[Quantlib-dev] qlxl dependencies and object updates

[Peter C. <pca...@vo...>]

Hi qlxl / excel experts,

can somebody help me with the following questions on qlxl (suppose 
excels automatic calculation is deactivated):

1. There seems to be a difference between a) updating a cell by 
range.calculate b) updating a whole sheet by worksheet.calculate, a) 
being "more reliable" than b). That is, sometimes an update of an object 
does not force the update of another object one of whose arguments is 
the first object using b), but a) will do the trick. Btw a) seems to be 
the same as place the cursor on the cell, press F2 and enter. b) same as 
pressing shift F9. My guess is that a) recalculates the cell no matter, 
if it is "dirty" in excels dependency tree, while b) only recalculates 
if a cell is "dirty". That would however imply that excels dependency 
tree is not fully reliable?

2. If I have a sheet where I construct an object depending on some input 
on the same sheet and these input cells does not change, then the 
version of the object is updated every time I press shift F9. Why is 
that? Excel should think that no recalculation is necessary, i.e. the 
cell should not be dirty in the dependency tree and the version should 
not be updated?

3. The trigger argument in constructors: Is that purely dummy forcing a 
dependency on excel level or is something done with that parameter in 
the object handler?

4. Overwrite: I suppose that not specified means true. When I 
recalculate a sheet very often it slows down until it is not usable any 
more. My workaround is to call the delete all objects - method in the oh 
on a suitable position in the recalculation loop. Then it works fine. 
This looks like objects are not overwritten, but new objects are created 
on every update?

Thanks for any hints
Peter