Double precision implementations, using equation (21)
with several Gauss-Legendre rules, and with the adaptive algorithm
described in the previous section (absolute error tolerance set at
),
were tested. The test used
,
,
with
,
and
, with results given in Table 2, which include
average computation time in seconds for the different integration methods.
Additional tests with
, to check for sensitivity of
the algorithms to nearly singular problems, did not produce significantly
different results.
Table 2:
Generalized Plackett Formula BVT Method Results
| |
 |
Maximum Error |
Average Time |
| 6-Point Rule |
0 |
 |
s |
| 12-Point Rule |
0 |
 |
s |
| 24-Point Rule |
0 |
 |
s |
| 24-Point Rule |
.01 |
 |
s |
| 48-Point Rule |
0 |
 |
s |
| 48-Point Rule |
.01 |
 |
s |
| Adaptive |
0 |
 |
s |
| Adaptive |
.01 |
 |
s |
A quadruple precision implementation of an algorithm based on the Dunnett and
Sobel (1954) paper was used for an accurate comparison.
A double precision implementation of the Dunnett and Sobel (1954) paper
algorithm reliably
achieves double precision results and typically takes about
seconds, approximately one tenth of the time taken by the
adaptive algorithm using equation (21).
This time difference and results in Table 2
do not support the use of methods that use equation (21)
with numerical integration for the efficient computation of BVT
probabilities.
2004-04-13