My nan bought me a book back in the 80's. It was the last of a trilogy and I never read the first two. The story was told by a princess and the world on which she lived royalty had auburn hair and the working class were blonde. The queen through special bracelets was able to harness the power of the sun but there was also something genetically different about her to do so. She had to through a life changing event in order "to change". The story starts off with the princess waiting at the foot of a mountain for her sister who is overdue. The sister had gone off on a hunt in order to change and it is implied that she has died like another sister. The princess meets a hunter instead, shares a meal with him and then heads back to the palace. There she finds her father is leaving because he can't bear seeing his daughters die. There are some other humanoid aliens living on this planet and are more scientifically advanced and are able to test the daughter and find she is missing this genetic component. The queen then takes the hunter for a mate and becomes pregnant. The princess, hunter and scientific alien then go off on a quest to find her paternal grandfather who was kidnapped by aliens years ago and cloned. My memory gets hazy now but there's something about cat like humanoid aliens called something like silth/ seeth and the grandfathers consciousness has been woven into silk by spinners. Anyway she returns home with the silk accepting that she won't be queen to find her mother has given birth to a daughter who will be queen.  If it helps I got the impression that the first two books are about the father and mother. The alien race who abducted the grandfather would clone their captives and then place the babies on different worlds and then harvest them when they are older. The mother changed by fighting off the aliens when they came back for the father.  Any ideas?

I read this set of stories in the 80's.  What I recall is this:  A planet where the ruling caste was made up of humanoid women.  These women would, as almost pubescent girls, go out into the wilderness with only a spear and attempt to kill an animal in a life or death struggle.  When it happened, they would burst open a DNA packet in themselves that caused them to rapidly mature, their skin to become bronze colored, and give them some kinds of other "powers", I think over fire.  They were called "Bahronas", I think.  The population of this planet was primitive, but they were in contact with an advanced humanoid species, I think of actual homo-sapiens, who were there observing and advising them.  The advanced species wasn't allowed to intervene, just advise and watch.  The main character was a castaway boy, crash landed on their planet and stranded.  He became friendly with the ruling family of Bahronas and entered their confidence.  We find out through the course of the story that he's been genetically engineered and is not a normal boy.  At some point, the advanced species notices him and explains that he is a clone of a famous explorer and a spy, and they explain that they won't do anything in front of him.  The central part of the story is something of a blur, but, the final part of the story is told in a dramatically different style and shifts to a planet populated by catlike creatures who live in boughs of silk scarves, some of which sing.  THey are recording devices which play back the songs.  On this planet, there is another silk scarf, a white one, which doesn't play a song at all.  The cat creatures are greatly disturbed by it when they hear it's message, which they don't understand.  The narrator then goes on to say that it's a spoken word recording, made by the explorer which the boy was a clone of, explaining that he is captured and held hostage on the planet which makes the scarves, and forced to help make them (I think.)


According to my ICT textbook, BIOS checks if the hardware is working properly and is necessary for loading up the Operating System; System software is programs that allow the hardware to work properly and allow the user to communicate with the computer. Firmware is software hard-coded on a hardware device. Then does it mean that BIOS is a type of firmware and firmware is a type of system software? or is BIOS just one of them, either firmware or system software?

The  software is built into the PC, and is the first code run by a   PC when powered on ('boot firmware'). When the PC starts up, the first   job for the BIOS is the power-on self-test, which initializes and   identifies system devices such as the CPU, RAM, video display card,   keyboard and mouse, hard disk drive, optical disc drive and other   hardware. The BIOS then locates boot loader software held on a   peripheral device (designated as a 'boot device'), such as a hard disk   or a CD/DVD, and loads and executes that software, giving it control   of the PC.[2] This process is known as booting, or booting up, which   is short for bootstrapping.   Which requisites determine that a computer system must have a BIOS installed on it?  Why can't the Operational System actually do all of the BIOS work?


I figured out that:     $$\mathop{\LARGEΣ}_{k = 1}^{n}k^3 = \bigg(\mathop{\LARGEΣ}_{k = 1}^{n}k\bigg)^2$$   Are there any other solutions for the following equation, for which $α \neq 3, \ β \neq 2$ and $α \neq β$?          $$\mathop{\LARGEΣ}_{k = 1}^{n}k^α = \bigg(\mathop{\LARGEΣ}_{k = 1}^{n}k\bigg)^β$$      P.S. The Sigmas in the equations look different to how its font usually looks like on the MSE and/or MO, (it's typical look appearing like this $\rightarrow \sum$) because I am using  \mathop{\LARGEΣ}_{k = 1}^{n}  just to test how it looks like, and because of its boldness, I don't mind its appearance.    Edit:  There is another answer that solves my problem , mentioned by .

We know that: $$\left(\sum_{k=1}^n k\right)^2 = \sum_{k=1}^n k^3 $$   My question is there other examples that satisfies:  $$\left(\sum_{k=1}^n k\right)^a = \sum_{k=1}^n k^b $$


I have a Canon 6D. I usually shoot RAW + JPEG. I shoot RAW so I have the option to edit, but I don't actually edit most of my pictures.  I've noticed that if I just import into Lightroom and export JPEG's at full resolution and where quality is roughly 80, the file ends up being about the same size as the full res JPEG version from the camera.  What's the difference (other than time taken) between these two? Is there a (practical) difference?

I've recently been shooting in raw with my new 100mm usm is macro but I'm getting strange results in out of focus areas with bright colours in. I've used Lightroom for ages and not had any issues with it but it's not giving me the results I'd expect, over saturated with what I'd describe as colour bleed. I gather that the camera and the eos utility might be showing me some sort of preview, but they look very different!  The first screenshot is what the canon eos utility v2.9 shows me (and the same in camera) and gives me the bokeh I'd expect from a lens like this.  The second is what lightroom 3.3 shows me without any developing done. I've reimported with settings reset, and copied over with adobe bridge and photoshop and had the same results. This is with lens corrections off.  Don't ask why the filenames appear to be different between the screenshots, I assure you they're the same photo.


‘But if Voldemort used the Killing Curse,’ Harry started again, ‘and nobody died for me this time – how can I be alive?’   ‘I think you know,’ said Dumbledore. ‘Think back. Remember what he did, in his ignorance, in his greed and his cruelty.’   ...   ‘He took my blood,’ said Harry.   ‘Precisely!’ said Dumbledore. ‘He took your blood and rebuilt his living body with it! Your blood in his veins, Harry, Lily’s protection inside both of you! He tethered you to life while he lives!’   ‘I live ... while he lives? But I thought ... I thought it was the other way round! I thought we both had to die? Or is it the same thing?’   If it's so then can Voldemort not die because Harry's blood once flowed through Voldemort’s veins? Someone please clarify.

Lily Potter chose to die instead of sacrificing her son Harry to Voldemort. In doing so, protective enchantments were created that protected Harry and made him less vulnerable to Voldemort and Voldemort's attempts to kill Harry.   Yet, I don't understand how Lily's enchantments, when Voldemort stole Harry's blood in the graveyard scene in Goblet of Fire (chapter 33, The Death Eaters), were helpful to Voldemort at all.     ‘He took my blood,’ said Harry.   ‘Precisely!’ said Dumbledore. ‘He took your blood and rebuilt his living body with it! Your blood in his veins, Harry, Lily’s protection inside both of you! He tethered you to life while he lives!’   Deathly Hallows - page 568 - Bloomsbury - chapter 35, Kings Cross   Yet I wonder about the following canon information:    Lily's enchantment was contingent upon Petunia Dursley giving Harry a home, which Petunia     grudgingly did¹. It was the blood bond between Harry and Petunia, plus the fact that Petunia gave Harry a home, where he could return to once per year, that sealed Lily's   protective enchantments and made them strong. Voldemort was never granted a home at the Dursleys, and in fact never stepped foot into the Dursleys' home at any point in canon. Never having been given a home at the Dursleys, how, then, did Lily, Petunia, and Harry's blood bond exist within Voldemort? Or did it? If it did, would it be because ? Lily's enchantments broke the moment Harry turned 17 and could not protect Harry any more². According to the 's page on Voldemort, Voldemort was 69 years old when he stole Harry's blood. If Lily's enchantment broke for Harry at age 17, why would the enchantments work for Voldemort when he was 69? Dumbledore tells Harry in Order of the Phoenix that Voldemort would not possess Harry because the love that fills Harry -- Lily's love -- is a force that Voldemort detests so greatly that he cannot bear to come into contact with it³. Yet the love Lily infused into Harry runs in his veins; Voldemort took Harry's blood, the blood that is imbued with Lily's love. How can he bear to be in contact with the love given to Harry in his own veins?   Given this canon information, why did Lily's enchantments work for Voldemort?  ¹Half-Blood Prince - chapter 3, Will and Won't and Order of the Phoenix - chapter 37, The Lost Prophecy ²Half-Blood Prince - chapter 3, Will and Won't ³Order of the Phoenix - chapter 37, The Lost Prophecy


If I make the position absolute, it moves up on larger screens and leave a blank space under it.
 Brought into existence by yours truly
  .footer { background-color: rgb(177, 74, 197); text-align: center; font-family: 'Knewave'; color: rgb(114, 245, 190); width: 100%; margin-bottom: 0; bottom: 0; left: 0; position: fixed;   }

I have a simple 2-column layout with a footer that clears both the right and left div in my markup.  My problem is that I can't get the footer to stay at the bottom of the page in all browsers.  It works if the content pushes the footer down, but that's not always the case.


I would like to modify an existing select so it outputs the row with the MAX(amount) per customer and all of its values. At the moment the result is like this.     AMOUNT CUSTOMERID     ITEMID USERNAME                        USERID SUMMARYDAY      60    198507        205 luk                                   12 03.10.18    300    198526        207 max                                   12 03.10.18  20000    198507        126 luk                                   12 03.10.18   6000    198526        158 max                                   12 03.10.18   1200    198526        206 max                                   12 03.10.18   But I want this:     AMOUNT CUSTOMERID     ITEMID USERNAME                        USERID SUMMARYDAY    20000    198507        126 luk                                   12 03.10.18   6000     198526        158 max                                   12 03.10.18   The query at the moment:  SELECT max(totalamount) as amount, cg.customerId, g.itemid,        (select c.nickname from customer c where c.customerId=cg.customerid) as nickname,        12 as clientId, sysdate as summaryDate FROM ItemBuy cg,      ItemToSell gf,      Item g WHERE cg.itemSellId = gf.itemSellId and gf.itemId = g.itemId   and cg.type = 0 and cg.shopId = 12   and cg.starttime >= sysdate-100 and cg.starttime < sysdate+100 group by cg.customerId having max(totalamount) > 0   I anonymized the query a bit but I my main question is:  How can I keep specific colums with an group by statement and tell sql to just keep it after group by and max () have "choosen" a row.  Thank you so much in advance!

Table:   UserId, Value, Date.   I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL? (Preferably Oracle)  Update: Apologies for any ambiguity: I need to get ALL the UserIds. But for each UserId, only that row where that user has the latest date.


I'm creating a Minecraft map that I want players to not have permissions to use cheats so they cant use the setblock command and set blocks as air and break the map. Is there any way I can turn off cheats after creating the world with cheats on? (to get command blocks)  Thanks

How can you turn on or off the cheats after you make an offline server?My brother did something in settings but I can't find it.


While upgrading from UBUNTU 14.04 LTS to 16.04 LTS, every process got done like Getting new packages, Installing upgrades, the last process LEFT that was CLEANING. Now, my pc is running fine on 16.04 but while turning it ON and shutting it down, it is showing to clean and giving errors. Due to electricity problem, cleaning process while upgrading didn't went well...  Please help and let me know, how can I fix this?  Because, I guess a single file will be there in two times in my system. Like there is two SOFTWARE CENTER in pc, older (from 14.04 LTS) and Newer (from 16.04 LTS)  Please give some command to do the left CLEANING process, which left while UPGRADING to 16.04 LtS  How can I do the cleaning process?  Plz tell the command and give the correct answers

While upgrading from Ubuntu 14.04 LTS to 16.04 LTS, every process got done like Getting new packages, Installing upgrades, the last process  was Cleaning. Now, my PC is running fine on 16.04 but while turning it on and shutting it down, it is showing to clean and giving errors. Due to electricity problem, cleaning process while upgrading didn't went well.


I have a quite big monitor and using different VMs in window mode - not full screen. In VirtualBox (6.1) I often change the resolution of the guest via the Display > Virtual Monitor 1-Menu. There's a long list (12 items) of available resolutions from 640x480 to 1920x1200. These are all common resolutions with a ratio of 4:3, 16:9 and 16:10 but most of them are irrelevant for me. So I would like to  remove unnecessary resolutions add new ones (e.g. 3:2 ratio resolutions)  I did not find any helpful advice online. Can anybody help me? Thank you in advance. Knut P.S.: I'm not talking about adding new resolutions for the guest so that may be selected in the VM graphical controller, but the outside menu from the host. I.E. my question is not answered yet!  This is a screenshot from the menu (it's in german but it should be clear, what I mean)

I am using my first VirtualBox VM in order to run Windows 8 Preview on my Windows 7 machine.  It looks like only a few resolutions are available for me to choose.  My physical display is 1600x900, so I'd like to be able to set my Windows 8 VM to that in order to have a fullscreen experience.  How do I add a 1600x900 to the choices I have in the "Screen Resolution" dialog?


Question scores show how a question is good or suitable to a specific site, or it is not suitable or has poor quality.   But there is something I wonder. After a question got closed, it still can receive upvotes/downvotes.  Downvoting means, a question is either not suitable or have poor quality or is duplicate. Downvoting a poor question, for example, shows the question owner and other users that there is something wrong about the question.  But after the question got closed, users can still downvote it. Since the question is already closed, what is the reason of letting it got more downvotes? Both users and the question owner already know that it has low quality and needed to be improved (if it is possible to reopen it after improvement). Close reason is also written under the question.  Similarly, a user with enough reputation may vote to reopen the question, if he had enough reputation to do so. Also, AFAIK there is no way to see how many upvotes/downvotes a question had received after it had closed. So, that also do not reflect the community thought about the closure of the question.  So I wonder, what is the logic behind letting closed questions still being able to vote?

That question of mine was closed a long time ago (relatively, to me at least).  However, from time to time I still get downvotes for it.  That got me thinking: is there any reason to still downvote closed questions?


I suspect iptables to refuse some connection attempts I do on some ports. How to view the log of connections refused by iptables?  I use iptables on Kubuntu 14.04 LTS x64.  sudo iptables -v -x -n -L outputs:  francky@francky-Aurora-R4:~$ sudo iptables -v -x -n -L Chain INPUT (policy ACCEPT 1735891 packets, 225230318 bytes)     pkts      bytes target     prot opt in     out     source               destination  6368899 10355529368 fail2ban-ssh  tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            multiport dports 22  Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)     pkts      bytes target     prot opt in     out     source               destination  Chain OUTPUT (policy ACCEPT 3860995 packets, 5648955269 bytes)     pkts      bytes target     prot opt in     out     source               destination  Chain fail2ban-ssh (1 references)     pkts      bytes target     prot opt in     out     source               destination  6362396 10355135821 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0

I have this rule in my iptables:  iptables -A INPUT -s 192.168.11.0/24 -j LOG   My question is:  Where is the iptables log file, and how can I change that?


I am using \begin{align} in my paper. Hence unwanted gaps are being created to accomodate the whole \begin{align} content in one page. how to prevent it ?

I have a very long derivation, that needs to look like:     A = B \\ = C \\ = D \\   etc. The derivation spans across many lines. I'm looking for a way to typeset it so that when it reaches the end of the page it can continue naturally on the next page, without trying to fit the entire equation into a single page. I'm currently using eqnarray and it insists that all its contents sit on a single page.  Can anyone suggest another environment that supports multi-page equations?


Last weekend our ORG pushed a major set of patches to our Redhat servers. One of our applications went down and we've had huge issues trying to connect to it from within the network or outside.  At the moment the primary issue is getting passed the:Failed to load resource: net::ERR_CONNECTION_REFUSED.  I'm confident at this point that the application itself is not erroring. Everything worked previously. We've rolled back the apache update that came along with the Redhat patches.  I need some steps to follow to isolate 'oddities'.  I've checked most of the common things:   We've rolled back ssl.conf files to working time periods, httpd.conf etc. Still no luck.  The external IP address used to access the server is 123.123.123.123 If I phpinfo(); from a file on that server it shows that the apache remote_addr is 123.123.123.124 Shouldn't they match?  output of iptables:  Chain INPUT (policy ACCEPT) target     prot opt source               destination ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:http ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:mysql state NEW,ESTABLISHED ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:http ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:http ACCEPT     tcp  --  anywhere             anywhere            multiport dports mysql ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:https  Chain FORWARD (policy ACCEPT) target     prot opt source               destination  Chain OUTPUT (policy ACCEPT) target     prot opt source               destination ACCEPT     tcp  --  anywhere             anywhere            tcp spt:mysql state ESTABLISHED

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


I'm posting my whole thought process, but I'd like to ask specifically about whether is my expansion of $\log(1+y)$ into Taylor series good & allowed in this situation? Is there an easier (not saying this isn't an easy way) to compute this limit?  $$\\ \lim_{x\rightarrow \infty}x(e-(1+\frac{1}{x})^x) = \lim_{y \rightarrow 0}\frac{e-(1+y)^{\frac{1}{y}}}{y} = \lim_{y \rightarrow 0}\ \frac{e-e^\frac{\log(1+y)}{y}}{y} = \lim_{y \rightarrow 0} \ \frac{e-e^\frac{y-\frac{y^2}{2}+O(y^3)}{y}}{y} = \\ =\lim_{y \rightarrow 0}\ \frac{e-e^{1-\frac{y}{2}+O(y^2)}}{y}= e\lim_{y \rightarrow 0}\ \frac{1-e^{-\frac{y}{2}+O(y^2)}}{y} = (-e)\lim_{y \rightarrow 0}\ \frac{e^{-\frac{y}{2}+O(y^2)} - 1}{y} =\\ (-e)\lim_{y \rightarrow 0}\ \frac{e^{y (\frac{-1}{2})+O(y^2)} - 1}{y}$$  And now, from $$ \lim_{y \rightarrow 0}\ \frac{e^{ay} - 1}{y}  = a$$  Follows  $$ (-e)*(\frac{-1}{2}) = \frac{e}{2}$$

Find the limit: $$\lim_\limits{x\to 0}{\frac{\left(1+x\right)^{1/x}-e}{x}}$$   I have no idea what to do, but I thought that this is the limit of the derivative of $f(x)=\left(1+x\right)^{1/x}$, as $x$ tends to 0. Any help?


I am new to the bayesian statistics and I most frequently see the conjugate prior distribution. Can you explain it with clear example? I would be very thankful.

I have been trying to understand the idea of conjugate priors in Bayesian statistics for a while but I simply don't get it. Can anyone explain the idea in the simplest possible terms, perhaps using the "Gaussian prior" as an example?


I know this question is already there in stack exchange. But I still do not understand it. So far I would bin my continuous variable if my target is discrete and find the correlation between them using Cramer's V-test.But how do I find strength of association between continuous variable and discrete variable in python?

I would like to find the correlation between a continuous (dependent variable) and a categorical (nominal: gender, independent variable) variable. Continuous data is not normally distributed. Before, I had computed it using the Spearman's $\rho$. However, I have been told that it is not right.  While searching on the internet, I found that the boxplot can provide an idea about how much they are associated; however, I was looking for a quantified value such as Pearson's product moment coefficient or Spearman's $\rho$. Can you please help me on how to do this? Or, inform on which method would be appropriate?  Would Point Biserial Coefficient be the right option?


Electric potential is defined as the work done in bringing per unit positive charge from infinity to a point in the electric field of some other charge.  let me explain what i actually want to ask. consider a battery   as the two electrodes are connected electrons start to flow from the right part towards the left.since electrons are moving the right part is at higher potential and the left at lower.but what actually does we mean by potential at right part and at the left one.

As written in Principles of Physics by Halliday, Resnick and Walker:     The electric field is a vector field; it consists of a distribution of vectors,one for each point in the region around a charged object. In principle, we can define the electric field at some point near the charged object. We first place a positive charge $q_0$, called a test charge,at the point. We then measure electrostatic force $\vec{F}$ that acts on the test charge. Finally, we define the electric field $\vec{E}$ at that point due to the charged object as $$\vec{E} = \frac{\vec{F}}{q_0}$$ .   So, this is the way they derive the electric field. But one thing that perplexes me is that as test charge has its own field, so when the test charge is introduced in the field of concerned charged object, say another point charge $+q$ , won't it get shifted due to the repulsion from the test charge $q_0$ (which is, by convention, positive)? Then consequently the field of $+q$ will also be shifted. In a word, it will get disturbed by that test charge. But the book derived the formula as if the positive point charge $+q$ remained fixed i.e. the test charge had no effect on the field of the point charge. But how can it be? If the test charge $q_0$ is a charge, then obviously it has also field which will exert force on $+q$. So how can the formula be true? Why did the book neglect this?  This phenomenon can be compared to earth's gravitational field. When a body moves upward, it exerts force on the earth downward. But as the earth has huge mass, its shifting can be neglected and hence it doesn't affect its gravitational field.   But here it is a point positive charge; it has no huge mass. So why did the book neglect its shifting and how can the formula be true? Please help.


I am trying to show that  $$\det \left(I_{n} +  \begin{bmatrix}  a_{1} \\ a_{2} \\ \vdots \\ a_{n} \end{bmatrix}  \begin{bmatrix}b_{1}&b_{2}&\cdots&b_n \end{bmatrix} \right)  = 1 + \sum_{m=1}^n a_{m}b_{m}$$     I know I have to use the fact that  $$\ M=QDQ^{T}$$  I can see that with a diagonal matrix its determinant its equal to its trace, but I am having a hard time figuring out what to do with that identity and that 1?

This question aims to create an ""  of numerous questions that ask about determinants of specific matrices (I may have missed a few):              The general question of this type is  Let $A$ be a square matrix of rank$~1$, let $I$ the identity matrix of the same size, and $\lambda$ a scalar. What is the determinant of $A+\lambda I$?  A clearly very closely related question is  What is the characteristic polynomial of a matrix $A$ of rank$~1$?


Surely this is easy, but I'm just beginning.  I've created a font and I want to change "My Words Here" without modifying the document font for the rest of the page.  I'm sure I just have the syntax wrong.  How do I fix it?  \newfontface\Gentium{Gentium}  \begin{Gentium} \begin{center} \begin{huge} \textsc{My Words Here} \end{huge} \end{center} \end{Gentium}

The standard font packages make global changes to the fonts in my document. What if I want to use a particular font for just a portion of my text?   How do I find the right name of the font? How do I select the font? How do I restrict the scope of the font change?     There are separate answers for different flavors of TeX (quick links):


The latest Civ5 patch has added three short but annoying movies displaying the logo of the publishers. Is there a way to disable these so the game loads faster?

It seems like the opening movie always starts up and won't let me cancel it until it has played for about 10 seconds.  Is that because it takes the game that long to load regardless?  Is there a way to turn off the movie?


Given $n+1$ real numbers $a_0,a_1,\cdots, a_{n}$ such that $0<a_0<\cdots<a_n$. Let $P(z)=\sum\limits_{i=0}^n a_i z^i $, where $z\in \mathbb{C}$. How to show that there must be $n$ roots of $P(z)$ in $\mid z\mid<1$?  Thank you very much!

Let $P(z)=a_0+a_1z+\cdots+a_nz^n$ be a polynomial whose coefficients satisfy $$0<a_0<a_1<\cdots<a_n.$$  I want to show that the roots of $P$ live in unit disc. The obvious idea is to use Rouche's theorem, but that doesn't quite work here, at least with the choice $f(z)=a_nz^n, g(z)=$ (the rest).  Any ideas?


I am using an embedded Arm with a Debian build. How does one list the compiled devices from the device tree? I want to see if a device is already supported.  For those reading this, the "Device Tree" is a specification/standard for adding devices to an (embedded) Linux kernel.

Commonly for arm systems, device trees supply hardware information to the kernel (Linux). These device trees exist as dts (device tree source) files that are compiled and loaded to the kernel. Problem is that I do not have access to such a dts file, not even to a dtb file.   I have access to /sys and /proc on the machine and I wanted to ask if that would allow me to "guess the correct values" to be used in a dts?  Also potential answer could highlight additionally the aspect if the answer to this question also depends on whether the device tree interface was used in the first place (i.e. a dtb was created and provided to the kernel) instead of some more hacking "we simply divert from vanilla and patch the kernel so as to solve the device information problem for our kernel only"-solution?


When you try to put two electrons or neutrons close together (e.g. in a white dwarf or a neutron star), these spin-$\frac{1}{2}$ particles, by the Fermi principle, tend to push each other apart.  For the electrons the quantum field involved is the one for electrons, which happens to carry charge, but degeneracy pressure is not an electric repulsion, but a quantum-mechanical effect of two particles not wanting to be in the same state.  So we cannot say it's the electromagnetic force pushing them apart. But it sure looks force-like, but it's not one of the four fundamental forces that's responsible.  I'm confused. What's going on here?

It is commonly known that it is the electron degeneracy pressure that prevents the collapse of a white dwarf into a neutron star, and it is not the electromagnetic force. However, it is also widely accepted that all the forces in the universe are just manifestations of the four elementary forces in the universe. So can the degeneracy pressure, caused due to Pauli's Exclusion principle, be shown to be due to one of these forces? I have read some other questions in SE , , and they do not answer my question fully.  In one of the links, the degeneracy pressure is described as an 'entropic force', but as far as I understand, all entropic forces can be explained by the underlying fundamental forces. If the degeneracy pressure is something that is fundamentally different from the other forces, why isn't it classified as a separate force?


In V8.h of Google V8 Javascript engine, there is a piece of code to check if two types match at compiling stage. I can understand large part of it, but can't comprehend the syntax of static_cast<T* volatile*>, what does it mean by adding unusual volatile* and why is it needed?  #define TYPE_CHECK(T, S)                                       \   while (false) {                                              \     *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \   }   I noted same code has been discussed in this topic below, but not in detail of the question I am asking.

What does the volatile keyword do? In C++ what problem does it solve?  In my case, I have never knowingly needed it.


I accidentally deleted python3 on Ubuntu from /usr/bin. Now every time i install python it gets installed in /usr/local/bin instead so i took python3.5 and placed it in /usr/bin and created a symlink for it from python3 as it was in the original. Somehow this doesn't work and I do not know what to do anymore.        sudo apt-get install *anything* returns        dpkg : error processing package python3 (--configure)             Errors encountered while processing              python3             python3-distupgrade             ubuntu-release-upgrade-core             ubuntu-release-upgrade-gtk   As a result even terminal doesn't work so have to use xterm.   My /usr/bin looks as below - it looks good so I don't know what is wrong           ls -l *python    in /usr/bin returns           python -> python2.7          python2 -> python2.7          python2.7          python3           python3 -> python3.5          python3.5    and some symlinks to config files.              dpkg -l    reveals Python in pFR state. Which I read as purge, failed, reinstall. Just not sure how to do this?

I am a new Ubuntu user running Ubuntu 13.04.  I've been trying to install and use a DeDRM tool, but I've been having problems doing so. I was following some directions that said I needed a version of Python 2.7, but not anything Python 3.0 or later (because 3.0 versions are missing some necessary libraries?). I tried to install Python 2.7.5.6, but it didn't work. I thought it was probably because I had the later version of Python, so I went through terminal and removed Python 3.3, so I could install the earlier version of Python.  Now that I've uninstalled Python 3.3, a lot of applications no longer work, including the terminal and the Ubuntu Software Center. I have no idea how to fix this problem now.


I've got a simple LaTeX-Template for a letter (a bit TikZ and a single paragraph of text) and would like to generate a PDF-file (PDFLaTeX) with 100 letters using this template and names from a CSV-file.  Is there a package for that?

I am looking for an example for using the  package to write a cover letter, with names and addresses on a spreadsheet. The package comes with an example, but you have to manually enter all the data.


After switching from windows 7 to Ubuntu 18.04, the number of partitions in my hard drive reduced from three to one and all my data got lost. Now, I want to recover all of my data.

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


Attempting to install hplip-3.20.3.run on Ubuntu 20.04  missing dependencies: Package-Name         Component            Required/Optional    pil                  scan                 OPTIONAL             pyqt4-dbus           gui_qt4              REQUIRED             reportlab            fax                  OPTIONAL             pyqt4                gui_qt4              REQUIRED             python-notify        gui_qt4              OPTIONAL   Unable to find dependent files. Install aborted.

I am running 14.04 and have a HP Deskjet 2545 wireless printer which is supported by Ubuntu. I have run HpLIP, the latest version and installed the printer.  The printer is recognised by Ubuntu, printer and network, but LibreOffice do not see the printer. Only a Generic printer.  I don't know what to do anymore and would like to get some good advice


I am trying to create a python server that listens on multiple ports at once, I know I have to create multiple sockets however I am not sure how to accomplish this. My current server uses the SimpleHTTPServer module and listens on Port 8000. However I would like it to also listen on 8001 and 8002.  Here is the current server code:  #!/usr/bin/env python  import SimpleHTTPServer import SocketServer import logging  PORT = 8000  class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):      def do_GET(self):         logging.error(self.headers)         SimpleHTTPServer.SimpleHTTPRequestHandler.do_GET(self)   Handler = GetHandler httpd = SocketServer.TCPServer(("", PORT), Handler)  httpd.serve_forever()   I have tried to adapt the code to listen on port 8001 and 8002 like so:  #!/usr/bin/env python  import SimpleHTTPServer import SocketServer import logging  PORT = 8000 PORT1 = 8001 PORT2 = 8002  class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):      def do_GET(self):         logging.error(self.headers)         SimpleHTTPServer.SimpleHTTPRequestHandler.do_GET(self)   Handler = GetHandler httpd = SocketServer.TCPServer(("", PORT), Handler) httpd = SocketServer.TCPServer(("", PORT1), Handler) httpd = SocketServer.TCPServer(("", PORT2), Handler)   httpd.serve_forever()   However this only listens on the last port (8002). How can I adapt the script to listen on all 3 ports?

I'm writing a small web server in Python, using BaseHTTPServer and a custom subclass of BaseHTTPServer.BaseHTTPRequestHandler. Is it possible to make this listen on more than one port?  What I'm doing now:  class MyRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):   def doGET   [...]  class ThreadingHTTPServer(ThreadingMixIn, HTTPServer):      pass  server = ThreadingHTTPServer(('localhost', 80), MyRequestHandler) server.serve_forever()


How can we compute $$I=\int_0^{+\infty } \frac{\log(t)}{1+t^2} \, dt$$ Mathematica gives $I=0$.

Evaluate $$\int_0^\infty\frac{\ln x}{1+x^2}\ dx$$ I don't know where to start with this so either the full evaluation or any hints or pushes in the right direction would be appreciated.  Thanks.


I want to export a raster that shows the mean values of ppt/monthly. I have this script and it shows the values, but the problem is that I can't export to drive, because it shows this error:  Exported bands must have compatible data types; found inconsistent types: Float32 and Float64.  Here is the script:

I am working with Sentinel-2 data in GEE and I added NDVI and a specific SAVI as new bands to an Image. I had an error downloading 6 bands (RGBI, and VIs) because the data type is not the same:  Error: Exported bands must have compatible data types; found inconsistent types: UInt16 and Float32.  Then I selected only the VIs (because I have already downloaded the other bands) and the error is still there but with a new data type:  Error: Exported bands must have compatible data types; found inconsistent types: Float32 and Float64.  I used the normal difference function for NDVI and a edited operation for SAVI. After that I used a operator for NDVI as well (to have 'same' result type) but the error is the same. Do you know how to manage it to obtain the same data format to export? Code sample: // Parameters for Vegetation Index (NDVI-SAVI). var nir = scene.select('B8'); var red = scene.select('B4'); var L = 0.38 var L1 = 1.38  var ndviParams = {min: -1, max: 1, palette: ['red', 'yellow', 'green']};  //Calculating VIs var ndvi = scene.normalizedDifference(['B8', 'B4']).rename('NDVI'); var savi = nir.subtract(red).divide(nir.add(red).add(L)).multiply(L1).rename('SAVI');  //Selecting to download var download = ee.Image(sorted.first()).addBands(savi).addBands(ndvi).select(['B4', 'B3', 'B2','B8','NDVI','SAVI']);


Migration flags and votes should be removed from the close menu. Instead, along with "share, edit, close, flag" at the bottom of the question, there is a "migrate" option.  When you click this, you will always have the option to migrate to that site's Meta page.  Beyond the meta site, however, the migration options are limited to sites for which you have a user account on (and there should probably be a soft-search menu in here for our particularly eclectic users).  More importantly, whether your migration vote counts as a flag or an actual migration vote depends on your rep on the migration target site.  If you're at 3,000 or more rep on the target site, your vote counts as an actual vote.  If you're below this, it shows up in the review queue on the target site.  So for example, let's say I'm a Stack Overflow user with over 3,000 rep. I'm also a user with a DBA account with less than 3,000 rep, and a Code Review account with over 3,000 rep.  If I see a question on Stack Overflow which looks like it'd be better posted elsewhere, I can flag it for migration to DBA (if that looks right to me) (which pops it up in the review queue for other DBA users with over 3,000 rep on DBA and SO to vote in agreement with my flag), or I can vote it for migration to Code Review (if CR looks appropriate to me).  Currently, if you try to vote a question to migrate away from Stack Overflow, you are presented with the following menu:    And it doesn't matter who you are, these are the five migration options you get.  And the fact of the matter is, I know I personally shouldn't be allowed to migrate to TeX or Stats.  I don't have an account on either of these sites, nevermind having in the slightest clue what sorts of questions on are on topic there.  Meanwhile, I do have a Super User account, and I do have a DBA account, but I have exactly 101 rep on both of these sites.  I've never asked a question, posted an answer, or even so much as left a comment.  I think I only created an account on these sites because I was thinking about asking a question or I wanted to upvote someone's answer (I have a use for these sites, but not much to contribute).  Meanwhile, there are other Stack Exchange network sites that have some potential for overlap with Stack Overflow.   Android Enthusiasts Ask Different Ask Ubuntu Drupal Answers Electrical Engineering Game Development Information Security Programmers Server Fault Theoretical Computer Science Unix & Linux User Experience Webmasters WordPress Development   This list only includes graduated sites whose designs have been completed.  There are even more if we count beta sites (or graduates sites whose designs aren't yet completed, like ).  But, I don't think all of these sites should be in the list either.  , I am primarily talking about the list of migration targets being dynamically generated for each member based on which other sites they are members of.  If you don't even have an account at the target site, how can you possibly know that this question is better suited here than there?

With all the new sites up and running it gets more and more difficult for users to really know the scope of a site and thus a lot of questions a migrated to places where they are (probably even more) off-topic, see e.g. . So I request the opposite of :  Allow migration if you have enough rep on both the source and the target site (the target reputation required could be a bit lower, say 5001)  That way questions could only be migrated by users familiar with the scope of both sites who can really estimate where the question is better. Maybe those who don't have the rep on the target site could still be able to cast a flagging-only-but-not-counting-as-vote vote...  1) Courtesy of


The following problem came up from a though I had while reading:  Let's say we have $M=\mathbb{Z}^n$ and we have another free $\mathbb{Z}$-module, $N$, inside of $M$ also with rank $n$.  We know we can make a matrix $A$ that changes $N$ to its representation in $M$ (ie has as columns the basis $N$ expressed in coordinates coming from the basis of $M$). If the index of $N$ in $M$ is $m$, I am pretty sure just from tinkering that the determinant of $A$ should also be $m$, however, I have not been able to show this.  It is unclear to me how to proceed. I though maybe I could do something related to the points in $\mathbb{Z}^n$ that are within the unit box of $N$, but I cannot really make sense of this.  Thank you for any help or direction.

I am asked to show that if $\phi_A$ is the homomorphism from $\mathbb{Z}^k \rightarrow \mathbb{Z}^k$ given by $\phi_A(x)=xA$ then the index of $\phi(\mathbb{Z}^k)$ in $\mathbb{Z}^k$ is finite if and only if $A$ is nonsingular.    While this seems intuitive to me, one obstacle to proving this is that I am not quite sure of how to represent the index of a sublattice in a lattice! The way I understand it, $j\mathbb{Z}^k$ has index $j^k$ in $\mathbb{Z}^k$, for an integer $j$. I am used to indices in finite groups but not infinite groups, so is the trick to show this sort of correspondence?  Furthermore, I would like to know if this is a valid sketch of a proof:   If $A$ nonsingular, $A'$ is in Smith Normal Form ($PAQ=A'$) and $\det A'$ is nonzero, so the columns of $P^{-1}$ form a basis for $\mathbb{Z}^k$ and the columns of $AQ$ form a basis for the sublattice such that each column in the basis for the sublattice is an integral multiple of the columns in the basis for the lattice $\mathbb{Z}^k$, and since these multiples are given by the diagonal entries of SNF, we have that for every one point in the sublattice, there are $\prod a_i=\det A'=\det A$ points in the main lattice. If $A$ singular, we have the same as (1) except now at least one of these columns is a multiple $0$ times the column for the basis in the main lattice, so there are infinitely many points in the main lattice for each point in the sublattice.


I doubt that they are going to continue the anime for the final arc of bleach. So I want to go read the manga instead.  The thing is I have never read a manga before and I am not sure where to get it online. Also, which "chapter" would I need to start with exactly?  Any help/guidance is welcome!

I live in Norway. Is there a site where I can read Bleach online legally? I have tried to look, but I have not found a suitable site yet.


I am practicing the strategy pattern and trying to apply the code here.  What I am confusing is I did not declare any static method in the Context class as it showed that cannot do such the operation as I made a static reference to the non-static reference method. I want to know why is this happening. Any help is highly appreciated. Here is part of my interface and relevant code. interface ArithmeticStratrgy { public int doOperation(int num1, int num2); }  class AddOperateion implements ArithmeticStratrgy  { @Override public int doOperation(int num1, int num2) {     return num1 + num2;     } }  class Context  { private ArithmeticStratrgy strategy;  public Context(ArithmeticStratrgy strategy) {     this.strategy = strategy;     }  public int executeArithmeticStrategy(int num1, int num2) {     // Cannot make a static reference to the non-static method      // doOperation(int, int) from the type ArithmeticStratrgy     return ArithmeticStratrgy.doOperation(num1, num2);     } }

The very common beginner mistake is when you try to use a class property "statically" without making an instance of that class. It leaves you with the mentioned error message:     You can either make the non static method static or make an instance of that class to use its properties.   Why? I am not asking for solutions. I would be grateful to know what is the reason behind it. The very core reason!  private java.util.List<String> someMethod(){     /* Some Code */     return someList;             }  public static void main(String[] strArgs){                // The following statement causes the error. You know why..     java.util.List<String> someList = someMethod();          }


I have a YAML File with following data and i want to Deserialize that into java Object.  connector:   provider: ABCD   nodes:    -  1.1.2.1   -  1.2.2.8   maxconnection: 1   minconnection: 1   1.First i created a class called Connector where i have defined all the variable like Provider, Nodes, maxconnections, Minconnections. 2.Then i created a class called group and call the Connector class. 3.then in the main function tried to load the yaml file and call it.  But i got Null pointer exception Error  #Connector Class public static class connector {              private String provider;              private String[]  nodes;              private int max_connections;              private int min_connections;               public String getprovider() {                 return provider;             }             public void setprovider(String provider) {                 this.provider = provider;             }            public String[] getnodes() {               return nodes;             }             public void setnodes( String[] nodes) {               this.nodes = nodes;             }                         public int getmax_connections() {               return max_connections;             }             public void setmax_connections(int max_connections) {               this.max_connections = max_connections;             }             public int getmin_connections() {               return min_connections;             }             public void setmin_connections(int min_connections) {               this.min_connections = min_connections;             }              @Override             public String toString() {                 return "connector: {provider: " + this.provider + ", nodes: " + this.nodes + ",max_connections: " + this.max_connections +",min_connections: " + this.min_connections +"}";             }   #Group class          public static class Group {             private ArrayList<connector> connector;              public ArrayList<connector> getconnector() {                 return connector;             }                         public void setconnector(ArrayList<connector> connector) {                 this.connector = connector;             }         }  #main Class  public static void main(String[] args) {              final URL resource = YamlConf.class.getResource("demo.yaml");             final Constructor peopleContructor = new Constructor(Group.class);             final TypeDescription peopleDescription = new TypeDescription(connector.class);             peopleDescription.putMapPropertyType("connector", connector.class, Object.class);             peopleContructor.addTypeDescription(peopleDescription);              final Yaml yaml = new Yaml(peopleContructor);             try {                 final Group group = (Group) yaml.load(resource.openStream());                 for (final connector connector : group.getconnector()) {                     System.out.println(connector);                 }              } catch (IOException e) {                 e.printStackTrace();             }         }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


We are trying to store some text with Japanese characters inside Maria DB 5. However, we can see only question marks after save.  We tried to set UTF-8 encoding with following command, but this also does not help.  ALTER DATABASE my_db COLLATE = 'utf8_unicode_ci'; SELECT * FROM INFORMATION_SCHEMA.SCHEMATA where schema_name = 'my_db';   Any clues?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


Sorry if this sounds like a dumb question but it's something that has bugged me for a while. I need some explanation on    function custom_function () {     global $post; }   I understand from PHP that a global variable is available is used to access global variables from anywhere in the script. I know global $post usually set when a new query is being set. What would happens if global variable is not declared in case of WordPress query posts? I know how to use it in WordPress but have not fully understand why. Thank you.

I am trying to understand when and why I should use the global $post variable. I have tried to do the following on a post page, outside the loop, and as expected it works.      <?php          global $post;         echo $post->ID;     ?>   If I do the same on an archive page (just wanted to see what happens), for some reason it also works, retrieving the ID of the previous post, even if I deleted the code above from the previous post page.  Is this like some kind of caching? How does this work exactly?  I understand global $post can be useful if I'm working on a fuction in functions.php. Is this the only use case?  Many thanks


The packages listings and minted present source code inline.  My publication target is PDF. From my own documents as well as from the documentation for those two packages, copying and pasting the source code listings omits all indentation. My students are not happy to have to fix the indentation to try a sample snippet of Python.  I suspect this is down to an inherent limitation in PDF, which places characters (not whitespace) on the page. Is there any way to make a TeX source code listing published in PDF whose indentation can be copied and pasted?

So I am using  package for code examples. But there is a problem. When I copy the code examples from the final PDF document, they are usually not the same - the indentation is gone, there are random spaces after parenthesis, etc. Does anyone know how to make sure that the code that I copy from the final document is the same as I wrote it in the LaTeX document?  Here is what I mean. Compile this document:  \documentclass[12pt,oneside]{memoir}  \usepackage{listings} \usepackage[T1]{fontenc} \usepackage{xcolor} \usepackage{textcomp}  \definecolor{codebg}{HTML}{EEEEEE} \definecolor{codeframe}{HTML}{CCCCCC}  \lstset{language=Awk} \lstset{backgroundcolor=\color{codebg}} \lstset{frame=single} \lstset{framesep=10pt} \lstset{rulecolor=\color{codeframe}} \lstset{upquote=true} \lstset{basicstyle=\ttfamily} \lstset{showstringspaces=false}  \begin{document}  This code example prints out all users on your system:  \begin{lstlisting}[language=c] #include <stdio.h> #include <stdlib.h> #include <string.h>  #define MAX_LINE_LEN 1024  int main() {     char line[MAX_LINE_LEN];     FILE *in = fopen("/etc/passwd", "r");     if (!in) exit(EXIT_FAILURE);      while (fgets(line, MAX_LINE_LEN, in) != NULL) {         char *sep = strchr(line, ':');         if (!sep) exit(EXIT_FAILURE);         *sep = '\0';         printf("%s\n", line);     }     fclose(in);     return EXIT_SUCCESS; } \end{lstlisting}  \end{document}   Now compile it, open it, select and copy the code example and paste it in a text editor. Here is the result I get:  # include <stdio .h> # include <stdlib .h> # include <string .h> # define MAX_LINE_LEN 1024 int main () { char line [ MAX_LINE_LEN ]; FILE *in = fopen ("/ etc / passwd ", "r"); if (! in) exit ( EXIT_FAILURE ); while ( fgets (line , MAX_LINE_LEN , in) != NULL ) { char * sep = strchr (line , ':'); if (! sep ) exit ( EXIT_FAILURE ); * sep = '\0 '; printf ("%s\n", line ); } fclose (in ); return EXIT_SUCCESS ; }   Jeez! What's this... The indentation is gone. There are spaces in included headers <stdio .h>, there are spaces after parenthesis [ MAX_LINE_LEN ].  Anyone knows how to fix this? I'd like the code examples in my book to be copy/paste-able into a text editor so people can try them out easily.


Blender started "randomly" deleting some of my scenes and when I checked, it was because it said there are no users. I figured out how to add a fake user now (via the "Orphan Data" Outliner) but I'm still unsure why this is necessary.  Why would a scene require a user, and how can I make sure this doesn't happen in the future?  I also haven't found any pattern to which scenes are marked as having no users.

I'm using blender 2.83 beta and I'm in the middle of a nightmare with a blender project that is randomly considering my scenes as 0 users datablocks.  It gives a red background on the scene name and a 0 on the left if I open the scenes list.  I didn't even know a scene can have 0 users, but I don't even see a fake user option so...  I'm using the 2.83 beta (updating to the today's version didn't help) on windows 10. I temporarily solved the problem by creating a full copy of every scene (all the scene were actually full copies of the master one) as backup.  Is this a feature? Is this a bug?


Is there a way to remove the "switch user" button shown in the photo below?  Thanks!

I don't like other people using my workstation in my absence How do I lock a workstation that is configured to let anyone with valid credentials to log in as a different user?


while digging into some secured communication protocol, I noticed a  usage of AES-128 CBC that raised my attention. In it, the IV is tightly coupled to the Key, being a xor of its values with the byte index:  for(i=0; i<16; i++) {   IV[i] = Key[i] ^ i; }    Could it be an issue if an attacker knows the first blocks of a plaintext? Does it weaken the implementation of the encryption?   Thank you in advance

Application uses AES in CBC mode with 128 bit key. In this implementation key is always same and is equal to IV. Can attacker get the key or decrypt data? If he knows:   First and second blocks of plaintexts; All blocks of ciphertexts.   The software mentioned above is malicious program, it encrypts all office files on user's computer. And I now attempt to help user get his data back. Reverse engineering of this program shows that key is unknown, but is always same and is equal to IV.


I have used sudo chown -R yourusername:yourusername /etc to get access to that folder to remove some files, but now I get errors when I try to install stuff, as seen below, and can't seem to change things back to normal.  vk137@alternate:~$ sudo apt-get install pulseaudio sudo: /etc/sudoers is owned by uid 1000, should be 0 sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin   To a similar question was advised to remount the filesystem, but I can't seem to do that either:  vk137@alternate:~$ mount -o remount,rw / mount: only root can use "--options" option   How can I put the access to /etc back in the right hands?

I stupidly ran sudo chown -R carlos:carlos / and carlos is my user. This changed all files to be Carlos and I could not boot up again (because the root files were now owned by #1000) and I cant get sudo acess in live cd (because the owner of /usr was changed to my user). Can anyone help me? FYI I have mounted my hard drive.


Here is the code. This is as simple as can be. Why won't it center?  .msg {     width: 600px;     height: 200px;     margin-left: auto;     margin-right: auto;     margin-top: 100px;     font-size: 42px;     font-weight: bold; } </style>
This is not centered. Why not?

How can I horizontally center a
 within another
 using CSS?

Foo foo


I found that with long.Parse, ToString can take argument and I can format it to desired string, for example.  Input:     Console.WriteLine(long.Parse("123").ToString("#-#-#"));  Output: 1-2-3   I wanted to do something similar with string, lets say I wanna parse string to format ####-###-####. Is there any way to do it without regex with one liner like example above?  EDIT  Ok, so I may be misunderstood, I didn't want to parse numbers, but string instead. I can do in python like:  '{}-{}-{}'.format(*'abc') and I will receive a-b-c. In C# it seems to work only with numbers.

I have a string "1112224444' it is a telephone number. I want to format as 111-222-4444 before I store it in a file. It is on a datarecord and I would prefer to be able to do this without assigning a new variable.  I was thinking:  String.Format("{0:###-###-####}", i["MyPhone"].ToString() );   but that does not seem to do the trick.  ** UPDATE **  Ok. I went with this solution  Convert.ToInt64(i["Customer Phone"]).ToString("###-###-#### ####")   Now its gets messed up when the extension is less than 4 digits. It will fill in the numbers from the right. so  1112224444 333  becomes  11-221-244 3334   Any ideas?


$G$ is a cyclic group of order $n$ and there is an integer $m$ that divides $n$. Prove that there is a subgroup of $G$ of order $\frac{n}{m}$.  Can I use Lagrange's theorem to help with this proof?

Let $G=\langle a\rangle$ be a cyclic group of order $n$. Show that, for every divisor $d$ of $n$, there exists a subgroup of $G$ whose order is $d$.  This time I have no approach. I haven't found any relation between the divisors of $n$ and the order of the subgroups of $G$. How would approach this?


I've noticed this only on MSE; the number of votes under the linked or related sections gets displayed in more than one rows if the number of votes exceeds 99 votes (two digits):    and    Using Google Chrome Version 34.0.1847.132 on Debian

The score for the 4 questions are 111, 1218, 261 and 5 respectively, but they display 2 digits per line. This is an obvious bug in design.


How many more  buttons can one add through the audiojack of android phone ? I know about the cicuit  of play/pause , skip Forward and skip Backward Button ...But can we add more Buttons by the combination of the above circuits .

A recent question over on  got me to wondering how volume control headphones work.  I don't mean volume control which works by , but the kind of volume control that signals to the device to increase or decrease the signal output.  For instance, according to the , the volume controls are only for apple devices:     Universal Compatibility and Microphone Communication   LP comes with 2 cables for universal compatibility with all modern mobile and audio devices. The 3-Button remote microphone cable is designed for the latest Apple devices, including iPhone®,iPad®, iPod®, and Macbook series. The long audio-only cable and 1/4" adapter is universally compatible with all audio devices and professional equipment.   However this sort of device apparently works with some android phones and the question implies that it works with some computer sound cards on Windows machines too, but not being an Apple buyer (and only recently getting my first smartphone) I haven't seen this sort of thing before. I've done a quick google search, but can't find anything on standards for this technology.   How does this work?   Is it something as simple as shorting left/right/mic channels? If so, could using headphones of this type with equipment that doesn't support this technology, damage that equipment? Is it a serial signal, for instance sent over the mic channel? Does it just require a headphone  connector or a headphone  +microphone TRRS connector?   Does this technique have a name?  Incidentally, is someone could answer this, I can probably look up the rest of the information myself. *8') Is it as standard as it appears, or is everyone just following Apple? Is this something that is patented?   If so, who holds the patent and do they charge a license fee for people to use this technology? If not, is there an open standard for it?    There is some excellent information in  to the question  but it doesn't answer the specifics of how this type of volume (etc.) control works, since it now seems to be rather more common and standard.


Getting records from the courthouse. They charge $1/page to print which is utterly insane but will let you discreetly take pictures of the computer screen instead.   I have my iPhone and the pictures are usually readable but there are always lines or rgb dots that show up. Is there a technique or anything you’d recommend to take better pictures?  And yes, I’ve already looked into uploading documents from the computer itself. The computer is on a network whitelist. It can access the court website and nothing else. Also it’s run on a vm on top of a basic windows pc. So it’s not an option to have a flash drive.   Here’s an example of a picture I’ve taken.

I have seen many bad pictures of LCD and CRT screens. How do I get a good picture of an LCD or CRT screen?


I'm preparing for exam and I have to solve this problem.  Please, how do I prove that $\lim\limits_{n\to\infty}\frac{1}{n}\left(1+\frac{1}{2}+\cdots+\frac{1}{n}\right)=0.$ Any Theorems to guide as well?

$$S_n =\frac1n \left(1 + \frac{1}{2} + \frac{1}{3} + \cdots+ \frac{1}{n}\right)$$ Show the convergence of $S_n$ (the method of difference more preferably)  I just began treating sequences in school, and our teacher taught that monotone increasing sequence, bounded above and monotone decreasing sequences, bounded below converge.  and so using that theorem here.. I found the $$(n+1)_{th} term$$, $$S_{n+1} = \frac1{n+1} \left(1 + \frac{1}{2} + \frac{1}{3} + \cdots+ \frac{1}{n+1}\right)$$  and then subtracted the (n)th term from it   What I was able to get was... $$S_{n+1}-S_n = \frac1{(n+1)^2} - \frac{\left(1+\frac12+\dots+\frac1n\right)}{n(n+1)}.$$ ...but then this is where I get stucked, but i'm trying to prove that the sequence > 0(i.e Converges) or < 0 (i.e diverges).


can one say "unpolite"? As in the following sentence: "it's hard for me to be unpolite." I was in class today and my teacher asked me to give him an example of an infinite sentence and that came out of my mouth just because, but my teacher corrected me. And told me to say "impolite" instead, but I found acouple of threads on the internet with opposed ideas. So please help me with this one.

Definition of  in OD:      not having or showing good manners; rude.   Definition of  in TFD:      Not polite; impolite; rude.


Lately, I stumbled across a historical source text from Victorian England (Henry Mayhew, London Labour) which had following sentence:      'He told me, at the commencement of his statement, that he was of oppinion that his people were far more speculative than the Gentiles, and therefore the English liked better to deal with them.'    My question is what does the pronoun 'them' refer to? Is it the 'Gentiles' or 'his people'?

Take the following sentence:     And even if the program inputted one token and then invoked newLine(), wouldn't it input a blank?   I've been told that this sentence has a clear pronoun reference. Why? Couldn't it refer to either program or token?


If a structure were sufficiently strong at a large enough radius from a black hole, could it completely enclose a black hole without collapsing in, since in some sense the material would pull on itself uniformly?

In this question, I'm not asking about the feasibility of building a black hole Dyson Sphere or the effectiveness, I simply want to know if an object could stay in a locked position encasing a black hole without collapsing in on itself. It doesn't matter if it would collapse before in place, I just care about the final position and if so, what shape would be best suited for this?


Is this code secured against SQL injections? If not how would I go about protecting this code against SQL injections? Thanks in advance.  error_reporting(E_ALL);  ini_set('display_errors', 1); $servername = ""; $username = ""; $password = ""; $db_name = "";  // Create connection $conn = new mysqli($servername, $username, $password, $db_name); // Check connection if ($conn->connect_error){   die("Connection failed: " . $conn->connect_error); }  $id = $_GET['id']; $id = mysqli_real_escape_string($conn,$id); $query = "SELECT * FROM `images` WHERE `file_title`='" . $id . "'"; $result = mysqli_query($conn,$query);   while($row = mysqli_fetch_array($result)) {         echo '<video width="100%" class="video" controls>';         echo '<source src="uploads/'.$row['file_name'].'" type="video/mp4">';     echo '</video>'; }

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I was in the middle of installing updates for Ubuntu when I came across an error, which allowed me to "Start a new shell to examine the situation". Doing so placed me at the top of my directory structure in the same window but appending # to the end.  What does the # represent?  How is this change achieved from the command line?

What is the difference between $ and # signs in Linux environment? As I started working on Linux and I found that both are different. I mean they do have different set of privileges...?   [root@localhost ~]# and [tom@localhost ~]$.


After installing Sun Grid Engine and trying to run the qmon GUI, the system shows the following errors:  Warning: Cannot convert string "intro" to type Pixmap Warning: Cannot convert string "toolbar_job" to type Pixmap Warning: Cannot convert string "toolbar_queue" to type Pixmap Warning: Cannot convert string "toolbar_submit" to type Pixmap Warning: Cannot convert string "toolbar_cplx" to type Pixmap Warning: Cannot convert string "toolbar_host" to type Pixmap Warning: Cannot convert string "toolbar_cluster" to type Pixmap Warning: Cannot convert string "toolbar_sched" to type Pixmap Warning: Cannot convert string "toolbar_calendar" to type Pixmap Warning: Cannot convert string "toolbar_user" to type Pixmap Warning: Cannot convert string "toolbar_pe" to type Pixmap Warning: Cannot convert string "toolbar_ckpt" to type Pixmap Warning: Cannot convert string "toolbar_ticket" to type Pixmap Warning: Cannot convert string "toolbar_prj" to type Pixmap Warning: Cannot convert string "toolbar_rqs" to type Pixmap Warning: Cannot convert string "toolbar_ar" to type Pixmap Warning: Cannot convert string "toolbar_browser" to type Pixmap Warning: Cannot convert string "toolbar_exit" to type Pixmap   The qmon window appears yet is small and missing the buttons that are usually there.   The Ubuntu 14.04LTS is almost a fresh install without updates. SGE qmon version installed is: 6.2u5-7.3  I did try to look for other answers. You may find a similar question issue to mine in:   However, the answer provided by Ray regarding using Son of Grid Engine does not seem to work for me since sge_8.1.6_amd64.deb complains on dependencies - lesstif2 (>= 1:0.94.4)   I know that qmon and SGE worked well on a fresh install of Ubuntu 12.04LTS in April. Since there were no changes in the package that was last changed in February. I assume that my options are either: A: Roll back to Ubuntu 12.04LTS B: Wait until there is a fix to either Ubuntu or qmon C: Build from source code   Option C seems too time consuming. Option B depends if there is someone on this list who can fix this. Option A seems the obvious choice, yet I rather upgrade to Ubuntu 14.04LTS If possible.  I hope there is a simple fix.

I recently tried to run qmon (from Sun Grid Engine job queueing system) and when I do, I get a bunch of warnings that look like this:  Warning: Cannot convert string "intro" to type Pixmap Warning: Cannot convert string "toolbar_job" to type Pixmap Warning: Cannot convert string "toolbar_queue" to type Pixmap Warning: Cannot convert string "toolbar_submit" to type Pixmap Warning: Cannot convert string "toolbar_cplx" to type Pixmap Warning: Cannot convert string "toolbar_host" to type Pixmap Warning: Cannot convert string "toolbar_cluster" to type Pixmap Warning: Cannot convert string "toolbar_sched" to type Pixmap Warning: Cannot convert string "toolbar_calendar" to type Pixmap ...   And then, when the GUI finally appears, all of the icons are replaced by a small dot.  I guess for some reason, the icons cannot be shown.  I tried to look for them in:  /usr/share/gridengine/pixmaps/   and indeed, the *.xpm files are there.  About half a year or so ago, it worked fine.  I guess something happened to my system during an upgrade or update that changed things.  Any ideas on what I should be looking for?  Any log files that could help me?  Thank you!  Ray  PS:  On Ubuntu 13.10.


I installed Ubuntu 14.04 on my new Toshiba Satellite C75D a number of months ago, and everything worked great for months. Then suddenly, I didn't have wifi access anymore.  I can connect by wire.    rfkill list says that my wireless LAN is both hard and soft blocked.  When I try to toggle the switch on the Network Manager to "on" for wifi, it won't let me.  My "hard switch" is the F12 key, but it doesn't seem to to anything.  Someone else had a similar question that didn't seem to get answered, except for the problem they had with suspend: .  Output of lspci -knn | grep Net -A2:   05:00.0 Network controller [0280]: Qualcomm Atheros AR9485 Wireless Network Adapter [168c:0032] (rev 01)     Subsystem: Lite-On Communications Inc Device [11ad:8631]     Kernel driver in use: ath9k   It is not a dual boot system.  I set it up to be Ubuntu only.

I have a toshiba l655d-s5145.  There is no physical toggle for the wireless, although the f8 key is supposed to do the trick.  It doesn't.  The wireless has been working since October, and suddenly, nothing.  RFKILL reports that the wireless is hard blocked, but unblock wifi, unblock 0, unblock all do nothing.  I inserted a usb dongle, and that is also disabled by hardware switch, although rfkill reports that it is neither hard nor soft blocked.  My onboard wireless is   02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter (rev 01)   according to lspci. Lsmod reports that these drivers are loaded.  rtl8192c_common        75767  1 rtl8192ce rtlwifi               110972 1 rtl8192ce   I resorted to reformatting the drive and reinstalling, but that also did not work.  In BIOS I restored system defaults as there is no specific entry for wifi.  Before reinstalling a pure xubuntu I went into Unity and saw that the airplane mode was on and despite being toggled off, it returned to the on position.  I'm not sure where to find airplane mode in Xubuntu.  What else can I do?  I need my wireless.


A number $a \in \mathbb{R}$ is an "universal chord" if for every continuous function $f:[0,1] \rightarrow \mathbb{R}$ with $f(0)=f(1)$ exists $x,y \in [0,1]$ with $|x-y|=a$ and $f(x)=f(y)$. Determine all universal ropes.

Let $f \in C[0,1]$ and $f(0)=f(1)$.   How do we prove $\exists a \in [0,1/2]$ such that $f(a)=f(a+1/2)$?  In fact, for every positive integer $n$, there is some $a$, such that $f(a) = f(a+\frac{1}{n})$.  For any other non-zero real $r$ (i.e not of the form $\frac{1}{n}$), there is a continuous function $f \in C[0,1]$, such that $f(0) = f(1)$ and $f(a) \neq f(a+r)$ for any $a$.  This is called the Universal Chord Theorem and is due to Paul Levy.  Note: the accepted answer answers only the first question, so please read the other answers too, and also this answer by Arturo to a different question:     This is being repurposed in an effort to cut down on duplicates, see here: .  and here: .


I'm making a test program for resource loading inside a jar and I'm having problems.  I've read that you should use ClassLoader or alternatively getClass() to access a file inside a jar. Since the method that i use to load the resource is static, I use ClassLoader.getSystemResource(String path). My program finds the file but says that the path contains invalid syntax for filenames or directory names. This is the code that I use to load my resources:  String path = ClassLoader.getSystemResource(file).getPath();  System.out.println(path);  try {     wave = WaveData.create(new BufferedInputStream(new FileInputStream(path))); } catch (FileNotFoundException e) {     e.printStackTrace(); }  AL10.alBufferData(buffers.get(i), wave.format, wave.data, wave.samplerate); wave.dispose();   Yes, I'm loading soundfiles for OpenAL.  Anyway, I should remind you that it actually finds the file but the path has invalid syntaxing. This is an example of the path I get when I run it in jar form:     file:\C:\Users\name\development\jars\test.jar!\sounds\test.wav   I've tried to remove the "!" and I still get the same error. If i remove the "file:" it doesn't find the file. Note that the program runs fine when I'm running in Eclipse.

I'm trying to access an XML file within a jar file, from a separate jar that's running as a desktop application.  I can get the URL to the file I need, but when I pass that to a FileReader (as a String) I get a FileNotFoundException saying "The file name, directory name, or volume label syntax is incorrect."  As a point of reference, I have no trouble reading image resources from the same jar, passing the URL to an ImageIcon constructor.  This seems to indicate that the method I'm using to get the URL is correct.  URL url = getClass().getResource("/xxx/xxx/xxx/services.xml"); ServicesLoader jsl = new ServicesLoader( url.toString() );   Inside the ServicesLoader class I have   XMLReader xr = XMLReaderFactory.createXMLReader(); xr.setContentHandler( this ); xr.setErrorHandler( this ); xr.parse( new InputSource( new FileReader( filename )));   What's wrong with using this technique to read the XML file?


I want to install windows 7 home premium on my ubuntu 12.04 LTS. I already have a windows 7 home premium setup .exe, I am using WINE to run it. When I execute it it shows "Windows was unable to create an installation folder error code 0x8007007A".  So I used GParted to create a new partition of size 30 GB and changed the file system to NTFS and selected for boot flag and then I started the setup again, but it made no difference. I dont know what to do next. Please help!

I have Ubuntu on my laptop. Now I want install Windows 7 in a dual-boot. How can I do this? I can't lose my Ubuntu files, and I'm afraid that I might break . Go  for UEFI only!


On the Vulcan's home planet they have creatures known as Sehlats. As explained they are basically giant bears with 6 in. fangs. What is the logical reason for Vulcans to have these as pets? Are they like protector dogs or just pets they keep?

In an episode of Star Trek TOS, Spock mentioned a childhood pet.  I think it was Dr. McCoy who teased him about his having a kitty-cat.  The animal Spock described was definitely not a kitty-cat -- it was bigger, with proportionally bigger fangs and claws and had a irritable temperament.    Is anything more known about this pet?  Is there a picture of it?  Was this the only pet species available on Vulcan, or was a ferocious animal selected on purpose to quash any human feelings of sentimentality the half-human Spock might feel for a kitten- or puppy-like creature?


Preface: this is no duplicate  This is not a duplicate of this question    and  are two totally different things. Only the question about which license is required for using each of them can be asked for both distinct Hubs. Please don't get confused. I've carefully split up these two questions and the duplicate mark is definitely wrong.  Original Question  Today I've tried to enable Environment Hub for some of our Developers. Environment Hub itself is working only for me as I am using a Salesforce license with the Profile System Administrator.   Since the Devs are not involved in selling activities, we use Plattform Licenses (Force.com) for them.  Now they should be able to spin up and manage SSO for our dev orgs.  I was able to grant them access to the tab and the objects - but not for the Environment Hub App.  Is there any way to allow these licenses to use the environment hub? If not, why such an restriction? It does not make sense to provide them with a Sales Cloud License.

Today I've tried to enable the new Dev Hub for some of our Developers. Dev Hub itself is working only for me as I am using a Salesforce license with the Profile System Administrator. Since the Devs are not involved in selling activities, we use Plattform Licenses (Force.com) for them.  Now the devs should be able to use the Dev Hub.  I was able to create the Permission Set as described .  But as I'm trying to assign the permissio set, I get only an error complaining about the license type.  Is there any way to allow these licenses to use the dev hub? If not, why such an restriction? It does not make sense to provide them with a Sales Cloud License.


I have to prove this result but I don't know where to start. The hint is, the measure of the set {$x:f(x)<1$} is $\infty$. Can someone help me?

Let $f : \mathbb{R} \to [ 0, \infty)$ be a measurable function. If $\int_{- \infty}^{\infty} f(x) dx =1$. Then I want show that $ \int_{- \infty}^{\infty}  \frac{1}{1+ f(x)} dx = \infty.$  Any help will be appreciated.  Thank you in advance.


This is my question:  I want to do a thesis but my qualifications are bad so I do not know if I will be able to find a thesis advisor.  What can I do? Are there universities who do not care about qualifications if you have some ideas?  I can propose some ideas for thesis (in .pdf) but do not know if they will be enough.

When applying to a PhD program in the US, how does the admissions process work? If an applicant is weak in a particular area, is it possible to offset that by being strong in a different area?  Note that this question originated from this . Please feel free to edit the question to improve it.


I was looking for examples of spaces that are not first countable.  they give the example of $[0,\omega_1]$. I think I understand that $\omega_1$ is  a limit point of $[0,\omega_1)$ since if $(\alpha,\beta)$ is an open containing $\omega_1$ it contains an ordinal smaller than $\omega_1$ and thus this ordinal is in $[0,\omega_1)$. Now why is there no sequence of $[0,\omega_1)$ converging to $\omega_1$. It is not entirely clear to me how to prove this. Also I don't really understand why this implies that $\omega_1$ doesn't have a countable basis.

The topological space $X=\omega_1\cup \{\omega_1\}$ is not first countable but $\omega_1$ is. Here $\omega_1$ denotes the set of all countable ordinals and $\{\omega_1\}$ is the first uncountable ordinal. Cardinality of $\omega_1$ is $\aleph_1.$And also $\omega_1$ is called the limit ordinal meaning it is the limit point of the set $\omega_1.$  Here I want to prove two things. $1)$ $\omega_1$ is first countable. and $2)$ $\{\omega_1\}$ is the limit point of $\omega_1$. But since no sequence converges to $\{\omega_1\}$, using this I could say that our space $X$ is not first countable.  $1)$ The proof of this I got from  with just one question: it says we need to prove that such an $S(y)$ exists,and I'm thinking $S(y)=\cap\{u\in \omega_1:u\gt y\}.$ This is correct$?$ But here is a chance that the countable base around $y$ may be finite and not countably infinite.  $2)$ If possible let us assume that $\omega_1$ is not a limit point of the set $\omega_1.$ $U$ be a nbd of $\omega_1$ that does not intersect $\omega_1.$ Then what are the elements of $U$ like? The ones coming before $\omega_1$  cannot be uncountable because $\omega_1$  is the first. Then they must be countable. This is absurd so no such $U$ exists. Thus $\{\omega_1\}$ is a limit point.  Are my proofs correct? Thank you.


I was asking someone "whom were you horrible to?" And thought, is it who or whom? I believe it's whom but when I typed the phrase into Google search It felt differently.

I can never figure out whether I should use who and whom. Most people use who for both colloquially, but some people say this is not correct.  What’s the rule for using who and whom correctly?


I found out that I am able to flag my answer on Stack Overflow. But I did not press ok. It appears to be an accepted answer.  I believe there is no use of having this option for my own answer because it seems meaningless. Shouldn't this thing be disabled for my own answer? I don't know how this is useful. How could flagging your own posts be useful?

It makes sense that I can delete my own question/answer if I think that it's not a good post. It also makes sense that I can edit it to improve it. But why would I flag my own question/answer?


Let's take: $$\int \frac{1}{x\sqrt{x+1}} \ dx  $$ I tried solve this by four hour, so I am asking for help

Make a substitution to express the integrand as a rational function and then evaluate the integral  $$\int {\frac{2}{x\sqrt{x+1}}}\, dx$$  What is the substitution that I have to make?


Does it make sense to hold a rock morally responsible for falling downhill due to the law of gravity and crushing somebody's head? Likewise, does it make sense to hold humans morally responsible for anything in the absence of  free will?

Are there any theories of moral responsibility that don't require free will?  Sam Harris  and attempts to construct some form of , but "The Moral Landscape" didn't sound very convincing to me exactly because the notion of responsibility wasn't there, it was all about optimization of multidimensional functions. (Disclaimer Or may be I missed/forgot the responsibility and need to reread the book).   Are there other attempts to formulate the responsibility without appeal to free will?


so I'm very new to all this, so I don't know a lot. My mountain bike will no longer shift gears, I've been told this is because my cables need lubricated, but I have no idea how to do this, so, how would I do that with a spray lubricant?  And please keep in mind, I don't really know anything about bikes.

What is the best way to lubricate gear and brake cables in their tubular housings? Up until now, I've used CRC/WD-40 with an extension tube and attempted to squirt the lubricant into the tube housings. However, I suspect that this is fairly ineffective because 1. WD-40 is not a great lubricant (judging by the other Q+A on this site), and 2. the lubrication doesn't travel very far into the tubes.  So what is a good way of doing this?


I'm stuck with a problem and I have to display these numbers correctly using the power of ten. I know that the number in the end has to do with the fact that the decimal point is shifted the number to the right, only how I can do it or how I have to parse the number is a mystery to me. I have the numbers as a string The whole thing is written in C # "1.11632e+007" "1.30357e+008" The result must look like this The output can be as int or string does not matter 11163200 130357000 I have no idea how to do this. Can you help me?

What's the proper way to convert from a scientific notation string such as "1.234567E-06" to a floating point variable using C#?


I would like to filter point data from LIDAR scans (3d) by parcel plot lines (2d).  I began with loading the lidar data into microsoft sql and performing a STIntersects between the MultiPoint and the Polygon. This provides a result, but loses it's 3rd dimension.  I then have tried loading the lidar .shp file into the  python library, calling .filter() to narrow down the features, and traversing points checking .within() against the plot line polygon. This seems to work but is super slow.  Next I loaded the lidar .shp into the  python library. However there doesn't seem to be the best 3d support. The methods that were obvious to me were limited by the inability to get a .bound on the shape that included the 3rd dimension. So when I added the shape to the index is complained the bound was 2d and the shape 3d.   Finally I attempted to load each point manually into the rtree index so that I could correct the 3rd dimension manually on the insert.  I have not validated that rtree will even work once I have a complete index.  Has anyone figured out a non brute-force method?

I am trying to clip or filter lidar files (.las, .xyz) using a shapefile that contains multiple polygons.  Is there open source software that can do this spatial operation?  My .las files are enormous, and I should say that I am very new to DEM data and analysis so any help would be very welcome.


My objective is to fetch maps provided by openLayers, as in openLayers_plugin, from a stand alone python script. I would like to get it superposed to my shp file.  As can be read on   layer = QgsVectorLayer(data_source, layer_name, provider_name) if not layer.isValid():print "Layer failed to load!"   provide a good way for loading layer in a stand alone python script. And it's possible to do it as well for wfs data source, or other data source types. I do it with shp files, and it works well, but what is the uri related to openLayers datas and maps  ?  I also tried to get openLayers_plugin ...  sys.path.append(r"C:\usr\python\plugins\openlayers_plugin") qgis.utils.loadPlugin('openlayers')      qgis.utils.startPlugin('openlayers') print qgis.utils.isPluginLoaded('openlayers') # return False   Is it possible to use openlayers plugin in stand alone pyqgis script ? cf [  ] which is deprecated now. No it's not ?

if I try to load the openlayers plugin in a standalone application it always fails with False, although paths are set, and plugin shows available.  (tested on Ubuntu 14.04, QGIS 2.4, python-2.7)  #!/usr/bin/python # -*- coding: utf-8 -*-  import sys, os  import qgis import qgis.gui, qgis.utils from qgis.core import * from PyQt4 import QtGui   # open an app app = QtGui.QApplication(sys.argv) # supply path to where is your qgis installed QgsApplication.setPrefixPath(u'/usr', True) # load providers QgsApplication.initQgis()  # set up the plugins qgis.utils.plugin_paths = \     ['/usr/share/qgis/python/plugins',     os.path.expanduser('~/.qgis2/python/plugins'),] qgis.utils.updateAvailablePlugins() print qgis.utils.available_plugins print "...load:", qgis.utils.loadPlugin(u'openlayers_plugin') print "...start:", qgis.utils.startPlugin(u'openlayers_plugin') print "active:\n",qgis.utils.active_plugins  canvas = qgis.gui.QgsMapCanvas() canvas.show()   what is the issue here ? post  refers to the embedded python console, where the plugin was magically available before.  thanks!


If you go to the definition page for a site already in beta (e.g. ) and double-click on the voting button, a notification box shows up that cannot be closed by clicking the "cancel" button.    The box still goes away (and is replaced by another box at the appropriate location) if you click on a different voting button, though.   My browser is Chrome 34 on Windows 7. I don't see any errors in the JS console.

Take a look on this friendly robot:   Looks innocent, right? Well, he is not.  I just went over the list of question on a , the home of that robot and tried to upvote a question I liked:        The robot appeared and explained to me I actually can't vote. Trying my luck, I clicked again. The dialog re-appeared as expected.  Time to give up, I wanted to read the other questions. I clicked the "cancel" in the dialog. Nothing happens. I clicked outside the dialog. Nothing happened. The robot is there to stay, and won't leave until I reload the page!  I know, I misbehaved by clicking twice, but still... do I deserve such extreme punishment? Can it please be closed when clicking "cancel" even if I clicked more than once?


I wanna write something quite simple, namely: 10 10 10 9 9 8 8 6 6 4 4 10 10 10 9 9 8 8 6 6 4 4 I tried the following code: \begin{matrix} 10 & 10 & 10 & 9 & 9 & 8 & 8 & 6 & 6 & 4 & 4\\ 10 & 10 & 10 & 9 & 9 & 8 & 8 & 6 & 6 & 4 & 4 \end{matrix}  However upon compilation the last "4" standing at the end of each row gets shifted to the next row standing all by itself so I get something like this: 10 10 10 9 9 8 8 6 6 4 4 10 10 10 9 9 8 8 6 6 4 4 I would like to avoid this behaviour and force the "4" in the position. Thank you very much in advance

I'm using bmatrix environment from the amsmath package, and I'm trying to do something like this:  \documentclass{article} \usepackage{amsmath}   \begin{document}      \begin{equation}          \begin{bmatrix}              1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11\\          \end{bmatrix}     \end{equation}  \end{document}   However, pdfLaTeX returns an error: "Extra alignment tab has been changed to \cr", and in the output the extra element is moved to the next row. (If I remove one element, then it works perfectly fine). I guess this means that I've hit some hard limit on the number of tab stops in a matrix. Is there a way to change this?  The elements in the matrix are short and could fit perfectly on a single row.


I'm on Ubuntu Gnome 15.10.  I am regularly downloading large files (~800 MB), but I have a very slow Internet connection. It usually take a relatively long time to download it.  Since I am not continuously working on the laptop, it automatically goes into sleep/hibernation mode.   When I press any key after it has gone to sleep/hibernation mode, it wakes up and takes me to the login screen.   I was able to find the power settings, which gave surprisingly few options:    However, I am unsure about a couple of things      Is there a way in which my computer does not suspend during downloads, but my screen is still shut off when I am not working on it during download? Are there settings to be made to achieve this, or other solutions?

It seems like there are many ways in which a Ubuntu's settings can be permanently manipulated to sleep when desired as long as predetermined conditions are met.  However, these are more permanent solutions that don't take into account rare tasks that may want to temporarily fore go standard policy.  The problem that I am running into is that I have a very long running script to do some backups and I don't want the computer to sleep or hibernate while that particular process is running which usually take 30-50 minutes.  Therefore, is there a command that I could include into my backup script that would prevent the system from hibernating/sleeping while the backup script is running and is there also a command to restore the normal default power policy after the backup has finished?  something like  #!/usr/bin/bash #disable normal powerpolicy disable-power-policies backup /dev/sda /dev/sdb /dev/fioa /dev/fiob #enable power policies. enable-power-policies


Could you please tell me how to properly write the following sentence?  I believe I know the grammar rule but I must not be creative enough to think of an alternative sentence structure.  Here's the sentence:     I would love to see houses you've been looking at.   I've never really figured out how to change a sentence like this without sounding really pompous.  Such as, "I would love to see houses at which you've been looking". This sentence sounds weird and awkward to me.

Like many others, I commonly find myself ending a sentence with a preposition.  Yes, it makes me cringe.  I usually rewrite the sentence, but sometimes (in emails) I just live with it.  To, with... you know who you are.  Should I keep fighting myself on this one, or is it okay in some circumstances?


I recently noticed that words are broken/split for , e.g.:   responsiveness enabled          responsiveness disabled          Could you please not break words in the question title?

For sites that have the new responsive theme enabled, where the "Ask Question" button is in line with the question title on question pages, the word wrap on long titles is not working correctly.  It will break a word across two lines.  Here is an  from Personal Finance and Money:  Maximum width, left nav hidden:   Narrow width:   This is also happening on beta sites.  Here is an  on Sports:    These screenshots were all taken on Firefox, but I am seeing the same problems in Chrome and Internet Explorer.  One more example:


Suppose we are in a spacecraft that is moving away from the Earth along a straight line with a constant acceleration of $1G$, and that this acceleration can be sustained indefinitely.  Accelerating at $1G$ seems to suggest at first glance that we should move 10m/s faster every second relative to the Earth, but does not sound right since that would take us a finite amount of time to reach the speed of light if that were true. What velocity and time are we talking about? What does constant acceleration mean and in what frame, and what is our speed relative to the Earth at any given time $t$?

A question has recently come up that goes beyond my knowledge of special relativity.  Suppose a pilot has his foot on the gas pedal of a rocket ship and keeps it applied to achieve a constant acceleration, and he has a magical engine that can maintain the thrust needed to accomplish such acceleration even as the vehicle acquires mass.  He measures his acceleration at periodic intervals and sums it up as he goes.  Observers perceive the rocket to increase in speed and gradually approach the speed of light (but never reach it). Two possibilities are being debated for what the pilot observes, and my preference is for the first:   Time dilation gives him the impression that the summation of his readings are approaching light speed at a constant rate, but there is an asymptote involved here even in the inertial frame such that he never actually perceives himself to reach, let alone exceed, $c$, because time slows down to a crawl (as seen from the reference frame) before this can happen. Although to observers he is only approaching $c$, it is possible for the summation of the measurements on his accelerometer to indicate that he has surpassed $c$ and is now traveling faster than light.  From the reference frame he is approaching $c$ and his instruments in the inertial frame tell him that he has surpassed it.   I assume (1) is true beyond a doubt?  If so, is there a straightforward explanation for this?