This page lists all exercises of this book. Doing all the exercises is an important part of getting the essence of this book.
Exercise: Trying Interactive ROOT
On an interactive ROOT session: Fill an array of 100 000 000 64Bit floating point numbers of the machine independent ROOT typeDouble_t with random numbers. Compute the mean of the array and print it to the console. Note the computation time.
Hint: You can get random real numbers by creating a pointer to an instance of the TRandom class. (The constructor takes one arbitrary integer as initialization.) Then you can call the method TRandom::Rndm() to get a simple pseudo random number uniformly distributed between 0 and 1. For example:
TRandom *R =new TRandom(time(0));// create a pointer to a new instance of TRandom in the heapcout<< R->Rndm()<< endl;
Once again, consider the code you should have previously written to compute the mean of an array of random numbers. Now, last but not least, make it a stand-alone application and run it independently of any ROOT session. Make sure that passing parameters will still work. Check the performance of your application. Take also care that your modifications don't disturb interpretation or on-the-fly compilation by CINT or ACLiC.