josdejong/mathjs

math.floor returns apparently wrong value for BigNumbers; possibly implement distinct epsilon for BigNumber operations?

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#2,608 opened on Jun 27, 2022

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featurehelp wanted

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Description

hello，math floor maybe wrong

case 1: math.floor(math.bignumber("1234567890123456.9951").mul( math.bignumber(100)),0).toString()

is wrong , accept '123456789012345699' but '123456789012345700'

case2: math.floor(math.bignumber("1234567890123456.9951").mul( math.bignumber(100)),1).toString() is ok , value is : '123456789012345699.5'

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Research direction
Inspect the implementation of math.floor for BigNumber values. Check how rounding is performed and whether there is an epsilon or precision issue when multiplying large numbers. Trace the code path in the mathjs source to understand where the loss of precision occurs.
Tech stack
javascript
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
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Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaScriptmath library concepts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65