# Sampling Observations — Numeric Row Ordering + Two-Measure Correlation

> Sampling Observations — Numeric Row Ordering + Two-Measure Correlation is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-15).

Analyzes up to 200 sampling observation rows by computing numeric row ordering and two-measure correlation between sample_value and sample_weight fields.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ib26-analytics-15-120?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sampling-observations-numeric-row-ordering-two-measure-correlation-7c6c04b5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0e3W6OH_odSaYbwgu6FnQ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sampling-observations-numeric-row-ordering-two-measure-correlation-7c6c04b5 -d '<json body>'
```

Example prompt: I have 4 sampling observations with dates, sample values, and weights — can you rank them numerically by sample_value and also compute the correlation between sample_value and sample_weight? The rows are: row-1 on 2026-10-01 in group-a with value 10 and weight 1, row-2 on 2026-10-02 in group-b with value 20 and weight 2, row-3 on 2026-10-03 in group-a with value 15 and weight 3, and row-4 on 2026-10-04 in group-b with value 30 and weight 4.

## When to prefer this

Choose this endpoint when you have up to 200 sampling observation rows with both a sample_value and sample_weight and need two analytical outputs in a single call: numeric ranking of rows and a correlation measure between the two numeric fields. It is ideal for lightweight statistical summarization of survey, environmental, or scientific sample datasets without requiring external lookups or predictions. Prefer alternatives if you need grouped summaries, duplicate detection, category frequency counts, or more than 200 rows.

## Known failure modes

- Submitting more than 200 rows returns a validation error
- Missing required fields (row_id, dataset_group, date, sample_value, sample_weight) cause schema validation failure
- Invalid date format (not YYYY-MM-DD) triggers a pattern validation error
- Numeric values outside the allowed range (-1e12 to 1e12) are rejected
- Submitting fewer than 1 row causes a minItems validation error
- Correlation computation may be undefined or degenerate if all sample_values or all sample_weights are identical (zero variance)

## How this service works

Sampling observations — Numeric row ordering + Two-measure correlation: Numeric row ordering + Two-measure correlation for supplied sampling observations records (sample_value, sample_weight). Up to 200 rows; 2 independent reports using shared local analytical engines. No live lookup, prediction, professional assessment or external action. 0.01 USDC includes 2 supplied-data reports for up to 200 rows.

## Output

Returns two analytical reports: (1) a numeric row ordering that ranks all submitted observation rows by the selected field (sample_value or sample_weight), and (2) a two-measure correlation report quantifying the statistical relationship between sample_value and sample_weight across all submitted rows. No external data is fetched; all analysis is performed on the supplied rows only.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "row_id",
     "dataset_group",
     "date",
     "sample_value",
     "sample_weight"
    ],
    "properties": {
     "date": {
      "type": "string",
      "default": "",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "maxLength": 10
     },
     "row_id": {
      "type": "string",
      "default": "",
      "maxLength": 80,
      "minLength": 1
     },
     "sample_value": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "dataset_group": {
      "type": "string",
      "default": "",
      "maxLength": 80
     },
     "sample_weight": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "date": "2026-10-01",
     "row_id": "row-1",
     "sample_value": 10,
     "dataset_group": "group-a",
     "sample_weight": 1
    },
    {
     "date": "2026-10-02",
     "row_id": "row-2",
     "sample_value": 20,
     "dataset_group": "group-b",
     "sample_weight": 2
    },
    {
     "date": "2026-10-03",
     "row_id": "row-3",
     "sample_value": 15,
     "dataset_group": "group-a",
     "sample_weight": 3
    },
    {
     "date": "2026-10-04",
     "row_id": "row-4",
     "sample_value": 30,
     "dataset_group": "group-b",
     "sample_weight": 4
    }
   ],
   "maxItems": 200,
   "minItems": 1
  },
  "field": {
   "enum": [
    "sample_value",
    "sample_weight"
   ],
   "type": "string",
   "default": "sample_value"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sampling-observations-numeric-row-ordering-two-measure-correlation-7c6c04b5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)