Re: [R] [External] replacing a value

Rui Barradas Wed, 06 Apr 2022 10:21:23 -0700

Hello,

The problem seems to be solved, btu maybe my answer to this thread [1]can be of help.


Using Bill's dput'ed data


equals <- function(x, y, tol = .Machine$double.eps^0.5) abs(x - y) < tol

x <- c(0x1.4p+4, 0x1.4p+4, 0x1.4p+4, 0x1.4p+4, 0x1.4p+4, 0x1.4p+4,

0x1.4p+4, 0x1.4p+4, 0x1.4p+4, 0x1.3ffffffffffffp+4,0x1.3ffffffffffffp+4,

       0x1.3ffffffffffffp+4, 0x1.3ffffffffffffp+4)

x == 20

#> [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE FALSEFALSE FALSE

#> [13] FALSE
equals(x, 20)
#>  [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE



[1] https://stat.ethz.ch/pipermail/r-help/2012-September/322938.html


Hope this helps,

Rui Barradas

Às 05:58 de 06/04/2022, ani jaya escreveu:

Dear All,

I will remain sipping the seawater until it changes its taste if this
community does not exist.
Thank you.

print(a,digit=18)

[1] 19.999999999999982 19.999999999999982 14.237564602994826
19.999999999999940 19.999999999999982
[6] 19.999999999999982 16.309207867721351 19.999999999999982
19.999999999999982 19.999999999999982
[11] 19.999999999999982 19.999999999999982 19.999999999999982
19.999999999999982 19.999999999999982
[16] 14.859093240879485 16.178935255298033 19.999999999999982
19.999999999999982 20.000000000000028
[21] 19.999999999999982 27.640407788607870 19.999999999999982
19.999999999999982 19.999999999999982
[26] 19.999999999999982 19.999999999999982 21.985706303744429
19.999999999999982 19.999999999999982
[31] 20.000000000000028 19.999999999999982


Best,
Ani

On Wed, Apr 6, 2022 at 1:47 PM Richard M. Heiberger <r...@temple.edu> wrote:


I believe you are not remembering that floating point numbers are not
exactly represented in decimal.
See FAQ 7.31

Here I have rounded a[4] to 12 places before comparing to 20.
The you get the answer you are looking for.

a <- c(20, 20, 14.2375646029948, 19.9999999999999, 20, 20, 16.3092078677214,

+ 20, 20, 20, 20, 20, 20, 20, 20, 14.8590932408795, 16.178935255298,
+ 20, 20, 20, 20, 27.6404077886079, 20, 20, 20, 20, 20, 21.9857063037444,
+ 20, 20, 20, 20)

a[1:6]

[1] 20.00000 20.00000 14.23756 20.00000 20.00000 20.00000

print(a[1:6], digits=17)

[1] 20.000000000000000 20.000000000000000 14.237564602994800 19.999999999999901 
20.000000000000000 20.000000000000000

a[1:6] == 20

[1]  TRUE  TRUE FALSE FALSE  TRUE  TRUE

a[1:6] - 20

[1]  0.000000e+00  0.000000e+00 -5.762435e+00 -9.947598e-14  0.000000e+00  
0.000000e+00

a[4] == 20

[1] FALSE

round(a[1:6], digits=14) - 20

[1]  0.000000e+00  0.000000e+00 -5.762435e+00 -9.947598e-14  0.000000e+00  
0.000000e+00

round(a[1:6], digits=13) - 20

[1]  0.000000e+00  0.000000e+00 -5.762435e+00 -9.947598e-14  0.000000e+00  
0.000000e+00

round(a[1:6], digits=12) - 20

[1]  0.000000  0.000000 -5.762435  0.000000  0.000000  0.000000

b <- a[1:6]
b[round(b,digits=12) == 20] <- 0
b

[1]  0.00000  0.00000 14.23756  0.00000  0.00000  0.00000

On Apr 06, 2022, at 00:18, ani jaya <gaaa...@gmail.com> wrote:

c(20, 20, 14.2375646029948, 19.9999999999999, 20, 20, 16.3092078677214,
20, 20, 20, 20, 20, 20, 20, 20, 14.8590932408795, 16.178935255298,
20, 20, 20, 20, 27.6404077886079, 20, 20, 20, 20, 20, 21.9857063037444,
20, 20, 20, 20)


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______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Re: [R] [External] replacing a value

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