Wikipedia:Reference desk/Archives/Computing/2017 April 8

= April 8 =

Qudratic Equations - Promise Problem
Is the follwing promise problem NP-complete?

Input: a system of quadratic equations with either one or zero solutions.

Question: does the system have a solution? 31.154.81.31 (talk) 06:56, 8 April 2017 (UTC)
 * A system of N quadratic equations potentially has $$2^N$$ solutions. Please, clarify your question. Ruslik_ Zero 20:50, 8 April 2017 (UTC)


 * The question seems to me to be well defined: Given a system that is known to have at most one solution, how hard is it to determine whether there is one? —Tamfang (talk) 08:30, 10 April 2017 (UTC)

A spreadsheet question
In a spreadsheet, is there a way to format a cell so that when you click it, it brings you to the what is in the cell? I mean, if cell A1 contains "=A3", I would like to be able to click A1 and it jumps me to A3. Cheers. Anna Frodesiak (talk) 20:19, 8 April 2017 (UTC)


 * There are many different spreadsheet programs, which all work differently, so there's no one answer that will be correct for all possible spreadsheet programs. If you're using Excel, take a look at this link: .  If you're using a different spreadsheet, you need to specify which one you're using.  CodeTalker (talk) 20:59, 8 April 2017 (UTC)


 * Hi CodeTalker. A thousand pardons. I am using OpenOffice. And holy moly, the stackoverflow link you provided is way beyond my ability to understand. I thought there might just be a command or something. Best, Anna Frodesiak (talk) 21:12, 8 April 2017 (UTC)


 * Wouldn't that behavior look like a bug to anyone who doesn't know that A1=A3 ? StuRat (talk) 23:10, 8 April 2017 (UTC)


 * Well, StuRat, good point. Actually, it is just for me. I have a list at the beginning of the sheet. Each cell contains =BA1 then the next cell down contains =CA1 then =DA1 then =EA1, etc. BA1 is the text heading of a table there. So, the display at the beginning of the sheet is a sort of index or table of contents of what all the tables are. I would like to be able to click one of those at the beginning of the sheet and magically get taken to that particular table. Anna Frodesiak (talk) 23:54, 8 April 2017 (UTC)


 * It seems what you need is a Table of contents, but Calc spreadsheets for some reason can't have a TOC like Writer documents. You can use Outlines (Data->Group and outline->Group) to selectively conceal sets of rows or columns. You'll get a vertical or horizontal bar with tiny + and - buttons on it that you can use to expand that part of the table. This is similar to folding.


 * that said, it is possible to do what you describe by having a macro that sets the focus to a particular cell. However, the macro would have to be assigned to something like a hyperlink or a button - clicking on a cell alone can't invoke a macro (without contortions...) This seems to work:


 * This transfers you to the cell whose coordinates are in cell A3. you'd have to manually insert this into the spreadsheet (Tools->Macros->Organize macros->LibreOffice Basic), then draw a button (View->Toolbars->Form controls), then set the button's "Execute action" event (right click->Form controls->Events) to "gotoCell".
 * This transfers you to the cell whose coordinates are in cell A3. you'd have to manually insert this into the spreadsheet (Tools->Macros->Organize macros->LibreOffice Basic), then draw a button (View->Toolbars->Form controls), then set the button's "Execute action" event (right click->Form controls->Events) to "gotoCell".


 * I played with OO once. It's completely over-engineered and evil (esp. UNO - the macro above uses only Basic, though) Asmrulz (talk) 15:41, 9 April 2017 (UTC)
 * Thank you very much, my friend, for taking the time. It is so far beyond my mental pay grade, you wouldn't believe. I must give up on this quest. I must say that it is odd. I am often at a cell that contains something like "=AD37" and would like to jump there to see what is in that cell. These spreadsheets should have a hotkey or something that does that. Thank you again, and best wishes. :) Anna Frodesiak (talk) 22:40, 9 April 2017 (UTC)