How to identify fonts from images/scans
How can I automatically determine fonts used in an image or PDF?
Meaning of tilde-greater-than (~>) in version requirement? PHP import Excel into database (xls & xlsx) Commenting out multiple lines of code, specified by line numbers, using vi or vim I have learned from  that it is possible to use vi/vim to comment out a specified range of line numbers.  For example, suppose I have the following bash script:  #!/bin/bash  This is my very very great script   Now suppose that I want to comment out line numbers 6 through 8 (which contain the words very, very, and great) using the # comment character.  In vi/vim, I can simply type :6,8s/^/# to obtain the following:  #!/bin/bash  This is my #very #very #great script   which comments out lines 6 through 8.  My question is, is it possible to type a similar one liner that will remove the # comment character from lines 6 through 8 (but not any other commented lines in the file)?  Having said this, I realize that there is some debate about whether I am actually using vi or vim.  In practice, I open a file script.sh with the command vi script.sh.  Also, when I type the command which vi, I obtain /usr/bin/vi.  Nevertheless, when I simply type vi and press Enter, I obtain this:  ~                              VIM - Vi IMproved ~ ~                               version 7.2.330 ~                           by Bram Moolenaar et al. ~                 Vim is open source and freely distributable ~ ~                           Sponsor Vim development! ~                type  :help sponsor&lt;Enter&gt;    for information ~ ~                type  :q&lt;Enter&gt;               to exit ~                type  :help&lt;Enter&gt;  or  &lt;F1&gt;  for on-line help ~                type  :help version7&lt;Enter&gt;   for version info   which seems to suggest that I'm actually using vim.  I am accessing a remote Ubuntu Linux cluster using SSH from my PC.  I am not using a Ubuntu Linux GUI. Two homologous but not homotopic loops on a closed surface of genus greater than one Suppose $S$ is a closed surface with genus greater than $1$. Give an example of two loops on $S$ which are not homotopic, but are homologous to each other.   I need help solving this question. I have read the Wikipedia page on it and I realize that it does not contain the necessary knowledge to visualize this problem.  And I was also wondering the relation between the fundamental group $\pi_1(S)$ and the first homology group $H_1(S)$? Some restrictions is that $S$ is a closed surface and the genus is greater than $1$. Segmentation fault on large array sizes How can I automatically forward Facebook messages to my email or phone? I can create email addresses that forward to other email addresses.  Likewise, can I automatically forward Facebook messages to either my email or phone? If $A$ is a square matrix and $A^2 = 0$ then $A=0$. Is this true? If not, provide a counter-example. "Element is no longer attached to the DOM” StaleElementReferenceException when selecting HTML table row I am using Selenium 2/WebDriver for automation. I have a table and am trying to select a row in it. When the test runs, I can see the row become highlighted as if it is clicked, but then immediately I get the "org.openqa.selenium.StaleElementReferenceException: Element is no longer attached to the DOM" error and the test fails.  The code is the following:  @Test public void rowSelection() throws Exception {     SeleniumHelper helper = new SeleniumHelper();     action = new SeleniumActionHelper(driver);      helper.login();      String testUrl = navigateToUrl("option/listOptions.xhtml");     driver.get(testUrl);      WebElement table = findElementById("tableSection:dataTableWrapped_data");     List&lt;WebElement&gt; allRows = table.findElements(By.tagName("tr"));     for (WebElement row : allRows)         {             List&lt;WebElement&gt; cells = row.findElements(By.tagName("td"));             for (WebElement cell : cells)             {                 WebElement listName = cell.findElement(By.xpath("./* [text()='body_build']"));                 listName.click();             }         } }   I have put a Thread.sleep(2000) in front and after the listName.click() action, but neither has helped. Any help would be greatly appreciated. "In the case of medical diagnostics, there is a cost associated with each medical procedure that provides additional information (blood test, x-ray, etc.)."   Should that end with "etc.).", "etc)." or "etc.)"? Permanently turn off new Google Maps and go back to old one I found new Google Maps slow, useless (routes with only two points) and wrong. Is there any way, I can turn it off completely and go back to favored old Google Maps? Or is this &mdash; as with everything in Google &mdash; one way trip?  I found  text on this matter, but it seems useless. I have the feeling, that it discuss something completely different. It says about lite indicator in bottom-right corner. I don't have something like that. And provided links, that should switch new Google Maps engine between WebGL and canvas-based, simply doesn't work. All of them opens new window with annoying advertisment about new maps.  I even tried pasing part of URL, they're talking about (force=canvas) into any URL that my new Google Maps uses. Of course without any luck.  So... is there any way, I can get rid of new Google Maps, once and permanently?  UPDATE: In these days (April, 2015) Google , that soon new Google Maps will be the only one available. To my extremely negative surprise, this question will become invalid soon! :( What is the formula for percent of frame filled at a specific distance and focal length? Probability Problem with $n$ keys A woman has $n$ keys, one of which will open a door. a)If she tries the keys at random, discarding those that do not work, what is the probability that she will open the door on her $k^{\mathrm{th}}$ try?  Attempt: On her first try, she will have the correct key with probability $\frac1n$. If this does not work, she will throw it away and on her second attempt, she will have the correct key with probability $\frac1{(n-1)}$. So on her $k^{\mathrm{th}}$ try, the probability is $\frac1{(n-(k-1))}$ This does not agree with my solutions.   b)The same as above but this time she does not discard the keys if they do not work.  Attempt: We want the probability on her $k^{\mathrm{th}}$ try. So we want to consider the probability that she must fail on her $k-1$ attempts. Since she keeps all her keys, the correct one is chosen with probability $\frac1n$ for each trial. So the desired probability is $(1-\frac{1}{n})^{k-1} (\frac1n)^k$. Again, does not agree with solutions.  I can't really see any mistake in my logic. Can anyone offer any advice? Many thanks When can uncountable nouns be countable? Integrating Knowledge into an existing website Is there a way to transfer more than one Pokemon at a time? Is there a way to transfer more than one Pokemon at a time to the professor?  Or possibly an addon that gives me this ability?  Vendoring all the trash Pokemon for candies individually is really annoying and time consuming. How can I install a package without root access? I have no root access on this machine.  I would like to know if there is a way I can download Ubuntu packages and install them as non-root?  Probably in my ~/bin or ~/usr/share or something like that? Would that work? Prediction in Cox regression I am doing a multivariate Cox regression, I have my significant independent variables and beta values. The model fits to my data very well.   Now, I would like to use my model and predict the survival of a new observation. I am unclear how to do this with a Cox model. In a linear or logistic regression, it would be easy, just put the values of new observation in the regression and multiply them with betas and so I have the prediction of my outcome.  How can I determine my baseline hazard? I need it in addition to computing the prediction.  How is this done in a Cox model? Been trying to this line to parse for a good 20mins, but all attempts have failed:  \beta = $-$0.84, t = $-$2.09, P = 0.04   Could anyone tell me why I'm getting a Missing $ inserted error here? Prove that $\liminf x_n = -\limsup (-x_n)$ Pullback of a Volume Form Under a Diffeomorphism. I have an exercise here, which I have no idea how to do.     Problem: Let $ U $ and $ V $ be open sets in $ \mathbb{R}^{n} $ and $ f: U \to V $ an orientation-preserving diffeomorphism. Then show that   $$   {f^{*}}(\text{vol}_{V}) = \sqrt{\det \! \left( \left[   \left\langle {\partial_{i} f}(\bullet),{\partial_{j} f}(\bullet) \right\rangle   \right]_{i,j = 1}^{n} \right)} \cdot   \text{vol}_{U}. $$   Notation:         $ \text{vol}_{U} $ and $ \text{vol}_{V} $ denote the volume forms on $ U $ and $ V $ respectively.   $ f^{*}: {\Lambda^{n}}(T^{*} V) \to {\Lambda^{n}}(T^{*} U) $ denotes the pullback operation on differential $ n $-forms corresponding to $ f $.