What exactly are limits used for in real life applications?
What is a simple example of a limit in the real world?
Conditional formatting of an entire row based on multiple cells I'm trying to make a conditional formatting rule in Google Spreadsheet that would highlight a row green based on text in multiple cells.   If cells L2, M2, and N2 = APPROVED; and cell O2 = X; then row 2 = highlighted green. A common good practice in Machine Learning is to do feature normalization or data standardization of the predictor variables, that's it, center the data substracting the mean and normalize it dividing by the variance (or standard deviation too). For self containment and to my understanding we do this to achieve two main things:   Avoid extra small model weights for the purpose of numerical stability. Ensure quick convergence of optimization algorithms like e.g. Conjugate Gradient so that the large magnitude of one predictor dimension w.r.t. the others doesn't lead to slow convergence.   We usually split the data into training, validation and testing sets. In the literature we usually see that to do feature normalization they take the mean and variance (or standard deviation) over the whole set of predictor variables. The big flaw I see here is that if you do that, you are in fact introducing future information into the training predictor variables namely the future information contained in the mean and variance.  Therefore, I do feature normalization over the training data and save the mean and variance. Then I apply feature normalization to the predictor variables of the validation and test data sets using the training mean and variances. Are there any fundamental flaws with this? can anyone recommend a better alternative? Calculate difference between two dates (number of days)? When I use the listings package with frame in my code the frame "breaks" when the page ends and it is open in the end of the page. I want the frame to be complete with four sides and continue in the next page again with all four frame sides complete. How can I do this? Why does the frame "breaks"? Can a parallel computer simulate a quantum computer? Is BQP inside NP? What's the intuition behind "stiff systems"? I dual booted ubuntu 11.04/11.10 a while ago with a USB stick and i want to uninstall it.   I would like to completely uninstall the old version and get 12.04.  I have a 64 bit laptop. Please help! I hope this is not a repeat question. I tried searching but couldn't come up with the right search words for this question.  I see the following in the sidebar of my flagging history tab:    I notice that I have raised 28 helpful flags from my user page, but I see "27 deemed helpful" and "1 deemed helpful". What is the difference between the top half and the bottom half of the entries in the flagging history sidebar? How should I interpret the results displayed in the sidebar? Drag and drop not working inside Nautilus on Ubuntu 17.10 This happened when I updated MikTeX to the latest version (as of time of this post) and tried the  regarding adding pdf pages to RevTeX documents. Running the code below produced text rotated by 90 degrees while commenting out the line which includes the pdfpages packages produces regularly positioned text. Note that the page number was not rotated. Can anyone reproduce this and what is the cause of this?  \documentclass[english]{revtex4-1} \usepackage{pdfpages}  % Including PDF  \makeatother \usepackage{babel} \begin{document}  Lorem ipsum dolor sit amet...  \end{document} What is the C# equivalent of NaN or IsNumeric? What is the most efficient way of testing an input string whether it contains a numeric value (or conversely Not A Number)? I guess I can use Double.Parse or a regex (see below) but I was wondering if there is some built in way to do this, such as javascript's NaN() or IsNumeric() (was that VB, I can't remember?).  public static bool IsNumeric(this string value) {     return Regex.IsMatch(value, "^\\d+$"); } How should an educational institute woo good faculty? hyperlink name with biblatex authoryear I am using biblatex with the authoryear styles.  So far I've been able to find everything I need easily in the excellent documentation, but I'm stuck on one thing.   With my current settings (below) citations only have the year hyperlinked to the bibliography entry. I think prior to using biblatex I would have the whole citation (authors + year) as a reference - I think this is easier to click etc. when browsing.  Is there an easy way to get this (or does it involve creating a new style).  \usepackage[style=authoryear,             bibstyle=authoryear,             citestyle=authoryear,             natbib=true,             hyperref=true,             backref=true,             abbreviate=true]{biblatex} Maximal ideals in the ring of real functions on $[0,1]$ Let $S$ be the ring of all continuous functions from $[0,1]$ to $\mathbb R$. How to prove that all maximal ideals of $S$ have the form $M_{x_0}=\{f\in S \mid f(x_0)=0\}$?   Thanks in advance. Sum of two squares modulo p When I'm using  find . -type f -name "*.htm*" -o -name "*.js*" -o -name "*.txt"  it finds all the types of file. But when I add -exec at the end:  find . -type f -name "*.htm*" -o -name "*.js*" -o -name "*.txt" -exec sh -c 'echo "$0"' {} \;  it seems it only prints .txt files. What am I doing wrong?  Note: using MINGW (Git Bash) How to clear bash history completely? How to export/backup Notes in macOS in one go I have a lot of Notes on my machine which I don't want to loose. It's not logical to export them one by one. Is there any way to export them in one go, which would make me either use them on my new   I learned that I could backup ~/Library/Group Containers/group.com.apple.notes but I am not really sure if this would be helpful. This is what I get as for this directory.  $ du -sh ./* 4.0K    ./Library 256K    ./NoteStore.sqlite  32K    ./NoteStore.sqlite-shm 3.0M    ./NoteStore.sqlite-wal   I am running macOS Mojave. What's the difference between the simple past tense and the present perfect? The simple past tense indicates that an activity or situation began   and ended at a particular time in the past.      The present perfect expresses the idea that something happened (or   never happened) before now, at an unspecified time in the past.The   exact time it happened is not important. It also expresses the   repetition of an activity before now. The exact time of each   repetition is not important.   Even though I understand the explanation above, I can't figure out: If the present perfect states the idea that something happened in the past, why not use the simple past?  For example, would you please explain the following sentence to tell the difference between these two tenses?         The plane crashed there.    The plane has crashed there.      What is the biggest difference between them? Installing Ubuntu after Windows 10 How can I install Ubuntu on Windows 10 as dual boot? I have a DVD with Ubuntu and when I tried to install Ubuntu I had a warning that the hard disk will be erased. How can I install Ubuntu and keep my Windows 10? Thanks