[Openmcl-devel] Floating point precision

[R. Matthew Emerson]

On Jan 17, 2009, at 8:18 AM, Sudhir Shenoy wrote:

> Sorry if this is slightly off topic but is there any way (CL standard
> or CCL specific) to make all floating point computations in double
> precision? I.e., to ensure that (sqrt 1/3) will return the same value
> as (sqrt 1/3.0d0) by default (without having to do (sqrt (coerce 1/3
> 'double-float))?
>
> I have tried web searches and can't find an answer to this question so
> I suspect that there is no standard way but would be grateful if
> someone can point me to even a CCL-specific method.


I don't believe there is any CL-standard way to do that.

The CL spec requires that either an accurate rational result or single- 
float approximation be returned when a SQRT gets a rational argument.

http://www.lispworks.com/documentation/HyperSpec/Body/12_acc.htm