Re: mid-rad, inf-sup, a caution...

[Arnold Neumaier <Arnold.Neumaier@xxxxxxxxxxxx>]

Jean-Pierre Merlet wrote:
> Kreinovich, Vladik wrote:
> > From: stds-1788@xxxxxxxx [mailto:stds-1788@xxxxxxxx] On Behalf Of Nate 
> > Hayes

> > we should be so lucky that some of the largest and most successful 
> > software
> > companies in the world, such as Autodesk, Dassault Systems, Parametric
> > Technology, etc. would some day use our P1788 standard. Having at 
> > least an
> > interchange format for mid-rad with standardized conversion rules I 
> > suspect
> > would be a minimal requirement.
> >
> > I would also point out that at least in this sense, mid-rad as an
> > "interchange format" is already a global, multi-billion dollar industry.
> > Something that can't be said for inf-sup.
>
> That's  not always true in mechanical engineering: when tolerancing a 
> hole it's usual to use tolerancing as 40 h6 where 40 is the nominal 
> diameter and h6 means that the tolerance is [0,+xx] while the male part 
> will be 40H6 i.e the dimension will be 40 with a tolerance [-xx,0]. Such 
> tolerancing are essential to define how "tight" will be the assembly. 
> For example a 40 d6D6 assembly provides clearance between the parts as 
> the female part is 40 with a tolerance [+x1,+x2] and the male part is 40 
> and a tolerance [-x3,-x4].
> On the opposite 40 n6N6 is a tight assembly (male= 40 [x1,x2], female= 
> 40 [-x3,-x4].
>
> And this not only true for hole but for any part that has to be 
> assembled or to receive other parts. Having non zero centered tolerances 
> is essential to ensure that all parts can be assembled...
>
> And there are some sensors whose accuracy is not a centered interval..

This clearly points to a triplex representation: main + error interval.