What are the differences between doing something in a period and doing something within a period? Are there any other differences between in and Within in other contexts?
I know that both can mean "inside" but what I don't have clear is whether both mean the same when talking about time. For example:   The party is in two days = The party is within two days ??   According to this link  within means a limit that can be exceeded, so I'm wondering too if say "the party is within two days max" is correct or redundant.
Infinite series $\sum _{n=2}^{\infty } \frac{1}{n \log (n)}$ Upgrade Debian Jessie (8) to Buster (10) possible or need to go sequential in versions upgrades? Just started working with a Debian Jessie (8) in a production environnent. While presently deployed it is not seeing any heavy use yet. I was looking at the OS , and I was thinking about how convenient it would be to just upgrade it before is start seeing some more steady use in our environment and possibly making things more complicated with a later upgrade.  I was looking for a procedure to upgrade from Debian v.8 to v.10 but most documented  are sequential in order (e.g. 8 -> 9, or 9 -> 10).  My question: should I upgrade sequentially, or there is some proper documented way to skip a main version while upgrading? Which site deals with career development questions for programmers? Is there any site in the network where career development questions about the programming profession can be asked ? I thought Programmer's was the site for it, but that doesn't appear to be the case. Context: I prepare my scientific documents using LaTeX and compile to a PDF. I often need to seek comments on drafts from collaborators who do not use LaTeX. Most of these collaborators use Windows OS. Assume also that the collaborator does not need to edit the document.  They only need to be able to add comments to the document. Most would be familiar with the commenting system in MS Word, for example. I'd like to be able to give the collaborator some clear instructions about what software and system they should use to comment on the draft.  This should involve free software and an easy to use interface.  Question: What is a good strategy for getting comments on draft documents when the collaborator does not know LaTeX?  Initial thoughts: I know Adobe professional allows you to add comments to a PDF.  However, some collaborators don't have this software and it costs money.  I could send the raw LaTeX to the collaborator. However, given all the markup, the collaborator may find LaTeX source a bit mysterious.  UPDATE: After posting I noticed  to a similar question. Along with a number of other good tips (such as printing and getting paper comments), he mentions jarnal, xournal, and gournal as free cross-platform PDF annotators. I'd be curious to know whether experts have found them adequate for the above mentioned purpose and whether any of them are to be preferred. Others mention FoXIt. And yet others discuss the option of exporting to MS Word or Open Office and using the reviewing system within these programs. Does a charged particle accelerating in a gravitational field radiate? A charged particle undergoing an acceleration radiates photons.  Let's consider a charge in a freely falling frame of reference.  In such a frame, the local gravitational field is necessarily zero, and the particle does not accelerate or experience any force. Thus, this charge is free in such a frame. But, a free charge does not emit any photons. There seems to be a paradox. Does a freely falling charge in a gravitational field radiate? Does anyone have an intuitive explanation (no formulas, just words! :D) about the "$n-1$" instead of "$n$" in the unbiased variance estimator $$S_n^2 = \dfrac{\sum\limits_{i = 1}^n \left(X_i-\bar{X}\right)^2}{n-1}?$$ Plotting recursive function using pgfplots \addplot Is it possible to plot a recursive function using pgfplots \addplot command?  I tried like this;  \documentclass{article} \usepackage{pgfplots}  \pgfmathdeclarefunction{fac}{1}{   \pgfmathparse{(#1&lt;=1)+                 (#1&gt;1)*#1*fac(#1-1)   } }  \begin{document} fac(5) is \pgfmathparse{fac(5)}\pgfmathresult  \end{document}   But the result seems to be an infinite recursion, as the entire function is being evaluated. Why does Java's hashCode() in String use 31 as a multiplier? Per the Java documentation, the  for a String object is computed as:   s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]       using int arithmetic, where s[i] is the    ith character of the string, n is the length of    the string, and ^ indicates exponentiation.   Why is 31 used as a multiplier?  I understand that the multiplier should be a relatively large prime number. So why not 29, or 37, or even 97? What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency.  I've also seen recursive copying functions with various flaws.  I'm surprised no canonical solution exists. Given (p ∧ q), use the Fitch system to prove (q ∨ r) I'm having trouble solving a Fitch Style Proof and I was hoping someone would be able to help me.  Premises: p ∧ q  Goal: q ∨ r  Would be an assumption (p ∧ q => q ∨ r) in first step a correct one?   Then, q ∨ r Implication Elimination: 2, 1  Why is it not correct?  Thank you very much for any help! Show/Hide function folding margin on Notepad++ Is it possible to get rid of the function folding margin on Notepad++? It seems like the sort of thing that should be in the prefs but I'm not seeing it anywhere. Using Python, how do I to read/write data in memory like I would with a file? In the case of languages with a C-like syntax, we declare the main() method to return an int or float value (or void).  Is it possible to declare a non-void return type from main() in Java?  If not, then why not?  Does this mean that a Java program doesn't return any value to the OS? Core Data - Storing Images (iPhone) You can reach this IP address  (if my computer is online). I want to assign a domain to it so I wonder how is that possible when I have no DNS? I do own my domain which is ".com". My IP is static.  Thanks What is the proper way to handle data between scenes? I am developing my first 2D game in Unity and I have come across what seems an important question.  How do I handle data between scenes?  There seems to be different answers to this:   Someone mention using , while other people told me this should be used to store other things like screen brightness and so on. Someone told me that the best way was to make sure to write everything into a savegame everytime that I changed scenes, and to make sure that when the new scene loads, get the info from the savegame again. This seemed to me wasteful in performance. Was I wrong? The other solution, which is the one I have implemented so far is to have a global game object that isn't destroyed between scenes, handling all the data between scenes. So when the game starts, I load a Start Scene where this object is loaded. After this ends, it loads the first real game scene, usually a main menu.   This is my implementation:  using UnityEngine; using UnityEngine.UI; using System.Collections;  public class GameController : MonoBehaviour {      // Make global     public static GameController Instance {         get;         set;     }      void Awake () {         DontDestroyOnLoad (transform.gameObject);         Instance = this;     }      void Start() {         //Load first game scene (probably main menu)         Application.LoadLevel(2);     }      // Data persisted between scenes     public int exp = 0;     public int armor = 0;     public int weapon = 0;     //... }   This object can be handled on my other classes like this:  private GameController gameController = GameController.Instance;   While this has worked so far, it presents me with one big problem: If I want to load directly a scene, let's say for instance the final level of the game, I can't load it directly, since that scene does not contain this global game object.  Am I handling this problem the wrong way? Are there better practices for this kind of challenge? I would love to hear your opinions, thoughts and suggestions on this issue.  Thanks I file 83(b) election, but did't include a copy of it in that year’s tax return Getting 2-factor Gmail authentication code from Sweden mobile number I have been facing a serious problem for many months. Usually I get a 2-factor authentication code from 51501 when I am supposed to log into Gmail. But for months I am getting a code from a Sweden-based mobile number: +46701327805. The first code I received from this number was in October 2015.  There is also a mobile number from USA that sometimes sends the code. I change my passwords every time this happens. What could be the possible reason for this and how to overcome this problem?   By the way, I must say I have been hacked for years. I don't use VPN; my internet runs off a broadband modem. dpkg: error: parsing file '/var/lib/dpkg/updates/0045' near line 0: Selecting features with NULL attributes in QGIS How do I identify which features have NULL attributes in the attribute table of a shapefile?  When i try [field]= 'NULL' it selects the features with value = 0 (see picture)