Integrating zXing in android
QR code scanner
Object Positions Reset On Blender Load So I am attempting to make a modular environment in Blender, so I'm modeling many pieces in one scene to make sure they all match up properly before separating them out.  However, whenever I restart Blender after saving and closing it, many of my grouped objects (and their subobjects) have positions reset NOT to where I placed them.  For example, take a look at this:   Here you can see that the door pieces are in the "open" state, when I left them closed AND the "column" for the wall on the left has been moved from being flush with the wall (on the side) to being inside it.  It appears to be trying to move all of the objects to 0,0,0 which is what is messing this up. I'm not sure if it's an object hierarchy problem, but here is my hierarchy if anyone has ideas there:  Wall_Normal (parent)   Wall_Normal_Column (child)   Empty Axis Object (parent)   Door_Left (child a) Door_Right (child b)   Is there a reason why object positions (and their relative subobjects) aren't being saved? One of the joys of high-school mathematics is summing a complicated series to get a “closed-form” expression. And of course many of us have tried summing the harmonic series $H_n =\sum \limits_{k \leq n} \frac{1}{k}$, and failed. But should we necessarily fail?      More precisely, is it known that $H_n$ cannot be written in terms of the elementary functions, say, the rational functions, $\exp(x)$ and $\ln x$? If so, how is such a theorem proved?    Note. When I started writing the question, I was going to ask if it is known that the harmonic function cannot be represented simply as a rational function? But this is easy to see, since $H_n$ grows like $\ln n+O(1)$, whereas no rational function grows logarithmically.  Added note: This  asks a similar question for “elementary integration”. I guess I am asking if there is an analogous theory of “elementary summation”. Given I have Drupal 9 composer installation with composer-patches plugin and given a contrib module with a stable v8 release, but no v9 release (not even dev branch) and given that contrib module has a working v9 patch in the issue queue  is there any method to install that module + patch in composer? Even if I manually add both, the package and patch, to my composer.json, I still can't require or update this module with composer due conflicting versions. I really want to avoid duplicating /contrib code into my project's /custom codebase. My current workaround is:  forking that module to my own, private git repo applying patch there creating a new composer.json in my private git, and changing the package vendor to my custom_private_vendor adding my private git as VCS repo in the D9 project's composer.json and then composer require custom_private_vendor/contrib_module  This fulfills my goal of not duplicating the contrib module in my project's custom codebase, but every time I do this I feel the urge to wash my dirty hands. Is there something more elegant like composer require drupal/contrib_module --apply-patch-first or can I somehow target drupal.org's git with a specific patch included? Lemma vs. Theorem I've been using Spivak's book for a while now and I'd like to know what is the formal difference between a Theorem and a Lemma in mathematics, since he uses the names in his book. I'd like to know a little about the ethymology but mainly about why we choose Lemma for some findings, and Theorem for others (not personally, but mathematically, i.e. why should one classify a finding as lemma and not as theorem). It seems that Lemmas are rather minor findings that serve as a keystone to proving a Theorem, by that is as far as I can go.  NOTE: This  doesn't address my concern, so please avoid citing it as a duplicate. Please stop using SoftwareEngineering.SE as your toilet bowl Stack Overflow users have been using the "off topic - belongs on SoftwareEngineering.SE" close reason as an alternative to all the other close reasons. It'd be helpful if people actually read the FAQ and the six  before voting to migrate questions like:   , no redeeming value to favorite lists that become argumentative , "help my exact situation" questions are too localized , fails 5 out of the 6 guidelines , fails 4 out of 6 , too localized and too vague , too broad   Absent a reversal of the Stack Overflow community from viewing SoftwareEngineering.SE as the Stack Overflow cesspool, can the "off topic - belongs on SoftwareEngineering.SE" close reason be removed in favor of manual migration by moderators who can actually spend the 10 seconds to determine if the question should be closed outright first?    To say that SoftwareEngineering.SE is such a nebulous place and nobody knows what its scope is as the reason why crappy questions keep getting migrated there is to miss the point. Good questions are good questions on all of the sites, and questions that are too vague, that are too argumentative, too localized, and too broad are universal close reasons. There is no special dispensation for SoftwareEngineering.SE to have bad questions, even if you personally think the questions on there suck.  Even the six subjective guidelines for subjective questions are universal guidelines: they affect all sites. So even if you had no idea what the consequences of using the "off topic - belongs on SoftwareEngineering.SE" close reason were, there are still all of the other close reasons for which bad questions, like the ones above, can be closed. How does the lens diameter influence photo quality? I have tested two different 50mm lenses in my camera. One was a Nikkor 50mm ∅52mm. The other one was a Sigma 50mm ∅72mm. I took some pictures with both lenses using the same setup for aperture and shutter speed, but couldn't notice significant differences in the quality of the pictures.   So, how does the diameter affects the photo quality, if it does? What advantages would the ∅72mm lens have over the ∅52mm one? Prove that if $a^2 = a$ for all elements of the ring $R$, then $R$ has characteristic 2. Is the converse of the statement true?  Attempt:  by the definition of characteristic of a ring, the first statement implies that characteristic of the ring is $\leq 2$. If the ring is assumed to be non trivial ring then, characteristic is 2.  About the last statement can we construct a field of say 8 elements and show that there exists a an element of order $\neq 2$?  Is there a simpler example ? How to remove zsh alias? I have a ASUS R500A notebook.Original OS is Windows 7 64bit.Few days ago I tried to Install Windows 8.1 64 bit version.But it failed &amp; error message is,     windows cannot be installed on this disk. The selected disk is of the GPT partition style.   My Steps: First i Deleted C: Partition ( Already installed windows 7 ). Then i Formatted that partition. Tried to install Windows 8.1 64bit.  In this hard disk i have another several partitions with Important data.  How do i Install Windows 8.1 without loosing Data from the Other partitions ? I really enjoying using control+r to recursively search my command history. I've found a few good options I like to use with it: # ignore duplicate commands, ignore commands starting with a space export HISTCONTROL=erasedups:ignorespace  # keep the last 5000 entries export HISTSIZE=5000  # append to the history instead of overwriting (good for multiple connections) shopt -s histappend  The only problem for me is that erasedups only erases sequential duplicates - so that with this string of commands: ls cd ~ ls  The ls command will actually be recorded twice. I've thought about periodically running w/ cron: cat .bash_history | sort | uniq &gt; temp.txt mv temp.txt .bash_history  This would achieve removing the duplicates, but unfortunately the order would not be preserved. If I don't sort the file first I don't believe uniq can work properly. How can I remove duplicates in my .bash_history, preserving order? Extra Credit: Are there any problems with overwriting the .bash_history file via a script? For example, if you remove an apache log file I think you need to send a nohup / reset signal with kill to have it flush it's connection to the file. If that is the case with the .bash_history file, perhaps I could somehow use ps to check and make sure there are no connected sessions before the filtering script is run? How to find the joint PDF? Ley X,Y two random variables with density $f(x,y)=8xy \  \text{if} \   0&lt;x&lt;y&lt;1$  Find the joint distribution F(x,y).  I find that $F(x,y)=2x^2y^2-x^4\ \text{  if}  \ 0&lt;x&lt;y&lt;1$ but I dont know how to find the didtribution in other points. Novel about interstellar war: Both sides win, both sides think they lost I recall reading this novel in the &rsquo;90s; my recollection is that the author was better-known for bad fantasy than for SF (but the SF of his that I&rsquo;d read was better than his fantasy).  The story opened in media res just before a battle was joined; there is a dialogue between the captain of one of the ships and one of his crew. We never see the actual battle; we instead see the conquest of Earth by the aliens - and the conquest of the alien homeworld by Earth.  It is slowly revealed that the two sides contrived a way to both avoid the destruction of actual war, and solve their respective worlds&rsquo; respective problems of overpopulation, infrastructure decay, et multae ceterae. We also see that the solution was that the conquering aliens were secretly selecting Earthmen to rule their homeworld, while the humans were selecting aliens to rule Earth.  About halfway through, there is suddenly a third world that must be &lsquo;conquered&rsquo; and brought into the network. The plot gets complicated after that. Sum of First $n$ Squares Equals $\frac{n(n+1)(2n+1)}{6}$ I am just starting into calculus and I have a question about the following statement I encountered while learning about definite integrals:  $$\sum_{k=1}^n k^2 = \frac{n(n+1)(2n+1)}{6}$$  I really have no idea why this statement is true. Can someone please explain why this is true and if possible show how to arrive at one given the other? Simple problem with Manipulate and Plot In a field that is the direct product of two fields, why isn't it a field? Suppose that we have the direct product of two fields, defined as: $\mathbb{F}^2 = \mathbb{F} \ \times\ \mathbb{F}$. Then, this is obviously not a field because we can take $(1,0)$, and this doesn't have a multiplicative inverse. However, I saw a mention to this today in a book, and the reasoning was:     "$\mathbb{F} \ \times\ \mathbb{F}$ has the zero-divisor $(1,0) \neq  (0,0)$, hence it is not a field".   (Lectures on Rings and Modules by Joachim Lambek, pg. 17).  I am not sure what they mean by zero-divisor here nor what $(1,0) \neq  (0,0)$ has anything to do with the direct product of fields not being a field. I always assumed there wasn't a multiplicative inverse, and that was it. Am I missing something deeper? Darth Vader threw Emperor Palpatine to a pit. Well, , but unlike other times, Palpatine wasn't injured or unconscious when he was thrown.  Why didn't he simply prevent his fall using his lightsaber (I have seen such action in Star Wars: The Clone Wars TV series lots of time) and make his way out? So: I have a Gantt chart created with pgfgantt where in order to fit my pages I have included  x unit=1.4cm,y unit chart=6mm   in its preamble.  This means that milestone shapes are spread out horizontally.  How can I change the vertical and horizontal units of a Gantt chart in a way which doesn't affect the aspect ratios of elements like milestones? How do you search through flags in the manpages? Whenever I search the manpages, I'm almost always trying to find out what's going on with a specific flag. For example, when searching the man pages for  I was searching the for -f flag. I'm not sure how to say, quickly get to the flag which is here:  OPTIONS    General options        -f FORMAT, -r FORMAT, --from=FORMAT, --read=FORMAT   and filter out stuff like:  iconv -t utf-8 input.txt | pandoc | iconv -f utf-8              or  pandoc -f markdown -t latex hello.txt   I've tried searching for /-f, and I've looked at  and tried (^|\s)-f($|\s\) but it was invalid. So I'm wondering how do you quickly search less for "only the flag -f"?  Would love your thoughts or some other tool that you use to quickly go through documentation How to delete ".."-folder under Windows? I have a folder on my desktop which is named ".." (which itself contains subfolders with an empty name). The folder can't be deleted the usual ways, even not when using the CLI. Does anyone know how I can remove this folder on Windows Vista 64-bit?  Renaming does not work, either (obviously).  This is what "dir /x" echoes:  09.10.2009  15:04    &lt;DIR&gt;                       . 09.10.2009  15:04    &lt;DIR&gt;                       .. 08.03.2007  11:18    &lt;DIR&gt;                       cgi-bin                0 Datei(en),              0 Bytes                3 Verzeichnis(se), 45.866.037.248 Bytes frei Numpy installation? I used VIRTUALBOX to install Ubuntu 12.04 on my windows pc. I used apt-get to install Python 2.7 that shipped with 12.04. I followed the directives I saw on this site to install Numpy, Scipy, Matplot all failed. I download tar source file of these modules. How do I install them manually? Someone pls help, I'm getting frustrated.