I am generating random number of normal distribution (0,1) but i suspect maybe I have done it wrong. The generator I use right now is
srand(time(0));
std::random_device rd;
std::mt19937 gen(rd());
std::default_random_engine generator;
std::normal_distribution<double> distribution(0,1);
Am I doing the right thing? Whether this is a real random number generator?
I want to generate random numbers of normal distribution and use scentence like
std::default_random_engine generator;
std::normal_distribution<double> distribution(0,1);
arrayX[i][j]=distribution(generator);
But I find that each time the array I got are the same. So how should I generate random numbers with different seedings with normal distribution?
I wrote the following program shown below that produces a normally distributed random number several times, and then takes the average of them. The problem that I have been having though is that the output it has been producing is 0.0288385 despite the fact that I set the mean of the normal distribution to be 0.1. Why this output value would be so far off from 0.1 despite having averaged over such a large number of random numbers namely 10,000 of them? Also, how to randomly seed this random number generator such that it gives a different value each time its run perhaps by seeding it with the windows timer? Below is the program.
#include <iostream>
#include <random>
using namespace std;
int main() {
default_random_engine generator;
normal_distribution<double> distribution1(0.1,3.0);
double number1,sum,n;
[code].....
Write a function that generates 1000 normally distributed (Gaussian Probability Distribution) random numbers. Range should be between -3 and +3. Numbers should be double floating point.
There's more to it than that, but I've got it from there.
How to generate a skew distribution random number? Or is there any place having refer the skew distribution random number?
View 2 Replies View RelatedHow to generate random and different number in a range. This is my code:
Code:
#include <stdio.h>#define n 8
#define m 7
int main() {
int i,j,a[n][n];
printf("Relaxed Latin Square (%d,%d)
[Code] .....
When I executed that code, the number is random but not different.
I'm implementing an normal_distribution to select objects on a vector. The thing is I can't use values greater then 1 or less then -1. Here is what could be done:
gausx=gaus_distributionx(generator);
while((gausx>1) || (gausx<-1))
gausx=gaus_distributionx(generator);
The question is if the distribution would loose it's power to be a normal distribution, because some of the gerated numbers wouldn't be used. Any way to set ranges for the distribution?
I am recreating a hangman game. I'm trying to generate a random number to choose which word from my words list to use and I've done it a billion times before just like this. So, here's my code:
#include <iostream>
#include <cstdlib> //standard library.
#include <ctime> //for random.
#include <fstream> //for reading and writing to a file.
#include <string>
using namespace std;
int main() {
int num_words;
string word[num_words];
[Code] .....
I have the text file "words.txt" info below.
5
dog
cat
horse
pig
bird
If I run the program as it is, I get a segmentation fault core dumped error, however, if I take all the stuff that reads in the words from the words.txt file, like so:
#include <iostream> //every program has this.
#include <cstdlib> //standard library.
#include <ctime> //for random.
#include <fstream> //for reading and writing to a file.
#include <string>
[Code] ....
it works correctly and generates a random number.
I'm using Linux Mint.
I need creating a unique form of binary tree. I will eventually drop 256 balls into this to see the distribution, but its creating a pascals triangle recursively.
To create it I need to use two classes, a tree and a node class, and friend them create it recursively.
I'm looking to code a completely random distribution of numbers that doesn't affect performance using rand. I believe this code would be ideal but I don't understand how to use it. Where would I input the range of numbers and the quantity?
double uniform_deviate ( int seed ){
return seed * ( 1.0 / ( RAND_MAX + 1.0 ) );
} int r = M + uniform_deviate ( rand() ) * ( N - M );
And for the seed...
unsigned time_seed(){
time_t now = time ( 0 );
unsigned char *p = (unsigned char *)&now;
unsigned seed = 0;
size_t i;
for ( i = 0; i < sizeof now; i++ )
seed = seed * ( UCHAR_MAX + 2U ) + p[i];
return seed;
} srand ( time_seed() );
I have a program that generates random numbers. After the random number is generated, the program asks if you want to generate another random number. However, if you generate another random number, it is always the same as the first random number. How can I fix this?
View 5 Replies View RelatedI want to generate big random numbers in C(not C++ please).By "big" I mean integers much bigger than srand(time(NULL)) and rand() functions' limit(32767).
I tried writing: (note:I am not able to see "code" tag button in this editor,so I am not using it)
//****
int randomnumber;
srand( time(NULL) );
randomnumber = (( rand() % 33 ) * ( rand() % 33 ) * ( rand() % 33) * ( rand() * 33) * (rand() % 33 )) + 1
//****
But I have doubts about it's randomness quality.Also there is another problem,the program can't know the maximum random number it should use before user input,so maximum random number may need to use much smaller maximum random number according to user input.
Is there a better algorithm to create big random numbers in C?
I'm creating a game in C++ and need to generate random numbers. I know about
int main()
{
srand(time(NULL)); //Initialises randomiser or sum' like that
int x=rand%10; //Generates from 0-9
cout<<x;
}
Now, I need the best way to generate random numbers. Do I call "srand(time(NULL));" every time I want to randomise? What is the best method to generate a nearly perfect random number?
I may need to call a randomiser more than once a second, so taking second as seed (I believe that's what srand(time(NULL)); does).
I want to generate big random numbers in C(not C++).By "big" I mean integers much bigger than srand(time(NULL)) and rand() functions' limit(32767).
I tried writing: (note:I am not able to see "code" tag button in this editor,so I am not using it)
//****
int randomnumber;
srand( time(NULL) );
randomnumber = (( rand() % 33 ) * ( rand() % 33 ) * ( rand() % 33) * ( rand() * 33) * (rand() % 33 )) + 1
//****
But I have doubts about it's randomness quality.Also there is another problem,the program can't know the maximum random number it should use before user input,so maximum random number may need to use much smaller maximum random number according to user input.
Is there a better algorithm to create quality big random numbers in C?
I generate a series of random numbers in parallel (using OpenMP), but depending on what number of threads I invoke, I get a different result. From that I conclude that I have made an error somewhere!
Here is the MWE, which generates a number between 0..1 and increments a variable if the generated variable is larger than 0.5:
Code:
#include <random>
typedef std::uniform_real_distribution<double> distr_uni;
#define max_threads 1
using namespace std;
[Code] ....
When I set max_threads=1 I get 50027, but when max_threads=60 (on a machine that supports it....) I get 50440.
The sensitive RNG and its engine I have declared within the parallelized area, so it's not really clear to me where the error can possibly be.
Looking for error that is apparently there?
Inside my loop is this
srand(time(NULL))
a=rand()%10;
So it will generate numbers again and again as the loop goes on but it always repeat some numbers. My question is, how would you generate numbers without repeating? Somebody told me that i have to use auto increment, but i really have no idea about that.
#include <ctime>
#include <iostream>
#include <cstdlib>
using namespace std;
int main() {
[Code] ....
Write a program that keeps generating two random numbers between 1 and 10 and asks the user for the product of the two numbers, e.g.: "What is 4 x 6?". If the user answers correctly, the program responds with "Right!"; otherwise, it displays: Wrong! 4 x 6 = 24.
Generate as many pairs of numbers as specified and get the answers from the user for each. If at any time, both numbers are the same as last time, generate two new numbers before asking for the answer. Continue generating 2 new numbers until at least one is different from last time.
After presenting the number of pairs of numbers specified and getting the answers, display how many the user got right; e.g.: You got 4 of 5 right. Then, ask if he or she wants to play again, like so: "Do you want to play again? [y/n]". If the user answers with 'y' or 'Y', it again reads the number of questions to ask and generates that many pairs of numbers and reads the answers like before. If the answer is n or N, it quits generating numbers. If the answer is anything but y, Y, n or N, it tells the user to enter one of those letters until it is.
When the user decides to quit and has got less than 75% of all the questions right, the program displays the multiplication table (1x1 through 10x10) before terminating.
After displaying the table, randomly generate two numbers between 1 and 10, display their product and first number and ask the user to guess the second as more practice. For example, the program will generate 7 and 9 and will display 63 and 7 and the user must guess the second number (i.e.: 9). Do this 3 times. Do not repeat code. Use a loop to do this 3 times.
Use a nested for loop to display the table; a bunch of cout statements will not be acceptable. You must also use a loop for any part that calls for repetition such as generating 5 pairs of numbers.
The following is a sample interaction between the user and the program:
Enter the number of questions to ask: 5
1. What is 3 x 9? 27
Right!
2. What is 2 x 7? 14
Right!
3. What is 8 x 9? 63
Wrong! 8 x 9 = 72
4. What is 6 x 3? 21
Wrong! 6 x 3 = 18
5. What is 2 x 9? 18
Right!
You got 3 out of 5 right which is 60%.
Play agian? [y/n] n
I'm trying to create a code that generates random numbers and spits out a sum average and lowest and highest number. I am stuck on the sum however and once I get that I think the average will fall into place. Here's what I have.
#include <iostream>
#include <iomanip>
#include <ctime>
#include <math.h>
using namespace std;
[Code] ....
I've noticed that it's almost always off by 1 or 3 for whatever reason
My problem says: Have the user enter a number from 1-80 then print out a string of random letters(a to z lowercase) of that length.
I have been able to enter the number and output the correct amount of letters but i can't figure out how to get them to be in a random order and not in alphabetical. Here is what I have so far.
#include <iostream>
using namespace std;
int main() {
int i=0;
int num;
cout<<"How many letters do yu want in your random string?";
[Code]....
We had to generate random, unique numbers in the range [1,15]. But running the program for several times showed a bug: It wouldn't always generate a new number for every repeated number. I can't figure out the problem, especially since it works half the time and I can't figure out what's making it work some times and not others.
bool flag1 = true, flag2 = true, flag3 = true;
int i, j = 1;
int[] A = new int[11];
Random rnd = new Random();
A[0] = rnd.Next(1, 15);
Console.WriteLine("1. = " + A[0]);
[Code] .....
for (int i=0; i<15; i++)
{
nx[i]=rand()%8+1;
printf("%d",nx[i]);
}
I want to the function of timer "srand(time(NULL))" to generate seed for random numbers. By running this for loop,I think I should expect random numbers ranging from 1 to 8.However, I get some wried numbers from the console window like 88,044,077,066,088,088,066,022,044,044,088,022,033,66814990522,-156026525933,1606416712. One more thing,I think I am going to have 15 outputs, but why I get 16 instead every time.
I'm running a game online and designing a program to generate Enemy Stats. Basically, it's supposed to generate 25 numbers between 0 and 7(to represent 8 Attributes on a 25 Point Buy system) and count how many times each number shows up.
Here's what the code looks like:
Code:
#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;
int Generate() {
int r= rand();
int s= r%7;
[Code] ....
And here's two outputs.
1: Code:
12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 12133089220 Stats[0]= 25 Stats[1]= 0 Stats[2]= 0 Stats[3]= 0 Stats[4]= 0 Stats[5]= 0 Stats[6]= 0 Stats[7]= 0 Stats[8]= 0 Disallowed system call: SYS_socketcall
2: Code:
14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 14787708434 Stats[0]= 0 Stats[1]= 0 Stats[2]= 0 Stats[3]= 0 Stats[4]= 25 Stats[5]= 0 Stats[6]= 0 Stats[7]= 0 Stats[8]= 0 Disallowed system call: SYS_socketcall
Note that the number does change, but only between runs.
How do I program c# code for generating electronic (license plate or number plate) randomly by using C# VS2012? The form of the vehicle license plate is like that:
GB LLNN LLL
Where GB = fixed letters
L = letters from (A to Z) randomly, except ( I, O,U and Z)
N = numbers from (0 to 9) randomly,
I am working with C++ in Visual Studio. It's my first semester doing anything like this ever. Still, I am embarrassed that I am having trouble with this simple "coin flipping" program. The user tells the program how many times to "flip the coin" & then the program tells the user the results of each flip. You'll see I am randomly generating a 1 or a 2 within the function coinFlip to represent heads or tails. However, the problem is that if the user wants more than one coin flip, the "random" number stays the same for all of them, resulting in all heads or all tails. I am thinking this is an issue with the for loop that I have within the function coinFlip.
Code:
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
using namespace std;
[Code] .....
I'm trying to generate random number from 7 to 10 but all i got is "Error C2661: 'rand' : no overloaded function takes 1 argument"
there is my code:
#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <time.h>
using namespace std;
void init_Function(); // init function
[Code] .....
When I run this program it always generates the number 41 or 42. Why is this? Even if I add the code
magic = rand()%100 + 1;
to specify a range of 1 to 100 it's still always 41 or 42.
This is exactly the same code my book uses just without the cout << magic statement
#include<iostream>
#include<cstdlib>
using namespace std;
[Code].....