I just made an edit and saved it without giving it an edit summary. The default summary was      added 24 characters in body   I made another edit to the same post within 5 minutes, this time changing the automatic edit summary, however, when I viewed the edit, the original automatic summary remained.  I suggest that we be allowed to edit the summary while we're within 5 minutes of posting the edit.  It has been suggested that users can make two edits to change the summary: the first by making a superfluous change, the second by undoing the change and changing the summary at the same time. This is counterintuitive and surprising behaviour. A user only has 5 minutes to change an edit before it becomes a new edit, and in that period they should be able to do anything they could have done on the first edit.  This feature was first suggested in early 2011 and was very popular, yet was never done. If the reason it hasn't been implemented is to avoid trivial edits, then the workaround (which didn't work for me) simply doubles the number of trivial edits needed to get the job done.
It often occurs to me to add an edit summary to a question-edit immediately after submitting the edit, especially if the changes aren't obvious (formatting etc.). So I:   Click "edit" again. Fill in the summary Click on "Save Edits".   The 'edit' (no actual change has been made to the title/body/tags)  is accepted, but the summary doesn't show up, i.e. it is silently rejected.   I don't think it should work this way because the summary has been added by the original editor within the original edit's edit-window. In fact if I remember correctly, it to used to work as expected earlier; so perhaps this is a recent change.
Making ffmpeg process first audio stream differently than all others I'm trying to write a command such that ffmpeg executes a given instruction for the first audio stream in a file and a different instruction for any and all others.  In the test case below, for example, I want the first stream copied to the output file and all others converted to mono.  If I write it this way  ffmpeg -i INPUT -map 0 -c copy -map 0:a:0 -c:a:0 copy -map -0:a:0? -c:a libfdk_aac -ac 1 OUTPUT   the first audio stream is ignored when the mapping is overridden later in the command line.  But if I move the instruction for that stream to after the others'  ffmpeg -i INPUT -map 0 -c copy -map -0:a:0? -c:a libfdk_aac -ac 1 -map 0:a:0 -c:a:0 copy OUTPUT   it's no longer ignored, but becomes the last audio stream in the file.  I know I'm close here; I just can't see what I'm doing wrong. I have up until Cov(X+Y,X-Y) = E[((X-E(X))+(Y-E(Y)))((X-E(X))-(Y+E(Y)))] and now I am stuck and do not know how this turns into Var(X)-Var(Y) I have QGIS 1.8.0 installed via OSGeo Installer and work on win 7. All I need is to upload the shapefile to the database via this plugin. Unfortunately I am receiving an error:  Something's wrong: ["'shp2pgsql' is not recognized as an internal or external command,\n", 'operable program or batch file.\n']   How to install and configure shp2pgsql to make this plugin work fine? How to use measured step response to tune control system How does one use a measured step response to tune either a PID or convolution control scheme? Inspired by , I'm interested a more detailed explanation of how to implement a control system based on the measured step response.  I would not try to guess all the effects.  There are probably some non-obvious things going on, and you can't know all the parameters. I would measure the step response.  Find two pump settings that both result in the ball being within the measurable range within the tube.  Then have the controller suddenly switch from one setting to the other open loop.  Meanwhile measure what the ball does over time.  That is the step response.  You can take the derivative of that and get the impulse response.  From the impulse response you can predict the motion of the ball for any history of pump settings, assuming this is a linear system.  It is probably linear enough over the small range of settings to keep the ball within its normal range. You can use this as a simulation base to find the parameters for old fashioned PID control.  Or you can use the impulse response directly to do a convolution control.  You have to low pass filter the control input enough so that convolution kernel doesn't go negative unless your pump is actually reversible and can suck the ball back down.  How exactly does this work? ; I assume &quot;convolution control&quot; is the use of the pole-zero or transfer function, but don't see exactly how to get the parameters. RELATED:  * Let $R$ be a finite ring with unity. Prove that every nonzero element of $R$ is either a unit or a zero-divisor. Is it possible to change the linkage of Nether portals? xcode app crashing on launch with breakpoint How can I reflect a transparent background? I'd like to make a glossy surface which reflects objects above it, but that also reflects a transparent background in the final render.  So in effect, the final render would contain only the reflections, not the surface itself.  Is this possible please? How to fix "Headers already sent" error in PHP A continuous, injective function $f: \mathbb{R} \to \mathbb{R}$ is either strictly increasing or strictly decreasing. How to construct a relative path in Java from two absolute paths (or URLs)? Given two absolute paths, e.g.  /var/data/stuff/xyz.dat /var/data   How can one create a relative path that uses the second path as its base? In the example above, the result should be: ./stuff/xyz.dat FaceTime and iMessage - an error occurred during activation I couldn't log in to FaceTime so I did a factory reset of my MacBook. It worked for a brief period of time and then suddenly it just logged out.  I believe it might have been after iCloud synced with keychain or after I changed my local host name and computer name.  I have seen other users facing this issue but no solutions. Is there a troubleshooting guide or should I just contact Apple support since I can't use their service without activation to my Mac? (Built-in) way in JavaScript to check if a string is a valid number I'm hoping there's something in the same conceptual space as the old VB6 IsNumeric() function? Allow the owner of a post to approve a suggested edit even if it was rejected by reviewers Any reason to have a strong user password? I recently decided to change my (very) strong user password to something trivial.  This was mostly to eliminate frustration with typing a long password each time I sudo or whatever.  My question is, is there any reason to have a strong user password? considering that most services which I run on my box do not use PAM for auth:   apache2 - uses .htpasswd for access   sshd - only private keys allowed   transmissiond - uses its own http auth   mpd - uses its own auth   samba - limited to LAN   Physical access to the box is out of the question. I'm running Bash scripting, but sometimes I get confused which of these commands I use belong to who. Sometimes man xxx works, sometimes doesn't, so I use --help or info, mostly one of these works to show description of the command. Can anyone tell me how I would know what command belongs to what? Bash builtin, GNU utility, etc. Partial SSL in rails Chrome is unable to connect to the Internet I'm getting the error code: DNS_PROBE_FINISHED_NO_INTERNET in Google Chrome. The thing is, I have a working internet connection. I am posting this using that connection, using Internet Explorer. It's only Chrome doing this.  What happened was my laptop was refusing to go to sleep mode, so it ended up running out of battery power. I charged it, and when I subsequently booted the computer, Chrome stopped working. I don't see the connection...  I added Firewall rules (inbound/outbound) to allow Chrome to connect...so unless I'm missing something.  UPDATE: Chrome portable is working for me...just not the regular chrome.  UPDATE 2 Now I realize it had to do with Covenant Eyes which I have installed. See the accepted answer Catenatives followed by infinitives and gerunds What is the difference in meaning when the catenative verb “like” is followed by an infinitive, or by a gerund? For example:      Do you like ski jumping?    vs.      Do you like to ski jump?   Also, what is the difference between:      My brother taught me to read and write.    vs.       My brother taught me reading and writing. How is Cycles different from Blender Internal?