Help with histogram

[Simone Landini]

Dear everyone,

I have Montecarlo simulated a "double DR[B]" array of B=10^6 
(strictly)-positive real numbers: my code does precisely what I want, I 
checked it analytcally.

Now, I would like to obtain a histogram of DR with a "int numOfBins = 
500" bins. Of course, I can print DR to a file and plot a histogram with 
a statistical package but I would like to learn more about GLS.

I went through the documentation but I wasn't able to obtain the result: 
as a GSL-beginner I surely missed something of the GSL fundamental rules.

Could you please help me understanding how to correctly obtain the 
histogram and estimate some q-percentile of it?

Bye

Simone