All derivations are directional derivatives
Does a linear operator obeying Leibniz rule imply it is a differential operator?
Detection of the Electric Charge of a Black Hole Why my sql query run faster than my stored procedure? I am trying to write a script in MYSQL Workbench to update my database every day using stored procedure but I find it too slow compared normal query or temporary tables. If i use temporary table the time of execution : 6 second but my stored procedure 370 second.  I really need help.        CREATE DEFINER=`datasll`@`...` PROCEDURE `product`()       BEGIN       EXPLAIN SELECT                cs.id,              cs.fk_c,              cs.so,               cs.pr,              cs.date,              cs.o_p,              cs.sh_c,              cs.x,              LEFT(cs.x,2),              cs.doc,              cs.fk_op,              cc.id_c_c,              cc.name,              cc.descrip,              left(cc.n_o,3) as bon,              cc.fk_c_br,              cc.de,              cc.m_mat,              cc.color,               cc.fk_c_s       FROM             data_pro.catas cs        LEFT OUTER JOIN             data_pro.c_co cc ON  data_pro.cs.fk_c_c = data_pro.cc._id_cc       WHERE             data_pro.cc.pap = 1       AND   data_pro.cc.stati = 'b';       END   When i use EXPLAIN this's the result :   Many Thanks for any help. how to reset gnome panel? I think my gnome-panel is messed up because I alt+right click it and nothing pops up.  I'm on 12.04, classic gnome desktop.  so I used locate and found gnome-panel in .gconf somewhere, how do I clear just gnome-panel's settings so that I can add things to my panel again?   edit:  matt: ~/.gconf $ find|grep -iw panel ./desktop/ibus/panel ./desktop/ibus/panel/%gconf.xml ./apps/gnome-settings/gnome-panel ./apps/gnome-settings/gnome-panel/%gconf.xml When should we consider a dataset as imbalanced? I'm facing a situation where the numbers of positive and negative examples in a dataset are imbalanced.  My question is, are there any rules of thumb that tell us when we should subsample the large category in order to force some kind of balancing in the dataset.  Examples:   If the number of positive examples is 1,000 and the number of negative examples is 10,000, should I go for training my classifier on the full dataset or I should subsample the negative examples? The same question for 1,000 positive example and 100,000 negative. The same question for 10,000 positive and 1,000 negative. etc... How to rename multiple files by removing the extension? Keyboard Shortcuts no longer working on GNOME 3.4.1 What is the symbol ''$\divideontimes$'' (DIVIDE TIMES) for? I looked "$\divideontimes$" up on Google and now I know that it's Unicode U+22c7 but when would it be used?  I am guessing that $5 \divideontimes 5 = 25$ and $1$...? How to log out of a Stack Exchange site? How To Set Default Wallpaper As Login Screen Wallpaper [Automatically]? Why do I have different IP addresses on different websites? My wireless router shows the IP address is 113.46.75.*, which some websites like ip138.com, www.ip.cn show as my IP.   But other websites, like googling for "what is my ip", www.whatismyip.com, www.whatsmyip.org, show that my IP is 121.18.126.*.   I am very curious why this happens and how is it possible.   So, why do different websites show that I have different IPs?  Thanks all!  Plus: I changed my IP address several times (restarting the modem) and all addresses is like 113.46.*.*, but my IP address does not change when googling for "what is my ip".  My ISP is a small company, so I think it is true that when visiting some websites, I am NATted or proxied to some IP addresses which have access to those websites -- not to avoid firewall though, since I am still blocked from some websites.  But I still want some more information or resources to support our guess. Thank you! For some tests in R, there is a lower limit on the  calculations of $2.22 \cdot 10^{-16}$. I'm not sure why it's this number, if there is a good reason for it or if it's just arbitrary. A lot of other stats packages just go to 0.0001, so this is a much higher level of precision. But I haven't seen too many papers reporting $p &lt; 2.22\cdot 10^{-16}$ or $p = 2.22\cdot 10^{-16}$.   Is it a common/best practice to report this computed value or is it more typical to report something else (like p &lt; 0.000000000000001)? When I open the terminal on my Mac, this is what it shows:  australia:~ rod$   I don't live in Australia, don't have anything to do with Australia, nor have ever setup terminal as Australia.   Where does that name come from, why is it there, what does it mean and how do I change it (or should I even change it at all)? $16$ rooks on a chess board. Place $8$ pairwise non-attacking white rooks and black rooks on a $8\times8$ chess board. If one can swap rows and columns, is it possible for the black rooks to take the initial position of the white rooks and vice versa?  My attempt:  Let the rows be $a_1,a_2,...,a_8$ and columns $b_1,b_2,...,b_8$. If there are white rooks at ($a_i$,$b_j$) and ($a_j$,$b_a$) as well as black rooks at ($a_i$,$b_i$) and ($a_j$,$b_j$), then we can reduce it to a $2\times2$ and a $6\times6$.   I don't know what to do next. Any help appreciated. Some common problems with displaying routes created from street data, such as bus routes, include:   Routes may overlap themselves, such as when a route takes the same road in opposite directions Routes may overlap other routes that take the same street. Routes are often overly detailed, or "noisy", owing to their derivation from street data. Indicating a route's direction unambiguously without overloading it with arrows can be a challenge.   What are some techniques for dealing with these issues in order to create a practical and usable route map, such as this ? Do you know of any such public transport maps that were produced by automatic techniques rather than manual illustration/digitization?  Specifically I am using ArcGIS 10, but solutions involving other software are welcome as well.  One technique I have had some success with for dealing with 1) is using ArcMap's  with a negative offset -- assuming the lines are oriented in the direction of travel, this will offset the lines such that the right and left-hand sides are distinct and oriented as you would expect (at least for  countries, for left-hand traffic countries one would use a positive offset). However the result tends to be a bit wonky around turns, interchanges and and U-turns, and is inflexible when dealing with multiple routes.  Another possibility that I am not very familiar with but which seems promising is  -- however, I have not had much luck in finding examples of using representations for transportation maps and whether it might fit the bill. Sometimes it is convenient to use an absolute path to include a preamble. To do so, I use the following "hack":  \documentclass[a4paper, 12pt]{article} \newcommand{\folder}{/path/to/folder} \input{\folder/preamble}  \begin{document} \end{document}   Now my question is, whether there is a more elegant way to do this, especially a way which is compatible with one of the flatten scripts from  ? Send request for "reason for down vote"? Each question in SO keeps a list of the users who voted it down. As we all know, the list is never shown to anyone. Only the down voter can see which questions he down voted.   Sometimes, down voters down vote rather hastily. Thats okay because no one is perfect (except chuck norris). But sometimes, the down voter might have a good reason to down vote but may not leave a reason behind. As a result, the poster is left wondering if his question is stupid/bad or okay. To remedy this situation, I suggest a feature below -   The poster should have a button "request down voters for reason" which can be pushed only once. The down voters in the down voter list get the notification and can choose to respond to it. I feel that this can serve as a polite reminder to those who down vote a question which would seem to be an okay (if not good) question to most people.   Example of question which I feel should have at least 0 votes -    If okay, then this feature can be combined with -    Do you agree to the proposal ?  As an aside, do you agree that the SO question above should not get negative points ? Can I download the Winter Bash hats for use as profile picture? Can I download  and use them as my profile picture?  I actually like some of them, and want to keep them for future use. Can any one help me out , based on quote line items can we create a layout like by prepopulating items, price &amp; qty and next 6 qtrs. Example below 2 part numbers are  in quote line items, also default the price from quote line item.  Upon saving ,it should save as detailed record for each quarter. Creating a custom object  and calling them in Visual force page or by using JavaScript and CSS .Any suggestions plz.I shall appreciate your help.  i tried previously in this way   &lt;apex:page standardController="CustomLineItem__c"  sidebar="false" showHeader="false"&gt;  &lt;apex:form &gt;   &lt;apex:pageBlock &gt;     &lt;apex:pageBlockButtons location="top"&gt;       &lt;apex:commandButton value="SAVE" action="{!SAVE}"/&gt;       &lt;apex:commandButton value="SAVE&amp;MORE" action="{!SAVE}"/&gt;       &lt;apex:commandButton value="CANCEL" action="{!CANCEL}"/&gt;     &lt;/apex:pageBlockButtons&gt;     &lt;apex:pageblockSection title="Schedule"&gt;       &lt;apex:inputField value="{!CustomLineItem__c.ProductPartNumbers__c}" label="Product"/&gt;        &lt;apex:inputField value="{!CustomLineItem__c.Year__c}" label="Year"/&gt;        &lt;apex:inputField value="{!CustomLineItem__c.PricingRequestsQuarterNos__c}" label="Quarter"/&gt;        &lt;apex:inputField value="{!CustomLineItem__c.Quantity__c}"/&gt;        &lt;apex:inputField value="{!CustomLineItem__c.Price__c}"/&gt;    &lt;/apex:pageblockSection&gt;   &lt;/apex:pageblock&gt;  &lt;/apex:form&gt; &lt;/apex:page&gt; Convergence of sequence of real numbers and (sub)subsequence Let $(x_n)_{n\in \mathbb{N}}$ be a sequence of real numbers. A well known result is:     The sequence $(x_n)_{n\in \mathbb{N}}$ converges to $a\in \mathbb{R}$ if and only if every subsequence $(x_{n_k})_{k\in \mathbb{N}}$ converges to $a\in \mathbb{R}$.   Now, I'm working on an exercise which essentialy asks to prove the following:     The sequence $(x_n)_{n\in \mathbb{N}}$ converges to $a\in \mathbb{R}$ if and only if for every subsequence $(x_{n_k})_{k\in \mathbb{N}}$ there is a (sub)subsequence $(x_{n_{k_j}})_{j\in \mathbb{N}}$ which converges to $a$.   Now, one direction is trivial. If in fact $(x_n)_{n\in \mathbb{N}}$ converges to $a$, then by the result I've mentioned, every subsequence of $(x_{n})_{n\in \mathbb{N}}$ converges to $a$. Let then $(x_{n_k})_{k\in \mathbb{N}}$ be an arbitrary subsequence. In that case, we know that it is a subsequence of itself, and hence we've found a (sub)subsequence which converges to $a$.  The other way around seems quite complicated for me. The reason is as follows: I must assume that every subsequence $(x_{n_k})_{k\in \mathbb{N}}$ has a (sub)subsequence which converges to $a$ and the proof that the original one converges to $a$.  My problem is exactly that "a". If it had all (sub)subsequences converging to $a$, then by the result i've mentionted, the subsequence $(x_{n_k})_{k\in \mathbb{N}}$ would converge to $a$. In that case, we would have every subsequence converging to $a$ and the result would follow.  My idea to prove the claim was then:  First remember that a subsequence is the restriction of the original one $x: \mathbb{N}\to \mathbb{R}$ to an infinite subset $\mathbb{N}'\subset \mathbb{N}$. In that case a (sub)subsequence is the restriction of $\tilde{x} = x|\mathbb{N}'$ to an infinite subset $\mathbb{N}''\subset \mathbb{N}$. But since $\tilde{x}$ is the restriction of $x$ to $\mathbb{N}'$ and since $\mathbb{N}''\subset \mathbb{N}'$, the restriction of $\tilde{x}$ to $\mathbb{N}''$ is itself the restriction of $x$ to $\mathbb{N}''$.  In other words, every (sub)subsequence can be viewed as a subsequence of the original one. Considering this, by hypothesis every subsequence has a (sub)subsequence which converges to $a$. But by this argument, this means that we can replace every subsequence with a convergent one. And then we can use the result I stated.  Is my idea correct? Is this really the way to prove the claim? My only doubt is that I need every subsequence converging to $a$ to use the result. In this case I can't see how I can argue that this implies every subsequence converges to $a$.  How can I finish this proof? ant deploy error - Maximum size of request reached I used to deploy metadata using ant migration tool successfully but from last night I am getting the below error:  John@John:~/mm_workspace/TEST_Project/deploy$ ant deployUnpackaged  Buildfile: /home/john/mm_workspace/TEST_Project/deploy/build.xml  deployUnpackaged:  BUILD FAILED /home/john/mm_workspace/TEST_Project/deploy/build.xml:72: Failed to submit request to https://cs19.salesforce.com/services/Soap/m/35.0/00D293456000Qaf for user john@test.com.dev. Error: {http://schemas.xmlsoap.org/soap/envelope/}Client - Maximum size of request reached. Maximum size of request is 52428800 bytes.  Total time: 2 minutes 10 seconds   I think this is because of too much metadata that I am trying to deploy. For now, I am deploying classes and then VF pages and so on but I am looking for an option to deploy everything in one go without running into the above error.  I am sure that people are working on more complex projects than mine with lots of metadata and I am wondering how are they deploying with out hitting this error?  Thanks