(08-13-2018 03:03 AM)Albert Chan Wrote: [ -> ] (06-09-2018 02:54 PM)Csaba Tizedes Wrote: [ -> ]In engineering practice more important the relative error. In this case the results are:

Code:

`+/- 1.000% error: 19/6, `

+/- 0.100% error: 22/7,

+/- 0.010% error: 289/92,

+/- 0.001% error: 355/113

Above table is mistaken, 355/113 is 100 times more accurate.

355/113 vs Pi, relative error = 85e-9 = 0.0000085%

I think the idea of the table is to give a fraction that – at least – matches a certain accuracy level. So if you need an accuracy of 0,001% or better, 355/113 is the first fraction to meet that target.

(08-13-2018 03:03 AM)Albert Chan Wrote: [ -> ]I agree that relative error is more useful than digits matched.

All estimates below had 5% relative error, but digits matched are all over the place.

That's exactly why I prefer stating the number of matching digits.

But I am not an engineer. ;-)

Dieter