I am dealing with multiclass classification problem where I have 10 classes to predict. I came across Logistic regression model in scikit-learn which can be applied to multiclass settings as well. The parameter 'multi_class' in logistic regression function can take two values 'ovr' and 'multinomial'.   What's the difference between ovr (one vs rest ) and multinomial in terms of logistic regression. I am using logloss as my evaluation metric. I applied both 'ovr' and 'multinomial' to my problem, so far 'ovr' gives less logloss value. But I really want to know how both works.
Lets say we have a dependent variable $Y$ with few categories and set of independent variables.    What are the advantages of multinomial logistic regression over set of binary logistic regressions (i.e. )? By set of binary logistic regression I mean that for each category $y_{i} \in Y$ we build separate binary logistic regression model with target=1 when $Y=y_{i}$ and 0 otherwise.
Is there a single word to describe a solution that hasn't been optimized? I am working with some code, and I would like to describe the difference in its performance when it is optimized versus when it is not optimized. Unfortunately, I can't find a word to describe the code before it is optimized; "sub-optimal" might work, but I want to emphasize that this is the first iteration of the code. If "unoptimized" were a word, I would use that, but I haven't found any references to it in any dictionary.  Perhaps "raw" or "original"? What is syntax highlighting and how does it work? I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange? Proof $1+2+3+4+\cdots+n = \frac{n\times(n+1)}2$ The storage on my iPhone is nearly full. Most of the space is used by apps. I'd like to see which apps consume the most space on my device.  Is there a way to get a list of the apps with their corresponding used space? By "used space I mean the installation size (bonus for added user data). Are Stormtroopers paid or rewarded in any way for their service? What are Vertex and Pixel shaders? share login/logout sessions across two installs? Reviewer Stats showing wrong count I have totally reviewed 716 suggested edits, but it shows I've approved 486 suggestions and rejected 228.     I searched about it on meta. But, can't get solution. I thought that some of my reviewed posts might get deleted. So, I went to the review history and found      .   It should be a bug. I want to display the pages 'famous' and 'mschief'.  Using this code, WP_query() doesn't return any result:  $args = array( 'post_type' =&gt; 'page', 'pagename' =&gt; 'famous,mschief', 'posts_per_page' =&gt; 3 );   This code returns one of the 2 pages:  $args = array( 'post_type' =&gt; 'page', 'pagename=famous,mschief', );   And this code returns the 2 pages correctly:  $args = array( 'post_type' =&gt; 'page', 'pagename=famous,mschief', 'posts_per_page' =&gt; 3 );   Why does the first piece of code (the only correct one to me) doesn't work? And why the two others produce these results? How is a second measured? And why is it measured that way? The earth's rotation around itself (one rotation around Earth's own axis) doesn't take exactly 24 hours. It off by some seconds which becomes somewhere around 6 hours per year and 1 day in 4 years(leap year), which brings the question why didn't we modify the measurement of 1 second ever so slightly so as to avoid leap years altogether.   Well how is 1 second measured exactly?  says      the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. []   Well, why is it measured that way? Is there any technical reason like it is easy to measure and can be standardized easily? Or is it really possible to modify the measurement of time? Is transferring to another university an option for an unhappy PhD student? Floquet and Bloch's theorems : connection? It is often stated that  and  are equivalent, even the Bloch's theorem is often referred as Floquet-Bloch theorem.  However, it seems quite confusing to me since the former involves a second order differential equation (Schroedinger equation with a periodic potential) while the latter is defined for a first order one.  Can someone clarify this to me? Also it would be nice if I can get references that connect the two. Remmina remoteapp over RDP I was wondering how to use remmina to open applications on a Windows machine over rdp using remoteapp (or seamless or whatever it's actually called).  I've already used Kim Knight's  to set up remoteapp on a Windows 7 machine and I can connect and run remote apps fine from another windows box.  Allegedly FreeRDP (which Remmina uses for its RDP Plugin) has support for remoteapp. I'm not sure how to make use of it though. I can't find any examples of people actually doing this online but there is a , from which I can infer that there is some way to run remote apps.   I've tried many combinations of settings for Client, Startup Program and Startup Path in the Advanced tab when configuring an RDP connection in Remmina, but I can't make it work. I can connect to Windows boxes with RDP just fine, just not running a remoteapp. Relativistic speed/energy relation. Is this correct? Prove by mathematical induction that $2^{3^n}+1$ is divisible by $3^{n+1}$ How to reinstall yum? I made a big mistake: I removed yum. So now when I for example run the following it gives me an error:  $ yum clean all yum command not found.   I can download the package succesfully:  wget mirror.centos.org/centos/6/os/i386/Packages/yum-3.2.29-40.el6.centos.noarch.rpm --2014-01-15 15:42:59--  http://mirror.centos.org/centos/6/os/i386/Packages/yum-3.2.29-40.el6.centos.noarch.rpm Resolving mirror.centos.org... 192.133.139.3 Connecting to mirror.centos.org|192.133.139.3|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 1019540 (996K) [application/x-rpm] Saving to: “yum-3.2.29-40.el6.centos.noarch.rpm.1”  100%[====================================================================================================================&gt;] 1,019,540    649K/s   in 1.5s  2014-01-15 15:43:01 (649 KB/s) - “yum-3.2.29-40.el6.centos.noarch.rpm.1” saved [1019540/1019540]   Trying to install the downloaded package gives the following error:  # rpm -ivh yum-3.2.29-40.el6.centos.noarch.rpm Preparing...                ########################################### [100%]     file /usr/lib/python2.6/site-packages/yum/__init__.py from install of yum-3.2.29-40.el6.centos.noarch conflicts with file from package yum-3.2.29-30.el6.centos.noarch [...] file /usr/share/yum-cli/yummain.pyo from install of yum-3.2.29-40.el6.centos.noarch conflicts with file from package yum-3.2.29-30.el6.centos.noarch   There is no directory "yum" in /usr/bin.  When I use the command "rpm -qa | grep yum".  yum-metadata-parser-1.1.2-16.el6.x86_64 yum-plugin-fastestmirror-1.1.30-14.el6.noarch yum-3.2.29-30.el6.centos.noarch   The distro is CentOS 6.3. How can I reinstall yum? iPhone's Bluetooth - What? Why? How? I googled a lot and read many documents. But I can't understand the concept behind iPhone's Bluetooth technology.  In my knowledge, Bluetooth was used for:   Transferring files between devices Wireless communication for things like video gaming and earphones   Recently I tried to copy some of the photos from my old Android mobile to my iPhone 4S via Bluetooth. It's quite simple in my older phones to connect with other devices by Bluetooth for file sharing. But I can't pair other devices (even another iPhone :( ) with my iPhone 4S.   Copying songs/videos may affect their iTunes as well as their business. But what about images? Why is the usage of Bluetooth restricted and what's the use of it being able to transfer images? Is there any other way to use iPhone's Bluetooth to transfer files? Maybe using an app? But I don't want to jailbreak my device.   I'm confused about the restrictions and Apple's thinking. Do newer laptop batteries still need to be drained before recharging? 10 years ago when I was doing hardware support it was best practice to fully drain a laptop battery prior to recharging in order to maximize its life.  Is this still the case or can a battery now be recharged at any point without worrying about shortening the lifespan? Extending my Root Paritition I've Win8/Ubuntu Dual boot. I already have 4 partition so i cannot create a new partition and mount it elsewhere. So, this () question did not help.  Here's a screen shot of my Gparted (run on Ubuntu Live)   How can I extend /dev/sda6  so that  i can make use of unallocated space ?  (w/o failing my current grub) What does the '!!!' syntax mean in javascript?