I am trying to understand what is the effective accuracy of a georeferenced image and how to attach a standard to the georeferencing process which can be used for future reference. To explain further, I am trying to assess what kind of RMSE would be acceptable when for example georeferencing an accurate architects drawing with an aerial image, or with a small scale landuse plan drawn with thick outlines using parcel data with an accuracy of plus/minus 1cm.  If I am using an inaccurate base map in which to base my passpoints, does the rms error have any meaning whatsoever? Logically, is it not so, that one can only use the rmse as a standard when the accuracy of the basemap can be certified? If the base map is not accurate, any passpoints referenced to it would be even less accurate and an RMS error meaningless.  Am I on the right track?
This is a generic inquiry on the common practice/standard for determining the acceptable values of RMS when georeferencing topographic maps.  Is there an absolute value?  Some literature suggests that it should be "less than or equal to 1/2 of the side of a cell which make up the total resolution of the image."
I looked up several tutorials on how to install and they dont work. I do everything correctly but then i get this:     The file   '/home/mike/Downloads/minecraft.jar'   is not marked as executable.  If this   was downloaded or copied from an   untrusted source, it may be dangerous   to run.  For more details, read about   the executable bit.   I run the minecraft.jar with the Sun java runtime 6 but it doesnt work:/. Any help would be greatly appreciated! Twin Paradox, calculating spacetime intervals from both perspectives I've very recently started to try to understand special relativity. I'm want to get a decent understanding of the twin paradox. I'll post what I've done so far and highlight what's gone wrong for me.  The situation is that Alice and Bob both begin at point $x_1$ in Alice's coordinate system $(x,t)$ (we have orientated the axis so that y and z will not matter). Bob then instantaneously moves off with velocity $v$ in the positive $x$ direction. Bob's coordinate system is now $(x',t')=(\gamma (x-vt), \gamma (t-v\frac{x}{c^2}))$. In Alice's coordinates, Bob reaches point $x_2$ after having moved distance $d$, then instantly turns around and travels back to Alice at $-v$. I want to show that Alice's space time interval $\Delta s_A^2$ is greater than Bob's $\Delta s_B^2$, as each path's space time interval is proportional to the proper time passed along that path.    According to Alice: $\Delta s_A^2=-c^2\Delta t^2 + \Delta x_A^2$ where $\Delta t=\dfrac{2d}{v}$ and $\Delta x_A=0$ as she didn't move, but the time elapsed is the time it took bob to travel the distance and then come back. Thus $\Delta s_A^2=-\dfrac{4c^2d^2}{v^2}$  Still according to Alice, Bob's $\Delta s_B^2=-c^2\Delta t^2+\Delta x_B^2$, where the change in time is the same, but now bob has moved distance $d$ twice, thus $\Delta x_B=2d$ ($\Delta x$ refers to total distance traveled rather than displacement which is 0 in this case). Now we have $\Delta s_B^2=-\dfrac{4c^2d^2}{v^2}+4d^2$.     The |size| of Bob's spacetime interval now definitely smaller than Alice's, and this would be all OK, except that when I do the calculations in Bob's frame, they don't agree. This is contradictory to the fact that $\Delta s^2$ is conserved under Lorentz transformations.    According to Bob: $\Delta {s'}_A^2=-c^2\Delta t'^2 + \Delta {x'}_A^2$ where $\Delta t'=\dfrac{2d'}{v}$. I'm not sure if I'm right in saying that $v$, the relative velocity of the two frames, is the only velocity upon which both Alice and Bob will agree on, other than the speed of light. Anyway, $d=\gamma d'$ as lengths contract by $\gamma$ i.e. $d'$ is smaller than $d$ by factor $\gamma$. Also, $\Delta {x'}_A=2d'$, so we have $\Delta {s'}_A^2=-\dfrac{4c^2d'^2}{v^2}+4d'^2=-\dfrac{4c^2d^2}{\gamma ^2 v^2}+\dfrac{4d^2}{\gamma ^2}=4d^2\dfrac{v^2-c^2}{\gamma^2 v^2}\neq \Delta s_A^2$  Although I haven't included them here, my calculations for $\Delta {s'}_B^2$ and $\Delta s_B^2$ agree. Sorry for the ultra-long post, but any help would we well appreciated! Prevent pdflatex from writing a bunch of files If I create just a basic hello.tex file an compile it using   pdflatex hello.tex   The pdflatex program is creating a plethora of file which is a little annoying. Currently it writes all those files about which I really don't care:  hello.aux, hello.log, hello.nav, hello.out, hello.snm, hello.toc   Is there a way to tell pdflatex to only write hello.pdf if the build is successful ? If not, can I specify the output directory of those files ? Maybe I could just write them in /tmp. Why can't I suggest edits on SE meta sites? When you click &quot;edit&quot; on a meta site as a non-edit-privileged user, the error message appears:  Suggested edits are not allowed on non-tag-wiki posts on meta sites.  Right as I was going to post this as a possible bug, I finally found  which says that per-site Metas don't have suggested edits by-design because it's &quot;not needed&quot;. However, I've been participating a lot over at  where there is a lot still to be figured out in terms of site guidelines.  The Meta is one of the most active I've seen and a lot of the questions are really trying to gather community-built suggestions.  So maybe more of those need to be Community Wiki, but it still brings me to ask why don't per-site-metas &quot;need&quot; suggested edits? Adding bounty: The more betas I participate in, the more I don't get this. Add optional box for spam flags letting you say why you think it's spam , where a user had taken the time to look at the link on a post and realized that the post wasn't just off-topic, it was actually half-decently-disguised spam. So he flagged it as spam, and an overworked mod declined it, giving the questioner the benefit of the doubt. And we probably want mods to be giving the questioner the benefit of the doubt.  We also want to get rid of spam ASAP, and make the lives of mods easier. I'd like to suggest a feature the mod in question mused might be useful: An optional textbox where you can add a note saying why you think it's spam, so the mod can see it easily. In this case, the helpful user who went the extra mile could have written "Site linked doesn't relate at all to the question, instead solicits BitCoins" or similar.  One can leave a comment on the question, but:   People sometimes leave...unhelpful...comments on spam questions, and we don't want mods to have to take the time to read through them hoping for something useful It allows the user flagging the spam to do so and say why without calling attention to themselves publicly     Update: We may well want this for all flags, but in particular I had reason to want it for an NAA flag, so I've posted . JavaScript variables declare outside or inside loop? In C#, why can't a List object be stored in a List variable It seems that a List object cannot be stored in a List variable in C#, and can't even be explicitly cast that way.  List&lt;string&gt; sl = new List&lt;string&gt;(); List&lt;object&gt; ol; ol = sl;   results in Cannot implicitly convert type System.Collections.Generic.List&lt;string&gt; to System.Collections.Generic.List&lt;object&gt;  And then...  List&lt;string&gt; sl = new List&lt;string&gt;(); List&lt;object&gt; ol; ol = (List&lt;object&gt;)sl;   results in Cannot convert type System.Collections.Generic.List&lt;string&gt; to System.Collections.Generic.List&lt;object&gt;  Of course, you can do it by pulling everything out of the string list and putting it back in one at a time, but it is a rather convoluted solution. I need a regular expression to select all the text between two outer brackets.  Example: some text(text here(possible text)text(possible text(more text)))end text  Result: (text here(possible text)text(possible text(more text))) Why Was Peter Pettigrew Sorted To Gryffindor? A word that says a person is both female and your friend It's often confusing for me to talk about my friends, especially my female friends. This is because in Dutch there are words for both male ("vriend") and female ("vriendin") friends. In English however, there's as far as I know only the word friend, which can mean both a male or a female friend.  For this reason I was wondering if there is a word to say a person is both female and a friend. Prove that $g$ is tangent to the graph of $f$ How do I press Ctrl+Alt+Delete in VirtualBox? I'm running VirtualBox with Windows Vista as host OS and Windows Server 2008 as guest OS. To login to Windows Server I have to press Ctrl+Alt+Delete, but my host OS reacts on that so I can not send it to VirtualBox. How can I do it? Data extension values in the "Update Contact" activity in Journey Builder I'm looking for a way to use fields from a data extension (that is the entry source for a journey) in the "Update Contact" activity.  I want to create a sort of log in a different data extension. Let's say I have a sourceDEthat is used by the journey and a journeylogDE where I would like to write the email of contact that's currently in the journey.  What should I write in the value field to get a value from the currently used record in the sourceDE?  I tried {{Contact.Attribute.sourceDE.email}}, but it did not return any values.   I would appreciate it if you could give me any tips how to fix this issue. SQL to LINQ Tool Is there a tool out there which can convert SQL syntax to LINQ syntax?   I just want to rewrite basic queries with join, etc., to . It would save me a lot of time. I have a table that I want to insert on a page, but at least one (perhaps both) of the following conditions are met:   The table is too wide to fit within the text block or page. That is, I'm exceeding some horizontal restriction. The table is too tall to fit within the text block or page. That is, I'm exceeding some vertical restriction.   What are my options to make this table fit? If it doesn't fit, regardless of my attempts, what other options exist? Is there a way to get the path for the assembly in which the current code resides?  I do not want the path of the calling assembly, just the one containing the code.   Basically my unit test needs to read some xml test files which are located relative to the  dll.  I want the path to always resolve correctly regardless of whether the testing dll is run from TestDriven.NET, the MbUnit GUI or something else.  Edit: People seem to be misunderstanding what I'm asking.  My test library is located in say      C:\projects\myapplication\daotests\bin\Debug\daotests.dll   and I would like to get this path:     C:\projects\myapplication\daotests\bin\Debug\   The three suggestions so far fail me when I run from the MbUnit Gui:   Environment.CurrentDirectory gives c:\Program Files\MbUnit System.Reflection.Assembly.GetAssembly(typeof(DaoTests)).Location gives C:\Documents and Settings\george\Local Settings\Temp\ ....\DaoTests.dll System.Reflection.Assembly.GetExecutingAssembly().Location gives the same as the previous. I installed blender for the first time, so I have the latest version, 2.78c.  I played with it for a bit.  Then I discovered I couldn't save my work.  I uninstalled it and reinstalled it.  Rebooted.  Same problem.  After a little testing, I realized I CAN save to my NAS storage drive.  I cannot save on my C: drive.  Any project.  Any folder.  C: always fails.  If I run blender as Administrator, it will save to the C: drive.  But not as my normal userid.  So it sounds like a bug of some kind.  I am running Windows 10.  Bitdefender A/V.  I use OneDrive.  I have a 2TB drive installed.  All clean and purring nicely.  Is there a better way to install it?  Or some change I can make (other than always running as administrator)?    Sounds like a bug - but hopefully there's a proper solution.  Thanks,  Jerry Can "but also" be split in "not only ... but also"? I think I generally agree with the statement  When using not only . . . but also in a sentence, parallelism should be the goal. It means that the words following both parts of this correlative conjunction (i.e., not only and but also) should belong to the same parts of speech.   However, the Cambridge dictionary has an example that is not 100% parallel in my eyes, as &quot;but also&quot; is split:  Not only did she forget my birthday, but she also didn’t even apologise for forgetting it.   What I would expect, with maximum parallelism, is  Not only did she forget my birthday, but also she didn’t even apologise for forgetting it.  Is my expectation wrong? Is my formulation acceptable? All internal links on Stack Exchange sites should be protocol-relative In preparation for the eventual deployment of full HTTPS support on Stack Exchange, and also to make the currently available "alpha" HTTPS support more usable, all links from Stack Exchange sites to other Stack Exchange sites should be .  Currently, at least the following places still feature links with explicit http: protocol prefixes:   the page footer, the "Hot Network Questions" and "Community Bulletin" modules in the sidebar,  (the site switcher menu is OK, though),   and, of course,   lots and lots of user-supplied links in post and comment content.   I've posted this feature request with the intent to provide a single central place for tracking these issues, rather than having them scattered across multiple meta threads.  If you find more places on SE where protocol-relative links should be used, please report them below.  I fully expect this request, in its full sense, to be treated as  for the time being; however, these issues do need to be fixed at some point before our HTTPS support is ready for "prime time".  Ps. Yes, the next release of  (v1.10) is going to include a general client-side fix for most of these issues.  In the mean time, the  plugin effectively provides the same functionality, and much more besides. My wife wants a 4th baby, but I don't.  We have been talking about it for the last few days (talking strongly).   I have raised points such as:   We will get less time to spend with our current kids. The age gap between the first and the last will be too wide. It will cost more money. She will be out of work longer. We will need a bigger house. And we don't even have our own house yet (we are still renting). We will have to start again. Sleepless nights, nappies, feeding, new cot, car seat, etc etc.   She says:   She feels like she is missing something. She has always wanted a large family. Things will be the same regardless of having 3, or 4 kids. She agrees that money will be tighter, but wants to push through it.   Our current kids are 9 months, 2 years, and 4 years. We are young married couple (25), and I have a fairly decent job.  What would be the pros and cons of having another child?   How can we rationally talk to the other about having/or not having another child?  And what should we do if we cannot agree?