Contingency margins check
contingency-margins-check · version 1.0.0 · Numbers & math · free, no key needed
Check claimed row, column and grand totals of a count table exactly; returns the first wrong total.
Use when you need to: check contingency table totals · verify row and column totals of a cross tab · are my marginal totals correct.
Decide before calling
Read the versioned contract and the supported scope below. Reuse contingency-margins-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 contingency-margins-check@1.0.0 for check contingency table totals. 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 contingency table totals
- verify row and column totals of a cross tab
- are my marginal totals correct
- check grand total of a count table
- find the wrong row total in a table
- validate crosstab margins exactly
- בדיקת סכומי שורות ועמודות בטבלה
Not supported
- compute expected counts or a chi-square statistic (use contingency-expected-check or chi-square-decomposition-check)
- weighted or fractional counts
- tables over 64 x 64 or 1024 cells
- locale-formatted numbers such as 2,757
Behavior
- Reference: NIST/SEMATECH e-Handbook of Statistical Methods (doi:10.18434/M32189), section 7.4.5 (row totals, column totals, N); every output carries reference_version "nist-sematech-ehandbook-doi-10.18434-M32189".
- table: 1..64 rows of 1..64 equal-length rows, at most 1024 cells, each a JSON integer 0..9007199254740991 (not -0). Sums are exact BigInt integers, so totals above 2^53 stay exact.
- Claims row_totals, column_totals and grand_total are optional but at least one is required; each total is a non-negative integer string without leading zeros, sign or separators.
- Check order: row_totals length (length_mismatch, field "row_totals"), row totals in row order (row_total_mismatch), column_totals length (length_mismatch, field "column_totals"), column totals in column order (column_total_mismatch), grand_total (grand_total_mismatch). first_discrepancy carries claimed and actual as integer strings.
- Optional row_labels / column_labels: exactly one unique non-empty label per row / column (at most 64 UTF-8 bytes, no lone surrogate, no Unicode normalization); they are echoed as row_label / column_label.
- Validation order: table shape and size limits, cell values row-major, labels, then claims; over-limit sizes are limit_exceeded before later elements are read.
Input
table(array of array of integer, required): min items 1; max items 64; each min items 1; each max items 64; each each min 0; each each max 9007199254740991row_totals(array of string, optional): max items 64; each min length 1; each max length 1000; each pattern^(0|[1-9][0-9]*)$column_totals(array of string, optional): max items 64; each min length 1; each max length 1000; each pattern^(0|[1-9][0-9]*)$grand_total(string, optional): min length 1; max length 1000; pattern^(0|[1-9][0-9]*)$row_labels(array of string, optional): min items 1; max items 64; each min length 1column_labels(array of string, optional): min items 1; max items 64; each min length 1
Output
valid(boolean, required)reason(one of "length_mismatch", "row_total_mismatch", "column_total_mismatch", "grand_total_mismatch", null, required)first_discrepancy(object or null, required)row_count(integer, required): min 0column_count(integer, required): min 0grand_total(string, required): pattern^(0|[1-9][0-9]*)$reference_version(constant "nist-sematech-ehandbook-doi-10.18434-M32189", required)
Limits
- max rows: 64
- max columns: 64
- max cells: 1024
- max claim chars: 1000
- max label bytes: 64
Example
Request input:
{
"table": [
[
762,
327,
468
],
[
484,
239,
477
]
],
"row_totals": [
"1557",
"1200"
],
"column_totals": [
"1246",
"566",
"945"
],
"grand_total": "2757"
}Response:
{
"result": {
"valid": true,
"reason": null,
"first_discrepancy": null,
"row_count": 2,
"column_count": 3,
"grand_total": "2757",
"reference_version": "nist-sematech-ehandbook-doi-10.18434-M32189"
}
}How to call it
MCP
Connect https://computefirst.net/mcp (setup), then call execute with:
{
"id": "contingency-margins-check",
"version": "1.0.0",
"input": {
"table": [
[
762,
327,
468
],
[
484,
239,
477
]
],
"row_totals": [
"1557",
"1200"
],
"column_totals": [
"1246",
"566",
"945"
],
"grand_total": "2757"
}
}HTTP (no key)
curl -X POST https://computefirst.net/v1/tools/contingency-margins-check/versions/1.0.0/execute \
-H "Content-Type: application/json" \
-d '{"table":[[762,327,468],[484,239,477]],"row_totals":["1557","1200"],"column_totals":["1246","566","945"],"grand_total":"2757"}'The machine-readable contract is at /v1/tools/contingency-margins-check/versions/1.0.0.
CLI
node cli.mjs run contingency-margins-check 1.0.0 --input input.json --base-url https://computefirst.netGet the client at /clients/cli/.
Related tools
- Contingency expected check: Check claimed expected counts (row total x column total / N) of a count table exactly; returns the first wrong cell.
- Chi square decomposition check: Check a claimed Pearson chi-square, its per-cell (O-E)^2/E terms and df exactly; returns the first wrong term.
- Polynomial identity check: Check a polynomial identity over exact rationals by expanding both sides; report the lowest disagreeing coefficient.
- Rational trace check: Check a step-by-step rational calculation trace; reports the first step whose operand, operator or result disagrees.
- Regression residuals check: Check claimed residuals and SSE for given regression coefficients and exact samples; reports the first wrong residual.
- Linear residual check: Check a claimed residual r = b - A x (per component and/or its max norm) exactly for an approximate solution x.