Why does C++ rand() seem to generate only numbers of the same order of magnitude?

Question

In a small application written in C/C++, I am facing a problem with the rand function and maybe the seed :

I want to produce a sequence of random numbers th

Answer 1

use pow(2,rand()) it will give the answers in order of desired magnitude!!

Answer 2

You need to be more precise: you want different base 2 logarithm values but what distribution do you want for this? The standard rand() functions generate a uniform distribution, you will need to transform this output using the quantile function associated with the distribution that you want.

If you tell us the distribution then we can tell you the quantile function you need.

Answer 3

If you want different orders of magnitude, why not simply try pow(2, rand())? Or perhaps choose the order directly as rand(), as Harold suggested?

Answer 4

There are only 3% of numbers between 1 and 2³⁰ which are NOT between 2²⁵ and 2³⁰. So, this sounds pretty normal :)

Because 2²⁵ / 2³⁰ = 2^-5 = 1/32 = 0.03125 = 3.125%

Answer 5

The lighter green is the region between 0 and 2²⁵; the darker green is the region between 2²⁵ and 2³⁰. The ticks are powers of 2.

Answer 6

If you want to use random numbers from an online service you can use wget for that, you may want to see you can also use services like random.org for your random number generation , you can catch them using wget and then reading the numbers from the downloaded file

wget -q https://www.random.org/integers/?num=100&min=1&max=100&col=5&base=10&format=html&rnd=new -O new.txt

http://programmingconsole.blogspot.in/2013/11/a-better-and-different-way-to-generate.html