20030411: Selecting variables from multiple files

John-

> In the ability to use multiple files for variables in display a graph, I
> tried to 
> use some arbitrary function = f(TA, QV) and in designing the formula (in
> this case, I 
> just used: (TA + QV)  ), the following display came up allowing me to
> choose which 
> variable (from the desired file) that I'd like to use... (that's a good
> design)...  
>
>
>    TA                                           QV              
>
>
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2.v5d     
> C\IDV_Stuff\vis5d_stuff\MET_CROSS_2.v5d
>        3D grid                                  3D grid
>           TA                                       TA
>           QV                                       QV  
>
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2BB.v5d   
> C\IDV_Stuff\vis5d_stuff\MET_CROSS_2BB.v5d
>        3D grid                                  3D grid
>           TA                                       TA
>           QV                                       QV  
>
>
>
> But when I wanted to utilize the arbitrary function: (TA + TA) and use
> the first "TA" from 
> one file and use the second "TA" from the other file, say, the IDV
> choice came up with : 
>
>    TA
>                                                         
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2.v5d    
>        3D grid                                
>           TA 
>           QV 
>
>
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2BB.v5d   
>        3D grid                                  
>           TA   
>           QV 
>
> Thus, I wasn't able to select a variable (TA in this case) from one file
> and also select the second TA (in "(TA + TA)"), from a second file... 
>
>
>
> I wonder if there shouldn't be something of this nature display: 
>
>    TA (for 1st occurrence of TA in "TA + TA")   TA  (for 2nd occurrence
> of TA in "TA + TA")              
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2.v5d     
> C\IDV_Stuff\vis5d_stuff\MET_CROSS_2.v5d
>        3D grid                                  3D grid
>           TA                                       TA
>           QV                                       QV  
>
>
>    C\IDV_Stuff\vis5d_stuff\MET_CROSS_2BB.v5d   
> C\IDV_Stuff\vis5d_stuff\MET_CROSS_2BB.v5d
>        3D grid                                  3D grid
>           TA                                       TA
>           QV                                       QV  
>
>
> This would allow the user to pick the TA of whichever file they wanted
> for each or any of 
> the TAs in the formula... So, with this type of system, it seems as
> though when the variables are not alike (ie.: "TA + QV"),  one can
> utilize the feature of using various variables from different files but
> if the formula had all like variables, (ie.: "TA + TA"), one may not be
> able to select the appropriate file for each "TA", in this case, to use
> in graphing the results.... 

The idea was that if a variable is used more than once in a formula,
it was assumed to be the same variable (ie. T-TD/T).  So, if you
had the variable in the formula 10 times, you didn't have to
select it 10 times. In the meantime, you could...

> (There may be better ways to accomplish this problem, Don, but the main
> thing (right now) is just  to make you aware of this problem...)....

....create a formula (D1+D2) (or TA1 + TA2 - anything to make
them different) and it should allow you choose arbitrary
values.  This way you could create an arbitrary formula
for addition and then select whatever you want to add.
Having the variable names does not give you automatic
selection in the datatree anyway, so using generic names
is just as well.

Don Murray
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