SUBTRACTION (-)
Category: Arithmetic operators
Overview
The SUBTRACTION operator subtracts one input from another after aligning both inputs to their common dimensions. In other words, subtraction uses the intersection of the shared dimensions.
The result keeps the coarser level in each shared dimension. Dimensions that exist on only one side are aggregated away.
Use this operator to calculate differences between two nodes.
Syntax
'Node1' - 'Node2'
Example usage: 'Revenue' - 'OPEX'
Parameters
| Parameter | Description | Type | Required |
|---|---|---|---|
| Node1 | Minuend node, specified using the node name in single quotes (e.g.'Revenue') | Node reference | Yes |
| Node2 | Subtrahend node, specified using the node name in single quotes (e.g.'OPEX') | Node reference | Yes |
Output Shape
| Aspect | Behavior |
|---|---|
| Dimensionality | Both inputs are aggregated to their common dimensions (the intersection of the shared dimensions). Per shared dimension, the coarser level is used. Dimensions that exist on only one side are aggregated away. |
| Level values | Non-matching level values are preserved in the result. |
| Row count | Equal or reduced, depending on how much aggregation is required before subtracting. |
Watch Out
- Subtraction uses the common dimensions (intersection), just like addition.
- Dimensions that exist on only one side are aggregated away before subtracting.
- When subtracting a constant such as
'Revenue' - 100, the node is aggregated first and the constant is then subtracted from the total. - We recommend storing costs as negative values where possible, so addition can be used consistently throughout the model.
- Both sides must have the same unit, unless one side is a scalar value.
Examples
Subtracting nodes with matching dimensions
Input node: Revenue
| Year | Value |
|---|---|
| 2025 | 500 |
| 2026 | 600 |
| 2027 | 550 |
Input node: Cost
| Year | Value |
|---|---|
| 2025 | 300 |
| 2026 | 350 |
| 2027 | 400 |
Formula: 'Revenue' - 'Cost'
| Year | -> SUBTRACTION Result |
|---|---|
| 2025 | 500 - 300 = 200 |
| 2026 | 600 - 350 = 250 |
| 2027 | 550 - 400 = 150 |
Subtracting nodes with different level values
When level values do not overlap, subtraction preserves both values in the result. The value from the second input appears as negative.
Input node: A
| Year | Value |
|---|---|
| 2025 | 100 |
Input node: B
| Year | Value |
|---|---|
| 2026 | 40 |
Formula: 'A' - 'B'
| Year | -> SUBTRACTION Result |
|---|---|
| 2025 | 100 |
| 2026 | -40 |
Subtracting nodes with different dimensionality
This example shows how subtraction aggregates Node B to the common dimensions before subtracting it from Node A.
Input node: Node A
| Year | Value |
|---|---|
| 2025 | 5 |
| 2026 | 10 |
Input node: Node B
| Year | Product | Value |
|---|---|---|
| 2025 | A | 2 |
| 2026 | A | 3 |
| 2026 | B | 4 |
Formula: 'Node A' - 'Node B'
| Year | → SUBTRACTION Result |
|---|---|
| 2025 | 5-2 = 3 |
| 2026 | 10-(3+4) = 3 |
Related Functions
| Function | When to use instead |
| ADDITION (+) | When you want to combine values across the same shared-level alignment logic but add them instead of subtracting them. |
| MULTIPLICATION (*) | When you want to multiply values instead of subtracting them. |