How to change PostGIS feature attributes via openlayers 3+? I am trying to find a working example of editing the attributes of a feature in a PostGIS table published in GeoServer (2.8), using Javascript libraries like openlayers (3 &amp; 4).  The closest thing I can find is  from the openlayers documentation, but it only touches geometry not attributes. In addition it is based on GeoJSON, not a database backend.  The next closest is an , but it's just a blog with a screenshot without and code snippet. Also relevant is a similar GIS.SE question: . The answer there suggests that one has to program it from javascript.   Before reinventing some wheels, can anyone give me some pointers how to implement such a function for setting the attribute of a feature?  FYI, I have copied the said openlayers 4 example below as a starting point.  &lt;!DOCTYPE html&gt; &lt;html&gt;   &lt;head&gt;     &lt;title&gt;Modify Features&lt;/title&gt;     &lt;link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css"&gt;     &lt;!-- The line below is only needed for old environments like Internet Explorer and Android 4.x --&gt;     &lt;script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"&gt;&lt;/script&gt;     &lt;script src="https://openlayers.org/en/v4.0.1/build/ol.js"&gt;&lt;/script&gt;   &lt;/head&gt;   &lt;body&gt;     &lt;div id="map" class="map"&gt;&lt;/div&gt;     &lt;script&gt;       var raster = new ol.layer.Tile({         source: new ol.source.OSM()       });        var vector = new ol.layer.Vector({         source: new ol.source.Vector({           url: 'https://openlayers.org/en/v4.0.1/examples/data/geojson/countries.geojson',           format: new ol.format.GeoJSON(),           wrapX: false         })       });        var select = new ol.interaction.Select({         wrapX: false       });        var modify = new ol.interaction.Modify({         features: select.getFeatures()       });        var map = new ol.Map({         interactions: ol.interaction.defaults().extend([select, modify]),         layers: [raster, vector],         target: 'map',         view: new ol.View({           center: [0, 0],           zoom: 2         })       });     &lt;/script&gt;   &lt;/body&gt; &lt;/html&gt;   -- EDIT --  This is not a duplicate of the said question , as that question is about OpenLayers 2. As said in the beginning, my question is about OpenLayers 3&amp;4, which is not backwards compatible with Openlayers 2, and missing a large number of features in OpenLayers2. So the said question/answers don't apply here. I've also used the openlayers tag per tag description to differentiate this from openlayers2 questions.
Using WFS-T in OpenLayers? How can I use WFS-T in openlayers-2?  I'm using  in server side.
Why does \cal{M}_n give “M>”? Why does \cal{M}_n give “M>” in parts of my LaTeX file and works correctly in other parts? In order to animate a character so that it grabs an object an throws it, I added a Child-Of constrained and keyframed its influence. In the F-curve Editor I can't set the curve which controls the influence to interpolation-mode Constant without changing the other curves (Which should be linear or bezier).   How can the interpolation mode of a curve changed independently? Find   $$\lim _{x\to \infty }x\Big(\ln\left(x+1\right)-\ln x\Big)$$  Here's how I do it:  $$x\Big(\ln(x+1)-\ln x\Big) = x\Bigg(\ln(x(1+\frac{1}{x}) - \ln x\Bigg)$$ $$x\Big(\ln x + \ln(1+\frac{1}{x}\Big)-\ln x =x\ln\Big(1+\frac{1}{x}\Big)$$ $$\ln\Bigg( \Big(1+\frac{1}{x}\Big)^x \Bigg) \rightarrow \ln 1^\infty = 0$$  What am I doing wrong? The answer is supposed to be $1$, but I get $0$. Proving replacement theorem? I want to see if I am understanding the proof of the replacement theorem correctly.   Let $V$ be a vector space that is spanned by a set $G$ containing $n$ vectors.  Let $L \subseteq V$ be a linearly independent subset containing $m$ vectors.  Then $m\leq n$ and there exists a subset H of G containing exactly $n-m$ vectors s.t. $L \cup H$ generates $V$.   The proof in the book says to start with $m=0$. In that case $L=\varnothing$, the empty set.        Let's assume this theorem is true for some integer $m \geq 0$.   Let $L = \{v_j\}_{j=1}^{m+1}$ and define it as a linearly independent subset of $V$ consisting of $m+1$ vectors.  Since any subset of a linearly independent set is linearly independent as well ($S_1 \subseteq S_2 \subseteq V$), then $\{v_j\}_{j=1}^m$ is linearly independent also.   It then says to use the induction hypothesis to say that $m \geq n$. Well, ok, but that seems sort of pulled out of nowhere to me. The next step is to say that there is therefore another subset, $\{u_k\}_{k=1}^{n-m}$ of G such that $\{v_j\}_{j=1}^m \cup \{u_k\}_{k=1}^{n-m}$ spans $V$.   That being the case there are scalars $(a_j)_{j=1}^m$ and $(b_k)_{k=1}^{n-m}$ which you can multiply by the vectors $v_j$ and $u_k$. You can then add the two sets of vectors, yielding $$\sum_{j=1}^m a_j v_j + \sum_{k=1}^{n-m} b_k u_k = v_{m+1}$$  At this point I am not sure I understand things. Because we are assuming $n-m&gt;0$ -- otherwise $v_{m+1}$ is linearly dependent. But then it says not only is $n&gt;m $ but $n&gt;m+1$, and that is where I am losing the plot to get to the next step. Why do DNGs only show in low resolution on Google Photos? How to generate a simple cartesian plane system? I need to make a cartesian plane for plotting the straight line joining the points (-3,1) and (6,-2). This is a very simple cartesian plane plotting. When I looked at the manual for tikz the graphics for cartesian planes are for more advance plotting, and what I need is very simple.  Something like this: Bibliography in Texmaker I'm having some problems with my bibliography in Texmaker. My code is:  \documentclass[11pt, a4paper]{article} \usepackage{graphicx} \usepackage{amsmath} \usepackage{natbib} \usepackage[utf8]{inputenc}     \usepackage{natbib} \usepackage[usenames,dvipsnames]{xcolor} \usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry} \begin{document}  ....  \cite{Johnson} \bibliographystyle{plain} \bibliography{mybib}  \end{document}   I also created a new file (File > New) that I saved as mybib.bib:  @Article{Johnson, author = {Edgar G. Johnson and Alfred O. Nier}, title = {Angular Aberrations in Sector Shaped Electromagnetic Lenses for Focusing Beams of  Charged Particles}, journal = {Physical Review}, year = {1953}, volume = {91}, number = {1}, }  @phdthesis{Zoran, author = {Zoran Racic}, title = {\'Etude et essais du spectromÃ¨tre Ã  plasma {DYMIO} de la  mission {MARS 96}}, publisher = {UniversitÃ© Pierre et Marie Curie}, year = {1996} }   When I compile my .tex file, I only have a [?] appearing.  Could you tell me what my mistake is? Consider the functional equation problem $$ f : \mathbb R \to \mathbb R \text , $$ $$ f \left( a ^ b \right) = f ( a) ^ { f ( b ) } \text , $$ when $ a , b \in \mathbb R $, $ a , b \ge 0 $. So far the only solution I have is the trivial $$ f ( x ) = x \text . $$ Does there exist any other possible solution? Even if the $ f $ doesn't have a closed form in terms of elementary functions, is there some way I could derive a series or an alternative expression for it? I tried to get a little more creative: $$ f ( w ) = f \left( w ^ { \frac 1 w } \right) ^ { f ( w ) } \text , $$ which nests deep into $$ f ( w ) = f \left( w ^ { \frac 1 w } \right) ^ { f \left( w ^ { \frac 1 w } \right) ^ { f \left( w ^ { \frac 1 w } \right) ^ \vdots } } \text , $$ which is equivalent to $$ \ln \big( f ( w ) \big) = \ln \bigg( f \left( w ^ { \frac 1 w } \right) \bigg) f ( w ) \text . $$ I was hoping to generate some sort of series using this. A word that says a person is both female and your friend Should black holes be considered two-dimensional or three-dimensional? Claim: Let $X$ be a metric space. If $A,B\in X$ are disjoint, if A is compact, and if B is closed, then $\exists \delta&gt;0: |\alpha-\beta|\geq\delta\;\;\;\forall\alpha\in A,\beta\in B$.  Proof. Assume the contrary. Let $\alpha_n\in A,\beta_n\in B$ be chosen such that $|\alpha_n-\beta_n|\rightarrow0$ as $n\rightarrow \infty$.  Since A is compact, there exists a convergent subsequence of $\alpha_n\;(n\in\mathbb{N})$, $\alpha_{n_m}\;(m\in\mathbb{N})$, which converges to $\alpha\in A$.  We have   $$|\alpha-\beta_{n_m}|\leq|\alpha-\alpha_{n_m}|+|\alpha_{n_m}-\beta_{n_m}|\rightarrow0 \;\;\;as\;\;m\rightarrow\infty.$$ Hence $\alpha$ is a limit point of B and since B is closed $\alpha\in B$, contradiction.  Is my proof correct? I feel as though I am missing something simple which would trivialize the proof. How to install software provided in software-center via terminal? How to convert wstring into string? What is the purpose of the word 'self'? If $f$ is continuous, nonnegative on $[a, b]$, show that $\int_{a}^{b} f(x) dx = 0$ iff $f(x) = 0$  "$\Rightarrow$" Assume by contradiction that $f(x) \neq 0$ for some $x_0 \in [a, b]$. Without loss of generality, assume that $f(x_0) &gt; 0$. Since $f$ is continuous, $\exists \delta &gt; 0$ such that $f(x) &gt; 0,  \forall x \in (x_0 - \delta, x_0 + \delta)$. Since $f$ is continuous on $[a, b]$, then it is Riemann integrable. Therefore $\int_{a}^{b} f(x) dx = \sup L(f, p)$ for some partition $p$. Now what I want to do is to show that the lower sum, $L(f, p) &gt; 0$, in that case its supremum is $&gt;0$, and that contradicts the condition that $\int_{a}^{b} f(x) dx = 0$. However, I don't know how to articulate it.  "$\Leftarrow$" If $f(x) = 0, \forall x \in [a, b]$, then $\int_{a}^{b} f(x) dx = \int_{a}^{b} 0 dx = 0$ My question is pretty simple.  Since $n! \gt n!!$, it's clear by the comparison test that $\sum_{n=0}^\infty \frac {1}{n!!}$ converges.      But what value does the sum converge to? How does one go about determining its value (if possible)? Date and time panel is greyed out, how do I restore it? Date and time is showing in the login screen (unity-greeter) but not when I login to my session.  When I go to date and time settings the panel is all grey :    Any idea how to recover from this ? What if robots.txt disallows itself? Why do files sometimes change but not the inode or vice versa? When a file is updated then the corresponding inode gets updated. But sometimes the following condition occurs    file is same and inode is new  file gets changed but corresponding inode is older   Why ? How to use articles with scientific words, such as mass, force, impulse, field and others? How are articles used with scientific quantities, such as mass, force, impulse, field and others?