I have 4TB hard drive, how to use it under both OSX, windows and linux?
Is exFAT now the best choice for an external hard drive that will be used for Windows, Mac, and Linux?
What is the difference between test set and validation set? I found this confusing when I use the neural network toolbox in Matlab. It divided the raw data set into three parts:   training set validation set test set   I notice in many training or learning algorithm, the data is often divided into 2 parts, the training set and the test set.  My questions are:   what is the difference between validation set and test set?  Is the validation set really specific to neural network? Or it is optional. To go further, is there a difference between validation and testing in context of machine learning? How can I get a pure white background in jewelry photography, without losing sparkle and shine? I've read through several threads similar to this, but I'm looking for a comparison of two options here.   I currently take photos on a raised glass platform against a white foam board background and run about 300w of lights (3 100x LEDs @ 5000k, Home Depot Specials in softboxes and umbrellas). As you can imagine, it takes me about 15 minutes of post processing to achieve a perfect white background, and sometimes I have a particular photo that I am unable to get there.  I want to upgrade to either a photography table with a translucent background that I can place a speedlight under, or a cyclorama infinity background such as the MyStudio MS20. The latter option may require an upgrade to my lighting, which I am planning to do anyways.  The idea of course is to get a blown out 255 background with no post processing, other than color correction on the jewelry or product as needed. This would cut my time after the shoot to a ridiculously small amount of time.   Which option would make my life easier?   For reference, I currently use a D5300 with a Tamron 90mm f2.8 macro lens.  This is the best shot I got after quite a lot of effort, before and after processing:      Note that the silver is not shiny like it should be, and the sparkle on the gems is lost. There is a book I read in the 1980s or 1990s from a Ca.  library. It was a hard copy not a paperback. It is not "To Outlive Eternity/Tau Zero" by Poul Anderson (I have that one). It may have been written by a woman or someone whose last name starts with an "L".  A large crew of men and women are in a new super fast space ship. They are being chased by someone and they outrun the collapse of the universe, but they have lost their home planet. They watch as the universe is reborn. They go into orbit around a planet that looks like it can support life like theirs. They are moving super fast. They look like a ring of radiation going around the planet. They put down 10 super metal markers with scientific info onto the surface of the planet. They watch the planet develop and form life like the dinosaurs and then evolve into human like life forms.  There are 2 warring countries on the planet. They block or turn off the sun to freeze the planet and force the countries to form one world government. The planet gets freezing cold and the people start to freeze. The countries agree to form one world government. The people on the ship are welcomed to the planet. Evolution of the Redundancy of the Genetic Code addtocontents not working with certain other packages This is a follow up question on   How do I change the toc dept mid document while using packages (in this case only mathtools).  An example:  \documentclass[a4paper,10pt,oneside]{book}  \usepackage{mathtools}  \begin{document}   \frontmatter             \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \setcounter{tocdepth}{3}  \tableofcontents   \mainmatter   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \appendix   \addtocontents{toc}{\setcounter{tocdepth}{0}}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}   \chapter{hello}  \section{hello}  \subsection{hello}  \subsubsection{hello}  \end{document}   This example generates an error and very strangely puts an exclamation mark in the ToC as you can see here   however when I comment out the \usepackage{mathtools} it suddenly works again or replacing it with a different package such as \usepackage[T1]{fontenc} also generates no errors.  But this is not limited to just this specific package, certain other packages also introduce the same behavior (I just took this package to keep the example small). Proving question on sets I am unable to understand this question. I have to say whether its true of false and then prove it but I can't proceed with the question unless I understand it.     Let $S$ be the set of stars in our galaxy. There is exactly the same   number of subsets of stars in our galaxy as there are functions   $f:S\rightarrow\{\alpha,\beta\}$ Infinite DeMorgan laws Let $X$ be a set and $\{Y_\alpha\}$ is infinite system of some subsets of $X$. Is it true that: $$\bigcup_\alpha(X\setminus Y_\alpha)=X\setminus\bigcap_\alpha Y_\alpha,$$ $$\bigcap_\alpha(X\setminus Y_\alpha)=X\setminus\bigcup_\alpha Y_\alpha.$$ (infinite DeMorgan laws)  Thanks a lot! How do I install nVidia graphics drivers from “X-Swat” ppa? How am I supposed to install nvidia drivers from xorg-edgers? I try  sudo add-apt-repository ppa:xorg-edgers/ppa -y sudo apt-get update sudo apt-get install nvidia-graphics-drivers-331   and I get  E: Unable to locate package nvidia-graphics-drivers-331   The   nvidia-graphics-drivers-331 for trusty, why wouldn't it install? I just installed Ubuntu 18.04 and one of my first negative impressions is the long animation of flying-in icons when opening the app menu.  Can I speed this up or disable it? Suppose $X$ and $Y$ are independent positive random variables with probability density functions $f_X$ and $f_Y$ respectively. Show that $Z=X/Y$ is absolutely continuous and find its probability density function.   $\textbf{My Thought:}$ In order to show that $Z$ is absolutely continuous, I need to show that it has a commulative distribution function. Then I can also differentiate the latter to obtain the probability density function of $Z$. I have the following calculation \begin{align*} P(X/Y\leq z)&amp;=P(X\ge zY,Y&lt;0)+P(X\le zY,Y&gt;0)\\ &amp;=\int_{-\infty}^{0}\left(\int_{yz}^{\infty}f_{X}(x)dx\right)f_{Y}(y)dy+\int_{0}^{\infty}\left(\int_{-\infty}^{yz}f_{X}(x)dx\right)f_{Y}(y)dy\\ &amp;=\int_{0}^{\infty}\left(\int_{0}^{yz}f_{X}(x)dx\right)f_{Y}(y)dy. \end{align*} Also, if $z&lt;0$, then we have that $F_Z(z)=0,$ since $X,Y$ are positive random variables. Therefore the random variable $Z$ is continuous, and we can differentiate it to obtain the probability distribution function of $Z$. We have that $f_Z(z)=0$ if $z\leq 0,$ and otherwise we have $$f_Z(z)=\int_{0}^{\infty}yf_{X}(yz)f_Y(y)dy.$$    Is my reasoning above correct?  Any feedback is much appreciated.  Thank you for your time. How to resume baking fluid simulation? It happens sometimes that after finishing bake (e.g., for fluid simulation) we wish we could continue the simulation for two more seconds :(    How to use the cached bake to continue the simulation?  We played with the settings, but with no success. Why I cannot ping 192.168.0.108 (my computer IP?) Ipconfig says that my IP is 192.168.0.108 C:\Users\vbcbu&gt;Reply from 192.168.0.108: Destination host unreachable.ip 'Reply' is not recognized as an internal or external command, operable program or batch file.  C:\Users\vbcbu&gt;ipconfig  Windows IP Configuration   Ethernet adapter Ethernet:     Media State . . . . . . . . . . . : Media disconnected    Connection-specific DNS Suffix  . :  Wireless LAN adapter Local Area Connection* 12:     Media State . . . . . . . . . . . : Media disconnected    Connection-specific DNS Suffix  . :  Wireless LAN adapter Local Area Connection* 13:     Media State . . . . . . . . . . . : Media disconnected    Connection-specific DNS Suffix  . :  Wireless LAN adapter Wi-Fi 2:     Connection-specific DNS Suffix  . : www.tendawifi.com    Link-local IPv6 Address . . . . . : fe80::3804:2d04:a591:7142%6    IPv4 Address. . . . . . . . . . . : 192.168.0.108    Subnet Mask . . . . . . . . . . . : 255.255.255.0    Default Gateway . . . . . . . . . : 192.168.0.1  Ethernet adapter Bluetooth Network Connection:     Media State . . . . . . . . . . . : Media disconnected    Connection-specific DNS Suffix  . :  C:\Users\vbcbu&gt;  I can ping router at 192.168.0.1 I can't ping 192.168.0.108 C:\Users\vbcbu&gt;ping 192.168.0.1  Pinging 192.168.0.1 with 32 bytes of data: Reply from 192.168.0.1: bytes=32 time=2ms TTL=64 Reply from 192.168.0.1: bytes=32 time=24ms TTL=64  Ping statistics for 192.168.0.1:     Packets: Sent = 2, Received = 2, Lost = 0 (0% loss), Approximate round trip times in milli-seconds:     Minimum = 2ms, Maximum = 24ms, Average = 13ms Control-C ^C C:\Users\vbcbu&gt;ping 192.168.0.8  Pinging 192.168.0.8 with 32 bytes of data: Reply from 192.168.0.108: Destination host unreachable. Reply from 192.168.0.108: Destination host unreachable. Reply from 192.168.0.108: Destination host unreachable. Reply from 192.168.0.108: Destination host unreachable.  Ping statistics for 192.168.0.8:     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),  C:\Users\vbcbu&gt;ping 192.168.0.8  Pinging 192.168.0.8 with 32 bytes of data: Reply from 192.168.0.108: Destination host unreachable. Reply from 192.168.0.108: Destination host unreachable. We're planning to upgrade an existing farm from 2007 to 2013. I learned that the best way and maybe the only way to achieve this is by migrating in two steps. 2007 to 2010 and 2010 to 2013. The actual farm is a sql-server(2008r2 64 bit) and a sperate sharepoint-server(web-frontend, etc....) I want to keep the sql-server as it is, if possible and we want to install a new 64bit host for sharepoint 2013. We will design a new branding for 2013 afterwards, so we need to keep the content, but not the layout. There's so much about migration available on the web, but Can I find something like best practises? I'm trying to install Anbox in my new Ubuntu 16.04 using instructions from  . It seemed to work, but I got no icon in my dash, so I suspect that the installation is not complete. With Synaptic  Package Manager I can see that anbox-common &amp; anbox-modules-dkms are installed, but I have no icon in my dash, so I tried running   sudo snap install --edge --devmode anbox   and got this error:  error: cannot install "anbox": Get    https://search.apps.ubuntu.com/api/v1/snaps/details/core?channel=stable&amp;fields=anon_download_url%2Carchitecture%2Cchannel%2Cdownload_sha3_384%2Csummary%2Cdescription%2Cdeltas%2Cbinary_filesize%2Cdownload_url%2Cepoch%2Cicon_url%2Clast_updated%2Cpackage_name%2Cprices%2Cpublisher%2Cratings_average%2Crevision%2Cscreenshot_urls%2Csnap_id%2Csupport_url%2Ccontact%2Ctitle%2Ccontent%2Cversion%2Corigin%2Cdeveloper_id%2Cprivate%2Cconfinement%2Cchannel_maps_list:    dial tcp: lookup search.apps.ubuntu.com on [::1]:53: read udp    [::1]:54255-&gt;[::1]:53: read: connection refused   What am I doing wrong? Why was the connection refused? According to the instructions, it seems this is the correct command to install it.  ps: I'm not that familiar with Linux, I'm more of a Windows guy, trying to learn Linux. Some people have a diamond after their username (e.g. )    What special privileges do diamond moderators have? How can I become a diamond moderator? Who are the diamond moderators?  How many are there?      For more information, see  in the .     Note: not to confuse with certain Stack Exchange employees, for example  members or "community managers", who often have diamonds as well, but are not ordinary moderators. When is it appropriate to end a sentence in a preposition? Can I apply for two Schengen visas if I have two subsequent trips within a short period? I am traveling to Germany on May 1st for an exhibition for which I have already obtained a visa and its validity is up to May 13th. I am returning on May 12th and then traveling on May 17th to UK, and from UK to Switzerland for vacation with family. As time is very short for applying for a Schengen visa again after returning on the 12th with May 13-14 being a Saturday and Sunday, can I apply for Schengen visa again and can I get 2 valid Schengen visa? Calling future method from batch class? I'm trying to install the  IDE in my Ubuntu and in the process it's asking for my root password which I don't remember. I know my  user password. How can I recover my root password? There are Recurrent Neural Networks and Recursive Neural Networks. Both are usually denoted by the same acronym: RNN. According to , Recurrent NN are in fact Recursive NN, but I don't really understand the explanation.  Moreover, I don't seem to find which is better (with examples or so) for Natural Language Processing. The fact is that, although Socher uses Recursive NN for NLP in his , I can't find a good implementation of recursive neural networks, and when I search in Google, most of the answers are about Recurrent NN.  Besides that, is there another DNN which applies better for NLP, or it depends on the NLP task? Deep Belief Nets or Stacked Autoencoders? (I don't seem to find any particular util for ConvNets in NLP, and most of the implementations are with machine vision in mind).  Finally, I would really prefer DNN implementations for C++ (better yet if it has GPU support) or Scala (better if it has Spark support) rather than Python or Matlab/Octave.  I've tried Deeplearning4j, but it's under constant development and the documentation is a little outdated and I can't seem to make it work. Too bad because it has the "black box" like way of doing things, very much like scikit-learn or Weka, which is what I really want.