random

问题 I need to run a MonteCarlo simulations in parallel on different machines. The code is in c++, but the program is set up and launched with a python script that set a lot of things, in particular the random seed. The function setseed thake a 4 bytes unsigned integer Using a simple import time setseed(int(time.time())) is not very good because I submit the jobs to a queue on a cluster, they remain pending for some minutes then they starts, but the start time is impredicible, it can be that two

问题 First off, hello everyone! This is my first ever question here, so I hope I am not screwing up. I googled a lot before writing here. I am new to coding, to c++ and I am learning it on my own. Considering that I was told that it is a good practice (i'm probably wrong here) to only seed any Random Engine once, what is the proper / best / more efficient way of using std::mt19937 from the random standard library inside a class, seeded by std::chrono::high_resolution_clock::now().time_since_epoch(

问题 First off, hello everyone! This is my first ever question here, so I hope I am not screwing up. I googled a lot before writing here. I am new to coding, to c++ and I am learning it on my own. Considering that I was told that it is a good practice (i'm probably wrong here) to only seed any Random Engine once, what is the proper / best / more efficient way of using std::mt19937 from the random standard library inside a class, seeded by std::chrono::high_resolution_clock::now().time_since_epoch(

问题 I would like to add random NA to a data.frame in R. So far I've looked into these questions: R: Randomly insert NAs into dataframe proportionaly How do I add random NAs into a data frame add random missing values to a complete data frame (in R) Many solutions were provided here, but I couldn't find one that comply with these 5 conditions: Add really random NA, and not the same amount by row or by column Work with every class of variable that one can encounter in a data.frame (numeric,

问题 I'm working on Pong in C# w/ XNA. I want to use a random number (within a range) to determine things such as whether or not the ball rebounds straight, or at an angle, and how fast the ball moves when it hits a paddle. I want to know how to implement it. 回答1: Use the Random class. For example: Random r = new Random(); int nextValue = r.Next(0, 100); // Returns a random number from 0-99 回答2: Unless you need cryptographically secure numbers, Random should be fine for you... but there are two

问题 I'm working on Pong in C# w/ XNA. I want to use a random number (within a range) to determine things such as whether or not the ball rebounds straight, or at an angle, and how fast the ball moves when it hits a paddle. I want to know how to implement it. 回答1: Use the Random class. For example: Random r = new Random(); int nextValue = r.Next(0, 100); // Returns a random number from 0-99 回答2: Unless you need cryptographically secure numbers, Random should be fine for you... but there are two

问题 I am running a cherrypy 3.2.0 server with Python 2.5.1, which gives the following error every few days on any instruction from UI until it is killed and re-started:- [29/Mar/2012:06:37:57] HTTP Traceback (most recent call last): File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 636, in respond File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 97, in run File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0

问题 I am running a cherrypy 3.2.0 server with Python 2.5.1, which gives the following error every few days on any instruction from UI until it is killed and re-started:- [29/Mar/2012:06:37:57] HTTP Traceback (most recent call last): File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 636, in respond File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0-py2.5.egg/cherrypy/_cprequest.py", line 97, in run File "/usr/lib/python2.5/site-packages/CherryPy-3.2.0

问题 I generate many many random numbers that need to be between 1 and 15 (included) in C++. Of course, I can generate zillons of std::uniform_int_distribution<std::mt19937::result_type> random(1, 15); but this is a waste since this mersenn twister generates 32 bits (or even 64 using mt19937_64) of random values, and I would only keep 4 bits and throw away all the rest, and in my case, performance is an issue and random number generation is a significant contributor. My idea was thus to generate

问题 I am finding something odd happening with my program. This program basically is used for component clicking, as it is a concept to test randomness. As you can see, it is printing correctly, as it should have a tendency to click towards the middle, which is does perfect. Problem is, it seems biased. import java.applet.Applet; import java.awt.Point; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.awt