Bioequivalence and Bioavailability Forum • Floating point arithmetic, again

Floating point arithmetic, again [Software]

posted by ElMaestro – Denmark, 2020-12-10 22:38 (1082 d 14:30 ago) – Posting: # 22130
Views: 7,780

Hi Ohlbe,

❝ Mmmm. But then if the problem comes from the nasty 0.1, how comes that if I type =(0.8-0.4-0.2-0.1-0.1) I get a nice 0, without any funky E-17 ? And then if I type =0=(0.8-0.4-0.2-0.1-0.1), or =0=0.8-0.4-0.2-0.1-0.1 I get a nice TRUE ?

Impossible to tell if this is an effect from Excel or from some degree of streamlining within the CPU.
It is fairly trivial (I think) at the CPU level as well as in Excel to check if you are handing objects of the type (x-x) and to substitute those with a zero where they occur.

—
Pass or fail!
ElMaestro

Complete thread:

Spreadsheet failures, any recent examples? ElMaestro 2019-07-18 13:43 [Software]
- Spreadsheet failures, any recent examples? Ohlbe 2019-07-18 14:32
  - Spreadsheet addiction Helmut 2019-07-18 16:12
    - Nasty beast Ohlbe 2019-07-18 17:30
      - Nasty beast Helmut 2019-07-18 20:26
        
        Nasty beast Ohlbe 2019-07-19 11:32
        
        Nasty beast ElMaestro 2019-07-19 12:32
        
        Decidedly off topic Ohlbe 2019-07-19 13:38
        
        OT: R limbo 101 Helmut 2019-07-19 13:00
    - Spreadsheet addiction Shuanghe 2019-07-18 18:59
      - Spreadsheet addiction Helmut 2019-07-18 20:04
        
        OT: Spreadsheet addiction Shuanghe 2019-07-19 12:41
        
        OT: Spreadsheet addiction Helmut 2019-07-19 14:29
        
        OT: Spreadsheet addiction nobody 2019-07-19 15:53
        
        OT: Spreadsheet addiction Helmut 2019-07-19 19:32
  - Spreadsheet etc. failures zizou 2019-07-20 00:18
    - As designed ☺ Helmut 2019-07-20 02:12
      - As designed ☺ ElMaestro 2019-07-20 09:08
        
        To round or not to round… Helmut 2019-07-20 12:53
        
        To round or not to round… ElMaestro 2019-07-20 19:59
        
        floating-point math is always more complex than you think it is mittyri 2019-07-20 22:43
- Spreadsheet failures, any recent examples? Ohlbe 2020-12-10 18:43
  - Floating point arithmetic, again Helmut 2020-12-10 19:12
    - Floating point arithmetic, again ElMaestro 2020-12-10 19:40
      - Floating point arithmetic, again Ohlbe 2020-12-10 20:18
        
        Floating point arithmetic, againElMaestro 2020-12-10 21:38
        
        Floating point arithmetic, again Ohlbe 2020-12-10 21:46
        
        Floating point arithmetic, again ElMaestro 2020-12-10 22:05
        
        Depressed Ohlbe 2020-12-10 23:35
        
        Depressed ElMaestro 2020-12-11 07:59
    - Floating point arithmetic, again Ohlbe 2020-12-10 20:13
  - From bad to worse Ohlbe 2020-12-10 22:11
    - From bad to worse mittyri 2020-12-11 00:22
    - All is good Helmut 2020-12-11 00:36
      - Float is float PharmCat 2020-12-18 20:53
        
        Float is float! Helmut 2020-12-20 23:27
        
        rational solution in R mittyri 2020-12-21 13:49
        
        related stuff Helmut 2021-01-14 12:53
        
        related stuff SDavis 2021-02-09 12:02
        
        related stuff ElMaestro 2021-02-09 19:55