi$ such that: $$ \phi &lt; \psi $$ Then there is a $\sigma$ such that: $$ \phi &lt; \sigma &lt; \psi $$ I have tried to use valuation to find what $\sigma$ could possibly be, so for all valuations v:  If $v(\phi)=0$ and $v(\psi)=0$ then, since $\models \sigma \rightarrow \psi$, $v(\sigma)=0$  If $v(\phi)=1$ and $v(\psi)=1$ then, since $\models \phi \rightarrow \sigma$, $v(\sigma)=1$  It is impossible that $v(\phi)=1$ and $v(\psi)=0$ since $\models \phi \rightarrow \psi$  If $v(\phi)=1$ and $v(\psi)=0$ then $v(\sigma)$ could be either 0 or 1, and it would satisfy the tautologies, but if:  $v(\sigma)=0$, then the valuation of $\sigma$ would be equal to valuation of $\psi$ for all valuations and thus $\models \psi \rightarrow \sigma$, which is a contraditcion; $v(\sigma)=1$, then the valuation of $\sigma$ would be equal to valuation of $\phi$ for all valuations and thus $\models \sigma \rightarrow \phi$, which is a contraditcion. If $A$ commutes with $B$ and $B$ commutes with $C$, then $A$ commutes with $C$ Let $A,B,C \in \ M(3,\mathbb{R})$ be such that $A$ commutes with $B $and $B$ commutes with $C$. $B$ is not scalar matrix. Then, $A$ commutes with $C$.   Is this true or false? I think it is not true, but cannot think of a counterexample. Any suggestions? Conjugate to $\cos z$ is not equal to $\cos z$ conjugate $\overline{\cos(z)}\neq\cos(\overline{z})$ I have a dilemma. I have a task where I'm supposed to show that $|\cos z|^2+|\sin z|^2=1$ if and only if $z\in \mathbb{R} $. In my argument I have that $$\cos z\cdot\overline{\cos z} + \sin z\cdot\overline{\sin z}=\cos z\cdot \cos\overline{z} + \sin z\cdot \sin\overline{z}$$ but my teacher said that $\overline {\cos z} \neq \cos \overline{z}$.  Is this true?  But $$\overline{\cos(z)} = \overline{\frac{e^{iz}+e^{-iz}}{2}}=\frac{e^{-i\overline{z}}+e^{i\overline{z}}}{2}=\cos(\overline{z})$$ Quotient of the ring of integers of a number field by a prime ideal Converting MultiLinestring to Linestring with PostGIS