How to convert a numpy to a float in python
Is floating point math broken?
I have continuous problems of network dropping connections on wifi with ubuntu 16.04, I have an ASUS R510J, this is my network card:  ##### lspci #############################  03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter [10ec:8821]         Subsystem: AzureWave RTL8821AE 802.11ac PCIe Wireless Network Adapter [1a3b:2161]         Kernel driver in use: rtl8821ae  04:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 12)         Subsystem: ASUSTeK Computer Inc. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [1043:200f]         Kernel driver in use: r8169   sudo service network-manager restart doesnt's help, as I never regain internet connection after it drops, and I have to restart the PC. On Ethernet cable I have no problem.  What do you think is the issue? drivers?  thank you AMT stock option scenario Does there exist a function such that $\lim_{x \to a} f(x) = L$ for all $a \in \mathbb R$ but $f(x)$ is never $L$? What are the dev-loop services that started on boot? Cardinality of the set of bijective functions on $\mathbb{N}$? Python: pop from empty list A few years ago Umber Ferrule wrote that the toolbars in the taskbar are defined in   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Streams.   This looks very plausible but cannot be the entire story.  Deleting this key will in no way affect the taskbar and on rebooting the system the key magically reappears.  Why do I want to know?  Simple.  I would like to export the key to a reg. file as a convenient backup. Calculating size of particular area below buffer in QGIS? I have a point shapefile of villages where data was collected in Northern Kenya. I created a buffer around those villages.   The second vector layer contains polygons defining areas according to vegetation type. So for example, a forest might be surrounded by a narrow ring of woodland in an area which is mainly grassland. I'm trying to obtain a percentage of each vegetation type within the buffer per village.   I'm using QGIS 1.7 Ubuntu touch - remote access to device in our company we developed an android app installed on nexus 7 tablets and on tablet we release to several customers. This app stays in foreground active 24/7 but we have problems in monitoring  the devices due to the restrictive access policies of unrooted Android devices.   We can't for example reboot the device remotely.  We are evaluating the possibility of installing Ubuntu touch to replace android on this tablets. Does Ubuntu touch offer more freedom for the remote access of the device? May I do remotely everything I could do normally with the tablet?   Moreover, are the apps developed with ubuntu sdk stable enough to run 24/7?  Thanks the (surely simplistic) model of a bipolar junction transistor one is taught in foundational physics course appears to be symmetric. - So, what is the difference between the collector and the emitter of a real BJT? If the transistor were symmetric one would not make this distinction...  Also:   Do BJTs have a 0.6V voltage drop like diodes? Are BJTs conductive in both directions, i.e. E-C and C-E?   Many thanks. Why is voltage same for the two resistors connected parallel in circuit? We know that the electric field inside resistor produced by battery is the actual thing that pushes the electrons in it to move and thus producing some current. We also know that strength of electric field can be described by the electric flux which is the total amount of fields passing through an area. That flux when combined(multiplied) with charge of electron gives the amount of force on it. Now comes our two resistors R1 and R2. Assuming a number of field lines coming out of a terminal going towards another terminal through these resistors, the field lines should get divided into the resistances R1 and R2. Therefore giving a reduced flux through each resistor than in a series. Which will then give a lower voltage for both resistors. Wasn't the electric fields strength divided across resistors in parallel? What is the main cause of voltage? How electrons get a force to produce current even when the wire is very long in? I think it is better to understand with reality than analogy. Please don't give misleading pictures Should I use the datetime or timestamp data type in MySQL? Possible Duplicate:          This is something I haven't quite figured out yet, but I have been using function(){}() just because my VIM syntax highlight screws up if I add the parenthesis, although I've seen (function(){})() around many times, maybe its an IE thing?  edit:  var singleton = function() {     // code }();  var singleton = (function() {     // code })(); Find $ P(Z>X+Y)$ where $X,Y,Z \sim U(0,1)$ independently I'm trying to follow a line in a derivation for $P(Z&gt;X+Y)$ where $X,Y,Z$ are independent continuous random variables distributed uniformly on $(0,1)$.  I've already derived the pdf of $X+Y$ using the convolution theorem, but there's a line in the answer that says:  $P(Z&gt;X+Y) = \mathbb{E}[\ P(Z&gt;X+Y\ |\  X+Y )\  ]$ where $\mathbb{E}$ is the expectation.  I'm not familiar with this result. Could anyone give a pointer to a similar result if one exists?  Thanks. An irreducible polynomial of degree coprime to the degree of an extension is irreducible over this extension I'm having a hard time showing this:     If $K$ is an extension of $\mathbb{Q}$ with degree $m$ and $f(x)$ an irreducible polynomial over the rationals with degree $n$, such that $\gcd(m, n)=1$, then $f(x)$ is irreducible over $K$.   I have tried it by writing $f(x)=a(x)b(x)$ and then looking at the coefficients of those polynomials (some of them must belong to $K-\mathbb{Q}$ which could possibly result in a contradiction) to no success. I have no idea where to use the hypothesis of m and n being relatively prime.  Any help would be appreciated. How to support different screen size in android If $X$ is an orthogonal matrix, why does $X^TX = I$? It's not immediately clear to me why this is true. My notes say that putting $n$ orthonormal vectors $ v_1, ..., v_n$ in the columns of $X$ gives $X^TX = I$, and it follows from this that the rows of $X$ are orthonormal.   Can you explain this better to me? I tried the $2\times 2$ case, but it isn't clear to me why this is true. How do I prove that a graph is a topological manifold Associated elements in a ring Please help me to find elements $a,b$ in a ring $R$ such that $a\mid b$ and $b\mid a$, but there does not exist any unit $u$ in $R$ such that $a=ub$. Attributing contributions to academic work that occur in Stack Exchange Sometimes we may ask questions on stack exchange or online forums wherein the response is helpful or even essential to a piece of work that gets published in an academic journal. If this occurs, how should credit be given to those involved in the exchange? Should they all be included as authors? Should a link to the forum be included as a reference in the paper?  Once something is in a stack exchange or forum, it's "published". Perhaps in the future, the current peer review model will transform into people writing blogs and posting in forums and databases. But for now, how might this issue be dealt with while forums, blogs, etc coexist with journals?