Is there any way to save processing.run("native:algorithm") output directly to string instead of file or temporary layer?  I'm aware of saving output to layer and exporting features using QgsJsonExporter(), however it adds ID to every feature therefore it's not what I'm looking for.  Now I'm going for approach where extra ID is generated for every feature in geojson result is generated. However then I change OUTPUT to file.geojson there are no extra IDs.  vl = QgsVectorLayer(sys.argv[1],"mygeojson","ogr")  def runProcessingNativeBuffer(inputGeoJson, distance):     processing.algorithmHelp("native:buffer")     return processing.run("native:buffer",                          {'INPUT': inputGeoJson,                           'DISTANCE': distance, 'SEGMENTS': 5,                           'END_CAP_STYLE': 0, 'JOIN_STYLE': 0,                           'MITER_LIMIT': 2, 'DISSOLVE': False,                           'OUTPUT': "TEMPORARY_OUTPUT"})  ats = runProcessingNativeBuffer(vl, sys.argv[2])  vl1=ats['OUTPUT']  features = vl1.getFeatures() exporter = QgsJsonExporter() print("GEOJSON",exporter.exportFeatures(features))
I run processing.run(&quot;native:buffer&quot;) and from newly created vector I get all features and export them to string using QgsJsonExporter(). My problem is that newly created vector gives new IDs to all features and they aren't equal to attribute ID's values. And after exporting them to GeoJSON using QgsJsonExporter() I get GeoJSON features with identifiers. However I can solve this by declaring processing.run(&quot;native:buffer&quot;) algorithm OUTPUT to .geosjon file and opening it afterwards. Is there a way that I can get GeoJSON string without IDs without having to save OUTPUT to .geojson and reading it to string afterwards. vl = QgsVectorLayer(sys.argv[1],&quot;mygeojson&quot;,&quot;ogr&quot;)  def runProcessingNativeBuffer(inputGeoJson, distance):     processing.algorithmHelp(&quot;native:buffer&quot;)     return processing.run(&quot;native:buffer&quot;,                          {'INPUT': inputGeoJson,                           'DISTANCE': distance, 'SEGMENTS': 5,                           'END_CAP_STYLE': 0, 'JOIN_STYLE': 0,                           'MITER_LIMIT': 2, 'DISSOLVE': False,                           'OUTPUT': &quot;TEMPORARY_OUTPUT&quot;})  ats = runProcessingNativeBuffer(vl, sys.argv[2])  vl1=ats['OUTPUT']  features = vl1.getFeatures() exporter = QgsJsonExporter() print(&quot;GEOJSON&quot;,exporter.exportFeatures(features))  IDs in properties are fine I don't need additional IDs in &quot;features&quot;
In sysctl, the /proc/sys/net/ipv[46]/conf/ keys have the following subkeys: all, default, and a key for each network interface. For example, on a machine with a single network interface eth0, it will look like this:  iserv ~ # ll /proc/sys/net/ipv[46]/conf/ /proc/sys/net/ipv4/conf/: insgesamt 0 dr-xr-xr-x 0 root root 0 12. Sep 23:30 all/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 default/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 eth0/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 lo/  /proc/sys/net/ipv6/conf/: insgesamt 0 dr-xr-xr-x 0 root root 0 12. Sep 23:30 all/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 default/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 eth0/ dr-xr-xr-x 0 root root 0 12. Sep 23:30 lo/   All the respective settings exist in each key separately. For example, if I want to disable IPv6 Router Advertisements with the accept_ra value, this value exists four times:  iserv ~ # sysctl -a 2&gt;/dev/null | grep "accept_ra " net.ipv6.conf.all.accept_ra = 1 net.ipv6.conf.default.accept_ra = 1 net.ipv6.conf.lo.accept_ra = 1 net.ipv6.conf.eth0.accept_ra = 1   My question now is: which of these values do I need to change? I figured all (to change all existing interfaces) and default (to change all new interfaces that may appear later), but changing these still leaves the value at 1 for lo and eth0:  iserv ~ # sysctl -w net.ipv6.conf.all.accept_ra=0 net.ipv6.conf.all.accept_ra = 0 iserv ~ # sysctl -w net.ipv6.conf.default.accept_ra=0 net.ipv6.conf.default.accept_ra = 0 iserv ~ # sysctl -a 2&gt;/dev/null | grep "accept_ra "   net.ipv6.conf.all.accept_ra = 0 net.ipv6.conf.default.accept_ra = 0 net.ipv6.conf.lo.accept_ra = 1 net.ipv6.conf.eth0.accept_ra = 1   Will the machine now accept Router Advertisements on eth0, or will it not? Getting image dimensions without reading the entire file Distribution of linear combination of OLS regression coefficients I have a simple linear OLS regression $Y_i = \alpha+ \beta_1 X_{1i} + \beta_2 X_{2i} + e_i$ where $e_i \sim N(0,\sigma)$. I have estimated the regression from the data and obtained estimates for my coefficients as well as the corresponding covariance matrix. Assume my dataset is large (>500)  Now I would like to construct the 95% confidence interval for $Z = a_1 \beta_1 + a_2 \beta_2$. My first thought was that I could assume that Z follows a normal distribution because my regression coefficients are approximately normal and a linear combination of normal variables is also a normal variable. I do find some sources where they treat $Z$ as a normal random variable.  But now I am in doubt because I found that a linear combination of normal random variables is only normal if they are independent. So is it still save to assume $Z$ is random? Given a group $ G $, how many topological/Lie group structures does $ G $ have? Age replacement policy for hard disks and SSDs at servers I'm planing an age replacement policy for our storage and servers. Most of them are for DBs and some for images (static content) so yes, they have an huge I/O everytime.  Also, we use Samsung 840 Pro SSDs for the RAID Controllers (PERC H700i) as CacheCade.  Are you guys managing the replacement of old hard drives and solid state drives? I have been taught to use the if I had form in conditional clauses referring to the past:     If the president had asked me, I would have told him the same thing.   As far as I can tell though, the would have construct is sometimes used in conditional clauses as well, so it wouldn't be incorrect to say:     If the president would have asked me, I would have told him the same thing.   What is the difference between the two and the proper use of the latter? Summing the power series $\sum\limits_{n=0}^\infty (-1)^n \frac{x^{2n+1}}{2n+1}\prod\limits_{k=1}^n\frac{2k-1}{2k} $ I'd like to determine the function corresponding to the following power series: $$x + \sum_{n=1}^\infty (-1)^n\frac{1\cdot3\cdot5\cdots(2n-1)}{2\cdot4\cdot6\cdots2n} \frac{x^{2n+1}}{2n+1}, $$ where $|x|&lt;1$. Direct observations of a black hole? I'm not very knowledgeable about physics generally, but know that nothing can escape a black hole's gravitational pull, not even light (making them nearly invisible?).   My question is: What has been obtained from direct observation of a black hole to prove their existence? Please note that I'm not questioning the existence of black holes, but am just curious as to how we have come to realize it. Windows batch command(s) to read first line from text file How can I read the first line from a text file using a Windows batch file? Since the file is large I only want to deal with the first line. As I prefer outer parentheses to grow larger in nested expressions, I happen to insert \bigl and \bigr and its larger cousins a lot. I have always wondered whether there is a way to do this automagically.  Inserting \left and \right prophylacticly before all opening and closing parentheses and hoping that it sorts things out doesn't do the trick in all cases as seen below.  The left column is without any size changing commands. The middle column as a \left \right pair at every parentheses/brace/bracket and the rightmost column shows my preferred version.    As seen in the middle column of the second and third line the \left and \right pair sometimes makes the outer parentheses larger, on the cost of an extra horizontal space between \Pr and (. The extra space is fine in case of really big opening parentheses but here I'd prefer the regular spacing.  \documentclass{scrartcl} \usepackage{amsmath} \usepackage{amsfonts} \begin{document} \begin{align*} &amp;1-(1-F(x))^n&amp;&amp;1-\left(1-F(x)\right)^n&amp;&amp;1-\bigl(1-F(x)\bigr)^n\\ &amp;\Pr(X_{(1)}\le x)&amp;&amp;\Pr\left(X_{(1)}\le x\right)&amp;&amp;\Pr\bigl(X_{(1)}\le x\bigr)\\ &amp;\mathbb{E}[\min\{X_1,X_2\}]&amp;&amp;\mathbb{E}\left[\min\left\{X_1,X_2\right\}\right]&amp;&amp;\mathbb{E}\bigl[\min\left\{X_1,X_2\right\}\bigr]\\ &amp;\left(\pi-\arccos(\frac{y}{r})\right)&amp;&amp;(\pi-\arccos\left(\frac{y}{r}\right))&amp;&amp;\left(\pi-\arccos \left(\frac{y}{r}\right)\right) \end{align*} \end{document}   As mathematical expressions can be arbitrarly complex there is probably no general way to do this. But I’m not asking for a solution of the general case. A partial solution that works in the simple cases shown above would be a big help. The simple rule could be, that parentheses never shrink below the size of an inner pair. Of course you can immediately think of extensions like a \mid in a conditional expectation that grows with the size of the expectation’s brackets.  What is your preference regarding the size of nested parentheses? Is there a better way to archieve your preferred style despite inserting \bigl \bigr manually?    EDIT:  A colleague pointed me to section 8.3 of Herbert Voß’  document where size problems with parentheses are solved by playing with two TeX parameters within a group around the expression in question. This led naturally to appendix G of the TeXbook where the mechanics of \delimitershortfall and \delimiterfactor are explained.  \delimitershortfall specifies the maximum space not covered by a delimiter (default 5pt) and \delimiterfactor is the ratio for variable delimiters, times 1000 (default 901).  I used them to implement the never shrink below a subformular size idea from above by setting the shortfall to 0pt and the ratio to 1.0.    While it works nicely in line one and three, in line two and four the parentheses now grow too much, and still there is the extra horizontal space introduced by \left. Exclusive differences Profiles vs permission sets? I understand, the differences between Profiles and Permission Sets. I just wanna ask are there some configs that make Profile or Permission Set unique.  Are there things that could only be done via permission set and not via Profiles and vice versa ? Whenever we have a changing magnetic flux through a conductor an induced electric field is generated. It is often said that these induced electric field lines are circular in shape.But why is this so?Why are these field lines not elliptical for example? How can this shape be mathematically derived?  Also does this have anything to do with equipotential surfaces?Do such non-conservative electric fields even produce a potential field?If not why? Where can I find the application executables in the filesystem? Sobolev inequality If $f\in H^2(\mathbb R^2)$, I want to show that    $||f||_{L^\infty}\le c||f||_{H^2}$ $||f||_{L^\infty}\le c||f||_{H^1} [1+\ln(1+||f||_{H^2})]$   For 1, I use $||f||_{L^\infty}\le \sup_{x\in \mathbb R^2} |f|\le\int_{\mathbb R^2} |\hat f(\xi)|d\xi = \int(1+|\xi|^2)^{-1}(1+|\xi|^2)|\hat f(\xi)|d\xi \le (\int (1+|\xi|^2)^{-2}d\xi)^2(\text {which is integrable in this case})||f||_{H^2}\to \text{is this correct?}$   But for 2, I am stucked. How can I get the "ln"? and how can I make it into a product of $H^1$ and $H^2$ norm? Has 'Ubuntu Software' been renamed to 'Snap Store'? I updated Ubuntu last night (sudo apt get update &amp;&amp; sudo apt get upgrade) and to  my surprise this morning I didn't find the 'Ubuntu Software' app and there's a new entry called 'Snap Store' which when opened looks just like the old 'Ubuntu Software' app. So has 'Ubunu Software' been renamed to 'Snap Store'? And if yes, why? "error: XDG_RUNTIME_DIR not set in the environment." when attempting to run nautilus as root I am attempting to run nautilus as root but when I run "sudo nautilus" from the terminal, I get the following error:     error: XDG_RUNTIME_DIR not set in the environment.      (nautilus:9341): Gtk-WARNING **: cannot open display:   The issue does not occur when I attempt to run nautilus as non-root. I am using ubuntu 14.04. Does anyone know how I can fix this? Using QGIS3 Processing algorithms from standalone PyQGIS scripts (outside of GUI) I'm writing a script which must work outside of QGIS GUI. I call some API functions from qgis.core but I'd like to use the processing plugin.  I'm able to import processing with sys.path.append() but I can't run any process. Moreover, all "native" algs are missing in QgsApplication.processingRegistry().algorithms()  So is it possible to run processing that way ? What am I missing ?  import os, sys from qgis.core import * QgsApplication.setPrefixPath('/usr', True) qgs = QgsApplication([], False) qgs.initQgis()  sys.path.append('/usr/share/qgis/python/plugins') from processing.core.Processing import Processing Processing.initialize() import processing  layer1 = QgsVectorLayer('data/ROUTE_PRIMAIRE.SHP') layer2 = QgsVectorLayer('data/ROUTE_SECONDAIRE.SHP')  processing.run('qgis:union', layer1, layer2, 'test.shp') # returns nothing   I'm on QGIS 3.0.1 - Debian 9 Database synchronization between dev/staging and production I have an ASUS N550JK laptop (BIOS version 204) running Ubuntu 14.04 (3.13.0-43-generic kernel).  My issue is that the battery indicator ALWAYS shows that it's using battery power - even when plugged in and fully charged. So even though I have selected to show the battery status in the menu bar only when charging or in use (in power settings), it is ALWAYS displayed. When it reaches a full charge, the indicator icon will either show just the percentage (usually 99% or 100%), or sometimes a very big number for time (like 22:14) along with the percentage. If I go to the power settings menu, it always says "Using battery power", with something like 40 hours remaining. This is all while plugged in and fully charged.  Are there any fixes less drastic than trying to update BIOS, or is a BIOS update necessary to fix this? The latest BIOS version is 208 according to the ASUS website, but the (very brief) descriptions of the updates don't mention anything about battery issues. If at all possible I'd like to avoid updating BIOS because of the risk involved.  I've already tried letting the battery drain all the way and then charging to full, with no luck.  Thanks in advance! lstlisting - line number gaps Is it possible to add non-number characters on the left of a code block?  Specifically, I want to add ... to correspond with some source code (see image).    I am currently using commands to stop / start the line numbers. Here is the code:  \documentclass[12pt]{article}  \usepackage[a4paper, margin = 20mm, top = 30mm, bottom = 25mm]{geometry} \usepackage{xcolor, soul} \usepackage{listings}  \definecolor{codebackground}{rgb}{0.95, 0.95, 0.92}  \lstset {     frame            = tb, % hrule above and below     keepspaces       = true,     columns          = flexible,     basicstyle       = {\normalsize\ttfamily},     escapeinside     = {(*@}{@*)}, % for escaping     backgroundcolor  = \color{codebackground},     showstringspaces = false,     language         = C,     keywordstyle     = \color{blue},     stringstyle      = \color{red},     commentstyle     = \color{teal},     numbers          = left, % {none, left, right}     firstnumber      = 1,     numberstyle      = \scriptsize\color{black},     numbersep        = 5pt }  \let\origthelstnumber\thelstnumber \makeatletter % for stopping line numbers \newcommand*\stopnumber {     \lst@AddToHook{OnNewLine}     {         \let\thelstnumber\relax         \advance\c@lstnumber-\@ne\relax     } } % for starting line numbers \newcommand*\startnumber[1] {     \setcounter{lstnumber}{\numexpr#1-1\relax}     \lst@AddToHook{OnNewLine}     {         \let\thelstnumber\origthelstnumber         \refstepcounter{lstnumber}     } } \makeatother  \begin{document} \begin{lstlisting}[firstnumber = 456] int third_function(const int c) {     /* error checking */     if(c &lt; 0)     {         return;     } (*@ \stopnumber @*)      ...     (*@ \startnumber{512} @*)     /* other stuff */     int d = 4;     char* word = "third function"; (*@ \stopnumber @*)      ...     (*@ \startnumber{678} @*)     return (c * d); } \end{lstlisting} \end{document}