ieee sets or gets the floating point exception mode

## Syntax

    mod = ieee()
                ieee(mod)

## Arguments

mod

  integer scalar whose possible values are 0, 1 or 2

## Description

`ieee()` returns the current floating point exception mode.

0

  floating point exception produces an error.

  `%inf` and `%nan` special values can be used in this mode without error. For instance, `%inf/%inf`, `%inf-%inf` or `%inf/%nan` are known operations.

1
  floating point exception produces a warning.
2
  floating point exception produces Inf or Nan.

`ieee(mod)` sets the current floating point exception mode to `mod`.

The default initial mode is 2. This default value may be set in any of the following ways:

- Through the Preferences GUI: `preferences`, in the section General => Environment => ieee.
- Equivalently, using `xmlSetValues` as follows (to set the mode to 1) :

  `xmlSetValues("//general/body/environment", ["fpe";"1"])`

- Or by using `ieee(mod)` in your startup file.

Floating point exception arising inside some library algorithms are not yet handled by `ieee` modes.

## Examples

    ieee(1); 1/0
    ieee(2); 1/0, log(0)

## See Also

- %nan
- %inf
- isinf
- isnan
- number_properties

## History

6.0.0 2 is now the initial mode value.