NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Steve, I may have misinterpreted your original posting by confusing quantity with RealType. Perhaps by quantity you mean a generalization of the quantityName field in BaseUnit to DerivedUnit (BaseUnits are things like meter, kilogram and second whereas DerivedUnits include the combinations Tom was talking about, like meter * second^-2). These quantities are distinct from RealTypes. For example, the quantity 'density' (kilogram * meter^-3) can apply to the densities of many different substances, which would each be RealTypes. To continue the example we discussed yesterday, 'speed' is the quantity for the DerivedUnit meter * second^-1, whereas 'wind speed' and 'current speed' would likely have different RealTypes. Giving these different RealTypes allows them to have different display roles, for example different magnitude scalings for flow rendering. Bill ---------------------------------------------------------- Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI 53706 whibbard@xxxxxxxxxxxxx 608-263-4427 fax: 608-263-6738 http://www.ssec.wisc.edu/~billh/vis.html
visad archives: