Creating bathymetry surface from xyz in GRASS?
Which interpolation technique is suitable for a bathymetry of a small lake?
Setting constraints causes the location of the constrained objects/bodies not be accessible I set up 2 bodies manually &amp; assigned Copy Location constraint to one with respect to another body. Then I set up the keyframe for the guiding body &amp; then I started to view the change in the location of the constrained body. What I noticed in the 3D viewport was the constrained object moves, but when I look into its real position the values are stagnant. Why is that? I was unable to find my answer in previously asked questions by other people !! Using Rule of Three to obtain confidence interval for a binomial population I have a large population of data instances (say, 1000 instances) that are either of class1 or of class2. I would like to obtain a confidence interval for how many instances are of class1 without exhaustively checking all instances. I have randomly sampled 50 instances, and all 50 were of class1. I used the  to determine that a 95% confidence interval for the percentage that an instance is of class1 is  [0.94, 1].  From my sampling, I know that at least 50 instances are of class1. For the remaining 1000 – 50 = 950 instances whose classes are unknown, I assume I can apply the [0.94, 1] confidence interval found above. Therefore, can I conclude that, with a 95% confidence, there are at least 50 + (1000 – 50)(0.94) = 943 instances from the population of 1000 that are of class1?  If this conclusion isn’t statistically sound, how can I obtain a confidence interval for class1? How to install Opera Browser? I am trying to install opera browser from the terminal.  I downloaded the 'debian' installer because it didn't show up in software center.  It completely destroyed my software center - it is frozen and I have no idea how to fix (I have a different thread for that though).  Can I use this thing called synaptic package manager to install Opera?  or am I stuck with Firefox?    How do I install Opera Browser? How can I set default value in ActiveRecord?  I see a post from Pratik that describes an ugly, complicated chunk of code:   class Item &lt; ActiveRecord::Base     def initialize_with_defaults(attrs = nil, &amp;block)     initialize_without_defaults(attrs) do       setter = lambda { |key, value| self.send("#{key.to_s}=", value) unless         !attrs.nil? &amp;&amp; attrs.keys.map(&amp;:to_s).include?(key.to_s) }       setter.call('scheduler_type', 'hotseat')       yield self if block_given?     end   end   alias_method_chain :initialize, :defaults end   I have seen the following examples googling around:    def initialize      super     self.status = ACTIVE unless self.status   end   and    def after_initialize      return unless new_record?     self.status = ACTIVE   end   I've also seen people put it in their migration, but I'd rather see it defined in the model code.  Is there a canonical way to set default value for fields in ActiveRecord model? I'm confused about why we should change door in the Monty Hall Problem, when thinking from a different perspective  gives me equal probability.   Think about this first: if we have two doors, and one car behind one of them, then we have a 50/50 chance of choosing the right door.   Back to Monty Hall: after we pick a door, one door is opened and shows a goat, and the other door remains closed. Let's call the door we picked A and the  other closed door B. Now since 1 door has already been opened, our knowledge has changed such that the car can only be behind A or B. Therefore, the problem is equivalent to: given two closed doors (A and B) and one car, which door should be chosen (we know it's a 50/50 thing)? Then, not switching door = choosing A, and switching door = choosing B. Therefore, it seems that switching should be equally likely, instead of more likely.   Another way to think: no matter which door we choose from the three, we know BEFOREHAND that we can definitely open a door with a goat in the remaining two. Therefore, showing an open door with a goat reveals nothing new about which door has the car.   What's wrong with this thinking process? (Note that I know the argument why switching gives advantage, and I know experiments have been done to prove that. My question is why the above thinking, which seems legit, is actually wrong.) Thanks. Find the volume common to two circular cylinders, each with radius r, if the axes of the cylinders intersect at right angles. (using disk/washer)  I saw no example of this problem anywhere.. I saw an example how to solve it without calculus but I'm afraid that'll be deductions on my test.. I have the volume of a cylinder and the method of area between two curves but this is out of my reach.... I don't know what I can try... My machine is continously making udp dns traffic request. what i need to know is the PID of the process generating this traffic.  The normal way in TCP connection is to use netstat/lsof and get the process associated at the pid.  Is UDP the connection is stateles, so, when i call netastat/lsof I can see it only if the UDP socket is opened and it's sending traffic.  I have tried with lsof -i UDP and with nestat -anpue, but I can't find wich process is doing that request because i need to call lsof/netstat exactly when the udp traffic is sended, if i call lsof/netstat before/after the udp datagram is sended is impossible to view the opened UDP socket.  Call netstat/lsof exactly when 3/4 udp packet is sended is IMPOSSIBLE.  How I can identify the infamous process? I have already inspected the traffic to try to identify the sended PID from the content of the packet, but is not possible to identify it from the contect of the traffic.  Anyone can help me ?  I'm root on this machine FEDORA 12 Linux noise.company.lan 2.6.32.16-141.fc12.x86_64 #1 SMP Wed Jul 7 04:49:59 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux How do I ensure a piece of code runs only once? What is migration and how does it work? What does accepting an answer actually convey (2015 edition)? As a mod when should I vote to close content that is not flagged? I know mods are supposed to step in to quickly close seriously problematic posts and otherwise allow the community to vote to close a post.  But what about when there are four close votes on a question, and I personally feel the question should be closed but isn't worthy of mod super-mega closing? Should I cast the final vote like a normal user (even though it's technically binding) or should I sit back and wait  for the community?  For me the problem is complicated because on UX.SE we hover close to the point where there's not enough high-rep activity to quickly close posts and I was one of those high rep users that used to VtC.  Should I always treat my mod close vote as binding and reserve it for extreme situations, or should I treat my close vote as "normal" when it's the fifth and final vote anyway? adding an item to filtered table My project has a table with '+add' button and filtering. The add button opens a dialog to add item, and then to 'save' which closes it too Today I noticed the following flow:  Filter table on subject with value 'dummySubject'  Add new item with subject 'somethingelse'  save and close the new item ==&gt; the new item is shown in the table   So the outcome is that an item that does not qualify the filtering appears in the table. When I asked around I got the following answer  We don't want the new item to 'disappear' on creation just because it does not qualify the filtering. So we display it If you filter again, it will disappear as it should  I can almost understand that logic, but still it sounds wrong. I would rather have like a toaster saying 'new item create' with a 'goto' link. My question is  is the current user experience considered a reasonable one? what is the best practice way to handle such scenario?      &ndash; Wireframes created with What is an ultra-wide lens? What is the point at which a lens is considered "ultra-wide angle" vs just wide angle? Is there a place on the internet where I could find actual Star Trek episode scripts? Through the years I have purchased a few Star Trek scripts. I even have a DS9 script a buddy of mine mistakenly took off set and dazzled me with at Christmas years ago. As neat as those are to own, they are impossible to search. Is there a place on the internet where the Star Trek show or movie scripts can be obtained in digital format?  (Sometimes I remember a quote and would love to find it. From time to time the internet delivers. Occasionally it does not. I want to have a resource to find quotes as I think of them.) Proof by Induction for inequality, $\sum_{k=1}^nk^{-2}\lt2-(1/n)$ Let $n$ be a positive natural number, $n\ge 2$. Then $\displaystyle\sum_{k=1}^n \frac{1}{k^2} \lt 2 - \frac{1}{n}.$   The basis step was easy but could someone give me a hint in the right direction as to how to do the induction step?  I tried this:  $\displaystyle\sum_{k=1}^k \frac{1}{k^2} + \frac{1}{(k + 1)^2} \lt 2 - \frac{1}{k + 1}$  But it's getting me nowhere or I am doing something wrong. I am no expert so a clear explanation would be appreciated. Thanks. Shutdown from terminal without entering password? I have desktop edition of Ubuntu.  I like the Terminal so that that I prefer to shutdown my computer with the shutdown command.  However when I type shutdown now it prompts me to enter my password.Is there any way I can shutdown my computer using this command without entering my password? Monitor cell value and copy it to another cell I am looking to build a camera trap for wildlife viewing, able to capture pictures (or even videos) in decent quality to be able to identify distinct features. I do however need to be able to see the pictures in real time, so the camera would need some sort of wireless connection to a receiving device such as a phone.  I thought of using an FPV setup as used in drone racing, but the quality and range seems to be quite low, and the strengths of an analog signal seem to be latency and fps, which are both not important to me. It would be nice to have some sort of digital signal to be able to do some editing, such as storing pictures. It would also be cool to connect several cameras to one device.  Are there any solutions to this problem? Would a raspberry pi/arduino setup work in some way? Thanks! Identical creatures entering the battlefield Rayleigh-Jeans Law My question is simple, why do we believe  to be absurd? Is the Ultra-violet catastrophe incorrect or is it only because we can not create or know of a perfect emitter? I am a bit confused as to why Quanta was necessary.