Description
Multiply nonnegative coefficient, originMass, and destinationMass and divide by positive distance raised to supplied exponent.
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.
Multiply nonnegative coefficient, originMass, and destinationMass and divide by positive distance raised to supplied exponent.
When to use this tool
Use Gravity Flow One Origin Destination Term when you need one explicit spatial or travel-model component.
How to use the tool and how it works
- Enter originMass, destinationMass, distance, coefficient, exponent. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read predictedFlow. Use the output convention below.
Multiply nonnegative coefficient, originMass, and destinationMass and divide by positive distance raised to supplied exponent.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| originMass | Origin Mass | Required. Finite number; minimum 0. |
| destinationMass | Destination Mass | Required. Finite number; minimum 0. |
| distance | Distance | Required. Finite number; strictly above 0. |
| coefficient | Coefficient | Required. Finite number; minimum 0. |
| exponent | Exponent | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| predictedFlow | Predicted Flow | Required. Finite number. |
{
"input": {
"originMass": 100,
"destinationMass": 200,
"distance": 10,
"coefficient": 0.01,
"exponent": 2
},
"output": {
"predictedFlow": 2
}
}Limitations and assumptions
- Coefficient carries the model's unit convention; this is one unconstrained gravity-model term without calibration, balancing, network effects, or causal prediction.
- 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
- Spatial Interaction Distance Deterrence Term
Return exp(-distance/scale) when exponential, otherwise (1+distance/scale)^(-power).
- Accessibility One Destination Decay Term
Return exp(-decayRate × travelTime) and opportunities times weight times that decay.