I am a bit new to git and would like some help with this. so here is what happened. I have a total of 6 commits in a branch, now I need to reset any changes made by me to specifically 2 files- abc.txt and xyz.txt  How can I achieve this? any help on this is highly appreciated. Thanks in advance.
I have made some changes to a file which has been committed a few times as part of a group of files, but now want to reset/revert the changes on it back to a previous version.   I have done a git log along with a git diff to find the revision I need, but just have no idea how to get the file back to its former state in the past.
Why is "glide symmetry" its own type? Artin's Algebra pages 155 &amp; 156 list the types of symmetry of a plane figure as:   Reflective Rotational Translational Glide   He then goes on to say "Figures such as wallpaper patterns may have two talk about other figures having combinations of independent" symmetries. EDIT: He says "... having combinations of independent translational symmetries". See Joriki's answer.  Why doesn't glide symmetry count as having two independent (reflection + translation) symmetries? If we're going to count combinations, why not have rotation + translation etc. as their own types too? if $x_i$ are IID  continuous random variables, with $E[x_i]=μ$, is the following correct?   $E\left[\prod_{i=1}^n(1+⍺\space x_i)^i\right] = \prod_{i=1}^nE\left[(1+⍺\space x_i)^i\right] =  \prod_{i=1}^n(1+⍺\space E\left[x_i\right])^i = (1+⍺\space μ)^n$  thanks! Base64 Encode String in VBScript I have a web service load driver that's a Windows Script File (WSF), that includes some VBScript and JavaScript files. My web service requires that the incoming message is base64 encoded. I currently have a VBScript function that does this, but it's very inefficient (memory intensive, mostly due to VBScripts awful string concatenation)  [Aside; Yes, I've seen . The concatenation is happening in a loop across messages that are 1,000's to 10,000's bytes in size.]  I've tried using some custom string concatenation routines; one using an array and one using ADODB.Stream. These help, a little, but I think it would help more if I had some other way of encoding the message rather than via my own VBS function.  Is there some other way of encoding my message, preferebly using native Windows methods? Run faster than outer turret attacks As the title says, is there any way to run faster than the turret attack (the missile like thing) so that you can arrive spawn before the attack reaches you, and therefore can't kill you? You know, when you have low health, and you are targeted by the turret? Is there any item sets or things like that? What does pwd output? Does the command pwd in a shell script output the directory the shell script is in? Let $R$ be a commutative ring with $1$. Suppose that all ideals $I \neq R$ are prime. Prove that $R$ is a field.   Help me some hints.  Thanks a lot. Prove $(a^2+b^2)(c^2+d^2)\ge (ac+bd)^2$ for all $a,b,c,d\in\mathbb{R}$.  So $(a^2+b^2)(c^2+d^2) = a^2c^2+a^2d^2+b^2c^2+b^2d^2$  and $(ac+bd)^2 = a^2c^2+2acbd+b^2d^2$  So the problem is reduced to proving that $a^2d^2+b^2c^2\ge2acbd$ but I am not sure how to show that Vandermonde Determinant This is an exercise from Ian Stewart's Galois Theory, $3^{rd}$ edition:     If $z_1,z_2,\ldots,z_n$ are distinct complex numbers, show that the determinant $$D=\left|\begin{array}[cccc]  11&amp;1&amp;\cdots&amp;1\\ z_1&amp;z_2&amp;\cdots&amp;z_n\\ z_1^2&amp;z_2^2&amp;\cdots&amp;z_n^2\\ \vdots&amp;\vdots&amp;\ddots&amp;\vdots\\ z_1^{n-1}&amp;z_2^{n-1}&amp;\cdots&amp;z_n^{n-1} \end{array}\right|$$   is nonzero.       Hint: Consider the $z_j$ as independent indeterminates over $\Bbb C$. Then $D$ is a polynomial in the $z_j$, of total degree $0+1+\cdots+(n-1)=\frac{1}{2}n(n-1)$. Moreover, $D$ vanishes whenever $z_j=z_k$ for $k\neq j$, as it then has two identical rows. Therefore $D$ is divisible by $z_j-z_k$ for all $j\neq k$, hence it is divisible by $\prod_{j&lt;k}(z_j-z_k)$. Now compare degrees.   My question is how to do this. I follow the hint and I'm thinking of $D$ as a cofactor expansion; is that the idea? Also, the fact that $D$ vanishes whenever $z_j=z_k$ for $k\neq j$ follows since it would have two identical columns, right? I don't see why $z_j=z_k$ would imply it has two identical rows, as the hint suggests. The fact that it is divisible by $(z_j-z_k)$ is easy since that would make $z_k$ a root for $k=j$, but I'm not quite sure I follow why the degrees would be different. I think the degree of the product would be $1+2+\cdots+(k-1)$, but then add these up for all $k&lt;n$?   I appreciate any clarification that you can provide! This is a canonical question that will hopefully encompass all of the questions we get asking us to determine what year a bicycle was manufactured (how old is my bike, how old is my frame, etc.). Each "answer" should address a different way to determine the manufacturing year of a bicycle. To some extent, these will also help you narrow down the model as well as it will tell you what distinguishing features to look at.  The span of answers would include things such as:      Skiptooth cranks Cartridge bottom brackets (BB30/90 etc) Elliptical chainring Quick releases versus contemporary through-axles How the steerer attaches to the fork (quill vs. threadless)  Braking system (especially with mountain bikes: v-brake, direct pull, etc.)   Shifting ramps and pins on cassettes/sprockets and chainrings (versus flat sprockets) Frame material (e.g., shift from tubular steel to use of CF and hydroformed aluminium)  Frame tubing type (e.g. Reynolds 531 tubing introduced around 1934, still used today; Reynolds 501 tubing introduced around 1983). So a frame with an original 501 decal can't be from the 70', 531 decal doesn't help as much because of the range of years produced. Also, see Decals.   *Decals: style/design, amount, placement, color, etc. can help not only determine models, but also year of manufacture. Many changed decal design for the same model bike often yearly, with special/limited editions even more specific. This applies only if decals are original or have been replaced with the identical design. Tubing decals (Reynolds, Columbus, etc.) also changed designs for same tubing made in different years, although the changes aren't made as often, and manufacturers didn't always put tubing Brand decals on every model. Earlier bikes tended to have less fancy, less colorful, less quantity of decals.   Headbadges: most early bikes had actual "badges", often quite detailed and fancy, made of metal, then plastic, and finally just using decals on the headtube. Most bikes lost their metal badges in the 60's and early 70's, although some brands still have actual badges to this day, but in general a real badge indicates an earlier model bike. Dropout style (including the later inclusion of lawyers lips) Presence or absence of CPSC reflectors (USA only) Manufacturing method (shift from lugs to TIG welding, for example)  Number of gears (shift from 2x5 ten-speed to 3x8, 2x9, 1x11, etc.)  Inspection of lug design: pantographs, cut-out, stampings, custom brazing/filing, chrome, fork crow n sweep, etc. Frame/Fork Braze-ons. Race bikes tended have less braze-ons the earlier the year of manufacture. Most 60's racers and earlier had few or none with cable guides/stops, shifters, bidons, etc. being clamp-on. By the 80's if it was clamp-on, it was a sign of very cheap models and most frames had braze-ons for all cables, with multiple bottle and accessory bosses depending on style and use.   and so forth. Please edit this question if you have an answer that isn't in the index above.   A couple of caveats:   A previous owner could have replaced or upgraded components on a bicycle, so this guide only applies to original equipment There is a delay between the introduction of a technology (such as indexed shifting) and when manufacturers start selling products that use it. Low-end manufacturers may continue using technology that is severely outdated (such as one-piece cranks, freewheels, or quill stems) because it is cheaper to do so. A number of bikes are built in a Retro style, but with modern components.  Dutch bikes, trendy coffee cruisers, and beach cruisers may be modern but appear to be 1950s styling.  These tend to have modern rims and brakes as a giveaway.     Note that bicycles.stackexchange does not do valuations of bicycles. How much your bicycle is worth depends on the location of the buyer and seller, how much the buyer wants the bike, etc. etc. etc. Do I need internet/3G to use GPS? I have a Samsung Galaxy S2 that has some problems with the GPS: If I use internet my navigation works but when I turn the 3G off, GPS does not work.  Do I need internet/3G to use GPS? Choosing GeoCoding service? I'm looking for a web service providing a full address based on coordinates (and reverse).  I'm ready to pay for that service.  I don't want to use Google's API. Reordering fields (permanently) in file geodatabase using ArcGIS Desktop? Using ArcGIS 10.0, is it possible to reorder the fields in a file geodatabase, and have the order persisted to the database?  We considered exporting to XML, and writing a parser to change the field order, then re-creating a new database from the XML. This seems like a laborious process.  Another idea is to import the existing field definitionss into Excel, re-order them, export to CSV, then write a Python script to create these fields in a new Geodatabase. Does a script like this exist, before we write it from scratch?  Unfortunately the ArcGIS Diagrammer doesn't seem to support field re-ordering.  Are there any scripts or hacks we could use to simplify this process? Question on operator: // N I'm looking for a way to insert continuous colour legend for a raster layer.  I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values on the bar, similar to the old plugin "One-Band Raster", that it doesn't work with the QGIS version higher than 1.7  I tried to set in properties->style, where I selected the  Render Type "Singleband pseudocolor" and see the "generate new color ramp" box.  I tried both "Continuous" or "Equal interval". However, in the Composer the legend always is displayed with discrete symbols.  Is there any way that can make QGIS Composer to display a nice continuous band for a raster layer? How do I disable "Link Preview" in Chrome? Problem: Suppose $f$ is continuous for $x\ge 0$, differentiable for $x&gt;0$, $f(0)=0$, and $f'$ is monotonically increasing.  Define $g(x)=\frac{f(x)}{x}$ for $x&gt;0$. Prove that $g$ is monotonically increasing.  Source: W. Rudin, Principles of Mathematical Analysis, Chapter 5, exercise 6. What's the difference between \usepackage{ngerman} and \usepackage[ngerman]{babel} Is there something additional that \usepackage[ngerman]{babel} does that a simple \usepackage{ngerman} won't be able to do? When using find, how do I return the file name and the line number when searching for a string? I manage to return the file name in one command and the line numbers with another one, but I can't seem to combine them.  File names: find . -type f -exec grep -l 'string to search' {} \;  Line numbers: find . -type f -exec grep -n 'string to search' {} \; WPF TextBox and Scroll behavior I have a problem. I need to host grid with controls in ScrollViewer to prevent textbox from being either truncated or collapsed to zero-with at the UI. Also I want the with of textbox to be expanded when user change windows width. I'm setting Window's content to following code  &lt;DockPanel&gt;     &lt;TreeView DockPanel.Dock="Left" Width="150"/&gt;     &lt;ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"&gt;         &lt;Grid&gt;             &lt;Grid.ColumnDefinitions&gt;                 &lt;ColumnDefinition Width="Auto"/&gt;                 &lt;ColumnDefinition /&gt;             &lt;/Grid.ColumnDefinitions&gt;             &lt;Grid.RowDefinitions&gt;                 &lt;RowDefinition Height="Auto"/&gt;             &lt;/Grid.RowDefinitions&gt;             &lt;TextBlock Text="Name"                         Margin="5"                         VerticalAlignment="Center"/&gt;             &lt;TextBox Grid.Column="1"                      Text="Some Name"                      Margin="5"                      VerticalAlignment="Center"                      MinWidth="200"/&gt;         &lt;/Grid&gt;     &lt;/ScrollViewer&gt; &lt;/DockPanel&gt;   All work fine, but when user types very long text in TextBox it is being expanded and horizontal scroll appears. Is there any easy way to limit TextBox maximum width and allow it to be expanded only when user changes window size. How to get client date and time in ASP.NET?