Description
Require leftX < rightX and return sign(rightY - leftY) as direction plus an exact flat flag.
Interpolation knots divide a coordinate range into intervals. Repeated nodes, unequal spacing, and exact boundary selection can change how a piecewise interpolant is interpreted.
Require leftX < rightX and return sign(rightY - leftY) as direction plus an exact flat flag.
When to use this tool
Use Monotone Linear Segment Direction when you need one knot-interval or multiplicity diagnostic.
How to use the tool and how it works
- Enter leftX, rightX, leftY, rightY. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read direction, flat. Inspect flat before interpreting the associated values.
Require leftX < rightX and return sign(rightY - leftY) as direction plus an exact flat flag.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| leftX | Left X | Required. Finite number. |
| rightX | Right X | Required. Finite number. |
| leftY | Left Y | Required. Finite number. |
| rightY | Right Y | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| direction | Direction | Required. Safe integer. |
| flat | Flat | Required. Boolean. |
{
"input": {
"leftX": 0,
"rightX": 2,
"leftY": 5,
"rightY": 1
},
"output": {
"direction": -1,
"flat": false
}
}Limitations and assumptions
- This reports one segment's direction, not the magnitude of its slope or monotonicity of a multi-segment curve.
- 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
Validate the complete knot sequence and interpolation method, including tolerance and extrapolation policies.
References
Similar or alternative tools
- Piecewise Linear One Knot Curvature
Subtract the left segment's secant slope from the right segment's slope for slopeJump.
- Interpolation: Monotone Endpoint Slope Clamp
Return zero when adjacentSecant is zero or candidateSlope has a nonpositive product with it.