Why does QGIS spontaneously corrupt shapefile data? I'm using QGIS 2.14 (Mac), but I have had the same problem with 2.8 (Ubuntu). When I am editing a shapefile, QGIS seems to spontaneously corrupt the data in unpredictable and catastrophic ways that include:   Duplication of features Deletion of features Scrambling of attribute data   Most recently, this occurred while using the Table Manager plugin to rename a column of the attribute table. Upon saving the change, one of the columns of the attribute table (not the one being renamed) was suddenly scrambled such that features were unpredictably reclassified, completely corrupting the file and forcing me to reload a backup version.    The problem seems to be associated with saving, though I usually don't discover the corruption until some time after it occurred, so I can't say for sure what the circumstances were in most cases, the exception being the case described above.   I realize this might be the same problem described here    If so, it is evidently still a problem in 2.14, and there was never a satisfactory answer provided. If not, does anyone have a clue as to what is going on? This makes QGIS completely unusable.   -------------- EDIT ---------------  I was able to replicate the result by reloading a backup version and repeating the renaming and saving that precipitated the corruption the first time. The problem seems to be specifically with the Table Manager plugin, similar to what was reported here:   Apparently it remains unresolved, so I guess one should stay away from Table Manager for the time being.
QGIS corrupting shapefiles? I'm hoping someone out there might be able to help or suggest some tests to try and resolve some very odd QGIS behaviour of late...  Our core GIS team of 4 users has been testing v2.10 prior to roll-out for the remainder of the organization.  In the past couple of weeks we have had some very odd shapefile corruption things happening and are yet to isolate or identify a potential cause...  These have included:   Editing one line (using the scissor tool to split into two records) and having the resulting records attributes completely replaced by attributes from another geometry no-where near the edited row (spatially or in the attribute dbf) Line geometries completely disappear while their attributes get associated with an unrelated geometry  Line geometry get partially deleted and replaced with a vertice in infinity (line visually extends beyond the dataset and no matter how far zoomed out you never see the end)   The above is happening in a polyline layer, that we did discover has some multi-line geometries..? Perhaps this is impacting... but never saw this issue with v2.8 and the same layer. The layer has undergone MANY save-as's in the past week and many verify geometry checks as we thought invalid geometry may have been the cause...  In another separate layer yesterday, to a separate user (me) i created a layer with approx 30 polygons... adding, deleting some and doing some 'avoid intersection' to remove overlaps. Layer looks fine in qgis, saved and also a save-as to a completely new file but when i load into ArcGIS online (and later is ArcMap as a test) some of the overlaps and deleted objects are still there. Close and reopen qgis,  reopen the file and they are definitely not.  The project was created in v2.8 that i was editing in (but had been saved in 2.10).  Does anyone have any ideas/suggestions.  We do still have 2.8 installed as well as 2.10? We have never encountered issues like this when testing other new qgis versions while still running old ones?
Do I have to move swap partition to the right side? According to  I just expand my sda4 to include unallocated space, my question is after create 2 new partitions sda7, sda8, do I need to move the swap partition to the most right of the disk? (I really don't know this, I saw  which moving the swap partition to the right side)  Thanks. How can continue the equation of the rectangle red in next line?   \documentclass[11pt,a4paper,twocolumn]{article}  ...  \begin{equation*}     \left| \dot{r} \right| =     \sqrt{{- \, {e}^{-t} \left( \cos t + \sin t \right)}^{2} \, + \, {{e}^{-t} \left( \cos t + \sin t \right)}^{2} \, + \, {(- \, {e}^{-t})}^{2}} \end{equation*} Quantum Field Theory from a mathematical point of view I'm a student of mathematics with not much background in physics. I'm interested in learning Quantum field theory from a mathematical point of view.  Are there any good books or other reference material which can help in learning about quantum field theory? What areas of mathematics should I be familiar with before reading about Quantum field theory? Per the kernel documentation:  This control is used to define how aggressive the kernel will swap memory pages.  Higher values will increase aggressiveness, lower values decrease the amount of swap.   However this is kind of vague. I'm trying to figure out exactly what the parameter ultimately controls. I know it adjusts how aggressively the kernel tries to swap out pages, but what decision making process in the kernel code does it affect?  Does it adjust how long ago a page must have been accessed before the kernel swaps it out? If so what does the default value of 60 represent? And how much is changed by a increment/decrement of 1 (a formula would be nice)? Or does it swap out pages based on their access frequency? Or something else? I am attempting to write a filter using something like sed or awk to do the following:   If a given pattern does not exist in the input, copy the entire input to the output If the pattern exists in the input, copy only the lines after the first occurrence to the output   This happens to be for a "git clean" filter, but that's probably not important. The important aspect is this needs to be implemented as a filter, because the input is provided on stdin.  I know how to use sed to delete lines up to a pattern, eg. 1,/pattern/d but that deletes the entire input if /pattern/ is not matched anywhere.  I can imagine writing a whole shell script that creates a temporary file, does a grep -q or something, and then decides how to process the input. I'd prefer to do this without messing around creating a temporary file, if possible. This needs to be efficient because git might call it frequently. How to integrate $\int_0^{\infty} \frac{e^{ax} - e^{bx}}{(1 + e^{ax})(1+ e^{bx})}dx$ where $a,b > 0$. Language Options -> Spell Checking in Windows 10 version 1803 How to Map a subset of list elements to a function? Multiplicative inverse in $\operatorname{GF}(2^8)$? I know how to do multiplication over ${\rm GF}(2^8)$:  uint8_t  gmul(uint8_t  a, uint8_t  b) {     uint8_t p=0;     uint8_t carry;     int i;     for(i=0;i&lt;8;i++)     {         if(b &amp; 1)             p ^=a;         carry = a &amp; 0x80;         a = a&lt;&lt;1;         if(carry)             a^=0x1b;         b = b&gt;&gt;1;     }     return p; }   So, I tried to create a ${\rm GF}(2^8)$ multiplication table using this code. I've given below the values in the 3rd row of the table, but I don't think they're correct:      0  1  2  3  4  5  6  7   8  9  A  B  C  D  E  F 0 1 2   0  2  4  6  8  A  C  E  10 12 14 16 18 1A 1C 1E  3 . . E F   I don't know what went wrong. I built the table by multiplying the values in the first row with those in the first column.  E.g. in the third row, I multiplied 2 &times; 0, 2 &times; 1, &hellip;, 2 &times; E, 2 &times; F.  How can I create a multiplication table for arithmetic in ${\rm GF}(2^8)$?    Also, how can I find the multiplicative inverse of a number in ${\rm GF}(2^8)$?  For example, how can I determine that the inverse of 95 is 8A?  I tried to do this using the multiplication table above, but when I took 9th row and the 5th column in the multiplication table I got 2D, not 8A. XeTeX: What happened to \mathcal and \mathscr? Recently I switched from pdflatex to xelatex to be able to use OpenType fonts. I like to use variables highlighted using \mathcal for specific variables, while I used to use \mathscr-typeset variables for matrices. But when I compile with XeLaTeX they look exaclty the same.  Old code  \documentclass{standalone} \usepackage{mathrsfs} \begin{document} $\mathcal{C} = \mathscr{C}$ \end{document}   Output        New code  \documentclass{standalone} \usepackage{unicode-math} \begin{document} $\mathcal{C} = \mathscr{C}$ \end{document}   Output        Broken code  I tried to get back the glyphs from mathrsfs, but it failed this way.  \documentclass{standalone} \usepackage{unicode-math} \usepackage{mathrsfs} \begin{document} $\mathcal{C} = \mathscr{C}$ \end{document}   Output        Question: How can I get back the behaviour? In principle I'd like to have the old \mathcal letters from the pdflatex-version of Computer/Latin Modern.    Alternate solutions (Addendum 2016/05/11) How do I execute PHP that is stored in a MySQL database? I'm trying to write a page that calls PHP that's stored in a MySQL database. The page that is stored in the MySQL database contains PHP (and HTML) code which I want to run on page load.  How could I go about doing this? "There are a good many scholars ..." is it right? In "Seeing like a state" of James C.Scott there is a sentence at the beginning of a paragraph (Acknowledgements xi):     There are a good many scholars whose writings opened up new   perspectives for me or provided outstanding analyses of issues that I   could not have hoped to study so comprehensively on my own.   What worries me is a good many scholars. Is this some type of inversion or ancient English? Is this grammatically right? Why is a here? I thought that appropriate version would be There are many good scholars. Am I wrong? How do I redirect to another webpage? I found the .bashrc file and I want to know the purpose/function of it. Also how and when is it used? I caught an Eevee, which of its evolutions will it evolve into? So I just caught an Eevee. Now, I need 25 candies to evolve it. The fact is that in the GameBoy color versions, that Pokémon needed a stone to evolve instead of experience. Depending of the stone he was fed with (thunder, water or fire), he was evolving in a different Pokémon.   Is the stone feature also in Pokémon Go? If not, what decide the evolution of this Pokémon?   Bonus point : If it's possible, how can I get a stone? How do I declare a 2d array in C++ using new? What can you use Python generator functions for? I'm starting to learn Python and I've come across generator functions, those that have a yield statement in them.  I want to know what types of problems that these functions are really good at solving. Suppress "In:" biblatex Background image shows in front of 3D objects, not behind them. I've done a quick 3D track in blender and I'm trying to render my output, but the plate I used to track is showing up over my 3d objects.  I want to render the objects in the scene with an alpha channel and comp them over the plate I tracked. My renders however, are covered by the aforementioned plate.  Un-checking "Background Images" in the camera properties (only removes it from the viewport) isn't doing it for my render outputs.  Working on some production tests and am not really proficient with the software yet, my apologies in advance. What is the difference between conditioning on regressors vs. treating them as fixed?