Physical Dimensions

[Paul Wellicome]

I've been using the backend of the database to drive some functionality in a piece of in-house code I am working on. I was asked to draw a graph and to label the y-axis with the physical dimension - so I used the physical dimension table, looked up the PD from the ISO code of the data channel and returned the text field and the default unit. So, for example if the PD were 'AA', I'd have an axis labelled 'Angle Acceleration [rad/(s*s)]'. All was fine... until I had to plot an index. Here the ISO code had '00' for the PD - and so I had returned 'Others' and '0'. I'd rather the graph were labelled 'Index, []'.

My suggestion would be, therefore, to introduce a PD code of 'IN' for index, with default Text_L1 of 'Index' and default unit as a blank string ' ' to get round this problem.
Any objections/ other thoughts?

[DiVe]

Hello Paul,

I would agree that the actual definition '0' for the PD '00' is no good choice. In our software we have implemented '1' as default unit for this PD. In my understanding anything multiplied by Zero is still Zero (with some exceptions like INF ).
Using [1] as the "SI" unit we have also some other units in this category as several curves and values have no real physical dimension or it is not used (percentage, NIC-Rear, HIC,...).
Also your Index falls in this category.
Would you (or your in-house customers) satisfied with a 'Other' and '[1]' combination? I am afraid if we start with a new PD 'IN' for Index we will need to setup several others also. But if they all have [1] as their "SI" unit it will be a better solution to have a change for PD '00' to have this unit.

Bye,
Dirk

[Admin]

Use Other and [1].

Item closed during on-line meeting 20120216.