gretlrandom

A D wrapper over Gretl's random number generators. Currently (05/29/2020) avoids any dependencies on other libraries so it's independent of those design decisions. Those functions will be provided in a different module.

Startup and shutdown

• Must call randInit before calling any of these functions.
• Should call randFree to clean up when you're done.

void randInit()
void randFree()

• Set and get the seed with setSeed and getSeed. Should normally do this to ensure replicability. setSeed requires a uint on the C side. Since this is a rarely called function, to!uint is used to convert the value for convenience. Note that this operation is safe. to confirms that the values are within the acceptable range and throws an exception if not.

void setSeed(long seed)
uint getSeed()

Generating integers

• uniformInt returns one integer over the full range of acceptable int values (0 through 2^31 - 1) if no argument is provided.
• uniformInt returns an integer less than the argument when called with an argument.

uint uniformInt(uint k) { 
  return gretl_rand_int_max(k);
}

Generating uniform double values

• runif returns one double between 0 and 1 if called without an argument.
• runif returns a double array of n elements if called with an argument.
• runifUnsafe should normally not be called. It is used by other library functions generating arrays of uniform values.

double runif()
double[] runif(int n, double min=0.0, double max=1.0)
void ruinfUnsafe(double * ptr, int len, double min=0.0, double max=1.0)

Generating normal double values