Simulation features/bugs

Submitted by gar..@..oo.com

Description

This is a little uber bug/feature report for the simulation tool...

Here's a simple model to illustrate the kind of simulation I'm looking for:

A		B	C

1 Mean Stdev 2 Rev Growth 20% 10% 3 COGS/Sales 50% 5% 4 5 Rev FY04 FY05E 6 Rev 10 =B6*(1+randnorm(B2,C2)) 7 COGS 5 =C6*randnorm(B3,C3) 8 Gross profit =b6-b7 =c6-C7

Here are the issues I see:

Inputs

a) Must the simulation inputs be set to all the random variables? Or simply intermediate variables in the model that I want simulation visibility of? In the former case must all inputs be specified? Based on the results, I expect it's the latter, but then why must I specify any at all? If I enter nothing the dialog box says the input is invalid. I just want to see how the output varies with the randomness I've created. I don't necessarily need to see anything about the input variance - at least for now.

b) I notice that I can't set multiple ranges in the simulation inputs or I crash gnumeric... e.g. "b6,b7" as opposed to "b6:b7". I would clearly want this capability as the model scales and the inputs to track are not contiguous. I suppose I could replicate the cells elsewhere so they are contiguous but this seems a bit much. Definitely the crash is a bug.

c) Minor item... How are the names generated in the report. If I select c6 as the input cell the output report names it Rev FY05E... that's what I want but how would I actually specify this myself in the case where the tool isn't so smart?

Saving settings - If I close the simulation tool and re-invoke it the settings are reset. It would be really nice if the last simulation's settings were retained. I'd say this is a bug.
Results detail - It would be really useful to be able to see the full results traces. E.g. for whatever inputs and outputs requested I'd like to be able to see the actual values for each iteration. Actually I don't need the full detail but a cumulative XY plot to get a better view of the distribution would be very powerful. I'd call this an important feature but I imagine it's not trivial. This is available in Crystal Ball.
Results location - Minor detail but it would be nice if I could get away with just specifying the top left cell for the output range if I elect not to use a new sheet. However if I do that all I see is the 3 lines of header info and the word SUMMARY - that's it.

Version: git master