Geoff, et al., I have the following comments on this excellent proposal:

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1) I still don't see the need for a "typeArray" attribute. The presence (or absence) of "dimensionDef" is sufficient for any parser to determine the size of any array that may be present. 2) As far as using "typeArray" to help if there is a MathML calculation (since MathML uses vector, matrix type attributes), I don't think this solves anything because what if the typeArray said "vector" but there were two <dim> in the <dimensionDef>? Or what happens if it is a 3 (or more) dimensional array? Also, the MathML has the whole <matrix> <matrixrow> ... <matrixrow/> syntax that we don't want to get into here... 3) As far as "typeData", I would suggest adding an explicit "boolean" type in addition to the real and integer. While nominally covered by "typeData" with a "base" of 2, it is (or could be) such a common item that it would be useful to be more explicit. I'm not as sure whether to use something separate, or use the MathML <true/> and <false/> for the values. 4.0) I hope that this section from your example: <dimensionDef> <dim>3.0</dim> </dimensionDef> doesn't mean that there are non-integer dimensions! It's been too long since I studied fractals, but I don't recall anything that would be too useful in DAVEML-type simulations. :-) http://en.wikipedia.org/wiki/Fractal http://en.wikipedia.org/wiki/Fractal_dimension Dennis --- Dennis J. Linse, Aerospace Engineer Science Applications International Corporation +1-703-294-4449 <mailto:[EMAIL PROTECTED]> -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian, Geoff Sent: Thursday, March 27, 2008 2:01 AM To: Aerospace Sim Standard discussion group Subject: FW: arrayDef & draft simstd comments Hi all, The following is an experimental scheme I have come up with that makes minimal change to the dtd to add a capability for vector/matrices. The major change is to the definition of the variableDef element. I have added to following in the element definition: "dimensionDef?, (calculation | array)?" Also I have added to following in the attribute list: typeData (real | integer) #IMPLIED base CDATA #IMPLIED typeArray (scalar | vector | matrix) #IMPLIED" The "dimensionDef" is used when listing the dimensions of the vector/matrix. The "array" is used to represent the associated data table for the vector/matrix. The "typeData" and "base" have been included to address Giovanni's wish to have data types for each variable. This concept I have taken from that used by MathML for the definition of "cn" and "ci" elements. The "typeData" is a subset of that defined in MathML (having the possibilities of integer | rational | complex-cartesian | complex-polar | real | e-notation [Default : real]). The "base" has an integer value of between 2 and 36, with a default of 10. The "typeArray" attribute is used to define whether the variableDef represents a scalar value, or vector/matrix values. This is again similar to the convention used by MathML for the "ci" element. <!ELEMENT variableDef (description?, (provenance? | provenanceRef?) , dimensionDef?, (calculation | array)?, isOutput?, isState?, isStateDeriv?, isStdAIAA?, uncertainty?) > <!ATTLIST variableDef name CDATA #REQUIRED varID ID #REQUIRED units CDATA #REQUIRED axisSystem CDATA #IMPLIED sign CDATA #IMPLIED alias CDATA #IMPLIED symbol CDATA #IMPLIED initialValue CDATA #IMPLIED typeData (real | integer) #IMPLIED base CDATA #IMPLIED typeArray (scalar | vector | matrix) #IMPLIED > To support this, the following is also required. <!ELEMENT dimensionDef (description?, dim+) > <!ELEMENT dim (#PCDATA)> <!ELEMENT array (dataTable)> My syntax may not be totally correct. I have attached a sample file on how vector/matrices might look in XML using this scheme. Supporting whatever scheme is agreed on through Janus will be the next challenge. Geoff IMPORTANT: This email remains the property of the Australian Defence Organisation and is subject to the jurisdiction of section 70 of the CRIMES ACT 1914. If you have received this email in error, you are requested to contact the sender and delete the email.