Bioequivalence and Bioavailability Forum

Float is float! [Software]

posted by Helmut  – Vienna, Austria, 2020-12-20 23:27 (558 d 16:34 ago) – Posting: # 22151
Views: 5,535

Hi PharmCat,

» I think in R it can be done...

At least consistently giving not zero.

library(Rmpfr)
prec <- 64
x <- mpfr(0.5, prec) - mpfr(0.4, prec) - mpfr(0.1, prec)
x
1 'mpfr' number of precision  64   bits
[1] -2.77555756156289135106e-17
y <- mpfr(-0.4, prec) - mpfr(0.1, prec) + mpfr(0.5, prec)
y
1 'mpfr' number of precision  64   bits
[1] -2.77555756156289135106e-17

—
Dif-tor heh smusma 🖖
Helmut Schütz


The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

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, again ElMaestro 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