Description
Return exp(-distance/scale) when exponential, otherwise (1+distance/scale)^(-power).
Spatial models compare distances, travel intervals, activity areas, or supplied interaction functions. Coordinates and model parameters must share a compatible basis, and a local term does not establish observed behavior.
Return exp(-distance/scale) when exponential, otherwise (1+distance/scale)^(-power).
When to use this tool
Use Spatial Interaction Distance Deterrence Term when you need one explicit spatial or travel-model component.
How to use the tool and how it works
- Enter distance, scale, power, exponential. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read deterrence. Use the output convention below.
Require nonnegative distance and power and positive scale. Return exp(-distance/scale) when exponential, otherwise (1+distance/scale)^(-power).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| distance | Distance | Required. Finite number; minimum 0. |
| scale | Scale | Required. Finite number; strictly above 0. |
| power | Power | Required. Finite number; minimum 0. |
| exponential | Exponential | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| deterrence | Deterrence | Required. Finite number. |
{
"input": {
"distance": 10,
"scale": 10,
"power": 2,
"exponential": true
},
"output": {
"deterrence": 0.36787944117144233
}
}Limitations and assumptions
- Distance and scale share units; the selected decay term is dimensionless and supplied rather than fitted, without origin/destination balancing or predicted flow totals.
- 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
Check projection, route definitions, calibration, and the complete model before interpreting access or predicted flows.
References
Similar or alternative tools
- Gravity Flow One Origin Destination Term
Multiply nonnegative coefficient, originMass, and destinationMass and divide by positive distance raised to supplied exponent.
- Accessibility One Destination Decay Term
Return exp(-decayRate × travelTime) and opportunities times weight times that decay.