print(0.1 + 0.2 == 0.3)   returns  False   Why?
Consider the following code:   0.1 + 0.2 == 0.3  -&gt;  false   0.1 + 0.2         -&gt;  0.30000000000000004   Why do these inaccuracies happen?
Is adjoint of singular matrix singular? What would be its rank? Using TP4056 module to charge battery while load remains connected &quot;I hate wizards. If he so much as points a finger at me, you stick him, Hook.&quot; &quot;Remind me to find out the name of that flooring company so I can be sure never to buy so much as a carpet tile from it.&quot; &quot;I didn’t listen so much as survive the conversation.&quot; Saving Photoshop multilayer file to PDF without layers size difference Why is it that when I save a file that has many, many layers to a PDF without layers as a copy that the file size is larger than flattening the layers and then saving the file as a copy to PDF? 19Mb vs. 5Mb?? Wouldn't saving a file without layers be the same as flattening the layers and then saving the file?? Can anyone explain this? Best practices for API versioning? Are there any known how-tos or best practices for web service REST API versioning?  I have noticed that . Is this the only way or are there other ways to accomplish the same goal? If there are multiple ways, what are the merits of each way? I am trying to get an Epson WF-2760 scanner that is network-connected working. I'm using Ubuntu 16.04.2 64-bit and the printer works a treat. I have installed the Epson drivers from their site, including the plugins. I have edited /etc/sane.d/dll.conf to enable epson, epson2, and epsonds. I have edited each of the respective .conf files to include the network address of the device (IPV4: 192.168.128.11).   The scanner is not detected in any software that I have tried (including Image Scan and Simple Scan).  Any help is appreciated! Escaping HTML strings with jQuery Does anyone know of an easy way to escape HTML from strings in ?  I need to be able to pass an arbitrary string and have it properly escaped for display in an HTML page (preventing JavaScript/HTML injection attacks).  I'm sure it's possible to extend jQuery to do this, but I don't know enough about the framework at the moment to accomplish this. I have a simple skull model, to which I applied the subdivision modifier. For the most part everything works as expected, except I keep getting these weird sharp vertices and I can't seem to figure out how to flatten them.    I'm using Blender 2.8. Is this some kind of feature I can disable/enable for particular vertices? The distance between the sharp vertices and the gray outline differ.    Any suggestions please? Thank you!  EDIT: I also tried selecting as both - vertexes and edges and then applied Edge->Clear Sharp, but nothing changed. Deputy badge after a reputation of 3000 Why am I still getting a password prompt with ssh with public key authentication? I am crawling some data using Apache Nutch and storing it on my USB Drive. The OS itself is Ubuntu Live Boot OS. But for every restart or shutdown I am losing my data. I also tried suspending my Ubuntu user still data was not visible when I reinserted my live USB.  Is there any way I can keep the data intact and does not loose and application settings installations when I do restart Ubuntu.  Used USB installer provided by pendrivelinux.com at Expected number of rolling a pair of dice to generate all possible sums A pair of dice is rolled repeatedly until each outcome (2 through 12) has occurred at least once. What is the expected number of rolls necessary for this to occur?  Notes: This is not very deep conceptually, but because of the unequal probabilities for the outcomes, it seems that the calculations involved are terribly messy.  It must have been done already (dice have been studied for centuries!) but I can't find a discussion in any book, or on line. Can anybody give a reference? Please let me know how to remove certain repositories in Ubuntu 11.04. I am getting the following errors while updating.  sudo apt-get update  Err http://ppa.launchpad.net natty/main Sources                                      404  Not Found Err http://ppa.launchpad.net natty/main i386 Packages                                404  Not Found ......  E: Some index files failed to download. They have been ignored, or old ones used instead. I see many posts on both this forum and elsewhere the discuss the use of a wide angle on a crop sensor.  For example, they discuss how at 14mm lens is 14mm on a 35mm film or full frame, but with a 1.6x crop sensor it is an effective 28mm.  My question is, is a 14mm on a crop sensor the same image as a 28mm on a full frame.  Or does "effective" include some other conotation.  I read that a 14mm can create distortion on a full frame and some vignette, so people seem to say using it on a crop takes out some of those edge problems. My confusion is how the lens is actually taking in the extra image.  Reading kenrockwells blog I learned that wide angle keeps lines straight, while fish eye actually skews the lines.    So with this as my understanding, I am still a bit confused how a lens that is curved in order to get a greater angle of view, will be the same as a cropped version of a less curved lens.  Or does "effective" only refer to the objects to the sides but not to the distortion of the image.  Or, if it is different, is it so small that for photography it does not matter?  A technically description would be welcome as long as a basic understanding of the situation.  Thanks!  Edit: To be more clear after the comments,  I am specifically talking about the end resulting 2d projection from 3d space.  I have read both those previous answers.  the first one is closer to what I am talking about.  However, it is still confusing for me.  I have experience with 3d modeling and projection matricies, which might be confusing me with this.  But for example, i dont understand the images having a 50 mm lens being drawn Starting from the sensor, so it shows a different fov for crop and full frame . If the lens is the same, it takes the same amount of information from the world, which makes a ray from a certain degree off the last lens projected into a smaller space, there is no projection from the sensor, so drawing the line from the sensor doesnt make sense to me.  The distance of the sensor to the rear of the lens must have some impact on the light projected but is not represented in the images.  Further, again from that first answer it says cropping is the same as zoom, but from what i understand from how perspective works, it is different, since a wide angle will project lines differently than a small fov to the same size, so cropping the center of a wide angle and zooming into something is very different.  This is easily recreated in an opengl application with varying fov projection matrix, i imagine in painting class people learn this as well.  A fisheye would be a good example, since if cropping was the same as zooming, a fish eye lens would keep the center exactly like a normal lens and then a gradient weighted towards the outside would rapidly create a warped perspective, but from what I see, it is even.  To me those images just look like its comparing cropped with full frame in regards to orthogonal projections. Defaults to true.  If set to true replaces all instances of known swear words with replacements (comical or * based). If false renders the content as originally presented.  Benefits:    Reduces moderation requirements necessary to ensure that people behind corporate firewalls are not blocked by an errent swear word.   Stops idiots like me complaining about it. What I am looking for is to have system wide implementation of sound enhancements like bass boosts, echoes, Fidelity, Stereo enhancement and so on.  Audio Video players have their own equalizer but they enhance only the audio / video files they are playing.  So to enhance sounds playing such as: YouTube, Spotify, System Sound, etc. I need a enhancer software. Back in Windows, I used to use SRS HD audio lab to do the same.  P.S. I have a horrible Speaker set. Who killed Ra's Al Ghul first, Batman or Arrow? What is Attribute Based Encryption? Proof of the square root inequality $2\sqrt{n+1}-2\sqrt{n}<\frac{1}{\sqrt{n}}<2\sqrt{n}-2\sqrt{n-1}$ How do I remove all sub-directories from within a directory? This question is kind of a phase II to the first question I posted at   I have a directory that contains a bunch of sub-directories, .zip files, and other random files not contained within a sub-directory.  I'd like a command line script to remove all sub-directories from within the parent directory, but keep all zip files and loose files that don't belong to any sub-directories. All of the sub-directories have content, so I believe I'd need to force their deletion with the -f command.  So basically, a command that looks inside the parent directory (or the current directory), deletes all folders from within it, but keeps all other content and files that are not a folder or contained within a folder.  I understand that deleting items from the command line requires special care, but I have already taken all necessary precautions to back up remotely.