GDAL installation in Ubuntu 20.04 LTS Has anybody been able to overcome this issue while installing GDAL in Ubuntu 20.04 LTS or should I just downgrade my Ubuntu version? sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable  Err:20 http://ppa.launchpad.net/mc3man/trusty-media/ubuntu focal Release   404  Not Found [IP: 91.189.95.83 80] Err:21 http://ppa.launchpad.net/ubuntugis/ppa/ubuntu focal Release   404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done                       E: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/ubuntugis/ppa/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.
What can I do if a repository/PPA does not have a Release file? When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?
I have a string User name (sales) and I want to extract the text between the brackets, how would I do this?   I suspect sub-string but I can't work out how to read until the closing bracket, the length of text will vary. Texture is missing in Cycles? Because I am pretty new to blender I watched the tutorial  from BlenderCookie.com.  I loaded  onto a sphere but then in all views the texture is just some kind of blurry with no details. Terminal : needs full path to execute a command Let's suppose i have an application in /Applications/MacPorts/KDE4/myapp.app/Contents/MacOS/myapp.  When i use cd to reach the directory 'MacOS' and then issue the command myapp it says command not found.  But when i issue the command with the full path like /Applications/MacPorts/KDE4/myapp.app/Contents/MacOS/myapp it works.  I had the same problem with mysql inside xampp.  Why is that? Question. Let $M = \left\{ \begin{bmatrix} a &amp; b \\ -b &amp; a \end{bmatrix} \,\middle\vert\,  a, b \in \mathbb R \right\}$.  Show that $(M,+)$ and $(\mathbb C,+)$ are isomorphic.  Show that $(M^{*},*)$ and $(\mathbb C^{*},*)$ are isomorphic.    (Here, $M^{*}$ is defined as excluding the zero-element) I understand that there exists an isomorphism $\phi:M \rightarrow\mathbb C$ defined by $\begin{bmatrix} \alpha &amp; \beta \\ -\beta &amp; \alpha \end{bmatrix}\mapsto \alpha+i\beta$, ie. I can show that $\phi(M_{1}+M_{2}) = \phi(M_{1})+\phi(M_{2})$ and $\phi(M_{1}*M_{2}) = \phi(M_{1})*\phi(M_{2})$. However, I'm unsure how to go about the two subquestions seperately. Is "I am sat" bad English? I believe it is incorrect and instead either the present continuous     I am sitting   or the predicate adjective     I am seated   should be used.  I hear this quite often, however, and ultimately usage overrules formality.  Does anybody know where this originated or how to describe it grammatically? Removing clock from the lock-screen I'm using Ubuntu 18.04.  I want to remove the digital clock from the lock screen because I just want to see a good wallpaper there, unobstructed.   How do I go about this? Resize images in PHP without using third-party libraries? Put your shoes on and Take your coat off I have often heard the following statements when someone talks about shoes, cloths, etc. I don't know which one is more appropriate or grammatically correct.   Hey, put your shoes on.  Hey, put on your shoes.  Take off your coat, please.  Take your coat off, please.    Any thoughts? Can we also say &quot;take out your coat&quot;? Let $A,B \subset \mathbb{R}$. Show that $\sup(A \cup B) = \max\{\sup A, \sup B\}$   Here's what I did so far:  Let $\sup A, \sup B$, and $\sup (A \cup B)$ denote upper bounds of $A,B$, and $A \cup B$, respectively. If $x \in A$, then $x \le \sup A$. If $x \in B$, then $x \le \sup B$. In either case, $x \in (A \cup B)$. So either $x \le \sup A$ or $x \le \sup B$. In either case, $x \le \max \{\sup A, \sup B\}$. So $\max \{\sup A, \sup B\}$ is the upper bound of $A \cup B$, which means $\sup (A \cup B) \le \max\{\sup A, \sup B\}$.  I do not know if there's a better way to go at it, but all I did was show the inequality. Can I do this, and show the reverse inequality? If so, how can I go about doing that? I have one script to allow for one user to run. The string calling it from the command line looks like  ./script path/to/folder -a option='value'   When I try to add it to the other commands in Cmnd_Alias line, sudo blames sudoers file for incorrect syntax. How can I set such commands properly? What happens to the Matrix if Neo takes the blue pill? If Neo defies his fate and refuses to be removed from the Matrix (by taking the blue pill) what happens next?   Would another "The One" get selected by The Architect or The Oracle and is there anything to suggest that the current instance of The Matrix actually could have multiple "The One"'s (perhaps one of the 'potentials') in the event that the Chosen One manages to get himself killed or simply refuses to play ball? How do I debug Node.js applications? I was having trouble playing the game on my android so I downloaded it to my wife's phone (Galaxy S6). I read some posts on how to get it running on my android and it worked but, my level 7 account is on my wife's phone.  How do I get it back to my android? When I sign out and back in it doesn't ask for any sign in info. I've tried deleting the app's data and even uninstalling and re-installing, but it still doesn't ask for sign-in info. ODBC connection to Access database in 64-bit Windows Convert a line drawing from raster to vector I have a raster image, basically a scanned drawing of the outlines (and some detail) of various objects, and I wish to convert these lines to vectors, using either Illustrator or Inkscape.  My present solution is to have the raster image as a background layer, and in a new layer above it I use the pen to follow the lines as close as possible.  Later I tweak these lines to fit the raster image better. That has worked fine for simple drawings. However for some of my extremely complex drawings, this is very tedious to do.  Is there any tool or filter of some sort that is capable of recognizing the lines in line drawings and creating vector paths from them? Time travel film: character with male and female reproductive organs is taken back in time by a barman who turns out to be themselves I have had a friend give me a rough description of a film and I'm curious to find out what it actually is. I don't know very much. I understand this will be difficult, especially since every time my friend explains the tale it's different so this description is likely to contain some inaccuracies.  The film's plot begins with a recounting given by the main character, who had both male and female reproductive organs but had one set removed (not sure which, think male ones were removed). The main character is narrating this tale to the barman in a bar. The barman then takes the main character back in time, where they make love to themselves and produce a child.  The child, once born, is abandoned by the mother in the past - but the barman takes the child to the orphanage and leaves them there, ensuring their survival. Eventually it is revealed that the child was the main character themselves, and so was the barman.  In other words every major character introduced up to that point was the same person who had severely messed with their own timeline. For many of my datasets I have the same imported data duplicated numerous times, each iteration displaying the data values for a different column (in my case it's fish catch weight per gridded cell per year, so lots of iterations of the same grid, with a different pattern of values per year).  For presentation purposes, it strikes me as helpful to use the same scale for each year, so I go to the original data and divide the maximum value into (arbitrarily) 10 classes and manually input the values and labels after setting the desired colour ramp and input data field:   This is extremely tedious, not just the manual excel calculation part, but also the input interface for the values &amp; labels*, hence my intention to make use of the 'save style' option. HOWEVER: when I save the style as QML and load it for the next layer, it saves everything - including the data field (in my case, year). When I change this field, QGis automatically generates the values &amp; labels based on the data for that field, ditching all of the values &amp; labels I set.   Is there any way to avoid this happening &amp; thereby duplicate class number, values and labels for each field by simply loading a style? (somewhat meta) Am I going around this the wrong way, OR, is there a different face I could use to climb this mountain? Just noticed a minor css issue on this question:    The related questions on the right hand side have some overlapping text in Chrome:        (This only applies to this very site, Meta Stack Exchange) Using the affine linearized polynomial $f(x)=x^p-x-b$ is irreducible over $\mathbb{F}_q$ if and only if $\operatorname{Tr}_{\mathbb{F}_q/\mathbb{F}_p} \neq 0$. But here $\mathbb{F}_3$ is not a field extension of $\mathbb{F}_5$.  Also we have that: Let $a \in \mathbb{F}_q$ and let $p$ be the characteristic of $\mathbb{F}_q$. Then the trinomial $x^P - x - a$ is irreducible in $\mathbb{F}_q[x]$ if and only if it has no root in $\mathbb{F}_q$. Lets say I'm building a base class which will be extended upon by the children class. So a base class is called Base and children can be Child1, Child2, etc.  In the base class's constructor, how can i get the value of Child1/Child2?  This is all using PHP