My regression model uses 4 independent variables and 1 dependent variable.  When I plot the dependent variables against the independent variables, only one of them shows a correlation. However, the regression analysis splits out 4 coefficients.   I'm trying to figure out how a variable can have a coefficient and affect the dependent variable when there doesn't seem to be a correlation between the two.  How exactly does this work?  Any help would be appreciated. I've tried looking this up but I'm not sure what to search.  Thanks,  I'm analyzing the following variables:avg. session length, time on app, time on website, length of membership, yearly amount spent.  Time on App is seemingly not correlated    Regression shows the following coefficients:  Avg Session Length: 25.98  Time on App: 38  Time on Website: 0.19  Length of Membership: 61
I have eight independent variables and one dependent.  I have run a correlation matrix, and 5 of them have a low correlation with the DV.  I have then run a stepwise multiple regression to see whether any/all of the IVs can predict the DV.  The regression showed that only two IVs can predict the DV (can only account for about 20% of the variance though), and SPSS removed the rest from the model.  My supervisor reckons that I have not run the regression correctly, as due to the strength of the correlations, I should have found more predictors in the regression model. But the correlations were tiny, so my question is: if IVs and the DV hardly correlate, can IVs still be good predictors of the DV?
I've been looking at  $$\int\limits_0^\infty  {\frac{{{x^n}}}{{1 + {x^m}}}dx }$$  It seems that it always evaluates in terms of $\sin X$ and $\pi$, where $X$ is to be determined. For example:  $$\displaystyle \int\limits_0^\infty  {\frac{{{x^1}}}{{1 + {x^3}}}dx = } \frac{\pi }{3}\frac{1}{{\sin \frac{\pi }{3}}} = \frac{{2\pi }}{{3\sqrt 3 }}$$  $$\int\limits_0^\infty  {\frac{{{x^1}}}{{1 + {x^4}}}dx = } \frac{\pi }{4}$$  $$\int\limits_0^\infty  {\frac{{{x^2}}}{{1 + {x^5}}}dx = } \frac{\pi }{5}\frac{1}{{\sin \frac{{2\pi }}{5}}}$$  So I guess there must be a closed form - the use of $\Gamma(x)\Gamma(1-x)$ first comess to my mind because of the $\dfrac{{\pi x}}{{\sin \pi x}}$ appearing. Note that the arguments are always the ratio of the exponents, like $\dfrac{1}{4}$, $\dfrac{1}{3}$ and $\dfrac{2}{5}$. Is there any way of finding it? I'll work on it and update with any ideas.    UPDATE:  The integral reduces to finding   $$\int\limits_{ - \infty }^\infty  {\frac{{{e^{a t}}}}{{{e^t} + 1}}dt} $$  With $a =\dfrac{n+1}{m}$ which converges only if   $$0 &lt; a &lt; 1$$  Using series I find the solution is     $$\sum\limits_{k =  - \infty }^\infty  {\frac{{{{\left( { - 1} \right)}^k}}}{{a + k}}} $$ I am trying to create the following trigger:      CREATE TRIGGER update_customers AFTER INSERT ON wp_usermeta     FOR EACH ROW      BEGIN             if new.wp_metakey = first_name then insert into test_customer(first_name) values (new.wp_meta_value);     END   I keep getting a 1064 error that says, "You have an error in your SQL syntax; check the manual that corresopons to your MySQL server version for the right syntaxt to use near " at line 5"  What am I doing wrong? Simplest way to prevent iTunes from automatically launching when iPhone/iPad is connected When I connect my iPad or iPhone to my Mac iTunes automatically launches. What is the simplest way to prevent this from happening? What are these stamps in my passport after I was advised to divert via the UK but didn't have a visa? I am from Myanmar. I was on my way to Venice from Brussels while holding Schengen visa (single entry). I bought a British Airways ticket to fly from Brussels to Venice. Unfortunately, on that day, all BA flights from Brussels were canceled. British Airway's customer service centre told me to go to from Brussels to London by train, where I could catch my flight to Venice. I took a taxi to Bruxelles-Midi train station and bought a ticket to London. A Brussels immigration officer inspected and approved my passport.   Then I had to to through UK Border Immigration. There, they said I can't enter to get my flight. Although I explained the situation with the airline and made clear of my destination (I already reserved my hotels in Venice, Switzerland and France as described in my travel itinerary), they detained me for some hours and also took my fingerprints on paper and photo.   They asked questions concerned about my finances and gave me a refusal letter for not having a transit visa. So I had to re-enter Brussels where the immigration officer put the below stamp in my passport. As I had a single entry Schengen visa, I had to buy another airline ticket to Venice and complete my Europe trip.   What do the stamps below mean on my passport?   Can they affect me and, if so, how and why, when I apply for another Schengen visa? Jumping in an elevator? Ubuntu 20.04 Font and UI elements too big on login I'm running Ubuntu 20.04 on an ASUS X99-E-10G WS w/ an NVIDIA 1080Ti and an LG 4k 32&quot; monitor which persistently gets recognized as 27&quot;. When I log in, the text of certain UI elements is ~2x the normal size. After I go to settings/universal access and turn large text on and then off again, everything is the normal size I expect. Screenshot after logging in  After turning &quot;large text&quot; on  After turning &quot;large text&quot; off  How do I get the conditions I have after cycling the &quot;large text&quot; feature to be present immediately after booting? I have the 440 version of NVIDIA's drivers installed. Prove that $\sum_{k=0}^{m}\frac{\binom{m}{k}}{\binom{n}{k}}=\frac{n+1}{n+1-m}$ Prove that $\sum_{k=0}^{m}\dfrac{\binom{m}{k}}{\binom{n}{k}}=\dfrac{n+1}{n+1-m}$.  We know, n > m. From the right side. we have $\dfrac{n+1}{n+1-m}=\dfrac{1}{1-\dfrac{m}{n+1}}$. since n > m. $0&lt;\dfrac{m}{n+1}&lt;1$. Then $\dfrac{1}{1-\dfrac{m}{n+1}}=1+\dfrac{m}{n+1}+(\dfrac{m}{n+1})^2+...$ I don't know what to do next? Did I choose the right path? Increase partition size on which Ubuntu is installed? I have Ubuntu installed on a drive. The problem is it is running low on disk space. This is installed on vmware. I expanded the virtual drive and booted into ubuntu. But when I opened gparted(sudo gparted), the move/resize option is unavailable. This is the partition Ubuntu is installed on, but I need to resize it. Any ideas? I am comfortable using command line Why are rings called rings? What is with words that have forms that end both in -zation and -sation, such as localization and localisation?  Many spell checkers recommend -zation. For example:     Ever wish you could share information broadly   Could it be rewritten to:     Ever wish you could broadly share information   Are there any rules for the position of the adverbs. Multiple Bluetooth speakers simultaneously I would like to pair two sticky dude Bluetooth speakers, at one time with my iPhone. With two of them at once it would be like stereo sound. Is there an app or something maybe? Sorry for the vague title--I don't want the title to be a spoiler.  I've seen the movie three times, and the last two times I looked specifically for clues to this question, but found none.  The final scene in  shows       Cobb's top spinning, as he goes off to be reunited with his children.  The top continues to spin, then the movie ends, without telling us if the top topples--and therefore revealing whether he's in the "real world" or still in a dream. Do we know if he was in a dream at the end of the movie?   I'm assuming the answer is that we simply cannot know.  But did I miss anything?  Were there clues that I missed? When is unbalanced data really a problem in Machine Learning? We already had multiple questions about unbalanced data when using , , ,  and a number of other similar questions, what makes it a very popular topic! Unfortunately, each of the questions seems to be algorithm-specific and I didn't find any general guidelines for dealing with unbalanced data.  Quoting , dealing with unbalanced data     (...) heavily depends on the learning method. Most general purpose   approaches have one (or several) ways to deal with this.   But when exactly should we worry about unbalanced data? Which algorithms are mostly affected by it and which are able to deal with it? Which algorithms would need us to balance the data? I am aware that discussing each of the algorithms would be impossible on Q&amp;A site like this, I am rather looking for a general guidelines on when it could be a problem. How to prevent mail from our website going into spam mail of users? I work for an educational services company based in India. We've around one million students enrolled as users. We're frequently facing the problem of our bulk mailers regarding upcoming exams, new product launches and promotions going into spam mail folders of the students. Is the problem in the headlines? Or where else? what can we do to reduce this number?   This is killing us, we cannot have an impossibly large precentage of mails not being opened..Please help. What is the physical meaning of $\epsilon_0$? string.format format string containing { I don't understand how to use Fermat's little theorem to find remainders e.g if we are asked to find remainder of $50^{50}$ on division by $13$, what is a and what is $p$ in the formula?  Also I wanted to check can we use both congruence classes as well as Fermat's little theorem to find such remainders? How would be write $50^{50}$ on division by $13$ in terms of congruence classes to find the remainder?  I don't exactly understand what a congruence class is, what does it tell us and how is it related to this? Let $A \in Mat_{n \times n}(F)$ a matrix which satisfies $A^n=0$ and $A^{n-1} \ne 0$ for some positive integer $n$. Let $v \in F^n$ be such that $A^{n-1}v \ne 0$.  Prove that $\{v, Av, A^2v,...,A^{n-1}v\}$ is a basis for $F^n$.     So, from definition of $A$, I know that $A^iv \ne 0$ for all $0\le i \le n-1$. I know I need to prove the set is linearly independent and span $F^n$ to prove it's a basis, but I just don't know how. Ok, after seeing , I have decided to skip to the end and go with .  So what I need is a beginner's practical guide to Git.  "Beginner" being defined as someone who knows how to handle their compiler, understands to some level what a  is, and has touched source control without understanding it very well.  "Practical" being defined as this person doesn't want to get into great detail regarding what Git is doing in the background, and doesn't even care (or know) that it's distributed.  Your answers might hint at the possibilities, but try to aim for the beginner that wants to keep a 'main' repository on a 'server' which is backed up and secure, and treat their local repository as merely a 'client' resource.  So:  Installation/Setup    How do you set up Git?  Try to cover Linux, Windows, Mac, think 'client/server' mindset.         Working with the code          How do you handle binary files (visio docs, for instance, or compiler environments)? How do you merge files changed at the "same time"?    Tagging, branching, releases, baselines    How do you pull a particular 'release'?   How do you resolve conflicts and complete the merge? How do you merge parts of one branch into another branch?        Other   Describe and link to a good GUI, IDE plugin, etc. that makes Git a non-command line resource, but please list its limitations as well as its good.    - Cross platform, included with Git  - Cross platform history viewer, included with Git  - Mac OS X  - Mac OS X history viewer  - Cross platform, commercial, beta  - console GUI for Linux  - GUI for Windows, Linux  - package for Windows, includes friendly GUI  Any other common tasks a beginner should know?     How do I work effectively with a subversion repository set as my source control source?   Other Git beginner's references                 Delving into Git     (and )    I will go through the entries from time to time and 'tidy' them up so they have a consistent look/feel and it's easy to scan the list - feel free to follow a simple "header - brief explanation - list of instructions - gotchas and extra info" template.  I'll also link to the entries from the bullet list above so it's easy to find them later.