Dimensional Measuring Interface
Standard
Standard Improvement Request
|
SIR No. 97-57 DMIS Release 3.0 SIR Type Enhancement Severity Documentation Deficiency Status Resolved Date Submitted August 13 1997 Date Validated August 13 1997 Date In Process Date Referred April 1 1998 Date Vote Pending Date Closed August 20 1998 Action Clarifications Submitted By Thomas Kramer NIST Room B-124, Bldg. 220 Gaithersburg MD 20899 USA Phone: (301)975-3518 Fax: (301)990-9688 kramer@cme.nist.gov |
Problem Topic
DATSET: Origin clarification
Problem Description
Note: This is the second of four SIRs relating to DATSET on pages 113 and
114. I will also have several comments on DATSET on pages 17 - 19.
Page 113, next-to-last line. This line reads:
"XORIG signifies that the x-component of the datum is used to establish the origin."
This is vague in that it does not say what aspect of the datum is to to be used, and it does not say how that aspect is used in establishing the origin.
It seems implicit in DMIS standard (maybe it is explicit somewhere in the document) that with each feature which may be used as a datum to establish coordinates, there is an associated point (call it the datum point). For each feature type, there is a rule for which point is the datum point of the feature. For any instance of a feature, the rule may be used to find the datum point of that specific feature instance. The quoted sentence above should be modified to refer to the datum point.
References
None
Related SIRs
None
Suggested Resolution
Reword the sentence above to read:
"XORIG signifies that the MCS x coordinate of the origin is the MCS x coordinate of the datum point of the feature referenced by the datum."
Similarly, reword the corresponding sentences for YORIG and ZORIG.
[Referred back to submitter for clarification on:
(1.) The significance of the MCS addition to the quoted statement; and
(2.) There are no implicit rules to determine the "datum point" of a specific feature.]
Support Documentation
None
Resolution
Warning!!
The following statement is only a resolution to a Standard Improvement Request (SIR) and is NOT part of the current DMIS standard, nor is it guaranteed to become part of the next revision of the DMIS standard even if voted and accepted by the DMIS National Standards Committee. This resolution is tentative because it may not be incorporated into the next version of the standard, it could be changed prior to the next release, or it could be changed as the result of the "public review and comment" period required for the next version of the standard. If you choose to use this tentative resolution, you do so at your own risk since at this time it is not part of the DMIS standard.
Change the definitions of XORIG, YORIG, and ZORIG in DATSET.
Change the definitions of XORIG, YORIG, and ZORIG in DATSET on pages 113,114 to read:
"XORIG signifies that the x-component of the datum is used to establish the x-axis origin."
"YORIG signifies that the y-component of the datum is used to establish the y-axis origin."
"ZORIG signifies that the z-component of the datum is used to establish the z-axis origin."
Attachments
None
Notes
Added by Mike Holloway, hkm@ornl.gov on 7/31/1998
No reference was found to this SIR in any meeting minutes.
I believe that the description for XORIG is misworded. It might should read:
XORIG signifies that the datum is used to establish the x-component of the coordinate system origin.
Added by Interpretation Subcommittee, hkm@ornl.gov on 8/7/1998
Change the definitions of XORIG, YORIG, and ZORIG in DATSET on pages 113,114 to read:
"XORIG signifies that the x-component of the datum is used to establish the x-axis origin."
"YORIG signifies that the y-component of the datum is used to establish the y-axis origin."
"ZORIG signifies that the z-component of the datum is used to establish the z-axis origin."