Bioequivalence and Bioavailability Forum • From bad to worse

From bad to worse [Software]

posted by Ohlbe – France, 2020-12-10 23:11 (2016 d 02:05 ago) – Posting: # 22133
Views: 27,931

Hi fellows,

Sorry guys, but there are some things going back behind the scene, which I really fail to understand.

If I get -2,77556E-17 when I type =(0.5-0.4-0.1), how comes that I get 0 when I type =(-0.1-0.4+0.5)? The same figures, just in a different order?

If I get FALSE when I type =0=0.5-0.4-0.1, how comes that I get TRUE when I type =0=-0.4-0.1+0.5?

And to be fair to Excel, the same happens in [image]

0==(0.5-0.4-0.1)
[1] FALSE
0==(-0.4-0.1+0.5)
[1] TRUE

Are they first calculating -0.4-0.1=-0.5, which is nicely binarily coded, then -0.5+0.5=0?

—
Regards
Ohlbe

Complete thread:

Spreadsheet failures, any recent examples? ElMaestro 2019-07-18 13:43
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  - Spreadsheet etc. failures zizou 2019-07-20 00:18
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        To round or not to round… Helmut 2019-07-20 12:53
        
        To round or not to round… ElMaestro 2019-07-20 19:59
        
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- Spreadsheet failures, any recent examples? Ohlbe 2020-12-10 18:43
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    - Floating point arithmetic, again ElMaestro 2020-12-10 19:40
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        Depressed Ohlbe 2020-12-10 23:35
        
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    - Floating point arithmetic, again Ohlbe 2020-12-10 20:13
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    - From bad to worse mittyri 2020-12-11 00:22
    - All is good Helmut 2020-12-11 00:36
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