mikejihbe/metrics

Histogram mean becomes NaN as sum becomes too large

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#13 opened on May 24, 2012

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bughelp wanted

Description

I have one metric based on a Histogram with about 90000 entries. The sum becomes huge... and the mean becomes NaN. Actually it becomes a strange number followed by NaNNaNNaN. e.g..

653238.5-217636.16666666666NaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaN...

Contributor guide

Tech stack
javascriptnodejs
Domain
backendapi
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
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
JavaScriptunderstanding of histograms
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate the histogram implementation in the metrics library, likely in lib/histogram.js. The mean calculation likely divides sum by count, but sum becomes too large causing NaN. Consider using a different algorithm or converting to double precision. Check for existing solutions in other metrics libraries.