Geoff,
This is a needed improvement to DAVE-ML.
My first thought is the arrayDef attribute should be something like
'dimensions="3"' and then a (set) of subelements that define the
actual dimensions:
<arrayDef name="myDataMatrixr_m" varID="myDataMatrix" units="m"
dimensions="3">
<dim>2</dim>
<dim>6</dim>
<dim>3</dim>
<description>My Data Matrix is a 2x6x3 matrix; the last
dimension changes most rapidly</description>
<initialValues>
111 112 113 <!-- the actual order is important, not the way
the data is formatted -->
121 122 123
131 132 133
141 142 143
151 152 153
161 162 163
<!-- second plane shows another valid way of listing a 6x3
matrix -->
211 212 213 221 222 223 231 232 233 241 242 243 251 252
253 261 262 263 <!-- whitespace is unimportant
-->
</initialValues>
</arrayDef>
I also need to think through a way to mux and demux from scalars, and
how well this fits into MathML matrix operations.
Have you guys been using this extension in any useful way?
Incidentally, the mailing list is getting rejections from several
dsto.defence.gov.au addresses, including yours:
A message addressed to [EMAIL PROTECTED] in
distribution list "simstds" has been rejected.
I'm working on a new revision to the 2.0 release that will hopefully
accompany the initial AIAA/ANSI Standard, but I don't think we'll be
able to get arrays defined by then.
-- Bruce
On Mar 11, 2008, at 11:00 PM, Brian, Geoff wrote:
Hi all,
I am gauging for interest in adding the ability to define a data
array element (such as a vector or n dimensional matrix) within the
Dave-ML dtd. First thoughts would be to include an element like the
"variableDef" maybe called "arrayDef" with attributes similar to
the variableDef, but with additional attributes defining the
dimensions for the array of data.
For example:
For a vector of size (4x1):
<arrayDef name="myDataVector_m" varID="myDataVector" units="m"
dim1="4">
For a 2-D matrix of size (4x6):
<arrayDef name="myDataVector_m" varID="myDataVector" units="m"
dim1="4" dim2="6">
For a n-D matrix of size (4x6x3x...):
<arrayDef name="myDataVector_m" varID="myDataVector" units="m"
dim1="4" dim2="6" dim3="3" ...>
The data associated with the array would need to be either stored
as a data table or computed using Math-ML expressions. It would
also be useful if an element of an array could refer to a
variableDef or another arrayDef (depending on the dimension of the
array). I would expect that if arrays were manipulated using Math-
ML then the interpreter (such as Janus) would need to manage the
compatibility checking - that is outside the XML file.
One of the significant advantages of having an array element within
Dave-ML would be the ability to encode matrix mathematics within
the XML file - via Math-ML. I would find this particularly useful
when processing axes transformation operations - eliminating the
requirement for addressing the components individually. Another use
would be the encoding of Inertia tensors and cg vectors as a single
variable instead of having a variableDef for each component. I am
sure there are many other uses.
I await in anticipations for comments on this proposal.
Geoff Brian
Aircraft Performance and Flight Dynamics
Air Vehicles Division
Defence Science and Technology Organisation
Ph: +61 (0) 3 9626 7318
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