Comparisons of floating point numbers are problematic due to errors associated with the binary representation of decimal numbers. Computer scientists and programmers are aware of these problems and yet people still use numerical methods which fail to account for floating point errors (this pitfall is the first to be highlighted in Circle 1 of Burns (2012) The R Inferno).

To avoid these and other numerical rounding issues, R’s help file for
relational operators (*e.g.*, `?'>'`

) suggests
using `identical`

and `all.equal`

when making
numerical comparisons:

```
<- 0.5 - 0.3
x1 <- 0.3 - 0.1
x2 == x2 # FALSE on most machines
x1 identical(all.equal(x1, x2), TRUE) # TRUE everywhere
```

Inspired by R FAQ 7.31 and this Stack Overflow answer, this package provides new relational operators useful for performing floating point number comparisons with a set tolerance:

`fpCompare` ^{1} |
`base` |
---|---|

`%>=%` |
`>=` |

`%>>%` |
`>` |

`%<=%` |
`<=` |

`%<<%` |
`<` |

`%==%` |
`==` |

`%!=%` |
`!=` |

These functions use the `base`

relational operators to
make comparisons, but incorporate a tolerance value
(`fpCompare.tolerance`

) similar to `all.equal`

.
The default `fpCompare.tolerance`

value is
`.Machine$double.eps^0.5`

, set via `options`

. This
is the same default used in `all.equal`

for numeric
comparisons.

```
# set telorance value
= .Machine$double.eps^0.5 # default value
tol options(fpCompare.tolerance = tol)
# perform comparisons
<- 0.5 - 0.3
x1 <- 0.3 - 0.1
x2 == x2 # FALSE on most machines
x1 %==% x2 # TRUE everywhere x1
```

`install.packages("fpCompare")`

```
library(devtools)
install_github("PredictiveEcology/fpCompare")
```

https://github.com/PredictiveEcology/fpCompare/issues

The

`%<<%`

and`%>>%`

symbols are used instead of`%<%`

and`%>%`

to avoid a conflict with`magrittr`

’s pipe operator (`%>%`

).↩︎