Random Numbers?

[NipsMG]

I'm sorry, I know this is a REALLY elementary post, but I've only recently (as in the past few days), started learning C++. (I've been a Basic/VB programmer my whole life).

I got a book on C++ and have been learning, as well as following OpenGL tutorials.. The syntax is the only major issue, however I'm not having too much of a problem following it..

What' I'm looking for is a Random Number function, that can give me a float value between 0 and 1. The only random function shown in the book I have, rand(), seems only to give integers and does not allow for the specification of a range.

I appreciate your help in advance.

Thanks!
--NipsMG

 

[shun]

I have one way,but I am sure this is not a good way;
u can redefine RAND_MAX,then after u got the randrom number,
divided the Rand_Max,It works.u can write a function to do this;

 

[IonelBurtan]

First you got to seed the random number generator with a different seed to have different start numbers generated each time you will start the rand function

this is one method(&quot;#include <time.h>&quot:
srand( (unsigned)time( NULL ) );

the RAND_MAX is the maximum value that can be generated. (0x7fff)

So you should be doing this to obtain numbers within 0 and 1:
float i=(float)rand()/RAND_MAX;

Hope this helps, s-)

Blessed is he who in the name of justice and good will, shepards the week through the valley of darknees...

http://www20.brinkster.com/ionelb

 

[Zyrenthian]

To expand on BurtanI's post.... to get a number in a range (say 0-51) you would use rand()%52, for a range of 10 - 20 you would use rand()%11+10.

Matt

 

[NipsMG]

Thanks for your posts..

Zyrenthian, That's actually exactly what I figured out.

I was looking to get a float between 0 and 1, so I just used (rand() % 11 ) * 0.1f and it seemed to work fine.

Thanks again!

--NipsMG X-)