Bug 40975

Summary:	Add "differentiation" function to Calc
Product:	LibreOffice	Reporter:	Francisco <franciscoadriansanchez>
Component:	Calc	Assignee:	Not Assigned <libreoffice-bugs>
Status:	NEW ---
Severity:	enhancement
Priority:	low
Version:	unspecified
Hardware:	All
OS:	All
Whiteboard:	VOTE
Crash report or crash signature:		Regression By:
Bug Depends on:
Bug Blocks:	108827

Description Francisco 2011-09-17 15:30:17 UTC

Well, I was thinking last night about this feature. And I think it could be very useful.

For those who don't know what I'm talking about: 
http://en.wikipedia.org/wiki/Numerical_differentiation

It could work *only* on cells with formulaes, in this way:

Supose
A1 = 5
B1 = 6
C1 = 2.5

D1= A1*B1^2*ln(C1) = 164.93....

then, one could add de "diff" function

A2 = diff(D1,A1) = 32.99 (becase the result should be the evaluation of B1^2*ln(C1))

B2 = diff(D1,B1) = 54.98 (because the result should be 2*A1*B1*ln(C1)

and so on...

And it doesn't need to end there, there could be higher order derivatives, for example

B3 = diff(D1,B1,2) = 9.16 (= 2*A1*ln(C1) )
C3 = diff(D1,C1,3) = 3.84 (2*A1*B1/C1^3)

What do you think? I'm one of those who would like to have this feature a lot.

Comment 1 Björn Michaelsen 2011-12-23 12:36:20 UTC Comment hidden (obsolete)

[This is an automated message.]
This bug was filed before the changes to Bugzilla on 2011-10-16. Thus it
started right out as NEW without ever being explicitly confirmed. The bug is
changed to state NEEDINFO for this reason. To move this bug from NEEDINFO back
to NEW please check if the bug still persists with the 3.5.0 beta1 or beta2 prereleases.
Details on how to test the 3.5.0 beta1 can be found at:
http://wiki.documentfoundation.org/QA/BugHunting_Session_3.5.0.-1

more detail on this bulk operation: http://nabble.documentfoundation.org/RFC-Operation-Spamzilla-tp3607474p3607474.html

Comment 2 Vasco Alves 2013-11-22 10:11:51 UTC

The bug definitely still persists. I don't know if this would be a feasible thing to do, and it's not really high priority (Excel doesn't have it AFAIK), but it would be nice to have.

Comment 3 Francisco 2013-11-22 13:47:17 UTC

Hi Vasco,

Feasible, I gess  it is, though now I don't know how good is for the entire comunity of LibreOffice Calc, divided the efforts it requires, with respect of course to other feateures requeted. 
I think it could be useful, for people how works with this kind of math but none else. When I got this idea, I never though about this. I'm lowering the priority of this enhancement request.
(Anyway, I would not like to close it (not even as won't fix), because it could happen, some day, that somebody with the skills, could see it and try to implement it, just because he wants/need it.)