Fess Center Line Offset Calculator
Fess center offset in an explicit rectangular envelope, y down from top; no shield centroid inference.
Description
A fess center can be compared with the field's geometric mid-height.
A fess center can be compared with the field's geometric mid-height.1
A signed offset retains whether it lies above or below the center in the supplied y coordinate system.
When to use Fess Center Line Offset Calculator
Use this tool to calculate or review the supplied observations under the stated rules. Establish the source tradition, viewing frame, coordinate units and independently annotated features.
How to use Fess Center Line Offset Calculator and understand its results
- Establish the source tradition, viewing frame, coordinate units and independently annotated features.
- Enter fieldHeight, observedFessCenterY, using the field meanings and rules below, then run the tool.
- Read result.signedCenterOffset, result.normalizedCenterOffset, using the output meanings and calculation rules below.
- Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| fieldHeight | Field height | number | Required |
| observedFessCenterY | Observed fess center y | number | Required |
Use positive field height and fess-center y in [0,height]. Return centerY−height/2 and centerY/height−0.5. Under viewer y-down coordinates, positive values place the center below the midpoint.
signedOffset=centerY−h/2; normalizedOffset=centerY/h−0.5 Use the matching field units and the exact boundary, ordering and reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Calculated observation or reference | object |
| result.signedCenterOffset | signed Center Offset; preserve the subtraction order and sign defined in the mechanics | number |
| result.normalizedCenterOffset | normalized Center Offset | number |
{
"input": {
"fieldHeight": 100,
"observedFessCenterY": 60
},
"output": {
"result": {
"signedCenterOffset": 10,
"normalizedCenterOffset": 0.09999999999999998
}
}
}Limitations and assumptions
The result compares a supplied center with a rectangular mid-height. No shape centroid, band depth or heraldic placement tolerance is determined.
Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Extremely large composite outputs are rejected.
Alternative or Complementary methods
For a related step, use Pale Vertical Band Position Calculator: A pale is a vertical band whose width and centering can be expressed geometrically. For a complementary comparison, use Per Fess Horizontal Split Position Checker: Per-fess geometry concerns a horizontal division across the field.
References
-
Fess Center Line Offset Calculator — tool.io
Similar or alternative tools
- Pale Vertical Band Position Calculator
A pale is a vertical band whose width and centering can be expressed geometrically.
- Per Fess Horizontal Split Position Checker
Per-fess geometry concerns a horizontal division across the field.