toFraction() behavior about bignumber.js

[MikeMcl]

The behaviour is as expected.

When you call toFraction, you are calling it on the number 3.08218318695106649937, not on the rational number 4913/1594 (which could not be stored as a BigNumber anyway as it has a non-terminating decimal expansion).
To clarify:

var BN = BigNumber; 
BN.config(20);
var n = BN(4913).div(1594);

n.toString();     // 3.08218318695106649937
n.toFraction()    // [ "308218318695106649937", "100000000000000000000" ]

BN.config(10);
n = BN(4913).div(1594);

n.toString();     // 3.082183187
n.toFraction()    // [ "3082183187", "1000000000" ]

Do you follow?

[markletp]

Thanks for the quick response Mike. I understand how it applies now. I'll have to track the rational expression separately.

Cheers,

-Thomas