[BUG] Problem manifesting in sum function

users
#1

Hello there,

I have a problem with a brand new spreadsheet, v 4.4.3.2, the sum version isn't recalculating, even if I press f9 (to force a recalculation)

Any blank cells are just that, blank, the values I expect to be summed are numeric, weirdly it works when the left-most column is positive. The leftmost column and the sum columns are being graphed.

Yet for the left column being greater than zero, all works fine.

I think there may be a dodgy optimisation in play and I'm happy to help you find it, first though has anyone ever dealt with it?

Reproducing:
The value cells are of the form:

if(t1+t2/60 < t, 0, c e ^ -k(t-t1-t2/60) )

This is the result of solving the differential equation dThing / dt = -k Thing, where the thing happens instantaneously at time t1:t2 (t2 in minutes)

I'm then trying to sum over multiple events, but the sum column isn't updating for negative time, BUT the value column is.

Alec

Screenshot for proof.

#2

This list doesn't allow attachments, so please put it on some temporary
internet storage service.

I guess that all the values in the formula are stored in cells like let's
say:
A1 stores t1
A2 stores t2
A3 stores t
A4 store c
A5 stores k
Would it be correct?

By the way please remember to always supply the operating system you are
working on, the bits of it and of LibreOffice (may differ in Windows).

I'd like to try but I'll have to find a LO 4.4.3.2 (which probably is still
the default for Ubuntu 14.04?)