[R] sensitivity logical operators in R
feuerwald at gmx.de
Mon Jan 24 20:48:27 CET 2011
I have checked the same code (see below) using MATLAB. It produces the
same error (i.e., equal numbers are evaluated as unequal). Do I miss
Thanks for help!
Marc Jekel schrieb:
> Hello R Fans,
> Another question for the community that really frightened me today.
> The following logical comparison produces a "false" as output:
> t = sum((c(.7,.69,.68,.67,.66)-.5)*c(1,1,-1,-1,1))
> tt = sum((c(.7,.69,.68,.67,.66)-.5)*c(1,-1,1,1,-1))
> t == tt
> This is really strange behavior. Most likely this has something to do
> how R represents numbers internally and the possible sensitivity of a
> computer? Does anyone know when this strange behavior occurs and how
> to fix it?
> Thank you all! This list is pleasure!!!
More information about the R-help