random

问题 I want to generate a random distribution of say 10,000 numbers with predefined min, max, mean, and sd values. I have followed this link setting upper and lower limits in rnorm to get random distribution with fixed min and max values. However, in doing so, mean value changes. For example, #Function to generate values between a lower limit and an upper limit. mysamp <- function(n, m, s, lwr, upr, nnorm) { set.seed(1) samp <- rnorm(nnorm, m, s) samp <- samp[samp >= lwr & samp <= upr] if (length

问题 In python the function random() generates a random float uniformly in the semi-open range [0.0, 1.0). In principle can it ever generate 0.0 (i.e. zero) and 1.0 (i.e. unity)? What is the scenario in practicality? 回答1: 0.0 can be generated; 1.0 cannot (since it isn't within the range, hence the ) as opposed to [ ). The probability of generating 0.0 is equal to the probability of generating any other number within that range, namely, 1/X where X is the number of different possible results. For a

问题 In python the function random() generates a random float uniformly in the semi-open range [0.0, 1.0). In principle can it ever generate 0.0 (i.e. zero) and 1.0 (i.e. unity)? What is the scenario in practicality? 回答1: 0.0 can be generated; 1.0 cannot (since it isn't within the range, hence the ) as opposed to [ ). The probability of generating 0.0 is equal to the probability of generating any other number within that range, namely, 1/X where X is the number of different possible results. For a

问题 Similar questions: Generating N random points with certain predefined distance between them choose n most distant points in R But they are either in matlab or does not fullfill the required task. I have to create N number of points inside a box of length that the distance between any two points is larger than delta. For example: Let's say I have a box of length 10 Angstrom on x,y,z axis. I want to have 200 random points inside this box so that minimum distance between any two points is larger

问题 I need to shuffle an array so that all array elements should change their location. Given an array [0,1,2,3] it would be ok to get [1,0,3,2] or [3,2,0,1] but not [3,1,2,0] (because 2 left unchanged). I suppose algorithm would not be language-specific, but just in case, I need it in C++ program (and I cannot use std::random_shuffle due to the additional requirement). 回答1: For each element e If there is an element to the left of e Select a random element r to the left of e swap r and e This

问题 This question already has answers here : Crash when casting the result of arc4random() to Int (7 answers) Closed 5 years ago . I'm having problems with this drawRandomCard function. It works just like it should for some time, but eventually it crashes the application. Here is the code: import Foundation var cardDeck = Array<PlayingCard>() class Deck { func addCard(card : PlayingCard , atTop : Bool = false){ if atTop { cardDeck.insert(card, atIndex: 0); }else{ cardDeck += card } } func

问题 I'm looking for a special hash-function. Let's say I have a large list of strings, if I order them by their hash-values they should be ordered quasi randomly. The most important point is: it must be super fast. I've tried md5 and sha1 and they're using to much cpu power. Clashes are not a problem. I'm using javascript, so it shouldn't be too complicated to implement. 回答1: Take a look at Murmur hash. It has a nice space/collision trade-off: http://sites.google.com/site/murmurhash/ 回答2: It

问题 I'm looking for a special hash-function. Let's say I have a large list of strings, if I order them by their hash-values they should be ordered quasi randomly. The most important point is: it must be super fast. I've tried md5 and sha1 and they're using to much cpu power. Clashes are not a problem. I'm using javascript, so it shouldn't be too complicated to implement. 回答1: Take a look at Murmur hash. It has a nice space/collision trade-off: http://sites.google.com/site/murmurhash/ 回答2: It

问题 Okay, final question and I'll have finished my number guessing game in Common Lisp! :D Whenever the game starts (or a new game begins after the first game), the following function is called. ;;; Play the game (defun play () ;; If it's their first time playing this session, ;; make sure to greet the user. (unless (> *number-of-guesses* 0) (welcome-user)) ;; Reset their remaining guesses (setq *number-of-guesses* 0) ;; Set the target value (setq *target* ;; Random can return float values, ;; so

问题 I've been working on a random concept idea of having 6 clouds appear on a page with random comments pulled from a database. That part is easy, however I'm finding it extremely difficult to make sure the 6 clouds don't overlap each other. I've looked into Collision Detection a lot and found that there's no real suitable method of checking for a DIV within a range at X or Y before placing the new "randomly positioned" div on the page. I have my code below which I know is extremely messy right