Dear R project team I used the function of "matrix" as follows: matrix(c(1:3030), 10.1/0.1) However, in the function, matrix, 10.1/0.1 was regarded as 100 not as 101. Therefore, a warning message appeared. On the other hand, matrix(c(1:3030), 101) or matrix(c(1:3030), 10.1*10) was OK. Of course, simply, 10.1/0.1 was successfully calculated. However, In the "matrix" environment, 10.1/0.1 was calculated as 100. Would you give me some answers? Sincerely Kazuki Sakura
Function of "matrix"
5 messages · 奈良県奈良市, Bert Gunter, Patrick (Malone Quantitative) +2 more
1. Answers on this list are from volunteers who are not part of any R project team. We have no official status and what we say comes with no guarantees. 2. There is no such thing as a "matrix 'environment' ". 3. The answer to your question is "computer arithmetic." See FAQ 7.31. Someone may follow up with a more specific answer for your particular calculation, however. Cheers, Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Thu, Oct 22, 2020 at 11:41 AM ?????? <jaajikan at gmail.com> wrote:
Dear R project team
I used the function of "matrix" as follows:
matrix(c(1:3030), 10.1/0.1)
However, in the function, matrix, 10.1/0.1 was regarded as 100 not as 101.
Therefore, a warning message appeared.
On the other hand, matrix(c(1:3030), 101) or matrix(c(1:3030), 10.1*10) was
OK. Of course, simply, 10.1/0.1 was successfully calculated. However,
In the "matrix" environment, 10.1/0.1 was calculated as 100.
Would you give me some answers?
Sincerely
Kazuki Sakura
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
(Neglected to cc the list--please reply-all to this version) What was the warning? I hazard a guess you've run into precision issues for binary representation, and the result of your division is not *exactly* 101. Pat
On Thu, Oct 22, 2020 at 2:42 PM ?????? <jaajikan at gmail.com> wrote:
Dear R project team
I used the function of "matrix" as follows:
matrix(c(1:3030), 10.1/0.1)
However, in the function, matrix, 10.1/0.1 was regarded as 100 not as 101.
Therefore, a warning message appeared.
On the other hand, matrix(c(1:3030), 101) or matrix(c(1:3030), 10.1*10) was
OK. Of course, simply, 10.1/0.1 was successfully calculated. However,
In the "matrix" environment, 10.1/0.1 was calculated as 100.
Would you give me some answers?
Sincerely
Kazuki Sakura
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Patrick S. Malone, Ph.D., Malone Quantitative NEW Service Models: http://malonequantitative.com He/Him/His
FAQ 7.31
10.1/.1
[1] 101
print(10.1/.1, digits=17)
[1] 100.99999999999999
floor(10.1/.1)
[1] 100
floor(10.1*10)
[1] 101
matrix(0, 2.9, 3.9)
[,1] [,2] [,3] [1,] 0 0 0 [2,] 0 0 0
note that the dimension arguments are passed through floor() before they are used.
On Thu, Oct 22, 2020 at 2:42 PM ?????? <jaajikan at gmail.com> wrote:
Dear R project team
I used the function of "matrix" as follows:
matrix(c(1:3030), 10.1/0.1)
However, in the function, matrix, 10.1/0.1 was regarded as 100 not as 101.
Therefore, a warning message appeared.
On the other hand, matrix(c(1:3030), 101) or matrix(c(1:3030), 10.1*10) was
OK. Of course, simply, 10.1/0.1 was successfully calculated. However,
In the "matrix" environment, 10.1/0.1 was calculated as 100.
Would you give me some answers?
Sincerely
Kazuki Sakura
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
10.1/0.1 was successfully calculated
Note that 'computed as' is not the same as 'printed as'. Computations are done with 52 binary digits of precision and printing is, by default, done with 7 decimal digits of precision. See FAQ 7.31.
101 - 10.1/0.1
[1] 1.421085e-14
options(digits=17) 10.1/0.1
[1] 100.99999999999999
trunc(10.1/0.1)
[1] 100
On Thu, Oct 22, 2020 at 11:42 AM ?????? <jaajikan at gmail.com> wrote:
Dear R project team
I used the function of "matrix" as follows:
matrix(c(1:3030), 10.1/0.1)
However, in the function, matrix, 10.1/0.1 was regarded as 100 not as 101.
Therefore, a warning message appeared.
On the other hand, matrix(c(1:3030), 101) or matrix(c(1:3030), 10.1*10) was
OK. Of course, simply, 10.1/0.1 was successfully calculated. However,
In the "matrix" environment, 10.1/0.1 was calculated as 100.
Would you give me some answers?
Sincerely
Kazuki Sakura
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.