DataLoader/MX Reference Manual (H06.03+, J06.03+)

Creating a Customized Version of DataLoader/MX
DataLoader/MX Reference Manual—543544-001
5-29
Generating Test Data
distributions. There are, however, other useful distributions, most notably the Normal
distribution, which can be generated from an even distribution.
DTLRandUnsignedLong
This procedure returns the next unsigned 32-bit number from a pseudo-random series
with a period of 1,073,741,824.
The syntax is:
The algorithm used is the multiplicative congruential random-number generator with a
seed value of 1, described in Modern Statistical, Systems, and GPSS Simulation by
Zaven A. Karian and Edward J. Dudewicz, W. H. Freeman & Co., October 1990, page
90.
DTLRandUnsignedLong2
This procedure returns the next unsigned 32-bit number from a random series with a
period of about 2**47. DTLRandUnsignedLong2 has a number of advantages over
DTLRandUnsignedLog and is recommended.
The syntax is:
The algorithm used is the Lagged Fibonacci Generator (17,5,31) after Marsaglia with a
LCG initialization method after Park and Miller.
DTLRandUnsignedLong2Init
This procedure optionally can be used to initialize DTLRandUnsignedLong2 to cause it
to start at a different point in its sequence of random values. By default,
DataLoader/MX initializes DTLRandUnsignedLong2 with the seed value 1305.
If you want to receive different sets of random numbers in different runs, you can use
DTLRandUnsignedLong2Init to give a different seed in each of your runs.
The syntax is:
Odometers
Another useful type of test data is modeled after an automobile’s odometer. Consider
this sequence of numbers:
00000
00001
unsigned long DTLRandUnsignedLong( void );
unsigned long DTLRandUnsignedLong2( void );
void DTLRandUnsignedLong2Init ( unsigned long Seed );