?Dear All, The following gives a very unpleasant experience with apparently random NAs - probably it's my bad formatting of the coding - but the effect is unexpected and if undetected can lead to considerable problems: myvector1 = NULL myvector3 = NULL myvector4 = NULL myvector5 = NULL myvector1 <- c(1:100) myvector3[[1]] <- seq(myvector1[1], myvector1["length"(myvector1)], by 0.01) myvector4[[1]] <- seq(95, 100, by = 0.01) myvector5[[1]] <- match(myvector4[[1]], myvector3[[1]]) myvector5 ## A solution (but rather annoying): myvector5[[1]] <- match(as.list(myvector4[[1]]), as.list(myvector3[[1]])) myvector5 ? Could anyone tell me why the NAs occur ?? Many thanks.? [[alternative HTML version deleted]]
I believe that you are in Circle 1 of The R Inferno. http://www.burns-stat.com/documents/books/the-r-inferno/ Pat On 15/03/2015 11:04, Jeremy Clark wrote:> ?Dear All, > > The following gives a very unpleasant experience with apparently random NAs > - probably it's my bad formatting of the coding - but the effect is > unexpected and if undetected can lead to considerable problems: > > myvector1 = NULL > > myvector3 = NULL > > myvector4 = NULL > > myvector5 = NULL > > > > myvector1 <- c(1:100) > > > > > > myvector3[[1]] <- seq(myvector1[1], myvector1["length"(myvector1)], by > 0.01) > > myvector4[[1]] <- seq(95, 100, by = 0.01) > > > > myvector5[[1]] <- match(myvector4[[1]], myvector3[[1]]) > > > > myvector5 > > > > ## A solution (but rather annoying): > > > > myvector5[[1]] <- match(as.list(myvector4[[1]]), as.list(myvector3[[1]])) > > myvector5 > ? > Could anyone tell me why the NAs occur ?? > > Many thanks.? > > [[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.
This list is a plain text list. Posting in HTML frequently leads to corrupted
code on the receiving end. Be sure to read the Posting Guide.
In no programming language is it a good idea to assume equality with floating
point values. See FAQ 7.31. In cases like this use integers to create sequences
and then generate floating point from them. Do not go fishing in floating point
data for specific values.
Also, you seem to be using list objects for no apparent reason.
myvector1 <- c(1L:100L)
myvector3 <- seq(10L*myvector1[1], 10L*myvector1[ length(myvector1) ])
myvector4 <- seq(950L, 1000L)
myvector5 <- match(myvector4, myvector3)
I think the as.list is working because match is internally converting to
character and comparing that... which makes the as.list solution rather
inefficient art best.
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On March 15, 2015 4:04:29 AM PDT, Jeremy Clark <jeremyclarkbio at
gmail.com> wrote:>?Dear All,
>
>The following gives a very unpleasant experience with apparently random
>NAs
>- probably it's my bad formatting of the coding - but the effect is
>unexpected and if undetected can lead to considerable problems:
>
>myvector1 = NULL
>
>myvector3 = NULL
>
>myvector4 = NULL
>
>myvector5 = NULL
>
>
>
>myvector1 <- c(1:100)
>
>
>
>
>
>myvector3[[1]] <- seq(myvector1[1],
myvector1["length"(myvector1)], by
>>0.01)
>
>myvector4[[1]] <- seq(95, 100, by = 0.01)
>
>
>
>myvector5[[1]] <- match(myvector4[[1]], myvector3[[1]])
>
>
>
>myvector5
>
>
>
>## A solution (but rather annoying):
>
>
>
>myvector5[[1]] <- match(as.list(myvector4[[1]]),
>as.list(myvector3[[1]]))
>
>myvector5
>?
>Could anyone tell me why the NAs occur ??
>
>Many thanks.?
>
> [[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.
Dear Jeremy The NAs do not seem random to me as the gaps between successive NAs are either 3, 8 or 11. Have you considered the possibility that the finite precision of real numbers in computers may be the issue here? On 15/03/2015 11:04, Jeremy Clark wrote:> ?Dear All, > > The following gives a very unpleasant experience with apparently random NAs > - probably it's my bad formatting of the coding - but the effect is > unexpected and if undetected can lead to considerable problems: > > myvector1 = NULL > > myvector3 = NULL > > myvector4 = NULL > > myvector5 = NULL > > > > myvector1 <- c(1:100) > > > > > > myvector3[[1]] <- seq(myvector1[1], myvector1["length"(myvector1)], by > 0.01) > > myvector4[[1]] <- seq(95, 100, by = 0.01) > > > > myvector5[[1]] <- match(myvector4[[1]], myvector3[[1]]) > > > > myvector5 > > > > ## A solution (but rather annoying): > > > > myvector5[[1]] <- match(as.list(myvector4[[1]]), as.list(myvector3[[1]])) > > myvector5 > ? > Could anyone tell me why the NAs occur ?? > > Many thanks.? > > [[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. > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2015.0.5751 / Virus Database: 4306/9307 - Release Date: 03/15/15 >-- Michael http://www.dewey.myzen.co.uk