How can I show the contact number of the Dialed contact
How can I see the phone number dialed after I initiate a call?
Why does k-means clustering algorithm use only Euclidean distance metric? Is there a specific purpose in terms of efficiency or functionality why the k-means algorithm does not use for example cosine (dis)similarity as a distance metric, but can only use the Euclidean norm? In general, will K-means method comply and be correct when other distances than Euclidean are considered or used?  [Addition by @ttnphns. The question is two-fold. "(Non)Euclidean distance" may concern distance between two data points or distance between a data point and a cluster centre. Both ways have been attempted to address in the answers so far.] Inexact measurement and wavefunction collapse What happens if you use the 32-bit int 0x80 Linux ABI in 64-bit code? Let $n$ be a positive integer. Show that the matrix  $$\begin{pmatrix} 1 &amp; 1/2 &amp; 1/3 &amp; \cdots &amp; 1/n \\ 1/2 &amp; 1/3 &amp; 1/4 &amp; \cdots &amp; 1/(n+1) \\ \vdots &amp; \vdots &amp;  \vdots &amp; \ddots &amp; \vdots\\ 1/n &amp; 1/(n+1) &amp; 1/(n+2) &amp; \cdots &amp; 1/(2n-1) \end{pmatrix}$$  is invertible and all the entries of its inverse are integers. This is an exercise in Hoffman and Kunze's linear algebra book. Any hints will be appreciated! Are global variables bad? In C/C++, are global variables as bad as my professor thinks they are? How is the amplitude of light related to number of photons? If you increase the number of photons leaving a light source you increase the brightness/intensity, so it could be said that intensity is directly proportional to number of photons. However intensity is directly proportional to amplitude squared, so this leads me to wonder that if you increase the amplitude of a light wave, are you just creating more photons rather than affecting each individual photon in some way? What is rank deficiency, and how to deal with it? Get driving directions using Google Maps API v2 Add the option to do a case-sensitive search I noticed that the search engine does not consider capital letters (just like most regular search engines). However, I have the feeling that in a "coding" context, this could be useful.  For example, searching pages about the standard C library "FILE" struct returns a lot of pages containing the "file" word, that are not (always) relevant.  Is there a way to force keeping capitals? If not, maybe it could be a nice feature to add? How can I use xindy on a system with libncurses.so.6? I can't write Chinese characters in edited posts, but OP could when posting Is it possible to check a bash script syntax without executing it?  Using Perl, I can run perl -c 'script name'. Is there any equivalent command for bash scripts? Why not use exceptions as regular flow of control? shopt works in command line, not found when run in a script I'm writing a script to copy some files around, and trying to use shopt -s dotglob  like .jshint and whatnot.    I can run shopt -s dotglob directly at a bash prompt with no error.  However, running the script throws the error:  script.sh: 81: script.sh: shopt: not found   I'm running this script in bash shell, with the shebang header #!/usr/bin/env bash.  Error line:  shopt -s dotglob cp -r $TEMP/img/* $TARGET/img/ cp -r $TEMP/js/* $TARGET/js/ cp -r $TEMP/less/* $TARGET/less/   Not finding anything helpful on google, any idea what the problem is here? How to study/prepare for the Salesforce Developer Certification I am fairly new to Force.com development (less than a year). I did not learn it from the ground up. So I think it will be good to study for the developer exam to strengthen my basics and improve my overall knowledge of Force.com + it will be great to have this certification.  Now it's surprising that there is not a lot of great information on the web about how to go about obtaining this certification. Most other major certifications have dedicated study guide books available but there are few for Force.com and I don't think any of them are official.   The official page has little information. The Study guide gives a broad description of the topics in the test.   I see a lot of the esteemed members are here certified developers. I think if you guys could give us a little information, hints/tips and some advice on how to prepare for this exam, it will really be of great help. Also is DEV401 required/helpful?  Also if we could get recommendations for great resources(books, online training etc) and practice tests it will be awesome. Magnetic Field in the presence of a conductor I am studying for my quals and came across an old question that reads like the following:      There are two regions in space separated by an infinite conducting plane. Region 1 has a magnetic dipole of moment $\vec{\mu}$ located a distance $d$ from the plane. What is the magnetic field $\vec{B}$ everywhere in region 1?   I know that for a perfect conductor (superconductor), the normal component of $\vec{B}$ is zero–although I don't exactly know why–but I don't know if that is the case when the problem involves a "conductor" (not explicitly a perfect conductor).  TL;DR: Can anybody give me some insight about the magnetic boundary conditions of a stationary magnetic field in the presence of a conductor?  Thanks! Which is correct: "drive safe" or "drive safely"? Solvability and reducibility of a polynomial in a "chain" of finite fields Overleaf V2 - How to get BBL File? Show that the polynomial $X^5 + X^3 + \bar{1}$ in $(\mathbb{Z}/2\mathbb{Z}[X])$ is irreducible