Introduction Uniform Distribution Classical Examples Construction Irreducible Polynomials Numerical Integraion Pricing Theory References

 

Uniform Distribution, Discrepancy and Low-Discrepancy Sequences

A sequence of points [Graphics:../Images/QRDemonstration_gr_7.gif] is uniformly distributed in the [Graphics:../Images/QRDemonstration_gr_8.gif]-dimensional unit cube [Graphics:../Images/QRDemonstration_gr_9.gif], if in the limit the fraction of points lying in any measurable set of [Graphics:../Images/QRDemonstration_gr_10.gif] is equal to the area of that set. The star-discrepancy of the first [Graphics:../Images/QRDemonstration_gr_11.gif] points of a sequence [Graphics:../Images/QRDemonstration_gr_12.gif] measures its deviation from the uniform distribution in the way that

[Graphics:../Images/QRDemonstration_gr_13.gif],     

where [Graphics:../Images/QRDemonstration_gr_14.gif] denotes the set of all rectangles in [Graphics:../Images/QRDemonstration_gr_15.gif] with one corner at the origin., [Graphics:../Images/QRDemonstration_gr_16.gif] the [Graphics:../Images/QRDemonstration_gr_17.gif]-dimensional Lebesgue measure and [Graphics:../Images/QRDemonstration_gr_18.gif] the characteristic function of [Graphics:../Images/QRDemonstration_gr_19.gif].
The Law of Iterated Logarithm for the discrepancy shows that the discrepancy of pseudo-random numbers is of the order [Graphics:../Images/QRDemonstration_gr_20.gif]. A lower bound for the discrepancy of any sequence in the s-dimensional unit cube is [Graphics:../Images/QRDemonstration_gr_21.gif], where [Graphics:../Images/QRDemonstration_gr_22.gif] is a constant depending on the dimension. Low-discrepancy sequences are sequences whose discrepancy is less than [Graphics:../Images/QRDemonstration_gr_23.gif].


Converted by Mathematica November 18, 1998