Description
Compute cellEast = floor((east-originEast)/gridSize) and the corresponding north index.
A spatial grid replaces a precise coordinate with a cell identifier or representative point. Grid size and origin control the disclosed resolution, but deterministic coarsening alone does not guarantee that a sensitive locality is protected.
Compute cellEast = floor((east-originEast)/gridSize) and the corresponding north index.
When to use this tool
Use Public Voucher Locality Grid Mask when applying an explicit planar grid-center locality mask.
How to use the tool and how it works
- Enter east, north, gridSize, originEast, originNorth. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read maskedEast, maskedNorth, cellEast, cellNorth. Use the output convention below.
Require positive gridSize. Compute cellEast = floor((east-originEast)/gridSize) and the corresponding north index. masked coordinates are origin+(cellIndex+0.5)*gridSize, placing the record at that cell's center.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| east | East | Required. Finite number. |
| north | North | Required. Finite number. |
| gridSize | Positive planar cell width and height in the coordinate length unit. | Required. Finite number; strictly above 0. |
| originEast | Origin East | Required. Finite number. |
| originNorth | Origin North | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| maskedEast | Masked East | Required. Finite number. |
| maskedNorth | Masked North | Required. Finite number. |
| cellEast | Cell East | Required. Safe integer. |
| cellNorth | Cell North | Required. Safe integer. |
{
"input": {
"east": 123,
"north": 278,
"gridSize": 100,
"originEast": 0,
"originNorth": 0
},
"output": {
"maskedEast": 150,
"maskedNorth": 250,
"cellEast": 1,
"cellNorth": 2
}
}Limitations and assumptions
- Use planar coordinates in one length unit. This deterministic grid mask is not guaranteed anonymization, geographic reprojection or sufficient protection for sensitive localities.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review sensitive-location disclosure policy and other identifying information; use a suitable geographic transformation when inputs are not planar.
References
Similar or alternative tools
- Raster Cell Ground Area Factor
groundArea = cellWidth*cellHeight*horizontalScale*verticalScale.
- Raster Pixel Ground Support Share
validGroundArea sums valid pixels; observedGroundArea additionally requires observed; share is their ratio when positive, otherwise zero with defined = false.