Sample histogram check

sample-histogram-check · version 1.0.0 · Numbers & math · free, no key needed

Check claimed histogram counts, outside count and densities for exact edges and an edge rule; returns the first bad bin.

Use when you need to: check claimed histogram bin counts · verify frequency table against raw values · validate histogram densities for given bin edges.

Decide before calling

Read the versioned contract and the supported scope below. Reuse sample-histogram-check@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use sample-histogram-check@1.0.0 for check claimed histogram bin counts. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• check claimed histogram bin counts
• verify frequency table against raw values
• validate histogram densities for given bin edges
• check which values fall in each bin
• audit numpy histogram counts
• confirm out of range count for histogram bins

Not supported

• choosing bin edges or a bin count (Sturges, Freedman-Diaconis)
• weighted histograms or cumulative frequency claims
• two-dimensional histograms
• drawing or rendering a histogram

Behavior

• Reference: NIST/SEMATECH e-Handbook (2012) 1.3.3.14 histogram counts; boundary rules from numpy.histogram and R graphics::hist; reference_version is returned with every result.
• edges: 2-1001 exact values (safe integers or ASCII decimal strings), strictly increasing; bin i spans edges[i] to edges[i+1].
• boundary_rule: left_closed_last_closed = [a, b) with a closed last bin (NumPy); left_closed = all [a, b); right_closed = all (a, b]; right_closed_first_closed = (a, b] with a closed first bin (R hist default). Values in no bin are outside.
• claim.counts: one non-negative integer per bin; claim.outside: values in no bin; claim.densities (optional): exact count / ((n - outside) * width) per bin, invalid with reason density_undefined when n - outside = 0.
• Check order: counts length, densities length, counts bin by bin, outside, densities bin by bin; the first failure gives field, bin_index, lower, upper, claimed and actual.
• Length mismatches report the claimed and required lengths; bin_index, lower and upper are null for length and outside failures. Exact values use the canonical form (integer, terminating decimal or reduced p/q).

Input

• sample (array of integer or string, required): min items 1; max items 10000
• edges (array of integer or string, required): min items 2; max items 1001
• boundary_rule (one of "left_closed_last_closed", "left_closed", "right_closed", "right_closed_first_closed", required)
• claim (object, required)

Output

• valid (boolean, required)
• reason (one of null, "counts_length_mismatch", "densities_length_mismatch", "count_mismatch", "outside_mismatch", "density_undefined", "density_mismatch", required)
• first_discrepancy (object or null, required)
• bins (integer, required): min 1
• reference_version (string, required)

Limits

• max sample items: 10000
• max value chars: 40
• max fraction digits: 30
• max edges: 1001

Example

Request input:

{
  "sample": [
    1,
    2,
    1
  ],
  "edges": [
    0,
    1,
    2,
    3
  ],
  "boundary_rule": "left_closed_last_closed",
  "claim": {
    "counts": [
      0,
      2,
      1
    ],
    "outside": 0
  }
}

Response:

{
  "result": {
    "valid": true,
    "reason": null,
    "first_discrepancy": null,
    "bins": 3,
    "reference_version": "NIST/SEMATECH e-Handbook (2012) 1.3.3.14; numpy.histogram and R hist() bin-edge rules; r60-sample-statistic-verifiers@1.0.0"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "sample-histogram-check",
  "version": "1.0.0",
  "input": {
    "sample": [
      1,
      2,
      1
    ],
    "edges": [
      0,
      1,
      2,
      3
    ],
    "boundary_rule": "left_closed_last_closed",
    "claim": {
      "counts": [
        0,
        2,
        1
      ],
      "outside": 0
    }
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/sample-histogram-check/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"sample":[1,2,1],"edges":[0,1,2,3],"boundary_rule":"left_closed_last_closed","claim":{"counts":[0,2,1],"outside":0}}'

The machine-readable contract is at /v1/tools/sample-histogram-check/versions/1.0.0.

CLI

node cli.mjs run sample-histogram-check 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Sample quantile check: Check claimed quantiles or percentiles of an exact sample under Hyndman-Fan type 1-9; returns the first mismatch.
• Contingency expected check: Check claimed expected counts (row total x column total / N) of a count table exactly; returns the first wrong cell.
• Multiset counts check: Check an exact claimed multiplicity table for canonical JSON scalars in first-occurrence order.
• Sample summary check: Check claimed count, sum, mean, median, range, variance or SD of an exact sample; returns the first mismatching field.
• Network cut capacity check: Check a claimed s-t cut: source-side membership, the edges crossing it and its capacity, with exact integers.
• Lp primal feasibility check: Check that a claimed LP point satisfies x >= 0 and Ax <= b exactly; report the first violated bound or row.