I am looking for ways to validate mileage charged by our contractors.  They are paid from a central location to a customer, and then from the customer to a drop off location.    I use QGIS for a bunch of stuff and also have access to MapInfo Pro.     I need to do the following:        route individual trips to get total distance in each direction   also need to know if parts of one trip overlap the other, and by how much (i.e. km)    and if the second trip ends anywhere along the route of the first trip (i.e. they came back the same way they went out)       I have been messing around with PostgreSQL and pgRouting for a couple days and it's pretty confusing to me.
I was wondering if there are any alternatives to  tools.  Thinking about it for a bit, I think the only alternative is to use R or RPY to do the analysis.   Basically I'm trying to solve routing problems based on nonPostGIS databases. As most of my data is actually stored in a different format; however, it's not to hard to convert. I'm finding that pgRouting to my dumb silly brain is difficult to implement. So perhaps a non-database solution that I can easily tweak would be ideal for me
How to determine function name from inside a function I need to add 30 minutes to values in a Oracle date column.  I do this in my SELECT statement by specifying   to_char(date_and_time + (.000694 * 31)  which works fine most of the time.  But not when the time is on the AM/PM border.  For example, adding 30 minutes to 12:30 [which is  PM] returns 1:00 which is AM. The answer I expect is 13:00.  What's the correct way to do this? Purely "algebraic" proof of Young's Inequality states that if $a, b \geq 0$, $p, q &gt; 0$, and $\frac{1}{p} + \frac{1}{q} = 1$, then $$ab\leq \frac{a^p}{p} + \frac{b^q}{q}$$ (with equality only when $a^p = b^q$).  Back when I was in my first course in real analysis, I was assigned this as homework, but I couldn't figure it out.  I kept trying to manipulate the expressions algebraically, and I couldn't get anywhere.  But every proof that I've seen since uses calculus in some way to prove this.  For example, a common proof is based on this  and integration.  The proof on Wikipedia uses the fact that $\log$ is concave, which I believe requires the analytic definition of the logarithm to prove (correct me if I'm wrong).  Can this be proven using just algebraic manipulations?  I know that that is a somewhat vague question, because "algebraic" is not well-defined, but I'm not sure how to make it more rigorous. But for example, the proof when $p = q = 2$ is something I would consider to be "purely algebraic":  $$0 \leq (a - b)^2 = a^2 + b^2 - 2ab,$$ so $$ab \leq \frac{a^2}{2} + \frac{b^2}{2}.$$ How to show the number of domains the disk is split into is $1+ C_n^2 + C_n^4$? Assuming there are n points on a circle, then there are $C_n^2$ chords. If any three chords don't intersect in circle. How to show the circle will be divided into $1+ C_n^2 + C_n^4$ domains?  Picture below is a example of 5 points on circle. Unlock by fingerprint only I have one feature-request with the objective of having duplicate questions with no answers:   To (try to) avoid people answering duplicate questions, add an alert that says the question has a probable duplicate if it has a close vote as Exact duplicate, asking the answerer to go to the original and answer there.   What do you think? My objective is letting the duplicate question exist for search purposes, but the answers centralized in the root question. My thinking:    acceleration corresponds to a force which is instantaneous, so the acceleration of a rigid body can be rather spiky (non-smooth) velocity (angular velocity) describes the ratio of change of the distance(angle), so it is smooth in the real world.   Conclusion, it makes sense to  (e.g., simple averaging) a velocity signal (temporal velocity), but it does not make so much sense to do smoothing on acceleration signal. Am I right? I deleted the "/etc/passwd" file and cannot log in I'm new to Ubuntu. What's the application extension for development reasons? I know Windows is mainly .exe and Mac is .dmg or .app. Does Linux have an unique one? What is wrong with \ifnum#1=0.09\relax? The following code does not compile with the following error message     Missing = inserted for \ifnum   \documentclass[pstricks,border=4pt]{standalone} \usepackage{multido}  \psset{linewidth=.5\pslinewidth} \psset{xunit=2cm}  \newcommand\FixedScale[1]{%     \multips(0,0)(.1,0){\the\numexpr10*#1+1\relax}{\psline(0,0)(0,-3pt)}     \multips(0,0)(.5,0){\the\numexpr2*#1+1\relax}{\psline(0,0)(0,-6pt)}     \multips(0,0)(1,0){\the\numexpr#1+1\relax}{\psline(0,0)(0,-9pt)}     \multido{\i=0+1}{\the\numexpr#1+1\relax}{\uput[-90](\i,-5pt){$\i$}} }  \newcommand\VernierScale[2][0.09]{%     \rput(#2,0){%     \psset{xunit=#1,linecolor=red}%     \multips(0,0)(1,0){11}{\psline(0,0)(0,3pt)}%     \multips(5,0)(5,0){1}{\psline(0,0)(0,6pt)}%     \multips(0,0)(10,0){2}{\psline(0,0)(0,9pt)}%     \ifnum#1=0.11\relax         \multido{\i=0+5}{3}{\uput[90](\i,8pt){\tiny$\the\numexpr10-\i\relax$}}     \else         \multido{\i=0+5}{3}{\uput[90](\i,8pt){\tiny$\i$}}     \fi     } }  \begin{document} \multido{\n=0.00+0.01}{21}{% \begin{pspicture}(0,-.5)(2,.55) \FixedScale{2} \VernierScale[0.09]{\n} \end{pspicture}} \end{document}   What is wrong with \ifnum#1=0.09\relax? Start Ubuntu Unity With Dash Open Recently I've noticed more and more sign-in / sign-up workflows defaulting to the sign-up option first and providing a minimal "Sign-In / Login" action somewhere else on the page. What's the reason behind this practice?  Examples where I've seen this recently: Redirect Restricted Page to 404 Is there a way to show a 404 page if the current logged in user does not have the right clearance to view the page? I am looking for a PHP method, something like  if( !current_user_can('administrator') ) { show_404(); exit(); }   I have thought about using a redirect, but I would like to keep the url the same. I wanted to create a WP plugin. So I requested and my request was approved by WordPress.org But I don't want to develop that plugin anymore. How can I delete the repository forever or request its deletion. Did English ever have a word for 'yes' for negative questions? The Germans have doch and the French have si as a word that means "yes" in response to a negative question, such as:     Don't you want some ice-cream?   Yes [I do]!   In English, we only have yes (as far as I know) and further clarification is required in order to be unambiguous.  Did we ever have such a word in English and, if so, what happened to it? If not, given the French and Germanic influences on English, any idea why not? macOS Sierra restarting download instead of resuming Finding the number of analytic functions which vanish only on a given set. Let $S = \{0\}\cup \{\frac{1}{4n+7} : n =1,2\ldots\}$. How to find the number of analytic functions which vanish only on $S$?  Options are   a: $\infty$  b: $0$  c: $1$  d: $2$ Prove that if $a \mid b$ then $\gcd(a,b) = |a|$ There is a problem 3.3 in :     Ambiguities in the energy-momentum tensor:      (a) If you add a total derivative to Lagrangian ${\cal{L}} \rightarrow {\cal{L}} + \partial_\mu X^\mu$, how does the energy-momentum tensor change?      (b) Show that the total energy $Q = \int d^3x \; {\cal{T^{00}}}$ is invariant under such changes   Given the definition of energy-momentum tensor:  $$ {\cal{T}}^\mu{}_\nu = \sum_n \frac{\partial{\cal{L}}}{\partial \left( \partial_\mu \phi_n \right)} \partial_\nu \phi_n - g_{\mu\nu} {\cal{L}} $$  It changes as:  $$ \delta {\cal{T}}^\mu{}_\nu =  \sum_n \left( \partial_\rho \frac{\partial{X^\rho}}{\partial \left( \partial_\mu \phi_n \right)} \right) \partial_\nu \phi_n - g_{\mu\nu} {\partial_\rho X^\rho} $$  $T^{00}$ changes as:  $$ \delta {\cal{T}}^{00}= \sum_n \left( \partial_\rho \frac{\partial{X^\rho}}{\partial \dot{\phi_n}} \right) \dot{\phi_n} - \partial_\rho X^\rho $$   From this point I’m stuck. The first term doesn’t seem to disappear at all after integration over space, and the second disappears only partially:  $$ \int d^3x \; \dot{X^0} $$  So even if I’d have assumed that $X$ depends on position, and not on the fields - the total energy doesn’t seem to be invariant under it.  What is the best way to proceed forward with this? Add a binary to my path I have an executable. I want to execute the executable in terminal with name only like other commands.  I can put my executable in /usr/local/bin or I could add its PATH to ~/.bashrc. Both will work.  What is better?  Is there  any difference?