When a question with some upvotes or downvotes but no answer is deleted by the person who posted, the reputation of that person does not change. Why is that?  EDIT: I figured out the answer to a question I asked, and therefore, deleted the question (with no answers) but overall 3 upvotes. I do not remember whether it had any downvotes. But there is no change in my reputation.
With regards to  post about  and the part about retaining reputation earned from deleted posts that have a score of 3 or better and were visible on the site for 60 days, does this also apply to self-deleted posts and will it continue to do so? I culled a few of my own answers over the weekend that were less than stellar, and my reputation dropped 1.8k, but the rep is back today after the changes were announced. I thought it would be useful to clarify that this also applies to self-deleted stuff.
What is a complete list of the usual assumptions for linear regression? How does the Higgs mechanism work? I'm not a particle physicist, but I did manage to get through the Feynman lectures without getting too lost. Is there a way to explain how the Higgs field works, in a way that people like me might have a hope of understanding? If a measure only assumes values 0 or 1, is it a Dirac's delta? Four complex numbers $z_1,z_2,z_3,z_4$ lie on a generalized circle if and only if they have a real cross ratio $[z_1,z_2,z_3,z_4]\in\mathbb{R}$ Let $[z_1,z_2,z_3,z_4]$ denote the  of the complex numbers $z_1,z_2,z_3,z_4\in \mathbb{C}$. Show that the distinct points $z_1,z_2,z_3,z_4\in\widehat{\mathbb{C}}$ lie on a generalized circle if and only if $[z_1,z_2,z_3,z_4]\in\mathbb{R}$.    I saw this statement claimed in , and wondered how one would go about showing it. I know of some facts we could work with:   First, the definition: A  in $\mathbb{C}$ is either a circle or a line in $\mathbb{C}$. I know that a Mobius transformation maps generalized circles to generalized circles. I know that if $f$ is a Mobius transformation and $z_j'=f(z_j)$, $j=1,2,3,4$, then $[z_1',z_2',z_3',z_4']=[z_1,z_2,z_3,z_4]$.   I have posted a potential proof as an answer below. Please let me know if you think it's complete. Thank you! Divergence of $\frac{ \hat {\bf r}}{r^2} \equiv \frac{{\bf r}}{r^3}$, what is the 'paradox'? So I came across this exercise: Show that if $Y$ is path-connected then the set of homotopy classes $[I,Y]$ of maps of $I=[0,1]$ into Y has a single point.   But I am confused here. If $Y=S^1$ then not all loops are homotopic! I mean, isn't true that $\pi_1(Y)\subset [I,Y]$? Or maybe I don't understand the set $[I,Y]$ well! Holomorphic functions: is it true that $f(\bar{z})=\overline {f(z)}$? Putting a table next to a figure Is there a way to load every label data and every SObject description data using only Javascript without any Apex Server-side code?  How do I import * from @salesforce/schema or @salesforce/label?  I am looking for a way to get all labels or all SObject describe information details to retrieve in LWC at once.  I can see that such syntax is provided by ES6 and is used widely by Salesforce itself, however, it is not possible to use the following syntax in LWC:   import * as schema from '@salesforce/schema'   import * as label from '@salesforce/label'   or this syntax  import {label, schema} from '@salesforce';   since both versions generate error     LWC1512: Missing resource value for @salesforce"   or      LWC1512: Missing resource value for @salesforce/label   Is there a way to load every label data and every SObject description data using only Javascript without any Apex Server-side code?  By the way, if we look as Salesforce Playground we could notice that   the same syntax is used to import everything from lwc  import * as Engine from 'lwc';   however, if we try to insert such line into any of Lightning Web Component, we would receive the following error     LWC1001: Invalid import. Namespace imports are not allowed on "lwc",   instead use named imports "import { LightningElement } from 'lwc'"   or   LWC1517: Invalid LWC import Prove if $|z| < 1$ and $ |w| < 1$, then $|1-zw^*| \neq 0$ and $| {{z-w} \over {1-zw^*}}| < 1$ I was born in Brazil and came to the United States at the age of 7, in 2007. I no longer need to live in the United States because I have found success in investing and no longer depend on having a job. I am going to buy property in my home country soon, but I have just turned 18.   Will I ever be able to return to the United States to see my friends and other family members? Even if it is a 30-day visa? And, if so, in the future, am I still eligible for the EB-5 visa? Will I be barred from entry? No command 'bla' found, did you mean:? So, when a command is not found, by what means is the "did you mean:" list populated? What program finds these alternate commands?  What is the meaning of: "(main), (universe)..."? Can I change which program finds these? How to prove that $d \sin(x)/dx = \cos(x)$ without circular logic such as L'Hôpital's rule? creating a csv file from two csv files I have two csv files:  sub_compiler.to_csv('sub_compiler.csv') sub_compiler.head()     and   sub_opt = pd.read_csv('sub_opt.csv') sub_opt.head()     and what I would like to do is to create a csv file where I have something of the form   compiler, opt   How could I do this? I need to do this to make a submission.  Thank's in advance.  [EDIT] Thank you for the answers. Now I have obtained :    don't understand why I have the columns called unnamed.   My objective is to get a csv file that contains only the columns compiler and opt. How could I do this? Thank's again.  [EDIT 2] I have solved my problem but if I open the csv file manually, so just click on the file, I have the following:    s it contains only 11 lines, but it contains 3000 lines in jupyter. Is it there something wrong?  [EDIT 3] I tried to to the following:  import pandas as pd  test = pd.read_csv('1495927.csv') test   and I have:    where 1495927.csv is the csv file I have created and that is in the image where I have 11 elements. Number of $(0,1)$ $m\times n$ matrices with no empty rows or columns For which $a \in \mathbb{C} -\ \{0,1\}$ does the equation $f(z) = f(az) $ has a non constant solution $f$ with $f$ being analytical in a neighborhood of $0$.  My attempt:  First, we can see that any such solution must satisfy:  $f(z)=f(a^kz)$ for all $k \in \mathbb{N} $.  If $|a|&lt;1$:  The series $z_{k} = a^k$ converges to 0 which is an accumulation point, and $f(z_i)=f(z_j)$ for all $i, j\in \mathbb{N} $. Thus $f$ must be constant.  If $|a|=1$:  For all $a \neq 1$ , $f$ must be constant on any circle around $0$, so again $f$ must be constant.  My quesions are:   Am I correct with my consclusions?   Also, I'm stuck in the case where $|a|&gt;1$. Any ideas?  Thanks Structure of a C++ Object in Memory Vs a Struct If I have a class as follows     class Example_Class     {        private:          int x;           int y;         public:           Example_Class()           {               x = 8;              y = 9;          }        ~Example_Class()         { }     };   And a struct as follows  struct {    int x;    int y; } example_struct;   Is the structure in memory of the  example_struct simmilar to that in Example_Class  for example if I do the following  struct example_struct foo_struct; Example_Class foo_class = Example_Class();  memcpy(&amp;foo_struct, &amp;foo_class, sizeof(foo_struct));   will foo_struct.x = 8 and foo_struct.y = 9 (ie: the same values as the x,y values in the foo_class) ?  The reason I ask is I have a C++ library (don't want to change it) that is sharing an object with C code and I want to use a struct to represent the object coming from the C++ library. I'm only interested in the attributes of the object.  I know the ideal situation would be to have Example_class wrap arround a common structure between the C and C++ code but it is not going to be easy to change the C++ library in use. In the two following snippets, is the first one safe or must you do the second one?  By safe I mean is each thread guaranteed to call the method on the Foo from the same loop iteration in which the thread was created?  Or must you copy the reference to a new variable "local" to each iteration of the loop?  var threads = new List&lt;Thread&gt;(); foreach (Foo f in ListOfFoo) {           Thread thread = new Thread(() =&gt; f.DoSomething());     threads.Add(thread);     thread.Start(); }   -  var threads = new List&lt;Thread&gt;(); foreach (Foo f in ListOfFoo) {           Foo f2 = f;     Thread thread = new Thread(() =&gt; f2.DoSomething());     threads.Add(thread);     thread.Start(); }   Update: As pointed out in Jon Skeet's answer, this doesn't have anything specifically to do with threading. I run Windows XP and the wallpaper I used to have got lost. I have backups of the system itself, so if I knew where to look, I could find a copy of the old wallpaper.  I have some idea of the original filename (searching now), and I recall it saves it as a bitmap, but an exact location would be helpful.  It was a photo/JPEG that used to be on the filesystem, and I don't have backups, so the Firefox, and Internet Explorer wallpaper locations are unlikely. I checked %SYSTEMROOT%\system32 as well - so I'm assuming it's somewhere else. Omitting article “the” in front of plural nouns I'm helping someone learn English (second language), and I'm having trouble explaining when to use the and when not to. For example:     Students learn better when teachers are passionate about teaching.   versus     The students learn better when the teachers are passionate about teaching.   There's a subtle difference. The first one is a general statement, whereas the second might imply a study where a group of students learned better than another.  Is the difference simply that, general v. specific?