Set roundingmode and other settings Per instance about bignumber.js

[MikeMcl]

No, you're right!

A new release is imminent that will allow the precision and rounding mode to be set for individual operations, and also for multiple instances of the BigNumber constructor itself.

[Xotic750]

+1

[josdejong]

See also the discussion at #17

[MikeMcl]

I have posted a preview of bignumber.js v2 as a jsfiddle here.

It includes new functionality such as support for non-integer powers, and has log, exp, and ln methods (although performance degrades quickly with increasing digits, particularly for pow). It also greatly increases the maximum exponent magnitude and allows the precision of operations to be specified in significant digits instead of decimal places. The precision and a min/max sd/dp can also be specified for each individual operation.

Multiple instances of the BigNumber constructor can also be created.

Perhaps vekexasia was referring to specifying the precision and rounding mode for each actual number at the time of creation and although that would be a radical change it is something I am also considering as the multiple constructor approach isn't very memory efficient and it would help to sove the problem of adding and subtracting numbers with massively different exponents.

[josdejong]

That's great news! I'm really happy to hear that we can specify a number of significant digits, and the support for log and exp is great! (And that means that we also have the constant e :) ).

[Xotic750]

Would be nice to see the non-minified version. Hard to give feedback about the multi-constructor approach you mentioned.

[ahansen1]

@MikeMcl I also need the rounding configurable more granular than globally, either per instance or the factory approach mentioned in #17 would work. I see the v2 preview, but am not finding this code in Git. Is there code in Git that will allow for per instance rounding configuration?

Should this issue be re-opened and marked as a feature request so others may easily find it vs. having to look at the closed issues.

[MikeMcl]

@ahansen1

I intend to provide per instance configuration, but it will be instance of BigNumber constructor, not instance of BigNumber, if you follow me. I.e. it will be the same approach I have used in decimal.js. Contrary to what I stated above, this multiple constructor approach is now memory efficient.

I estimate it will be another month before it will be ready for publication, as I am using the time I have available at the moment on a major update to decimal.js. If that is too long, you could try decimal.js or even email me to offer an incentive to meet your preferred time scale.

The v2 preview I linked to above will not now be how v2 is going to be, and it is not production-ready and may not be reliable.

I have marked this issue as a feature request.