Re: [R] Inverse of FAQ 7.31.

Thanks to Peter Dalgaard and to Baptiste Auguie (off-list) for the insights they provided. cheers, Rolf turner __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R

Re: [R] Inverse of FAQ 7.31.

On Aug 2, 2011, at 08:02 , Rolf Turner wrote: > > > Why does R think these numbers ***are*** equal? > > In a somewhat bizarre set of circumstances I calculated > >x0 <- 0.03580067 >x1 <- 0.03474075 >y0 <- 0.4918823 >y1 <- 0.4474461 >dx <- x1 - x0 >dy <- y1 - y0 >xx

[R] Inverse of FAQ 7.31.

Why does R think these numbers ***are*** equal? In a somewhat bizarre set of circumstances I calculated x0 <- 0.03580067 x1 <- 0.03474075 y0 <- 0.4918823 y1 <- 0.4474461 dx <- x1 - x0 dy <- y1 - y0 xx <- (x0 + x1)/2 yy <- (y0 + y1)/2 chk <- yy*dx - xx*dy + x