Re: [O] Precision in the spreadsheet
Eric S Fraga writes: > On Tuesday, 1 Mar 2016 at 11:59, Nick Dokos wrote: >> Marcin Borkowski writes: >> >>> Hi all, >>> >>> is it at all possible to set different precision for display and >>> calculations in Org's spreadsheet? I mean, things like $1+$2;%.2f (as >>> in the manual) mean (IIUC) that (1) Org should show 2 decimal figures >>> and (2) further calculations which use this value also use this >>> approximation. Am I right? If yes, is there a way to change this >>> behavior? (I suspect not, but I wanted to make sure.) >>> >> >> I believe that internally, calculations are done in 12-decimal place >> precision: the %.2f is for display only. > > Actually, surprisingly (to me), it appears not. This simple example > gives different results depending on the formatting of the first entry: > > #+begin_src org > ,* table > | 0.1 | > | 1. | > | 10. | > ,#+TBLFM: @1$1=1/8;%.1f::@2$1=@-1*10::@3$1=@-1*10 > #+end_src Yes, I got it wrong: internal calculations may be done in extended precision, but once the result is in the table, that's that. Achim explains the situation (and potential solutions) clearly in his response. -- Nick
Re: [O] Precision in the spreadsheet
On Tuesday, 1 Mar 2016 at 11:59, Nick Dokos wrote: > Marcin Borkowski writes: > >> Hi all, >> >> is it at all possible to set different precision for display and >> calculations in Org's spreadsheet? I mean, things like $1+$2;%.2f (as >> in the manual) mean (IIUC) that (1) Org should show 2 decimal figures >> and (2) further calculations which use this value also use this >> approximation. Am I right? If yes, is there a way to change this >> behavior? (I suspect not, but I wanted to make sure.) >> > > I believe that internally, calculations are done in 12-decimal place > precision: the %.2f is for display only. Actually, surprisingly (to me), it appears not. This simple example gives different results depending on the formatting of the first entry: #+begin_src org ,* table | 0.1 | | 1. | | 10. | ,#+TBLFM: @1$1=1/8;%.1f::@2$1=@-1*10::@3$1=@-1*10 #+end_src -- : Eric S Fraga (0xFFFCF67D), Emacs 25.0.91.1, Org release_8.3.4-626-gb62d55
Re: [O] Precision in the spreadsheet
Nick Dokos writes: > Marcin Borkowski writes: >> is it at all possible to set different precision for display and >> calculations in Org's spreadsheet? I mean, things like $1+$2;%.2f (as >> in the manual) mean (IIUC) that (1) Org should show 2 decimal figures >> and (2) further calculations which use this value also use this >> approximation. Am I right? If yes, is there a way to change this >> behavior? (I suspect not, but I wanted to make sure.) I guess everything is somehow possible, but it either requires to store the data with full precision somewhere or re-calculate the table with full precision each time and only then apply the display rounding. I've had this idea for some time that tables should have a shadow that determines formatting and other behaviour, there should probably be a way to keep raw data in the shadow as well. Meanwhile you could experiment with putting the data in a table somewhere with full precision and use Babel to display that data somewhere else the way you want it. If you wanted to be able to edit some data in that second table it would be more bothersome. > I believe that internally, calculations are done in 12-decimal place > precision: the %.2f is for display only. Sure, but as far as org-table is concerned, the data that is displayed is the data that gets used: * Table precision | 1 | 0.00 | 0. | | 2 | 0.00 | 0. | | 3 | 0.00 | 0. | | 4 | 0.00 | 0. | | 5 | 0.01 | 10. | | 6 | 0.01 | 10. | | 7 | 0.01 | 10. | | 8 | 0.01 | 10. | | 9 | 0.01 | 10. | | 10 | 0.01 | 10. | | 11 | 0.01 | 10. | | 12 | 0.01 | 10. | | 13 | 0.01 | 10. | | 14 | 0.01 | 10. | | 15 | 0.01 | 10. | #+TBLFM: $2=$1/1000;%.2f::$3=1000*$2 When calculating the third column, the formula to calculate the second column doesn get re-evaluated to regain the precision lost while displaying it. Org also doesn't keep shadow data and computes the display on the fly like most other spreadsheets do. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptations for Waldorf Q V3.00R3 and Q+ V3.54R2: http://Synth.Stromeko.net/Downloads.html#WaldorfSDada
Re: [O] Precision in the spreadsheet
Marcin Borkowski writes: > Hi all, > > is it at all possible to set different precision for display and > calculations in Org's spreadsheet? I mean, things like $1+$2;%.2f (as > in the manual) mean (IIUC) that (1) Org should show 2 decimal figures > and (2) further calculations which use this value also use this > approximation. Am I right? If yes, is there a way to change this > behavior? (I suspect not, but I wanted to make sure.) > I believe that internally, calculations are done in 12-decimal place precision: the %.2f is for display only. See org-calc-default-modes for details. -- Nick
[O] Precision in the spreadsheet
Hi all, is it at all possible to set different precision for display and calculations in Org's spreadsheet? I mean, things like $1+$2;%.2f (as in the manual) mean (IIUC) that (1) Org should show 2 decimal figures and (2) further calculations which use this value also use this approximation. Am I right? If yes, is there a way to change this behavior? (I suspect not, but I wanted to make sure.) Best, -- Marcin Borkowski http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski Faculty of Mathematics and Computer Science Adam Mickiewicz University
