Eliminating Subscript Dependency in Subsequent Equations

[geo_curious]

Hi,

Relating to viewtopic.php?p=33432, I would like to take an output from an auxiliary variable that has a subscript dependency, placing it into a subsequent function without requiring the subsequent function to also be dependent on the subscript.

For example,
Where:

gfunction output[borehole array size] = gfunct subscript[borehole array size]

I would like to avoid subsequent dependency, using only the value of the output from the previous function, such as:

wall temperature = initial temp+temp change+((q/(2*pi*k)*gfunction output))

This does not appear to be possible without inheriting a subscript error. Is there a work around? I have so many dependencies, that I do not want to introduce an erroneous subscript requirement for each of many auxiliary variables such as the one shown here.

[tomfid]

You can use VECTOR SELECT or SUM for this, combined with an indicator variable that shows which of the RHS elements to select.

[tomfid]

k : k1-k10
y[k] = x[k]
y active[k] = IF THEN ELSE( k=3, 1, 0)
y out = SUM( y[k!]*y active[k!] )

Another option for picking a single value would be,

y out = VECTOR ELM MAP( y[k1], offset )

where offset is the index of the value you want as a 0-based offset from k1.

[geo_curious]

So far as I can tell, it is not true that SUM() prevents the propagation of subscripts in subsequent equations. I cannot get anything to run, whatever the case, but here is one example where SUM() is doing nothing to prevent propagation of subscripts:

Gives "incorrect number of subscripts for gfunct subscript" error:
gfunct selected[borehole array size, Interval,Instance]= INITIAL(
sum(
IF THEN ELSE ( array size selected = array size[borehole array size!]
,gfunct subscript[borehole array size!, Interval!, Instance!]
,0)
))
~ Dmnl
~ |

Still requires (depends on) subscripts from gfunct selected and will not run:
borehole wall temp Tb[borehole array size,Interval,Instance]=
initial production temperature
+sum(gfunct selected*diff dQ[Interval!,Instance!])
*c0
~ Celsius
~ |

Also, it is a bit excruciating to have to come back to the forum every time there is an error with subscripts. The error handling message should read what the problem is specifically - like the number of subscripts expected or why else something is wrong, etc. That is a suggestion!

[Administrator]

Try removing the @"[borehole array size, Interval,Instance]" from the left hand side of the equation for "gfunct selected".

gfunct selected= INITIAL(
sum(
IF THEN ELSE ( array size selected = array size[borehole array size!]
,gfunct subscript[borehole array size!, Interval!, Instance!]
,0)
))

[geo_curious]

Removing the subscripts from the left hand side did not prevent the error. The equation still returns "Incorrect number of subscripts for -gfunct subscript-."

I am posting a smaller version of this model to troubleshoot here. A change from some posts that Tom had previously helped me work through is that this model is trying to select a borehole array size from table data, instead of using a fixed lookup. With that change I have the addition of one more subscript (array size), and now another error to figure out. Thank you for any assistance you might offer here.

subscript hand holding.mdl

(3.55 KiB) Downloaded 417 times

ground_response_functions.xlsx

(17.52 KiB) Downloaded 417 times

[geo_curious]

Ok, I solved my own problem. The starting point of the subscript use needed to be added to the Excel data variable. I also omitted a few subequations in the first posting of the mdl. Here is the corrected .mdl, that will run.

subscript hand holding.mdl

(4.15 KiB) Downloaded 527 times