distribution

问题 This question already has an answer here : Closed 7 years ago . Possible Duplicate: Generating a random Gaussian double in Objective-C/C Is there any way of getting a random number not from a uniform distribution, but from a Gaussian (Normal, Bell Curve) distribution in iOS? All the random number generators I have found are basically uniform and I want to make the numbers cluster around a certain point. Thanks! 回答1: Just use a uniform distribution generator and apply the Box-Muller Transform:

问题 Users of my application (it's a game actually) answer questions to get points. Questions are supplied by other users. Due to volume, I cannot check everything myself, so I decided to crowd-source the filtering process to the users (players). The rules are simple: each user is shown a question to rate as good/bad/unsure when question is rated 5 times as "bad" it is removed from the pool when question is rated 5 times as "good" it is removed from the poll and flagged to be played by other

问题 In order to distribute my iPhone for test purposes on a couple of device Over the Air, I have created an AdHic distribution profile and followed the explanation I found in this blog (sorry it's in French but the screenshot are quite detailled): http://www.media-business.biz/content/iphone-cr%C3%A9ez-votre-propre-appstore I install the position profile on the device from my web site but when it comes to the application I have an error message saying it's impossible to download the app. Is this

问题 Suppose I have the variable x that was generated using the following approach: x <- rgamma(100,2,11) + rnorm(100,0,.01) #gamma distr + some gaussian noise head(x,20) [1] 0.35135058 0.12784251 0.23770365 0.13095612 0.18796901 0.18251968 [7] 0.20506117 0.25298286 0.11888596 0.07953969 0.09763770 0.28698417 [13] 0.07647302 0.17489578 0.02594517 0.14016041 0.04102864 0.13677059 [19] 0.18963015 0.23626828 How could I fit a gamma distribution to it? 回答1: A good alternative is the fitdistrplus

问题 I am wondering how i could generate random numbers that appear in a circular distribution. I am able to generate random points in a rectangular distribution such that the points are generated within the square of (0 <= x < 1000, 0 <= y < 1000): How would i go upon to generate the points within a circle such that: (x−500)^2 + (y−500)^2 < 250000 ? 回答1: import random import math # radius of the circle circle_r = 10 # center of the circle (x, y) circle_x = 5 circle_y = 7 # random angle alpha = 2

问题 I am about to upload an app to iTunes Connect. I am not Team Agent, nor does it seem the Team Agent can make me a Team Agent. So he logged onto Member Center and downloaded a Distribution Certificate, which is in my Keychain along with the WWDR Certificate. The bundle identifier is set to se."companyname"."appname". When I set the Code signing identity to Distribution, it says no profiles match. Can only the Team Agent build the final apps for upload? How do I make XCode "use the right set of

问题 I am about to upload an app to iTunes Connect. I am not Team Agent, nor does it seem the Team Agent can make me a Team Agent. So he logged onto Member Center and downloaded a Distribution Certificate, which is in my Keychain along with the WWDR Certificate. The bundle identifier is set to se."companyname"."appname". When I set the Code signing identity to Distribution, it says no profiles match. Can only the Team Agent build the final apps for upload? How do I make XCode "use the right set of

问题 Are there any R packages for the calculation of Kendall's tau-b and tau-c, and their associated standard errors? My searches on Google and Rseek have turned up nothing, but surely someone has implemented these in R. 回答1: There are three Kendall tau statistics ( tau-a , tau-b , and tau-c ). They are not interchangeable, and none of the answers posted so far deal with the last two, which is the subject of the OP's question. I was unable to find functions to calculate tau-b or tau-c, either in

问题 I have to plot 10 frequency distributions on one graph. In order to keep things tidy, I would like to avoid making a histogram with bins and would prefer having lines that follow the contour of each histogram plot. I tried the following [counts, bins] = hist(data); plot(bins, counts) But this gives me a very inexact and jagged line. I read about ksdensity, which gives me a nice curve, but it changes the scaling of my y-axis and I need to be able to read the frequencies from the y-axis. Can

问题 Is it possible to fix parameters while fitting distributions in SciPy? For example, this code: import scipy.stats as st xx = st.expon.rvs(size=100) print st.expon.fit(xx, loc=0) results in non-zero location ( loc ). When some parameter is provided to the fit function it is considered as an initial guess. And if it is provided to the constructor ( st.expon(loc=0) ) the distribution becomes "frozen" and can not be used for fitting. 回答1: To fix loc , use the argument floc : print st.expon.fit(xx