Can't upgrade to 18.04 (due to seemingly unupgradable packages)?

Trying to upgrade 16.04 to 18.04 (following  article) and having problem that seems to be related to packages not being upgraded, yet when trying to upgrade the packages am told that those packages cannot be upgraded. Upgrade attempt logs provided below, but not sure the best way to interpret the problem from them. Any advice would be appreciated.  ➜  ~ /usr/lib/ubuntu-release-upgrader/check-new-release-gtk /usr/lib/ubuntu-release-upgrader/check-new-release-gtk:30: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version('Gtk', '3.0') before import to ensure that the right version gets loaded.   from gi.repository import Gtk Checking for a new Ubuntu release Please install all available updates for your release before upgrading. ➜  ~ sudo apt update                                        .... http://ppa.launchpad.net/qbittorrent-team/qbittorrent-stable/ubuntu xenial InRelease                   Hit:43 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease        Fetched 326 kB in 2s (125 kB/s)                     Reading package lists... Done Building dependency tree        Reading state information... Done 2 packages can be upgraded. Run 'apt list --upgradable' to see them. W: http://download.ebz.epson.net/dsc/op/stable/debian/dists/lsb3.2/Release.gpg: Signature by key E5220FB7014D0FBDA50DFC2BE5E86C008AA65D56 uses weak digest algorithm (SHA1) ➜  ~ apt list --upgradable                                  Listing... Done cuda/unknown 10.1.105-1 amd64 [upgradable from: 9.2.148-1] cuda-drivers/unknown 418.40.04-1 amd64 [upgradable from: 396.44-1] ➜  ~ sudo apt upgrade cuda cuda-drivers                     Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  cuda-drivers : Depends: nvidia-418 (>= 418.40.04) but it is not going to be installed                 Depends: nvidia-418-dev (>= 418.40.04) but it is not going to be installed                 Depends: libcuda1-418 (>= 418.40.04) but it is not going to be installed                 Depends: nvidia-opencl-icd-418 (>= 418.40.04) but it is not going to be installed E: Broken packages ➜  ~ sudo apt upgrade                                       Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done The following packages were automatically installed and are no longer required:   cuda-command-line-tools-10-0 cuda-command-line-tools-10-1 cuda-compiler-10-0 cuda-compiler-10-1   .... Use 'sudo apt autoremove' to remove them. The following packages have been kept back:   cuda cuda-drivers 0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded. ➜  ~ sudo apt upgrade cuda cuda-drivers                     Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  cuda-drivers : Depends: nvidia-418 (>= 418.40.04) but it is not going to be installed                 Depends: nvidia-418-dev (>= 418.40.04) but it is not going to be installed                 Depends: libcuda1-418 (>= 418.40.04) but it is not going to be installed                 Depends: nvidia-opencl-icd-418 (>= 418.40.04) but it is not going to be installed E: Broken packages


I've got a PHP script that needs to invoke a shell script but doesn't care at all about the output. The shell script makes a number of SOAP calls and is slow to complete, so I don't want to slow down the PHP request while it waits for a reply. In fact, the PHP request should be able to exit without terminating the shell process.  I've looked into the various exec(), shell_exec(), pcntl_fork(), etc. functions, but none of them seem to offer exactly what I want. (Or, if they do, it's not clear to me how.) Any suggestions?


In Captain America: The Winter Soldier, HYDRA had a plan that seemed good on paper, but I wondered how would they deal with the Hulk?  We know from Avengers that conventional guns (e.g., his suicide attempt) or the alien weapons used by the Chitauri couldn’t kill him. Did SHIELD or HYDRA have some specialised weaponry to neutralise or kill the Hulk?  If they couldn’t kill him, did they have some other plan to contain him?


No Wifi in Qualcom Atheros - Ubuntu 16.04 - Acer Aspire E 15

After Installing Ubuntu 16.04 in Acer laptop with Qualcom Atheros , it does not work. I tried ,   sudo rfkill list all 0: hci0: Bluetooth     Soft blocked: no     Hard blocked: no 1: acer-wireless: Wireless LAN     Soft blocked: no     Hard blocked: no   Then , checked  uname -r 4.4.0-21-generic   and , as suggested I tried ,   lspci -nnk | grep -iA2 net; dmesg | grep ath10k 02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 15)     Subsystem: Acer Incorporated [ALI] RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [1025:0987]     Kernel driver in use: r8169     Kernel modules: r8169 03:00.0 Network controller [0280]: Qualcomm Atheros Device [168c:0042] (rev 30)     Subsystem: Foxconn International, Inc. Device [105b:e09a]     Kernel driver in use: ath10k_pci [    7.100283] ath10k_pci 0000:03:00.0: pci irq msi interrupts 1 irq_mode 0 reset_mode 0 [    7.390307] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/cal-pci-0000:03:00.0.bin failed with error -2 [    7.390332] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-5.bin failed with error -2 [    7.390336] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-5.bin': -2 [    7.390350] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-4.bin failed with error -2 [    7.390353] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-4.bin': -2 [    7.390365] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-3.bin failed with error -2 [    7.390369] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-3.bin': -2 [    7.390381] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-2.bin failed with error -2 [    7.390384] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-2.bin': -2 [    7.390396] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware.bin failed with error -2 [    7.390398] ath10k_pci 0000:03:00.0: could not fetch firmware (-2) [    7.390401] ath10k_pci 0000:03:00.0: could not fetch firmware files (-2) [    7.390404] ath10k_pci 0000:03:00.0: could not probe fw (-2)   Now what should I do ??


Why is my date comparison not working in JavaScript?

I have pretty extensively researched this issue, and I've found some useful information, but I haven't been able to solve my problem. All I'm trying to do is parse a date and compare it to another date. Seems simple, right? Here is what I've tried:       function getCurrentDate() { //this function simply returns today's date                 var today = new Date();                 var dd = today.getDate();                 var mm = today.getMonth() + 1;                  var yyyy = today.getFullYear();                  if (dd < 10) {                     dd = '0' + dd                 }                  if (mm < 10) {                     mm = '0' + mm                 }                 today = mm + '/' + dd + '/' + yyyy;                 return today;  }  $("#TxtDate").blur(function () {             var projectDueDate = Date.parse($("#lblDueDate").val()); //parses the project due date label to create a date variable             var itemDueDate = new Date($("#TxtDate").val()); //parses the value the user entered into the due date box to create a date variable             var actualProjectDueDate = new Date(projectDueDate);              if (Date.parse(document.getElementById('TxtDate').value) > getCurrentDate()) {                 alert("The date you entered precedes today's date. Please enter a valid date.");                 $("#TxtDate").val() = "";             }         });   The if statement isn't working in the TxtDate blur function. It is not showing the alert window, even though I am entering a date that precedes today's date. As you can see, I've tried some different things. Any suggestions?


Is there a way to modify a core admin page table?

I would like to modify the "pages" section of WordPress dashboard to add this custom column "views" to tell how many times one page was viewed. Is there a way to do this?


How can I send single file to multiple remote sites at the same time?

Can scp be used to send a single file to multiple remote servers at the same time? If so, how? If not, what's the alternative?


Looking for the title of a graphic novel featuring a spaceship shaped like a bird and a gigantic earthworm

I am trying to identify a book that I read in the mid 1980's. Some details:   It was a graphic novel, or comic. All black and white, if I remember correctly. The main character was a human, though I believe all of the other characters were anthropomorphized animals. There was a cat-woman who acts as a kind of mentor/mother to the main character, along with some varied animal "children".   I believe the main character's name was Phaedrus, or a variation of this.   The main character flies a spaceship shaped like a falcon, and arrives on the animal planet as a stranger, looking for something specific that I can't remember.   There is a metal sphere that, when opened, has a simple pattern inside: a single concentric circle with a cross extending through it to the edges of the sphere.   There is a human-sized earthworm that appears in the background of panels early in the story, but becomes a vital part of the story later on, eventually merging with the main character.   It's incredible that despite all of these details, I can't seem to find anything via Google. I've even gone so far to return to the library that I remember checking it out from as a child, but they no longer have the book.  Thank you for your help, this has been bugging me for years now.


Let $E$ be a measurable set and let $g$ be a function defined on $E$. The product $fg$ belongs to $L^1(E)$ for every function $f \in L^1(E)$ if and only if $g ∈ L^{\infty}(E)$.


Should there be a comma in this:  providing young adults access to drugs grants younger teens complete access, which can not be accepted given the consequences that would follow


Can GPS positioning work in "airplane mode"?

I need to test positioning only by wi fi network .For this i turned on "airplane mode "and after this GSM transmitters/receivers were completely disabled. In indoor cases the location is not determined even when i conected to wi fi but in outside  (in open space ) location is determined. i want to understand the services locate me by GPS or wi fi ? Isn't Gps receiver disabled in "airplane mode" ?


My BLU Studio 5.5 won't allow me to install anymore apps. I have a 18G SD card installed. When accepting to install it says "Error downloading phone had insufficient space". What do I do to install more apps.?


use for loop to add elements to an existing dictionary in a list

I have the following list of dictionaries:  d = [{'Sport': 'MLB', 'Position': 'SP', 'Age': '25'},      {'Sport': 'NBA', 'Position': 'PG', 'Age': '28'}]   I have another list that i would like to append to the above by using a for loop:  c = [{'2015 Salary' : '25'}, {'2015 Salary': '35'},     {'2016 Salary' : '30'}, {'2016 Salary' : '40'}]   I would like the final output to be  e = [{'Sport': 'MLB', 'Position': 'SP', 'Age': '25', '2015 Salary': '25',        '2016 Salary': '30'},      {'Sport': 'NBA', 'Position': 'PG', 'Age': '28', '2015 Salary': '35',        '2016 Salary': '40'}}]   The positions would always be the same thats why i was going to use a for loop.


Can I enter a Schengen country (France) during the last two days of validity of my tourist visa?

I have an Afghan passport.    If I remain in Europe during the last two days of a Schengen tourist visa, can I enter France?


Find the point which is furthest away from existing points while remaining within the convex hull

I have a set of x,y coordinates and wish to find a new coordinate pair which is as far away from any point in the initial set, while also being within the convex hull of the original points.   The current process I have to determine the new point is as follows:   Generate every possible midpoint between the original coordinate pairs. Compute the distance between the midpoints and every original point. Find the smallest distance calculated in Step 2 for each midpoint. Find the midpoint with the largest distance from Step 3.   If multiple points have the same maximum distance to the nearest original set of points, only one of those points is needed (for my purpose) and can be selected arbitrarily.  Is there a better method for finding these coordinates?


I tried the Euler substitution: $t=x+\sqrt{x^{2}+a}$ and I got $\int \frac{4ta}{(t^{2}+a)^{2}}dt$ and I don't know wnat now or if it is the right way.   Thank you in advance.


how to get a launcher desktop icon for matlab R2019a

i am very new to Linux as a whole. I use an alienware 15 R2 with Ubuntu 18.04.2 LTS on it.  i have installed matlab R2019a in the folder /media/srikar/Code/Matlab.  The ./matlab code path is /media/srikar/Code/Matlab/bin.  Please help me create a desktop launcher icon. I have gone through other answers for similar cases, but i couldn't figure out how to solve the issue in my case where the installed directory is different from the default. I installed matlab on my external drive.


Find closest match in two columns, one containing wildcards

no script to attach as I can pull the data just fine, I am struggling to join my two tables though. The column I want to join on has the same information formatted differently in each table, making it worse, one of these columns uses wildcards for the program that takes data from there. Example of what I mean: T1.Col1 would contain the actual value, say EXAMPLE   A , EXAMPLE   B , EXAMPLF A T2.Col1 would have one entry like EXAMPL*[AB] The Program using that table would treat all values the same if it started in EXAMPL, and ending in EITHER A or B. Meaning the following would all be a match, this is what I need to recreate for my script: EXAMPLE A , EXAMPLE B , EXAMPLF A Can I recreate that logic in SQL? To find a match/closest match based on certain conditions? T2 Column contains about 200 values just like that and all different, so I need a solution that can apply to everything and not just this case. I've tried formatting T2 values using Replace to be more like T1 but the square brackets are killing me. Making new rows in the output table might help but we're at the limit of what I can do in SQL.


Currently there are about 4,000 international students from 110 different nations across the world, thus/so the university offers perfect conditions for socializing and making new friends.   Is this sentence correct formal English? I don't know if I can use "thus" here, or if I should use "so" instead. Or is it better to rephrase as follows?     With about 4,000 international students from 110 different nations across the world, the university offers perfect conditions for socializing and making new friends.   In German we would write the latter, but is it possible to use "with" this way in English?


I have some doubts about the usages of That and Who. Sometimes I read sentences such as. "You are someone I love" "You are someone WHO I love" Or "People were asked to describe the qualities they look for in a friend" "People were asked to describe the qualities THAT they look for in a friend"  Why in some of these sentences WHO or THAT are omitted and others are not. Could somebody help me with this? I'll appreciate it! Thanks a million.


Let $a_n>0$,$\sum a_n$ is convergent,$na_n$ is monotone, Prove: $$\lim\limits_{n\to\infty}na_n\ln(n)=0.$$  I try to prove $a_n=o(n\ln(n))$, but it doesn't work.


Why is a quantum state described by a complex vector in the Hilbert space?

In classical theory (e.g., classical mechanics and electromagnetic theory), we introduce the complex values for the mathematical convenience, e.g., A=(a+a*)/2. There, the use of complex values (or vectors) is not necessary as we can in principle describe everything with real values (or vectors).  However, in quantum mechanics and quantum optics, why do we need to use the complex vector to express a quantum state? Would it possible to describe a quantum state with a real vector although it will not have a mathematically elegant forms?  Some book says it is just a postulate. Does this mean that we should not try to prove or demonstrate why the complex vector is a necessary since it is just correct as the complex vector based description fits experiment results very well?   Would there be any kind of reasonable explanation for why we describe a quantum state as a complex vector in Hilbert space?


Why does pgfmaths's ifthenelse evaluate both expressions?

Consider having to compute some value using an operation that might not be defined for certain values, like e.g. the tangent function. To avoid raising exceptions, I tried using pgfmath's ifthenelse(<expression>, <true code>, <false code>), like in the following example:  \documentclass[tikz, border=2mm]{standalone} \usepackage{xifthen}  \begin{document}  \begin{tikzpicture}     \foreach \D [count=\C] in {85,...,95}     {   \pgfmathsetmacro{\goodAngle}{ifthenelse(or(\D<=86, \D>=94), 1, 0)}         \pgfmathsetmacro{\Tan}{ifthenelse(\goodAngle == 1, tan(\D), 0)}         %\ifthenelse{\goodAngle = 1}         %   {   \pgfmathsetmacro{\Tan}{tan(\D)}}         %   {   \pgfmathsetmacro{\Tan}{0}}         \node[right] at (0,-\C*0.7) {\D$^{\circ}$, \goodAngle, \Tan};     } \end{tikzpicture}  \end{document}   I expected this to only compute the tangent of the given angle if it was previousely determinded to be a good angle (it would have been sufficient to exclude just 90°, but here I excluded anles from 87° to 93°), but it appears to be evaluating both expressions which obviousely fails for 90°. The result is the same when doing it in "one step", that is without computing the \goodAngle first, as well as using the shorthand notation for ifthenelse (which is <expression> ? <true code> : <false code>). To check that it's not my thinking that is flawed, I used the \ifthenelse macro from the xifthen package, which, as expected, only evaluates the correct expression. If one uncomments the three commented lines and comments out the line above like this  \begin{tikzpicture}     \foreach \D [count=\C] in {85,...,95}     {   \pgfmathsetmacro{\goodAngle}{ifthenelse(or(\D<=86, \D>=94), 1, 0)}         %\pgfmathsetmacro{\Tan}{ifthenelse(\goodAngle == 1, tan(\D), 0)}         \ifthenelse{\goodAngle = 1}             {   \pgfmathsetmacro{\Tan}{tan(\D)}}             {   \pgfmathsetmacro{\Tan}{0}}         \node[right] at (0,-\C*0.7) {\D$^{\circ}$, \goodAngle, \Tan};     } \end{tikzpicture}   one obtains the expected result:    This behaviour is not limited to the tangent function, it also emerges for e.g. simple division by zero, like in   \begin{tikzpicture}     \foreach \D [count=\C] in {-5,...,5}     {   \pgfmathsetmacro{\goodValue}{ifthenelse(or(\D<=-2, \D>=2), 1, 0)}         \pgfmathsetmacro{\byZero}{ifthenelse(\goodValue == 1, 1/\D, -1)}         %\ifthenelse{\goodValue = 1}         %   {   \pgfmathsetmacro{\byZero}{1/\D}}         %   {   \pgfmathsetmacro{\byZero}{-1}}         \node[right] at (0,-\C*0.7) {\D, \goodValue, \byZero};     } \end{tikzpicture}   Is this expected behaviour (I doubt it), or is this a bug? Are there facilities in pgfmath who work like a try ... except statement, or even better, a non- exception approch that lets me catch specific error types, like a try ... except ErrorType1 ... except ErrorTypeN ... finally construct? If not, does something like this exist at all in the world of TeX, and is it even possible?


How do i check if an instance is in the terminating state?

This returns InstanceStatuses:  aws ec2 describe-instance-status --include-all-instances --instance-ids i-123123123   Which looks like:  {     "InstanceStatuses": [         {             "AvailabilityZone": "us-west-2a",             "InstanceId": "i-123123123",             "InstanceState": {                 "Code": 16,                 "Name": "running"             },             "InstanceStatus": {                 "Details": [                     {                         "Name": "reachability",                         "Status": "passed"                     }                 ],                 "Status": "ok"             },             "SystemStatus": {                 "Details": [                     {                         "Name": "reachability",                         "Status": "passed"                     }                 ],                 "Status": "ok"             }         }     ] }   What does the state looks like when the instance is "terminating"? Not already terminated but pending termination? How can I check if an instance is in the pending termination state?


I received a second hand I phone 4s as a gift it has not been reported stolen or lost. being the 3 party owner how can I delete the account attached to this phone to activate it


Hello can anyone tell me why this is happening.... here is my scene in the viewport shader with render ticked in object mode.  However, when I render the image in cycles blender I get this.....  [![enter image description here][2]][2]  Help. Now it looks like this....


Is a UV filter better for lens protection than a protector filter?

I'm usually very good at getting water/finger marks on lens, so I must use something for protection. Is there any downside of using an UV filter instead of a protector filter?  Example: Hoya HD Protector or Hoya HD UV?


Is there a way to reset/change my Steam email without being logged on?

I cannot access the email that is linked to my Steam account and need to change it. However, Steam Guard sends a verification code to that email address.  Is there any way around this?


Why aren't identical arrays, when passed as strings considered equal?

1)  if I set  int[] set1 = new int[]{1, 2}; int[] set2 = new int[]{1, 2};   how come when I pass them as strings using  System.out.println(Arrays.toString(set1) == Arrays.toString(set2));   it returns false?  2)  Is there any way to compare equality of entire arrays without looping through each index of the array?


When should we use '=== ' operator in javascript?

When and why should we use '===' in javascript or jquery. Is it recommended to test string using === and if yes why.  I have a code where i am checking a condition on the string like. if(a == "some-thing") is this right or should i use '==='


WIndows Vista upgrade to Windows 10 device driver compatibility

I have a Windows Vista computer.  How can I check if all my hardware is supported by Windows 10?  I don't want to purchase it and then find out there are no drivers for the chipset or whatever.


I every so often hear claims like:  M-Theory predicts that there are 10 spatial dimensions!  Now I'm not really sure what these claims mean.  There are three spatial dimensions that I normally observe so 7 of these dimensions must be different in some way.  (Several seconds of researching reveals that the difference is that these dimensions are compact and have very small measure which explains why they are not apparent in every day life) However there are a ton of dimensions that are not quite like our three spatial dimensions.  Time is the one that very clearly springs to mind, but we could also talk about momentum.  In fact dimension is pretty frequently used to mean unit (e.g. dimensionless, dimensional analysis). So there must be some thing relevant about these 7 spatial dimensions that is not relevant with these other dimensions. My question then is: What is the relevant factor that unites the spatial dimensions not present in other dimensions? For example if I discovered (or theorized) a new degree of freedom, how would I determine if it corresponded a spatial dimension?  What properties would it need to count as spatial?  helps explain the difference between spatial and time dimensions with respects to the Minkowski tensor, but I would like to see a more authoritative answer that would allow me to fully categorize a potential new dimension. I am looking for a definition that is rather precise rather than intuitive.  I have plenty of intuition as to what space is since I live in it and all the sources I can find a couple describe the intuition (e.g. the ). I am curious about a more mathematized definition. Some notes in response to comments:  I am already very well aware of what a dimension in general and this question is asking about how we separate dimensions into spatial and non-spatial.  I already understand compactification.  I am not at all confused by the concept and I am not asking for an explanation of compact dimensions.


How to print a List of Arrays (with elements) using Java 8 Streams?

public static void main(String[] args) {     List<Integer> numbers1 = Arrays.asList(1,2,3);     List<Integer> numbers2 = Arrays.asList(3,4);      List<int[]> intPairs = numbers1.stream()             .flatMap(i -> numbers2.stream()                     .filter(j -> (i+j)%3 == 0)                     .map(j -> new int[]{i,j}))                     .collect(Collectors.toList());      intPairs.stream().forEach(System.out::println); }   For the above code, I am getting output as:    [I@214c265e [I@448139f0   But my expectation is to get [(2, 4), (3, 3)].  Could you please guide me to achieve this?


How to sort List based on column provided as input

I have a generic list e.g:  public class Person {        public string Name {get;set;}        public string loginId {get;set;}        public string ContactNo {get;set;}        public string City {get;set;}        public string Country {get;set;}   }   After filling the list, I bound the list to Repeater control. In HeaderTemplate of my repeater control I have defined LinkButton as:  <HeaderTemplate>
                     <asp:LinkButton ID="lnk1" runat="server" CommandName="Sort" CommandArgument="Name" Text="Name"></asp:LinkButton>         	                      <asp:LinkButton ID="lnk2" runat="server" CommandName="Sort" CommandArgument="loginId" Text="loginId"></asp:LinkButton>         	                          <asp:LinkButton ID="lnk3" runat="server" CommandName="Sort" CommandArgument="City" Text="City"></asp:LinkButton>
 </HeaderTemplate>   When user click any of the link, it fires ItemCommand event. In my ItemCommand method, I check for the command and if its a sort then Sort the list based on the CommandArgument.   Here is my command event:  protected void Repeater1_ItemCommand(object sender, RepeaterCommandEventArgs e)    {       if (e.CommandName == "Sort")       {          string str= e.CommandArgument.ToString();          //var lst=ListPerson.OrderBy(c=>c.[PropertyName from CommandArgument ????]);          var lst=ListPerson.OrderBy(?????)        }    }  NOTE:ListPerson is my previously populated list of type Person.   Any help is appreciated.


How do you achieve a retro 3D style, today?

Limitations of 90's 3d computer graphics produced some very stylized images. See here:  I can't quite articulate, in 3d terms, why it looks retro. Low resolution? Harsh shadows? Lighting? Unrealistic materials? Of course, today's technology has gotten a lot better and more realistic. What techniques would you use to create a 90's 3d retro style today? I'm a beginner in 3d software. Thanks!  Robert A. Mickelsen


I downloaded the ubuntu .iso file in Windows 10.  How do I create either a bootable USB or dvd from here.


Why are there two tensions on my free body diagram?

A man sits on a platform attached to a pulley and pulls himself up as shown (ignore the angle of the rope - it should be vertical). Apparently, the man/platform object has a force of 2T pulling it up. Why is it not just T?  Much appreciated!


How to model an equilateral triangular pyramid?

How to create triangular pyramid with equal length of edges?    Note - I'm not looking for a way to create one with a single click, but I want to be able to model one from scratch.


I have a Mongoose MTB and I'm trying to convert my tires from MTB tires to road tires/thin tires. The frame on my bike is 6061 Aluminum Ledge 2.1 so if anyone knows what kind of tires to switch to please help me out. All help is appreciated! Because I don't know what kind of road tires will fit. And could you recommend cheap tires and dropbars that would be helpful.  Updates: My tire is 53-559 and is 26x1.95


I want to prove whether the following is true using congruencies: If $n$ is odd and $3\not | n$, then $n^2\equiv 1\pmod{24}$. I tried a direct proof. Let $n=2k+1$ for an integer $k$ such that $3\not| n$, or $3c=n+r$ such that $r=1$ or $r=2$ for an integer $c$. Then in the first case, $3c=n+1$ implies $n\equiv 1\pmod 3$. Or in the second case, $3c=n+2$ implies $n\equiv 2 \pmod 3$. Then $$n^2\equiv 1 \pmod 3 \text{ or } n^2\equiv 4 \pmod 3$$ iff $$3|{n^2-1} \text{ or } 3|n^2-4$$ or $$8n^2\equiv8, 32 \pmod{24}$$ This was the farthest I got. I'm having a hard time going from mod 3 to mod 24 just given the conjunction that $n$ is odd and that $3\not| n$


return to newly custom object created page

I am creating a new object with an apex class and a controller. My goal is when I call my method that create a new instance of that custom object, to redirect me to the page where the new object is.  For now I am doing :   PageReference test789456 = new PageReference('/' +parent);  return test789456;   where parent is my customobject id.  Is there any better way ? Meaning I don't like absolute path


New bib(la)tex-entrytype for music-scores

Short question: How can I create a new entry type (@music) with fields for the composer, title, opus, editor, series, location and year?  \begin{filecontents*}{\jobname.bib} @music{citekey,     composer={Johann Sebastian Bach},     title={Motetten},     number={BWV 225--230}, %   opus={}, % no opus in this case     editor={Konrad Ameln},     series={Neue Bach-Ausgabe Serie III, Band 1},     loaction={Kassel},     publisher={Bärenreiter},     year={1965}, } \end{filecontents*}  \documentclass[ngerman]{scrartcl} \usepackage[style=authortitle]{biblatex} \bibliography{\jobname}  \begin{document} \cite{citekey} should look like  Johann Sebastian Bach: Motetten. BWV 225-230, hrsg von Konrad Ameln = Neue Bach-Ausgabe Serie III, band 1. Kassel: Bärenreiter, 1965  or in general  (composer): (title)[, (opus)][, (number)][hrsg. von (editor)][= (series)]. [(location)][: (publisher)][, (year)][.]  where (xxx)=field and [yyy]=optional  \printbibliography \end{document}


How do I prevent my graph from adding multiple custom edges?

I have defined a custom edge and vertex type to use in an undirected sparse graph. The problem is that the graph is adding multiple edges which I don't want. For instance, considering the code below:  UndirectedSparseGraph<Vertex, Edge> graphX = new UndirectedSparseGraph<Vertex, Edge>(); graphX.addEdge(new Edge("1#2"), new Vertex("1"), new Vertex("2")); graphX.addEdge(new Edge("1#2"), new Vertex("1"), new Vertex("2")); graphX.addEdge(new Edge("2#1"), new Vertex("2"), new Vertex("1")); graphX.addEdge(new Edge("1#3"), new Vertex("1"), new Vertex("3")); graphX.addEdge(new Edge("1#4"), new Vertex("1"), new Vertex("4"));   I've intentionally added two similar edges (the first ones). I've overrided an equals method for both classes I've created, i.e, Edge and Vertex, but the graph assumes as the edges as the vertices are differents and adds all of them.  Here's the output:  Vertices:1,4,1,1,2,1,1,2,2,3 Edges:1#3[1,3] 1#4[1,4] 1#2[1,2] 1#2[1,2] 2#1[2,1]    So, what am I doing wrong?  PS. FYI here are the classes I've created:  public class Vertex {      private String id;     //More info in the future      public Vertex(String id){         this.id = id;     }      public String getId() {         return id;     }      public void setId(String id) {         this.id = id;     }      @Override     public boolean equals(Object obj){         return ((Vertex) obj).id.equals(this.id);     }      @Override     public String toString(){         return this.id;     }  }  public class Edge {      private String id;     private double weight;      public Edge(String id, double weight){         this.id = id;         this.weight = weight;     }      public Edge(String id){         this.id = id;         this.weight = -1;     }      public String getId() {         return id;     }      public void setId(String id) {         this.id = id;     }      public double getWeight() {         return weight;     }      public void setWeight(double weight) {         this.weight = weight;     }      @Override     public boolean equals(Object obj){         return ((Edge) obj).id.equals(this.id);     }      @Override     public String toString(){         return this.id;     }  }


How to use an alpha map in Blender Render?

Whenever I download Nintendo models I come across this texture with the black. I can't transparent it, but how do I use this for stuff in Blender Render mode? If it's possible can you tell me what I do with these kind of textures?


What is the cause and disadvantages of high memory usage as time passes on Windows 8.1?

My laptop is used in long time intervals without restarting. The OS tends to use extensive memory (~8GB) as time passes. Below are screenshots of two different states with exactly the same programs are running.  Long Time      Right After Boot      It seems that caching causes this situation. I have two questions:   Is this amount of memory usage a bad thing and therefore something to fix?  Why cached amount increases as time passes?    Edit  Here's the Poolmon output as I appear to be using 6GB of RAM in another long session. Anything suspicious here?


How to sort a ConcurrentSkipListMap by value?

I'm trying to sort a ConcurrentSkipListMap by value in Java, here is my code :  ConcurrentSkipListMap<String,Float> cslMap = new ConcurrentSkipListMap(new Comparator() {     public int compare(Object o1,Object o2) {         return ((Comparable)((Map.Entry)(o1)).getValue()).compareTo(((Map.Entry)(o2)).getValue());     } }); cslMap_Map.put("B",0.2f); cslMap_Map.put("A",0.1f); cslMap_Map.put("C",1f);   Got an error message when compiling it:     Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Map$Entry   What's the correct way to do it ?  Thanks for the answers, but in it's Java doc, it says "The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time", so how to supply it with a Comparator that sort by its values ?


In activity monitor what time frame is the data sent / received data from?

In the network tab in activity monitor there is a read out of data usage showing sent and received in GB. What this dosnt tell you is over what time period this is, is it from a day, a week and month ?   This is from OSX Yosemite.


"reflect" vs "reflection on" or "reflection of"

The bride's elegant dress reflected her good taste. The bride's elegant dress is a reflection on her good taste. The bride's elegant dress is a reflection of her good taste.  Would you tell me if they mean the same thing? If they would mean the same thing, what about the following question--link--? or I mean how could we distinguish such a distinction between these functions? Similarly, what about these:  A student's grades reflected her teacher A student's grades are a reflection on her teacher A student's grade are a reflection of her teacher  When, where or in which situation don't they mean the same? How can we distinguish such a distinction?


Can I install Ubuntu 12.04 LTS on Lenovo Ideapad S510p

I have a Lenovo Ideapad S510p (59-411351) Laptop (4th Gen Ci3/ 8GB/ 1TB/ Win8.1/ 2GB Graph). Can I install Ubuntu 12.04 LTS on it? Any specific steps I need to follow?


In my class, my teacher told us that, we should find the differences between "make" and "do".   I'm Vietnamese so I'm confused with this question! Can you help me?  And the similar between them is the meaning? Right?


Login interface completely changed in Xubuntu 18.04

My hard drive got full yesterday and some weird things started to happen, like uGet not working anymore and the trash can not emptying. I switched to another OS and cleaned some stuff in the Xubuntu's partition. However, when I restarted the computer, the login GUI changed to this and I can't fix it.    Does anyone know how to get back the original Xfce interface?


Run an application as a domain user from VPN

I am connected to a VPN as a domain user. I would like to run a local application as the domain user from the VPN instead of my local workgroup user.  If I select run as a different user and insert the username; domain\user and the respective password I get:     login failure: unknown user name or bad password   Does Windows know that I am referring to the domain from the VPN? How do I achieve this?


Why is the determinant of a symplectic matrix 1?

Suppose $A \in M_{2n}(\mathbb{R})$. and$$J=\begin{pmatrix} 0 & E_n\\   -E_n&0  \end{pmatrix}$$ where $E_n$ represents identity matrix. if $A$ satisfies $$AJA^T=J.$$ How to figure out $$\det(A)=1~?$$ My approach: I have tried to separate $A$ into four submartix:$$A=\begin{pmatrix}A_1&A_2 \\A_3&A_4 \end{pmatrix}$$ and I must add a assumption that $A_1$ is invertible. by elementary transfromation:$$\begin{pmatrix}A_1&A_2 \\ A_3&A_4\end{pmatrix}\rightarrow \begin{pmatrix}A_1&A_2 \\ 0&A_4-A_3A_1^{-1}A_2\end{pmatrix}$$ we have: $$\det(A)=\det(A_1)\det(A_4-A_3A_1^{-1}A_2).$$ From$$\begin{pmatrix}A_1&A_2 \\ A_3&A_4\end{pmatrix}\begin{pmatrix}0&E_n \\ -E_n&0\end{pmatrix}\begin{pmatrix}A_1&A_2 \\ A_3&A_4\end{pmatrix}^T=\begin{pmatrix}0&E_n \\ -E_n&0\end{pmatrix}.$$ we get two equalities:$$A_1A_2^T=A_2A_1^T$$ and $$A_1A_4^T-A_2A_3^T=E_n.$$ then $$\det(A)=\det(A_1(A_4-A_3A_1^{-1}A_2)^T)=\det(A_1A_4^T-A_1A_2^T(A_1^T)^{-1}A_3^T)=\det(A_1A_4^T-A_2A_1^T(A_1^T)^{-1}A_3^T)=\det(E_n)=1,$$ but I have no idea to deal with this problem when $A_1$ is not invertible.


modify global variable value based condition with in a function in python

I am declaring global variables before i run the user defined function.  global x x=2   Now I want to change the value of the global variable based on some conditions with in the function it throws UnboundLocalError.  UnboundLocalError: local variable 'x' referenced before assignment   i am changing the value of  global variable as follows.  if pd.isnull(x):    x=1   The above code i used in user defined function.  Anyone can help me to tackle this.  Thanks in advance.


Importance of GRE for computer science PhD applicant

I am currently a prospective computer science Ph.D. applicant with a 3.75/4.00 GPA at an R1 CS school ranked in the top 30. I am considering applying to 15 schools roughly in the top 50. I have an extremely strong research background with one first author ML pub in a reputable IEEE conference and a second author applied ML/psychology journal article under review. My letters of rec will all likely be very strong and from well-known professors that I have worked under or with for at least 6 months. That said, I have a few questions about the application process:  I am not the best standardized test taker, and I currently am looking at quantitative GRE scores of around 75th-80th percentile with verbal scores in the same range. Will my subpar GRE scores likely prevent the comparatively stronger portion of my application from being reviewed at many schools? With this in mind, should I retake the GRE until I'm closer to the averages of the schools? I am going to complete my undergraduate in 2.5 years and am hoping to enter a Ph.D. program directly after graduation. Will the reduced length of my undergraduate career reduce my chances of acceptance, or is this viewed somewhat favorably?  Any insight would be greatly appreciated. Thank you.


Which elements in $\mathbb{Z}_{26}$ do not have multiplicative inverses?

How would I find which elements in $\mathbb{Z}_{26}$ do not have multiplicative inverses? I assume I would find them by finding which elements in $\mathbb{Z}_{26}$ have a $\gcd(a, m) \neq 1$. Is this the correct approach? I have gotten that 2, 4, 6, 8, 10, 12, 13, 14, 16, 18, 20, 22, and 24 don't have multiplicative inverses in $\mathbb{Z}_{26}$.


Where I can find a repository for an old version of Ubuntu

I am using raring and just noticed that I can't install packages any more (404). I checked a couple repositories and raring is not there. Turns out it's been EOL'd, at barely 10 months old, it seems a bit harsh.  Is there some way I can avoid an entire reinstall? I really don't want to go through the whole thing of setting up the desktop again, etc. It doesn't matter if the repository isn't being maintained any more, I just want to grab a couple packages. Can I do a dist-upgrade without a ton of stuff breaking?  I just switched over from Debian six months ago, and I am pretty shocked that they expect me to upgrade. Why do some version have no scheduled EOL date? (Ref )  To the person that closed this post, this question is time relevant and an answer that is more than 3 years old doesn't necessarily help. Both the articles linked in that post are 404 or way out of date.


How are quantum gates implemented in reality?

Quantum gates seem to be like black boxes. Although we know what kind of operation they will perform, we don't know if it's actually possible to implement in reality (or, do we?). In classical computers, we use AND, NOT, OR, XOR, NAND, NOR, etc which are mostly implemented using semiconductor devices like diodes and transistors. Are there similar experimental implementations of quantum gates? Is there any "universal gate" in quantum computing (like the NAND gate is universal in classical computing)?


What is the meaning of the end scene in Portal?

In Portal, we are promised cake and a party at the end of our tests. However;       we soon discover that the cake is a lie.     Then, at the final scene;       there really is a cake (and my companion cube is waiting for me).   What's the meaning of this?  Was GLADOS not deceiving me? Her comments seem to suggest that;       ...she had the intention of killing me. Was the cake for us (player) and not for the character in the game?


Given: $$f(x)=\frac{x^2-4}{x-2}$$  First thoughts would be than $x\ne 2$   But since $f(x)$ can be simplified to: $$f(x)=x+2$$  It now seems than $x$ can be a solution to $f(x)$.  If I graph this function I get the line $f(x)=x+2$, but it that with the point $(2,4)$ not included?  My book gives an answer where $x\ne 2$


What is the temperature of the black night sky, outside the atmosphere?

The sky at night is rather black. If it were completely black, it would correspond to a black body at absolute zero. But the sky is not completely black. Is there a way to assign a temperature value to the actual black night sky?  The question is not about the temperature of the air of the atmosphere, nor that of the stars in the sky. The question is about the the temperature that corresponds to the blackness seen by, say, the Hubble telescope; the question is about the pure blackness of the night sky, between the stars, outside the atmosphere of the Earth.  Nela


API only user accounts and security tokens

I have an API only user account and I am wondering if these accounts have a security token?  Obviously, I cannot access it because I don't have the ability to view the UI anymore.  Do I need my administrator to set this up?


NullPointerException error when trying to add to ArrayList

Trying to add the object member to the ArrayList loggedInList when logging into the Website class.  public class Website { // The name of the website. private String name; // The number of hits on the website. public int hits; // The amount of money taken at the checkout. private double salesTotal; //  private ArrayList<Member> loggedInList;   Is the code for my Website class.      public Website(String newName) {     // Intialises the name of the website.     name = newName;     // Intialises the number of hits on the site.     hits = 0;     // Intialises the amount of money taken at the checkout.     salesTotal = 0;     //      loggedInList = new ArrayList<Member>();   }   Is the constructor for the Website class.      public void memberLogin(Member member) {     member.setLoginStatus(true);     member.setWebsite(this);      System.out.println(name + " welcomes member " + member.getMembershipNumber() + "," + " you are now logged in.");      member.setWebsite(this);      hits +=1;      loggedInList.add(member); }   Is the method which SHOULD add the current member into the ArrayList.  The error I get is a NullPointerException on the line:  loggedInList.add(member);   I honestly have no clue why.


Using HTML5 canvas where would be the best place to start to move my 3 balls in random trajectories (along a smooth line, no jumping) and when they hit each other bounce away and then go on another path, until again they hit each other and again bounce away.  So far I have set up a simple example on   where each ball follows its own path (though they do disappear off the screen).  At the moment the trajectory is as simple as   function animate(){    // Yellow Circle   circles[0].x+=1;   circles[0].y+=-1.5;    // Blue Cirlce   circles[1].x+=-1;   circles[1].y+=-1.5;    // Red Circle   circles[2].x+=1;   circles[2].y+=-1;   draw();   }   I would love to see an example, but also to know what methods and calculations I should be looking at.


Print all possible k-combinations of n in python

I have to write a function that takes as input two numbers n and k and prints on the screen all the k-length subsets of a set created by n (order is not important), so basically a function that prints all the k-combinations of n.  For example: If n = 4 and k = 2 the initial set becomes (1,2,3,4) and it prints the following subsets:  (1,2),(1,3),(1,4),(2,3),(2,4),(3,4)  I know that there is already a function that does that, but I have to create the function from scratch, so the use of the itertools or any other module is prohibited, and no, I can't copy the combinations function from the documentation and paste it on my code. As you may have understood, this is an assignement from my university, so I am not asking you to solve it for me and give me a code, I would like someone to explain to me how can I do it.  I know that it has to be done with a recursive function, because the number k is not known. I've also thought of 2 different solutions of how can I do this and I'm not sure if they're correct:  1st solution:  Create the powerset of the given set, and then remove all the subsets whose length is different than k.  2nd solution:  Populate a list with numbers from 1 to n^k, and then remove all the numbers that have duplicates in them. Then transform the numbers to strings and print them as sub-sets.


Output negative values, regardless of original sign, on selected lines

I am using the following code to read specific lines in an ASCII file "text.dat"  sed -n '/Columnaxis/p' text.dat   The output is   Columnaxis: 100   In order to output only the second part previous line, I added the following to the previous command line:   sed -n '/Columnaxis/p' text.dat | awk '{ print $2 }'   The output of the last command is "100"  How can I update the last code to output negative numbers, regardless of the number's original sign? ( i.e if the input is "+100" I want the code to output "-100" also if the input is "-100", I want the code to output "-100"  PS. The content of text.dat is something like the following :  Columnaxis: 100 Columnaxis_1: 100 Columnaxis_2: -100 Columnaxis_3: 50 Columnaxis_4: -2.3 Columnaxis_5: 1.2 Columnaxis_6: -5 Columnaxis_7: -2 Columnaxis_8: -4 Columnaxis_9: -2   I want the code to output the following:  Columnaxis: -100   Let's say that the input has "Columnaxis: +100", then I want it to be  Columnaxis: -100


I wanted to know if there is any way to install Sagemath in Ubuntu 17.10. I haven't found the install package, but I just wanted to check if it was just me.  Thanks in advance!


"Error splicing file: Input/output error"

I recently obtained a Seagate Expansion 3TB external harddrive. I'm trying to copy over all of my stuff to prepare for reformatting and installing a new OS. A handful of my mp3s did not transfer when I was doing my music folder. I checked them after the fact and the ORIGINAL files became corrupted somehow. I am certain of at least a few that were not corrupted in anyway before doing this. Every now and then during my transfer I got  There was an error copying the file into /media/***/Seagate Expansion Drive. Error splicing file: Input/output error   Each of these files that I check after are corrupted at some point in the duration and will not play. Why did this happen and what can I do to fix it?


How can I backup my RAW photos while travelling without Internet access?

This question seems similar to , but my needs are different :   I shoot in RAW exclusively I'm looking for a 100% offline solution: while traveling, Internet won't be accessible the "laptop" solution is too heavy for me: I'm looking for a lightweight solution the simplest, the better: one device to rule them all   EDIT:  I'm using good old Compact Flash cards (yes, the bigger ones), so I need a device that can read it. If it can read from other cards, this question might be interesting for more people than myself  - that's the whole purpose of the website.    Also asked by :  Portable Storage Device while traveling  I need storage device which is able to read CF cards and make a backup of my photos while traveling. I do not want to carry laptop (it's bulky) and tablet (too little storage) but looking into some other solutions.   So far I found:   Epson PXXXX - price is blocker for me Jobo Giga Vu - same as above Nexto DI - bit better, but still a lot Hyperdrive Colorspace UDMA - this looks the best for price/options Wolwerine PicPac - cheap, bad opinions DigitalFoci PhotoSafe - same as above Ex-Pro® Picture 2 Drive - didn't find much about it   So ladys & gents what do you use?


Is this a valid definition of "exact duplicate"?

A moderator on one of the Stack Exchange sites provided the following answer regarding how one should determine whether or not a question is an "exact duplicate" or not:     Forget the "exact" wording. Whether a question is a duplicate of   another can be answered by reviewing what information would be   required to generally cover each question. If a good answer (even if   such an answer doesn't exist yet) to one of the questions would cover   the basics of the other question they can be closed as duplicates.   This seems to me to be out of step with what is explained in .     Exact Duplicate means that the question asked is the same question as one that has been asked before (the answers are irrelevant).  In   most cases, this means that the new question will be about a 95% match   to the original.      The words "Exact Duplicate" are used because people find many reasons   to vote to close questions as duplicates that are not really   duplicates, such as:         Questions that cover similar ground, but are not really asking the same question.   Questions that have answers that answer the supposed duplicate, but the question is different.   Questions that duplicate a question asked on another SE site.      Am I missing something or is the moderator being too loose in the guidelines he is suggesting for closing questions as duplicates?


Is it possible to run 3+ versions of Google Chrome?

How might I run 3+ versions of google chrome so I can log into to 2 different google accounts.  More specifically I am looking to have separate icons in the dock for the 3 separate running applications.  How might I run duplicate and or copy versions of the same application.  The following  by Mark works for a lot of applications but not for Google Chrome.  It appears the following might work .


What are the functions that are their own inverse?  (thus functions where $ f(f(x)) = x $ for a large domain)  I always thought there were only 4:  $f(x) = x , f(x) = -x , f(x) = \frac {1}{x} $ and $ f(x) = \frac {-1}{x} $   Later I heard about a fifth one     $$f(x) = \ln\left(\frac {e^x+1}{e^x-1}\right) $$ (for $x > 0$)  This made me wonder are there more? What are conditions that apply to all these functions to get more, etc.


Who are the footballers with most free kicks scored? We all remember Juninho Pernambucano, but who else?


Is this the cheapest and time-saving combination to get from LAX to Downtown LA?

suggests a cheap way of getting from LAX to downtown LA via LA's Metro Rail. Could someone please verify whether it is still a valid itinerary, and whether it is possibly the best time+price combination to get from LAX to downtown LA?  Also, if this itinerary is still valid, then the it would cost $3 for 3 TAP cards (I'm travelling with two others) and 1.75*3=$5.25 for 3 one-way trips, totaling to $8.25. Is this calculation correct? It seems that this would be cheaper than 3 tickets from the airport to Union Station (3x9.75=$29.25).  Also, the Metro rail's site says that a one way TAP card use "Includes transfers to other Metro lines for up to two hours to complete a one-way trip." By "2hrs" are they referring to the transfer time between any two stops or are they referring to the total time of the journey (including stops)?  EDIT: my question isn't a duplicate another existing question because that question does not have the metro route combination I'm referring to. Also, I'm travelling with three people, each of whom will have a luggage. My luggage in particular will have to be checked, unlike the one in the already-existing question.  EDIT 2: the route whose link I've given in the question is this: Take the free Green Line shuttle to Aviation/LAX stop, then remain on the green line to travel to Willowbrook station, transfer onto the blue line and travel to 7th center/Metro station in downtown. This route is not the same as that of another existing question. I figured from the calculation above it would be cheaper to take this metro route than it would to take the FlyAway Bus. Secondly, the FlyAway bus may be a little more susceptible (although less so compared to taxicabs) to congestion at around the time I'll be leaving LAX (approx. 5:40pm).


The new delete-votes limit should not apply to one's own answers

The  kicked in today but they also apply to deleting one's own answers. From the discussion I gather that this new rule is intended to protect valuable questions.  As it works now it stops me from cleaning up noise and mistakes.  So, please make a distinction between deleting questions and deleting one's own answers.


I'm trying to factor $x^6+x^5+x^4+x^3+x^2+x+1$ in $\mathbb{F}_2[x]$. But I don't know how to do that. Anyone can tell whether there is a nice way to solve all these kinds of problems?


Switching from Ubuntu 16.04 LTS to Ubuntu 17.10

As we know, Linux Ubuntu is published in two releases with different release-cycles. The latest ones are: Ubuntu 16.04 LTS Xenial Xerus, one presenting the long-term support version with a less-frequent release-cycle; and Ubuntu 17.04 Zesty Zapus, one with a faster release-cycle, though with an approximately 18 months guaranteed support period only.  My question is, is it possible to switch from Ubuntu 16.04 LTS Xenial Xerus to Ubuntu 17.04 Zesty Zapus without the so called clean install? At least it is possible from the short-term version to the LST one, but I am not sure if it works the other way around.  I am sorry if I appear a total newbie - which I certainly am - but how could I do this? Terminal-wise speaking, I mean (what commands I have to drive)?  Thanks a lot in advance!


subcaption package changing algorithm2e caption position

I have a project which makes use of the subcaption and algorithm2e packages. For whatever reason, the subcaption package is causing the captions in the algorithms to be misplaced.  Here we have a MWE of the issue. Note that the algorithm2e package is defined with the [figure] option.  \documentclass[12pt]{book} \usepackage{subcaption} \usepackage[figure,tworuled]{algorithm2e} \begin{document} \begin{algorithm} \DontPrintSemicolon $f_1$ = Fase a calcular\; \tcp{Início e fim do período considerado} $t_1$ = Idade química do concreto na fase anterior à $f_1$\; $t_2$ = Idade química do concreto na fase $f_1$\; \caption{Cálculo das perdas por fluência do concreto para uma fase} \label{fig:AlgFluencia} \end{algorithm} \end{document}   Which results in the image below. Note that the caption is clearly not centered, with the text almost entirely flushed to the right.    If I then comment out the \usepackage{subcaption} line, I get the result below. The caption is nice and centered, no problems. (though there does seem to still be more space to the left than the right, though that might just be me. Regardless, its clearly better)    If the [figure] option in algorithm2e is removed, then there is no conflict between the packages, but I'd much rather keep it. The documentation on algorithm2e doesn't point to anything in regards to this (that I saw)... any suggestions?  EDIT 1: After seeing Werner's link to a solution, I thought all was solved, but thought too soon. Unfortunately, unlike the MWE shown, my project must in fact adopt an university-defined class file which makes use of . With this package the same error occurs and is not corrected by the solution liked to be Werner. A more precise MWE (including Werner's solution) follows, along with the resulting image. It still makes use of the book class just to allow compilation by others, but the addition of atbeginend is sufficient to give the error.  \documentclass[a4paper,12pt]{book} \usepackage{atbeginend} \usepackage[figure,tworuled,linesnumbered]{algorithm2e} \usepackage{subcaption} \usepackage{etoolbox} \AtBeginEnvironment{algorithm}{%etoolbox   \captionsetup{margin={-\algomargin,\algomargin}}% } \begin{document} \begin{algorithm} \DontPrintSemicolon $f_1$ = Fase a calcular\; \tcp{Início e fim do período considerado} $t_1$ = Idade química do concreto na fase anterior à $f_1$\; $t_2$ = Idade química do concreto na fase $f_1$\; \caption{Cálculo das perdas por fluência do concreto para uma fase} \end{algorithm} \end{document}


Mount cifs Network Drive: write permissions and chown

I have access to a cifs network drive. When I mount it under my OSX machine, I can read and write from and to it.   When I mount the drive in ubuntu, using:  sudo mount -t cifs -o username=${USER},password=${PASSWORD} //server-address/folder /mount/path/on/ubuntu   I am not able to write to the network drive, but I can read from it. I have checked the permissions and owner of the mount folder, they look like:  4.0K drwxr-xr-x  4 root root    0 Nov 12  2010 Mounted_folder   I cannot change the owner, because I get the error:  chown: changing ownership of `/Volumes/Mounted_folder': Not a directory   When I descend deeper into the network drive, and change the ownership there, I get the error that I have no permission to change the folder´s owner.  What should I do to activate my write permission?


Cannot boot Thinkpad T470s from any media after installing Ubuntu 16.04 (\EFI\BOOT\mmx64.efi - Not Found)

I needed to downgrade from 18.04 to 16.04 in order to make use of Intel's OpenCL. I put Ubuntu 16.04 on a USB and configured the USB with the "Startup Disk Creator" tool. I booted my  laptop using the installation media, and all went fine until it needed to shut down and restart to complete the installation. I got a black screen with some white text telling me that the core temperatures were too high. I powered down the laptop, and then when I booted again, I was brought to the BIOS "choose startup device" menu. I selected the recently installed Ubuntu option, but the screen just flashed and went back to the selection menu.  I tried to boot from the (same) USB again, and reformatted it first this time, to see if I could just re-install in a colder area, but I got this very strange message:     Failed to open \EFI\BOOT\mmx64.efi - Not Found Failed to load image   \EFI\BOOT\mmx64.efi: Not Found Failed to start MokManager: Not Found   Something has gone seriously wrong: import_mok_state() failed: Not Found     It should be looking for the grub EFI file, shouldn't it? I have tried wiping the USB and putting the image back on with the startup creator, but I get the same error.   Under EFI/BOOT/ on USB device, I have the following files: BOOTx64.EFI and grubx64.efi. I have tried copying the grubx64.efi file and renaming it with the "mmx64.efi" name it's looking for, but I am unable to paste anything into the device. I suspect that the USB device got set to read-only after the disk startup utility completed. In which case, how could I set it to write? I have tried adjusting the permissions by right-clicking in the file explorer and going into properties, but it won't let me change it to allow write permissions. Is there a way to force this by issuing commands in a shell?  Has something gone wrong with the bootloader in my laptop's hardware? How can I repair it?


Android - Call log/ history : Retrieve a dialed number when there was no network coverage

I dialed a number when I had no network support but it does not appear in the call history of my android phone.  Is there any way to get it ? (system logs or whatever)  THanks a lot in advance, Jack


Deja Dup backup at specific time of the day?

Is there a way to backup my Ubuntu machine (14.04) at a specific time of the day using Deja Dup? I'd like to backup my computer at night when I am asleep. But it doesn't seem to give a choice for the backup time.  Any help is appreciated.


Does number of programs installed on my pc affect its speed?

I have windows xp and it has started responding very slowly, so was thinking if the various software I've installed might be affecting its speed.  PS: Even if I run one program/software at a time the same thing happens


I wanna ask you guys about extending battery. I run precise, My laptop can't work more than 1 hour, after it's fully charged. The notification after I unplug the charger only shows 0:45. How can I work with that condition?


Find all digits $a,b$ such that the number $\overline{aabb}$ is a perfect square

What is the method for finding numbers $a$ and $b$?


Method to connect to DB giving a null pointer exception

Currently I have an java object called work, that object has this method inside of it.  public void Connection(Connection conn) throws NamingException, SQLException {       // Setup the Database datasource     Context ctx = new InitialContext();     Context env = (Context) ctx.lookup("java:comp/env");     DataSource ds = (DataSource) env.lookup("jdbc/carRentalSystem");     conn = ds.getConnection(); }   I am calling this method inside of my servlet to connect to my DB and add a table row. For what ever reason I keep getting a null pointer exception when running it through debug. Can anyone guide me how to get this to work properly?  protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {      // Obtain submitted form data      Work work = new Work();     String firstName = req.getParameter("First_Name");     String lastName = req.getParameter("Last_Name");     String username = req.getParameter("User_Name");     String email = req.getParameter("Email_Address");     String password = req.getParameter("Password");      ResultSet rs = null;     Connection conn = null;     Statement st = null;      try {         work.Connection(conn);           // Prepare the SQL statmenet to insert the values          PreparedStatement stmt = conn.prepareStatement("INSERT INTO userdetails(First_Name, Last_Name, Email_Address, Password, User_Name)  VALUES (?,?,?,?,?)");         stmt.setString(1, firstName);         stmt.setString(2, lastName);         stmt.setString(3, email);         stmt.setString(4, password);         stmt.setString(5, username);          // Execute the insert         stmt.executeUpdate();         conn.close();          // Dispatch into success page         RequestDispatcher requestDispatcher = req.getRequestDispatcher("login.jsp");         requestDispatcher.forward(req, res);     } catch (Exception e) {         work.ErrorHome(req, res, e);     } finally {         try {             if (st != null)                 st.close();         } catch (java.sql.SQLException e) {         }         try {             if (conn != null)                 conn.close();         } catch (java.sql.SQLException e) {         }         try {             if (rs != null)                 rs.close();         } catch (java.sql.SQLException e) {         }     } }   }


Ajax file uploading to php file gives error 4

in my web page i've got this form:   <form style="width:100%; clear:both; margin-top:50px; background:#fff; border:1px solid green" id="upload_form" enctype="multipart/form-data" class="form" action="" method="post">     <fieldset>         <input name="somefield" style="display:none" value="">

                 Upload                 <input  type="file" name="upload" id="upload" required accept=".pdf, .doc"/>

                 Language                  <select name="language">                                  </select>

                 Category                  <select name="category">                                   </select>

                 <input style="margin-top:22px; " name="submit2" class="button" type="submit" value="Save" />

     </fieldset> </form>   As you can see there is a Files input and two dropdown. I need to pass these informations to a php file called 'upload' via Ajax.  so i write this script in Jquery:       $(document).ready(function()      {           // Form Upload         var uploadForm = $("#upload_form");         var formData = new FormData(uploadForm[0]);         // submit action         uploadForm.submit(function(e) {             e.preventDefault();              $.ajax({                 url: 'upload.php',                 data: formData,                 type: 'POST',                 contentType: false,                 processData: false,                 success: function(d) {                     alert(d);                 }             });          });              }  );    And for testing this is what there's in my upload.php file  print_r($_FILES); die(); // Testing    In the alert box i receive this output:    Array (     [upload] => Array         (             [name] =>              [type] =>              [tmp_name] =>              [error] => 4 // In the documentation the error 4 is for file not uploaded             [size] => 0         )  )   How can i submit all the form in the same Ajax Call? Is this the correct way to do it? Should i set two different ajax call?  Thanks for all the help.


Possible to run graphical sessions on multiple TTYs?

On a default Ubuntu (15.04) installation, We have 7 TTYs that we can switch with Ctrl+Alt+F1 (or F2 - F7), where TTY1-6 are terminals and TTY7 is the graphical X session.  I would like to have more than one TTY with graphical login, so e.g. make TTY6 an additional GUI terminal.   Is this possible and if yes, how do I set it up and are there restrictions (like don't log into the same account graphically twice)? And when I manually start an x session in a TTY, how do I quit that graphical session again afterwards and revert the TTY back to a terminal?


How to Compare two DataTables and Return another DataTable3 with the rows that only exist in the second DataTable?

I have two DataTables DT1 y DT2. DT1 has two rows and DT2 has three rows. In both DataTables row1 and row 2 have the same columns and values. But row3 not exist in the DT1, it will be my result.  DT1: row1, row2  DT2: row1, row2, row3     Res: DT3: row3


Check weather internet is available or not

I need some help with my html code. I need to integrate javascript in it which upon loading checks whether internet is available or not. If active it should perform specific task, else it should show "no internet".   `<html>  <head>  </head>  <body onload="myClickHandler();         startTime()"> <script language="JavaScript">         var t;         document.onclick = myClickHandler;         function myClickHandler() {             clearTimeout(t);             t = setTimeout("location.href='index.html'", 60000);            //for refreshing the page in every 60 sec.         } </script> <h1> test </h1> <script type="text/javascript"> var url = "https://www.google.co.in";   var img = new Image();   img.src = url;      img.onerror = function()  {     // If the server is down, do that. alert ("no connection");         }  img.onload = function() {     // If the server is up, do this.  //some task to perform.   return true;   } </script> </body> </html>`       This is what i code, but page is keep on loading after the performance also we need to manually stop the loading.


Make a bootable internal drive to install Ubuntu on current drive?

Is it possible to mount/burn Ubuntu 10.10 on a clean Drive, so that I can boot using that drive with the ISO image and install the OS on my other internal drive, while currently being in Try Ubuntu state?   My problems is that the DVD drive is corrupted and does not burn ISO properly; after install the hard drive wont boot. The only way is to use that CD to get my computer running in Try Ubuntu state.   Downloaded the new Ubuntu 10.10 ISO and trying to figure out how to make my 2nd internal hard drive become a bootable device so I can choose from to boot in BIOS.


How to prove that in a linear model with an interaction term, centering the covariates doesn't impact the estimate of interaction coefficient?

So if the model is $y_i = \beta_0 + \beta_1 x_{i1} +  \beta_2 x_{i2} + \beta_{12} x_{i1} x_{i2} + \epsilon_i$, how can it be proved that the estimate and standard error for $\beta_{12}$ the same if we center $x_{.1}$ and $x_{.2}$ ?


I was try to plot the Poisson distribution as a discrete graph and only found continuous graph examples like this:    Formula is:  &space;0" target="blank">&space;0" title="P{\lambda}(k) = \frac{\lambda^k}{k!}e^{-\lambda} \quad for \quad k \in \mathbb{N}_0,\quad \lambda > 0" />  How can I plot the discrete graph?


How to represent kWh usage by year against average temperature?


Let $f\in C^{\infty}(\mathbb{R},\mathbb{R})$ such that $f(x)=0$ on $\mathbb{R}$\ $(-1,1)$. Prove that there exists $n\in\mathbb{N}$ such that $f^{(n)}$ has at least n+1 zeros on $(-1,1)$  My attempt :   Assume $f$ is strictly positive  (if not n=0 works). Let $Z(f^{(n)})$ the number of zeros of $f^{(n)}$ on $(-1,1)$. Then we have: $$ \forall n\in\mathbb{N}:\;f^{(n)}(-1)=f^{(n)}(1)=0 $$ so that iterating the Rolle theorem to the successive derivatives of f we have  $$  \;Z(f^{(k+1)}) \geq Z(f^{(k)}) +1 $$ thus, by induction : $$ \forall n\in\mathbb{N}: \;Z(f^{(n+1)}) \geq Z(f^{(n)}) +1 $$ Therefore, $$ Z(f^{(n)}) \geq n $$ How can I find an another zero ?   I'm still looking for an another proof which does not use the lemma ..,  Thank you in advance.


How to deal with an error such as "Coefficients: 14 not defined because of singularities" in R?

When doing a GLM and you get the "not defined because of singularities" error in the anova output, how does one counteract this error from happening?   Some have suggested that it is due to collinearity between covariates or that one of the levels is not present in the dataset (see: )  If I wanted to see which "particular treatment" is driving the model and I have 4 levels of treatment: Treat 1, Treat 2, Treat 3 & Treat 4, which are recorded in my spreadsheet as: when Treat 1 is 1 the rest are zero, when Treat 2 is 1 the rest are zero, etc., what would I have to do?


I have a container  with every measurement defined in 'mm' for printing purposes. However, I want to show its preview inside a 600px wide block with perfect fit. What would be the best way to scale it down?


Any hints on how to find the following limit ?.  I haven't been able to figure it out still. $$ \lim_{n \to \infty}\left(\, 1 - \frac{1}{3}\, \right)^{2} \left(\, 1 - \frac{1}{6}\, \right)^{2}\left(\, 1 - \frac{1}{10}\, \right)^{2}\ldots\left[\, 1 - \frac{1}{n\left(\, n + 1\, \right)/2}\, \right]^{2} $$  Pardon me if it's a silly question.  Edit: Solved upto this much   $$ \prod_{n = 2}^{\infty}\left[\, 1-\frac{2}{n\left(\, n + 1\, \right)}\, \right] = \prod_{n = 2}^{\infty}\left(\, \frac{n + 2}{n + 1}\,\frac{n - 1}{n}\, \right) $$  I did'nt notice most of the terms cancel out.


Match everything after char occurs 5 times and before 6th

i would like to get 847F56B42427DCCD3CB311F905BBEF2097F3AA5F  from "ImageURL": "http://cloud-3.steamusercontent.com/ugc/929312733724516985/847F56B42427DCCD3CB311F905BBEF2097F3AA5F/",  i allready found the regex for this (?<=\/ugc\/.*?\/)(.*.)(?=(\/"))  But Java doesn't accept the "*" in the lookbehind and i struggle to find another solution. The url is always the same, only the numbers after ".../ugc/" are changing.


How to store unicode encoded string (JSON) in database?

In my web app I need to store JSON in one of the database fields (just one field). On the backend side (PHP) I am converting array to json via json_encode().  The output of the above is:  [{"przyczyna":"Niezgodno\u015b\u0107"}]   Which is encoded:  [{"przyczyna":"Niezgodność"}]   And this is correct.  Then I am sending this string to my database via mysqli (standard $mysqli->query()).   And when I go to my database I can see that the field has value:  [{"przyczyna":"Niezgodnou015bu0107"}]   The backslashes are gone and I can't properly decode it. How can I upload this to my database without backslashed being stripped? On the PHP side and database (MySQL) I am using utf8 coding. I tried to use utf8mb4 but the result was the same.


I've a problem with GPU activation in blender. I've found same problem  already, however it didn't help.  I've a GeForce 750Ti graphics card with proprietary drivers installed (not from site but from repo) version 334.  I've also installed nvidia-cuda-toolkit package. Nothing helps.  Is there any way to run blender in a verbose mode from console to find out what's wrong in cuda detection?


How do I report a bug on Launchpad when I don't know which package it affects? I tried just reporting it directly to "Ubuntu", but "Report a Bug" on  just redirects to  rather than a form for filling out a bug.  In my particular case this is a bug with  in /etc/sysctl.conf. I have no clue in the world which package would have bugs for this configuration file.


Wildcard tags should show all pulled tags and not just the main one

In this case I'm filtering by the tag [tag:css*], but it's showing this as [css*] and showing the  tag's exerpt.


Process Priority value is different in procfs

For example, let's examine the value of PRI of firefox with ps, and then see what is the value stored in procfs.  $ ps -o pid,comm,pri,ni 7000   PID COMMAND         PRI  NI  7000 firefox          19   0  $ cat /proc/7000/stat 7000 (firefox) S 1 6447 6447 0 -1 4194304 3162595 624998 158 10 30467 6903 3360 488 20 0 63 0 464836 9472659456 123045 18446744073709551615 94866409246720 94866409429052 140727418541056 0 0 0 0 4096 33572095 0 0 0 17 2 0 0 342 0 0 94866411526576 94866411528296 94866422095872 140727418542495 140727418542520 140727418542520 140727418544095 0   According to man proc, we will find the value of PRI in the 18th value (counting from 1), so in this case PRI = 20  I want to know why there is such difference between the output of the ps command and the value stored in the /proc stat file?


best command command to help add a line /etc/network/interfaces config file

I am new to Ubuntu and I have been researching and doing practice but I couldn't figure out exactly the correct command to help me solve my problem. I would be very grateful if someone could help me out here. I want to know how I could use nano command to add the line "dns-servers" to the /etc/network/interfaces.


Why do HSA qualifying plans have a max deductible?

In order to be eligible to make tax deductible contributions to an HSA account, you must have a qualifying HDHP (High deductible health plan). Among the requirements, is a deductible and max OOP within certain limits, which for 2016 has an upper bound of .  From my point of view, if the deductible and/or max OOP was higher than that, you still would have a "High deductible health plan". Perhaps it could be thought of as "Extremely High", but you would no longer be eligible to contribute to an HSA, which seems generally unfair to me. To make matters worse, the ACA plans available on the exchange are allowed to have a max OOP of $13,700, and after doing a quick search of them yesterday, it turns out that the majority of the plans are maxed out at $13,700, and thus are incompatible with an HSA.  What are the reasons for having an upper bound on the deductible of a qualifying HDHP? Is the fact that the exchange plans have a higher deductible just a mishap?


Is there a way to update the GPS' (Garmin nüvi 255) maps with Ubuntu?  I'm hoping for a free (as in doesn't cost anything... I already bought the darn thing) solution.  I have installed the plugin, and it works with myGarmin, however I cannot register my device because I need to install whatever Windows software (Garmin Express) it requires, and all I can find is "Purchasing maps update"...  This is my first GPS and I just want to get the most recent maps as my local streets don't show up.


How I can share wifi from my laptop for using it on Google Nexus 7? I try do it with WEP-40/128 and with WEP-128, It's work for my another laptop but not for Nexus.


Hypothesis Testing of endpoint of Uniform distribution

Let $c$ be a positive constant. Suppose I have $X$~$Unif(0,\theta)$ and I wish to test the null hypothesis $H_0: \theta \leq c$ against the alternative hypothesis $H_1:\theta > c$. Suppose I did a sample $X_1,...,X_n$ but I obsrerve them with perturbation - that is, I actually have on hand $Y_1:=X_1+\epsilon_1,...,Y_n:=X_n+\epsilon_n$ where $\epsilon_i$ are i.i.d. ~ $N(0,\sigma^2)$. How should I conduct a hypothesis testing?  Idea: I was thinking of using Likelihood ratio test, since that allows me to do hypothesis testing on a composite null hypothesis. I can take into account the errors in my likelihood function by convolving the uniform with the normal. However, when I want to define critical values, I have difficulty because I have no idea how to approximate the test statistic to any distribution and hence derive rejection regions.  Idea 2: Rao's score test, since here I know how to approximate the test statistic distribution for large sample size, but the only form of Rao's test I know involves point null hypothesis (i.e. testing $\theta = c$) - sadly, my bound $c$ is conservative upper bound, so there is a large chance that $\theta$ is smaller than $c$ and I dont want this case to be a rejection case.  Other ideas would also be appreciated.


I have been working with the algorithm gdalogr:warpreprojectand have failed several times in the parameter in the title. Now, the problem is solved. It was about the EXTRA parameter. I read 3 books, and I know the explanation, but what I do not understand is the fact that it accepts an empty string. Furthermore, it ONLY accepts that empty string. My code is:   reproj = processing.runalg("gdalogr:warpreproject", raster, "EPSG: 25830", "EPSG:4326", '0', 0, 0, 0, 0, 2, 1, 1, False, 1, False, "", "G:\\pyQGIS\\MIRAR_COMP\\nuevo.tif")   Can anybody explain how does this parameter work?


jquery event handler inside updatepanel not working after postback

I have a div with "id=ShowDetails". In my javascript I have this:      $(document).ready(function () {        UIactions();     });      function UIactions () {         $('#ShowDetails').click(function () {             alert("bingo");           }      });   The div is inside the update panel that gets posted back. When the page loads, if I click the div, I get the bingo but after the postback, I don't. Any idea why?  Thanks.


Show that the polynomial $x^3-xy^2+y+1$ is irreducible in $\mathbb{Q}[x,y]$

I know that $\mathbb{Q}[y][x]=\mathbb{Q}[y,x]$; thus, we can see this polynomial as a polynomial with variable $x$ and with coefficients in $\mathbb{Q}[y]$. Someone explains to me that we could use Gauss's Lemma to reduce to proving irreducibility over the $\mathbb{Q}(x)[y]$ where $\mathbb{Q}(x)$ is the fraction field and after apply Eisenstein for the prime $y+1$. I am blocked for a while on this problem.   Could anyone solve this problem?


I want to compute $$l = \lim_{n\to\infty} \frac{1}{n^2} \left(\frac{2}{1} + \frac{9}{4}  +\ ... \ +\frac{(n+1)^n}{n^{n-1}}\right)$$ My first thought was to use Riemann's sums, that is $\lim \frac{1}{n} \sum_{k=1}^n f(k/n) = \int_0^1 f(x)\ dx$. In order to apply this identity, I did this $$l = \lim_{n\to\infty} \frac{1}{n^2} \sum_{k=1}^n \frac{(k+1)^k}{k^{k-1}}  = \frac{1}{n^2}  \sum_{k=1}^n k\frac{(k+1)^k}{k^{k}}  = \frac{1}{n}  \sum_{k=1}^n \frac{k}{n}\left( 1 + \frac{1}{k}\right)^k  $$ But from this, I don't know how to follow. Any help is welcome. Also I want to say that maybe this idea doesn't work to compute the limit. In that case, I will appreciate any hint to calculate $l$. Thanks in advance.


When transiting between two flights, will my luggage be automatically transferred?

I have flight where I need to move from airplane to another. Do I need to check out my luggage and then check it in again, or will it be automatically transferred to another plane?


C99 stdint.h header and MS Visual Studio

To my amazement I just discovered that the C99 stdint.h is missing from MS Visual Studio 2003 upwards.  I'm sure they have their reasons, but does anyone know where I can download a copy?  Without this header I have no definitions for useful types such as uint32_t, etc.


I made a total mistake here. Anyway I ran chmod -R 777 /* and immediately regretted my decision.  I had to boot into single user mode to and ran chmod -R 755 /etc/* in order to login to the server.  The only problem is ssh now and obvious security issues.  How do I get SSH working again?


Book with short stories about travel gates, and a lizard race with 12 digits

I read a book many years ago that had a set of short stories about a set of travel gates. It started with the invention and went through many uses. The final story was about a lizard race with 12 digits that took over things at some point noting it was odd to use a 10 digit number system.


no permission to modify boot file rc.local

I'm trying to add a program path /usr/bin/xscreensaver-demo, to file so my screensaver will start at boot. But I can't save it. I don't have the permission to change it and save it. I have tried this in both Brackets and gedit.  /etc/rc.local:  # By default this script does nothing /usr/bin/xscreensaver-demo exit 0   I thought of using a sudo command in the terminal but I don't know what command to execute to edit that file with superuser privilege and save it.


How would you write a non-recursive algorithm to calculate factorials?

How would you write a non-recursive algorithm to compute n!?


Why are methods always added to the prototype and not defined in the constructor function?

Most guides on JavaScript explain object creation using constructor functions as follows:  let Person = function (fn, ln) {     this.fn = fn;     this.ln = ln; }; Person.prototype.greet = function () {     console.log("hello "+ this.fn+ " "+ this.ln) };   That is: fields are defined in the constructor function while methods are added to the prototype.  Now I understand that the properties defined inside the constructor function will form N copies for N instances, while those on the prototype will have 1 copy shared among all N instances. So it makes sense that properties are defined inside the constructor, as we obviously don't want the copies to be sharing mutable properties like arrays etc.   What I don't get is why the methods aren't defined in the constructor function too. Like this:  let Person = function (fn, ln) {     this.fn = fn;     this.ln = ln;     this.greet = function () {        console.log("hello "+ this.fn+ " "+ this.ln)     }; };   I understand that it will result in there being a copy for each instance and the methods belonging to the object itself rather than its parent/prototype, but is there any particular downside to it?  It just seems a lot more coherent and similar to Ruby etc. style-wise.


Coefficients of Color Potential in Quarks

I was wondering if there was a relation between the fractional coefficients $$2/3, 1/3$$ obtained when calculating color potential for quarks and the value of electric charge for the up and down quark. Is there a reason these numbers are the same or is it just a coincidence?


What is a current replacement of gnome-open command (generic open of files based on the type)?  Before:   gnome-open mydoc.pdf  # opened PDF in default application   Now:  gnome-open The program 'gnome-open' is currently not installed.  You can install it by typing: sudo apt-get install libgnome2-0


How to set a memory limit for a specific process?

I tried to execute mpiexec -16 ... on a 384 GB RAM server, but it induced OOM Killer and was aborted.   How can I set a memory limit for mpiexec execution?  I know ulimit, but it might affect other processes.   Thank you.


In this problem, we give an algorithm for computing $\sqrt{2}$. Let $a_1$ = 2, and define $a_{n+1}$ = $\frac{1}{2} (a_n + \frac{2}{a_n})$ for n ≥1.  (a) Prove that $a_n^2$ ≥ 2 for all n. (Use proof by induction.)  Here I have: Let $a_{n+1} = \frac{1}{2}(a_{n}+\frac{2}{a_{n}})$ for all n ≥1. Therefore, $a_{n+1-1} = \frac{1}{2}(a_{n-1}+\frac{2}{a_{n-1}}) = a_n.$ Therefore, $a_n^2 = (\frac{1}{2}(a_{n-1}+\frac{2}{a_{n-1}}))^2 = (\frac{1}{2}a_{n-1}+\frac{1}{a_{n-1}})^2 = \frac{1}{4}a_{n-1}^2 + \frac{a_{n-1}}{2a_{n-1}} + \frac{a_{n-1}}{2a_{n-1}} + \frac{1}{a_{n-1}^2} = \frac{a_{n-1}^4+4}{4a_{n-1}^2}+1$. Additional Thoughts: if n≥1 for $a_{n+1}$ then n-1≥0 for $a_n$. Since $a_1$=2, then all $(n-1)^2$≥0, so $n^2-2n+1$≥0 = $n^2-2n$≥1 = $n(n-2)$≥1,  such that all n≥3 or n≥1. I have no clue if this is how I should be approaching it or not, I just wanted to try something. Please let me know what I need to do for this and the following parts, such as hints! Thanks.  (b) Use part (a) and equation (1) to prove that $a_n − a_{n+1}$ ≥ 0 for all n.   (c) Conclude that the sequence $(a_n)$ converges.   (d) Prove that $\lim_{n\to\infty} a_n = \sqrt{2}$.   (e) Modify the sequence $(a_n)$ so that it converges to $\sqrt{c}$. No formal proof is required for this part, but you should give a brief justification.


What is "OP" referring to for nested citation?

I've already read through this , and I know "OP" stands for Original Poster. Now I would like to know what is "OP" referring to for nested citation?  Assume,   asker A posted a question (question_1) where an article is cited,   and then Answerer B posted an answer to that question  and then asker C posted another question (question_2) where question_1 is cited.  Now, when answerer D use the term "OP" in answer to question_2, what is "OP" referring to?  when answerer B use the term "OP" in answer to question_1, what is "OP" referring to?


Changed hostname, closed before changing hosts, now sudo is broken, catch-22!

I'm using Lubuntu 12.04.  I was trying to change my computer name to "main" and I messed up, I'm not sure what to do now.  I was following the directions on .  Here's what I did:  sudo leafpad /etc/hostname   I changed the name, then stupidly closed the file, before changing "/etc/hosts"  Now when I try to move on to the next step (sudo leafpad /etc/hosts), or try any command that begins with "sudo" I get this error:  sudo: unable to resolve host main No protocol specified No protocol specified   I can see that the problem is that I've changed the hostname, so the computer's bewildered by my efforts to use sudo because now hostname and hosts don't match. All I need to do is change the name in hosts, but of course I can't do that without sudo.  Any ideas?


If adjusted R squared is superior to R squared, then why do statistical software continue to report the latter? Is there any kind of situation when a researcher may prefer to use R squared instead of adjusted R squared?


How can I create a 3D shapefile containing line features or point features? I have to extract the elevations from a DEM and then export a shapefile containing 3D features. I'm currently working with QGIS 2.8.4


GUI program to create partition backup image no larger than its files?

I like 'Disks' (gnome-disk-utility) and its ability to create backups of system partitions.    But at some point I read on the internet about a program that would create such images that are not as large as the whole partition, but only as large as the files on it. Now I cannot find it again.  Is there such an utility?


Does SE standardise [!] on American English or is British English allowed too?

I had a recent edit which "corrected" my spellings to American English. Should I care?


Help, Error : Type 'sudo' is not known on line 1 in source list /etc/apt/sources.list.d/mono-official-stable.list

I am still new to Linux and when I was trying to update Mono, I believe the part where I had to copy and paste, the echo - tee command lines is where my mistake happened. Anyhow, I can't do anything in the terminal without getting this error. I read in other forums and their solutions didn't help. I also cant paste my,  cat /etc/apt/sources.list, because with all the links, this website assumes I am spamming. Typing in: cat /etc/apt/sources.list | nc termbin.com 9999   gives: https://termbin.com/t1noy  which seems to change every time I type it in. Finally, typing in:   sudo nano /etc/apt/sources.list.d/mono-official-stable.list  returns: sudo apt-get update  Thank you!


In Linux, let us assume we have a directory with the following properties:  drwx---r-x 29 user1      group1 4096 Jun 22 14:11 dir1   can I, as user2 having group group1, navigate into dir1?   Since other has r and x permissions, I was thinking I could, but I could not navigate into the directory and got the following error:  -bash: cd: dir1/: Permission denied   What am I missing?


I really want to know what is proper the cpu temperature for my Mac book

I'm using Mac book pro 13 inch , 3.1 ghz i5 dual core.  I have set up Mac book fan control and I am able to check the temperature.  I was just surfing the internet, and the cpu temperature shows about 65-75 degree Celsius. which made the fan run  Is it normal thing to happen???  I cannot find any proper temperature for my Mac.   I also looked up at some website but it does not have my MacBook model.     please help me


In mathematical induction, does assuming $P(n)$ also assume all $P(k), 0 \leq k < n$?

I am writing a proof by mathematical induction.  I prove the base case: $n = 0$. In the inductive step I want to prove $P(n + 1)$ by assuming $P(n)$. As it turns out, to show $P(n+1)$ I need to rely on  all $P(k), 0 \leq k \leq n$.  Is this possible? Or do I need to reconsider my proof strategy?


It is possible to make a hyperref to go to page x, but how we can define a custom anchor to go a destination line?  For example:  \documentclass{article} \usepackage{lipsum}  \begin{document}   \lipsum[1]   \lipsum[2]   THE DESTINATION LINE (anchor x)   \lipsum[3]   \lipsum[4]   CLICK HERE (go to anchor x)   \lipsum[5] \end{document}   How to click on CLICK HERE and goes to the DESTINATION LINE? I mean displaying THE DESTINATION LINE as the first line in the pdf reader.


How can I have two shortcuts to FireFox in dock bar

I want to have two shortcuts to FireFox in the dock bar. However when I pull a second one to the bar, it just replaces the old one and I still have one shortcut!  I want to dedicate one of the Firefoxes to my Jupyter nootbooks and the other for surfing the web, I even prefer for them to have different icons I mean two icon of Firefox in the left bar:


Why some people think that "pretty sure" means "totally sure"?

I was talking with a friend of mine when she told me that "pretty sure" means something like "more or less sure". I've always known that it meant "totally sure" and was astonished to find this out.  Thinking about it, I could not remember why or how I learned the wrong meaning and looking on the Internet I found more people that thought the same before being corrected.  Edit: I do know that there is a question answering the meaning of the expression. What I'm trying to find out with this one is the reason why some people like me learned the wrong meaning and was sure it was correct. Sorry if I wasn't clear enough.   What could be the origin of such misunderstanding?


Problems with dates in MongoDB / Windows 10

I'm having a weird issue with MongoDB in Windows 10. I've migrated a database that's working perfectly fine in MacOS and Linux to a Windows 10 machine.  Same mongodb version : 3.4.7  The issue seems to be related to one that other people experienced but it's not exactly the same ( )  I get an error saying "gmtime failed - your system doesn't support dates before 1970" when I call a view that uses $dateToString in the projection.  And I also get only 101 records if I call the same view via Robo 3T.  But the difference in my case is that I don't have dates before 1970 in this particular collection.  So I ran this code on Robo 3T to try something, and I can't understand the result:  db.getCollection('vehicles').find({}).forEach(function(vehicle){    var date = new Date(vehicle.dates.entry);    print(date);    print(date.getYear());    })   This is the result for one record:  Fri Oct 02 2015 00:00:00 GMT+0100 (GMT Standard Time) 115   So the date seems to be constructed properly but the getYear() returns 115 instead of 2015.  The same code on MacOS or Linux works as expected.  Any ideas? Thanks


If $3$ divides $a^2 + b^2$, then $3$ divides $a$ and $3$ divides $b$

This is a part from a homework. I solved all examples apart from this one. So the task is: We know that $3$ divides $a^2 + b^2$. Prove that $3$ divides $a$ and $3$ divides $b$. I cannot think of anything useful. I know that $a^2 + b^2 = (a + b)^2 - 2ab$, but I don't see how it can help me :(  Best regards, Petar


Cartoon movie where the main character had a robotic arm

During the 90's I saw parts of a science-fiction cartoon on TV. I don't remember for sure, but the graphics resembled , and I think it was American, but again, I'm not sure.  What I do remember is that the main character had a robot arm that looked just like a regular one. I think the humans were at war with robots controlled by an evil overlord, and someone believed the main character was also a robot because of his arm.  Another relevant memory was related to the bad guy (or one of the bad guys): in the end, it turns out it was a bratty teen who thought it was a game or who didn't realize exactly what he did.    [edit] Based on the feedback received so far, I need to add that:   this was a cartoon, not anime / japanese animation.  It was a movie, not a cartoon series. The robots were more like androids / humanoid robots, not mecha.   I also remembered a female protagonist. She's the one who notices the main character had a robotic arm after he has some sort of accident and robotic parts become visible beneath his arm skin.   Do these details sound familiar to anyone?


I need to create an NS record for a domain that is a CNAME, for the purpose of having two domains pointed at one IP, and not having to maintain the current IP address in two different places.  The DNS provider for this domain is DynDNS, but they block this operation:     CNAME cannot be created with label   that is equal to zone name   I can do this with another domain whose DNS is served by 1and1:  root@srv-ubuntu:~# dig myseconddomain.co.uk  ; <<>> DiG 9.4.2-P1 <<>> myseconddomain.co.uk ;; global options:  printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61795 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0  ;; QUESTION SECTION: ;myseconddomain.co.uk.             IN      A  ;; ANSWER SECTION: myseconddomain.co.uk.      71605   IN      CNAME   myfirstdomain.co.uk. myfirstdomain.co.uk.     59      IN      A       www.xxx.yyy.zzz  ;; Query time: 298 msec ;; SERVER: 10.0.0.10#53(10.0.0.10) ;; WHEN: Tue Aug 18 14:17:26 2009 ;; MSG SIZE  rcvd: 78   Is this a breach of the RFCs or does DynDNS have a legitimate reason for blocking this action?  Followup Thanks to the two answers already posted I now know that 1and1 IS breaching RFCs to do this. However it does work and they seem to support it. For a company that hosts so many domains it seems very odd that they get away with doing this on such a massive scale without objection.  More followup  The output of "dig myseconddomain.co.uk ns" as requested.  root@srv-ubuntu:~# dig myseconddomain.co.uk ns  ; <<>> DiG 9.4.2-P1 <<>> myseconddomain.co.uk ns ;; global options:  printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18085 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2  ;; QUESTION SECTION: ; myseconddomain.co.uk.             IN      NS  ;; ANSWER SECTION: myseconddomain.co.uk.      4798    IN      NS      ns67.1and1.co.uk. myseconddomain.co.uk.      4798    IN      NS      ns68.1and1.co.uk.  ;; ADDITIONAL SECTION: ns67.1and1.co.uk.       78798   IN      A       195.20.224.201 ns68.1and1.co.uk.       86400   IN      A       212.227.123.89  ;; Query time: 59 msec ;; SERVER: 10.0.0.10#53(10.0.0.10) ;; WHEN: Wed Aug 19 12:54:58 2009 ;; MSG SIZE  rcvd: 111


Let $a, b$ and $c$ be posetive real numbers such that $abc=1$. I want to prove this inquality $$\sum_{cyc}\frac{ab}{a^5+b^5+ab}\le 1$$ I used AGM inequality but I didn't prove it.   Which should I use inequality? So thanks