Source: https://guthlabs.ai/docs/instruments/garden-plant-spacing-planner/mechanism/

instrument mechanism / verified-clean

# Garden Plant Spacing Planner mechanism

The inspectable method record for Garden Plant Spacing Planner, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The grid calculation can pass after defining row_spacing, units, boundary clearance, and input validation. The offset pattern requires a complete geometric formula or algorithm before the instrument can be verified as fully correct.

- The grid formula is valid only under the explicit convention that plant centers may be placed on both bed boundaries: floor(bed_length/spacing)+1 and floor(bed_width/row_spacing)+1.

- The input specification names one plant spacing requirement but the formula requires both spacing and row_spacing; it is ambiguous whether row_spacing equals plant spacing or is independently supplied.

- The offset-pattern rule is not a standard complete formula. Saying triangular packing gives approximately 15% more density does not define row spacing, horizontal offset, boundary handling, or the exact count, so its output is not reproducible.

- The formula does not account for required edge clearance, plant diameter, or whether spacing is a minimum center-to-center distance rather than an exact grid interval.

- The layout-diagram output has no specified data format or deterministic construction rules.

## Units and conventions

- bed_length, bed_width, spacing, and row_spacing must use the same linear unit before division; unit conversion is not performed by the stated formulas.

- Unless separately provided, row_spacing is assumed equal to the plant spacing requirement for the grid examples.

- The +1 endpoint convention assumes a plant can be centered exactly at each usable bed boundary.

- All dimensions and spacings are real, finite, positive values; zero or negative spacing is invalid.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "bed_length": 3,
    "bed_width": 2,
    "spacing": 0.5,
    "row_spacing": 0.5,
    "unit": "m",
    "layout_pattern": "grid"
  },
  "expected_outputs": {
    "plants_per_row": 7,
    "rows": 5,
    "total": 35,
    "layout_diagram": "7 columns x 5 rows"
  },
  "working": "plants_per_row = floor(3 / 0.5) + 1 = floor(6) + 1 = 6 + 1 = 7; rows = floor(2 / 0.5) + 1 = floor(4) + 1 = 4 + 1 = 5; total = 7 x 5 = 35."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The offset-pattern rule specifies only approximately 15% greater density and does not define the triangular-packing geometry, integer rounding, or edge handling. For a grid count of 24, it produces 27.6 before rounding, so the exact required plant count is not uniquely determined. Zero spacing also yields undefined division and must be rejected.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/garden-plant-spacing-planner/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/garden-plant-spacing-planner/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/garden-plant-spacing-planner/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`