Acceptable tolerance in computed results

The tolerance on the results of the specified analyses should as follows:

Signal Statistics

Number of samples processed should be exact.

Other results should be accurate to 4 significant figures. (This is considered to be acceptable for normal analysis purposes)

RMS Level spectra

As will be noted from the plots the signals reach a noise floor above approximately 100 Hz and it is recommended that comparisons with the reference results should only be made in the range 0 to 60 Hz.

Due to differences in computational algorithms it is not anticipated that exact agreement will be attained. However, good agreement should be achieved for the significant peaks in respect to both amplitude and frequency.

Typical benchmark 5 erroneous results and their causes

If good agreement is not achieved for the basic statistics then the tests specified in benchmarks 1-3 should be run to check that good agreement for basic statistics for deterministic signals could be obtained ensuring that the computation of the statistics is correct. If results from benchmarks 1-3 are correct then the length of data in the selected section and its position within the original data should be checked.

Overlaying the supplied reference spectra on the locally derived spectra best checks computed spectra.

Possible causes of differences are:

Incorrect application of or failure to apply the Hanning window.
Difference in overlapping of spectral segments.
Incorrect scaling of first and last point in the spectra.
Differences in methods employed for normalizing to zero mean.
Incorrect handling of an incomplete block at end of data.

Results return documents.

In order to aid the working party in the development of benchmark data users are invited to submit the results obtained when employing the tests. These submissions will be assessed by the working party and summaries may be used in presentations and publications of the working party’s activities.

If you wish to submit results please use the document contained in Appendix A.

Appendix A

Benchmark 5  Analysis results return.

Name:                                                Organisation:                                                Date:

Address:

Email:                                                 Tel:                              Fax:

Analysis Package used:                                                      Version:

Computer Hardware and operating system details

Processor:                             Speed:                                    Memory size:                        Mb:

Operating System:              Version:

Results for basic statistics

Minimum value                   Located at

Maximum value                   Located at

Mean Value

Root Mean Square Value

Standard Deviation Value

Number of points

Spectral Density Results

Comparison of reference points

Please detail any differences found and supply the data in ASCII form in datasets named

{Identifier}_BM_6_RESULT_{signal}.TXT

 where Identifier your name and signal is the appropriate signal name.

Comments:

Suggestions for further benchmark tests:

Return results to:  Dr. B. J .May  1, Westhall Road, Mickleover, Derby. DE3 0PA. UK

Email: verification@e-i-s.org.uk               Tel/Fax: +44 (01332) 737034

NOTES:

1.      Numeric precision

All results should be quoted to 4 significant figures.

2.      Trailing zeros

Trailing zeros may be suppressed.

3.      Use of results

The working party may make use of the information received in Analysis results returns for the purpose of promoting the work of the party and for informing the Data Analysis community of the variation of results obtained.

When results are used for presentations no reference will be made to either the source or analysis package employed.