When I fit a linear model in R with categorical variables of X (I have 3 levels). As R works it does not include one of these levels in the model output to avoid overfitting the model. But I need to know one of these levels estimated values how can I do this?
If a factor variable (e.g. gender with levels M and F) is used in the glm formula, dummy variable(s) are created, and can be found in the glm model summary along with their associated coefficients (e.g. genderM)  If, instead of relying on R to split up the factor in this way, the factor is encoded in a series of numeric 0/1 variables (e.g. genderM (1 for M, 0 for F), genderF (1 for F, 0 for M) and these variables are then used as numeric variables in the glm formula, would the coefficient result be any different?  Basically the question is: does R use a different coefficient calculation when working with factor variables versus numeric variables?  Follow-up question (possibly answered by the above): besides just the efficiency of letting R create dummy variables, is there any problem with re-coding factors as a series of numeric 0,1 variables and using those in the model instead?
Is there a way to see questions with a certain tag from all Stack Exchange sites? For example, I see there are questions with the  tag on Stack Overflow, but there are also such questions on Super User, Unix/Linux, and other sites in the network.  Is there a way to follow a tag across all of the Stack Exchange sites, so that one can see the global activity of a topic without visiting all the sites separately? Usage of into vs in vs inside When should 'into', 'in' and 'inside' be used?  What are the differences between the three?   For example, what are the differences between the following statements?  Are any of them incorrect?        The frog jumped into the well.   The frog jumped in the well.   The frog jumped inside the well. Azimuth and Distance, NumericalDigitize, Numerical Vertex Edit, XY tools and other plugins are not on QGIS Plugin Manager version 2.0.1 Will these plugins no longer be available in QGIS 2.0.1? How could I execute a script in Shell when a shortcut key is pressed.   Essentially what I need is when a shortcut key is pressed the script should read from a file and display that content in the terminal. On machine A I have the folder /home/a/  On machine B I have the folder /home/b/  I wish transfer all files, directories and sub-directories of /home/a in /home/b with sftp On machine A I tried the commands: sftp fibon82@machineB.com put /home/a/* /home/b/  but it doesn't work, i get the error message: &quot;skipping non-regular file /home/a/a1&quot;... [a1 is a sub-directory of a] How could I modify the put instruction? Thanks! :) EDIT: I solved using scp: scp -r /home/a/ fibon82@machineB.com:/home/b/ I showed up here to write a perfectly normal rant about misaligned pixels, and there's a big fat checkbox cluttering up the "Ask" page:    WHAT THE EEEEK IS THIS NEW ABOMINATION? How do I find the files installed by a particular package? Where is the .deb file to look at? I have installed pulseaudio-module-bluetooth using apt.  $ type pulseaudio-module-bluetooth bash: type: pulseaudio-module-bluetooth: not found $ which pulseaudio-module-bluetooth $ whereis pulseaudio-module-bluetooth pulseaudio-module-bluetooth:   Clearly, I'm looking for the wrong thing.  The package does not simply install a command that is the same name as the package.  Alright, then.  I want to find out what all commands (or executables) this package installed, and their locations.  The answers to "" tell me how to find the files installed by the package if I have a .deb file.  I'm not installing directly from a .deb file, though.  I'm using apt.  Where is the .deb file that that used?  Is there a copy on my system somewhere that I can query with the commands in the answers to that question?  Where?  If there isn't a local copy on my system, can I get one with apt?  How?  Is there some handy apt (or similar) command that wraps this up for me, so that I do not have to run dpkg-deb directly?  What is it?  Can I find the package's file list entirely on-line, without explicitly downloading any .deb files and before installing anything with apt?  How? How to close entire application when application has more than 2 forms without showing messagebox more than once In many experiments in quantum mechanics, a single photon is sent to a mirror which it passes through or bounces off with 50% probability, then the same for some more similar mirrors, and at the end we get interference between the various paths. This is fairly easy to observe in the laboratory.  The interference means there is no which-path information stored anywhere in the mirrors. The mirrors are made of 10^20-something atoms, they aren't necessarily ultra-pure crystals, and they're at room temperature. Nonetheless, they act on the photons as very simple unitary operators. Why is it that the mirrors retain no or very little trace of the photon's path, so that very little decoherence occurs?  In general, how do I look at a physical situation and predict when there will be enough noisy interaction with the environment for a quantum state to decohere? Find weak form of linear transport equation I am stuck on the following problem that says:       a) Find a weak formulation for the partial differential equation $${\partial u\over\partial t\ }+ c{\partial u \over \partial x\ }=0$$    b) Show that $u=f(x-ct)$ is a generalized solution of $${\partial u\over\partial t\ }+ c{\partial u \over \partial x\ }=0$$ for any distribution $f$    My Attempt:   I know that in order to find a weak form of a pde, we need to multiply it by a test function, then integrate it. Also, to find a generalized solution, we need to find a weak solution and just multiply it by the Heaviside function.  Let's take any test function $\phi $, then we have (integrating by parts second part of the integral) $$\int_{\Omega } ( {\partial u\over\partial t\ }+ c{\partial u \over \partial x\ })*\phi(x) dx= \int_{\Omega } {\partial u\over \partial t}\phi(x) dx - c\int_{\Omega } u(x,t)\phi'(x)dx$$ where $\phi $ vanishes at boundaries. So, is it the final form or can we proceed further? And how am I supposed to find a generalized solution?  Can someone help me out? Thanks in advance for your time. Does Facebook allow a user to give my app access to their friends email addresses? We've been talking a lot about the efficacy of community self-evaluations lately, both internally on the Community Team and out in the open . Lots of ideas were tossed around, but the underlying theme of these discussions has been that site self-evaluations are not useful in their current form. The review queue format hampers discussion, the meta thread posted by the Community user is trivially ignored, and the sample question size is far too small to be useful, but big enough to be non-trivial for participants. They also don't provide much in the way of useful information to community managers behind the scenes.  So we're going to shut them down this week, and we'll be using the time it saves us to digest the ideas y'all have thrown out in the previous discussions and figure out where to go from here.   I'll be going over the previous threads with a fine-toothed comb to try and suss out what worked well and what was broken and determine a more useful mechanism - if one is required at all. I'd also welcome continued suggestions from the communities about how to continue capturing what the evals accidentally did right - encouraging communities to stop and examine how they're doing at somewhat regular intervals.   So: if you have ideas on how to get communities to monitor their own Q&amp;A quality and get a little introspective, feel free to sound off in the answers.  Update: with a creative application of per-site feature toggles, we've shut down evaluations except on a handful of sites where they're currently running. Once those evaluations run their course, no new ones will be started anywhere on the network. Why 'mkpasswd -m sha-512' produce different result every time it is called? I am using this function to create a password in the shadow file  $ mkpasswd -m sha-512 password $6$o50n4EfNOBzfs$K5l5AcOI5e0I9n2df0LmR11OLSPKSVM6AGBOnWVfDDfMubb46MrAj0zehdLNEoYzD2fj5q4XUdDwexj/dWLHy/ $ mkpasswd -m sha-512 password $6$ADmDOhDpW$gsYQuiKPpV1ewaUpRq2VGAvrcocffLQ8XGF94e6LNLZfKIjy6Ku.cZoR/5exeCi1ESjPB9TRM6HxCiY5BCNCV0 $ mkpasswd -m sha-512 password $6$Efj1agaI$HGkny3q1OTYT4KREh18gueHJae/3Bvil0iOEhfXj8bD.qy9Lg2UIQJMuBcq0XtG3xzueK.7cp0GfKr7tEo5YI/ $ mkpasswd -m sha-512 password $6$zdVPlCPai4Y$x3CBvlP99xZXZcr4PTiE..YLpZx39h5OHDxqazd9wFLImPuwsXF0M6KmqLzlCCrnQhI2lmEPdCzfmHA/fDiOz.   It makes me wonder how does the output value work as a password Restricting SSH sessions for accounts on ubuntu server May someone please show me how I would restrict accounts/people logging into an ubuntu 10.04 server by SSH to a single active session at a time for each account that logs into the server.  Regards Is it possible to have site-specific badges? Operator Theoretic Perspectives on Bayesian Inference UTF-8 -> ASCII in C language This time when I used certbot it created a certificate for "www.$website" instead of $website. This is not what I need.  Here it is:    $ website="my_website123.com"   $ sudo certbot certonly --standalone -d $website -d www.$website --email admin@$website              Saving debug log to /var/log/letsencrypt/letsencrypt.log   Plugins selected: Authenticator standalone, Installer None   Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org   Cert not yet due for renewal    You have an existing certificate that has exactly the same domains or certificate name you requested and isn't close to expiry.   (ref: /etc/letsencrypt/renewal/www.my_website123.com.conf)    What would you like to do?   -------------------------------------------------------------------------------   1: Keep the existing certificate for now   2: Renew &amp; replace the cert (limit ~5 per 7 days)   -------------------------------------------------------------------------------   Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2   Renewing an existing certificate   Performing the following challenges:   http-01 challenge for my_website123.com   http-01 challenge for www.my_website123.com   Waiting for verification...   Cleaning up challenges    IMPORTANT NOTES:    - Congratulations! Your certificate and chain have been saved at:      /etc/letsencrypt/live/www.my_website123.com/fullchain.pem      Your key file has been saved at:      /etc/letsencrypt/live/www.my_website123.com/privkey.pem      Your cert will expire on 2018-10-18. To obtain a new or tweaked      version of this certificate in the future, simply run certbot      again. To non-interactively renew *all* of your certificates, run      "certbot renew"    - If you like Certbot, please consider supporting our work by:       Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate      Donating to EFF:                    https://eff.org/donate-le   Why did it create one for "www" instead of the bare domain?   On all my own servers this exactly command has always created a cert. without "www" - this is what I need. I even tried yesterday on a different server -- without "wwww".  How can I make it create a cert. without "www"? How do I write a mathematical equation for ARIMA (2,1,0) x (0,2,2) period 12 Is there a way to get reverse numbering on the enumerate environment? To build a list of publications, I wish to show the most recent on top of the list, while keeping the numbering similar. This can be achieved manually by doing something like:  \begin{enumerate} \item[42] pub num 42 \item[41] pub num 41 \item[...] \item[1] pub num 1 \end{enumerate}   but is there a more principled approach?