Hi – a question that has some similarities to one asked in the previous post “Addressing cells programmatically”.
I am writing a simple script to replicate an excel-style goal-seek functionality. The script is to work on a matrix with a filter category (‘PhaseName’). The idea is to change the value of a particular item ‘Decline Rate’ (incrementing it up or down), depending on the value returned by the model. Only the value of ‘decline rate’ for the ‘PhaseName’ currently selected in the filter should be changed, however.
I can use the .itemIndex property of the .getFilterItem method to obtain the index number of the currently selected ‘PhaseName’, and can get the particular value for the ‘Decline Rate’ of the currently selected ‘PhaseName’ as follows:
int current = |Phase Details|.getFilterItem(|Phase Details::PhaseName|).itemIndex
|Phase Details::Combined Peak.Decline Rate|.values[current].value
However, it appears that using values with an index number in this way is a read-only property – one can’t set this to a new value.
In the earlier post “Addressing cells programmatically”, I found a useful code snippet from dom, achieving something similar by creating an ArrayList based on all of the different values of the item being changed, changing only that value corresponding to the currently selected filter category, and then writing the ArrayList back to the item. In my case, this would work as follows:
def ArrayList<Item> declines = |Phase Details::Combined Peak.Decline Rate|.values
declines.set(current, |Phase Details::Combined Peak.Decline Rate|.values[current].value-increment)
|Phase Details::Combined Peak.Decline Rate|.values = declines
This does in fact work – but it seems an inordinately complicated way of doing something that users must surely want to do all the time. Is anyone able to suggest a better way of doing this?
On a related note, since when the model is complete, the filter category “PhaseName” will have several hundred ‘phases’ in it, I have a related question on the model.ensureCalculated() method. With only a few phases, calculation times for this model are generally under a second – so if the goal-seek algorithm I have put together takes 6-10 iterations to find an answer, and must calcuate each time, while it is slow, it is not unbearable. Once several hundered phases have been added to the model, a full recalc will almost certainly take well over 10 seconds, meaning 6-10 iterations will become painfully slow – frustrating since in this case, only one of those several hundred phases actually needs to be calculated. Is there any method that can be called that will calculate the model only for the currently selected phase, rather than for all of them? This would seem like an essential ability for anyone with a large, complex model…
Thanks Luca – this is a very useful thought. It occurs to me that the actual section of my model that is needed to perform the goal seek calculation is very small and simple, and a separate, temporary, very small model with just these pieces could even easily and very quickly be created anew each time through code, have the goalseek run on that and return a result, then feed that result back to the main model. Doing this programatically would mean that users would not have to even know of the existence of a separate model – everything would happen behind the scenes.
I’m not very familiar with the methods of quantrix application object itself, however, which would be required to implement this – the autocomplete in the script editor only seems to give you prompts for objects at the matrix level and below, and while I’ve seen examples of scripts that create and delete new matrices, I haven’t seen any examples of scripts that programatically create and delete a new model.
In Excel VBA, one would simply do something like this:
Dim Wk As Workbook
Set Wk = Workbooks.Add
Is there an equivalent in Quantrix?