# Variable Comparison

> Symcon documentation · English · generated on 2026-09-26  
> Index: https://www.symcon.de/en/llms.txt

Source: https://www.symcon.de/en/service/documentation/module-reference/logic/variable-comparison/

_Requires Symcon >= 6.0_

This module was sponsored by [IB-Jaetzel](https://ib-jaetzel.de/).

The module creates a graph of point clouds based on one or more pairs of variables and a line through the point cloud using simple linear regression. The diagram can be output as SVG or PNG.

### feature
- Create a diagram with one or more pairs of values
- Output of the diagram as SVG or PNG
- Output of slope, y-axis intercept, function and coefficient of determination of the graph

### software installation
- Via the [Module Store](https://www.symcon.de/en/service/documentation/components/management-console/module-store/) install the 'VariableComparison' module.

### Set up instances in IP-Symcon
- Under 'Add Instance' the 'VariableComparison' module can be found using the quick filter.
  - More information about adding instances in the [Instances documentation](https://www.symcon.de/en/service/documentation/basics/instances/)

#### Configuration Page:
Values:

| name              | description                                                |
| ----------------- | ---------------------------------------------------------- |
| X value           | Variable selection for the X axis                          |
| Y value           | Variable selection for the Y axis                          |
| point             | Color selection for the point macro                        |
| Line              | Color selection for the line                               |
| Aggregation Level | Level of how detailed the data is fetched from the archive |

Diagram settings:

| Name             | Description                                                  |
| ---------------- | ------------------------------------------------------------ |
| Axes small steps | Specifies in which steps small markings should be            |
| Axes large steps | Specifies in which steps the marking with labeling is        |
| Width            | Specifies how wide the diagram is                            |
| Height           | Indicates how high the diagram is                            |
| Y - Min          | Indicates the minimum value on the Y-axis                    |
| Y - Max          | Indicates the maximum value on the Y-axis                    |
| X - Min          | Indicates the minimum value on the X-axis                    |
| X - Max          | Indicates the maximum value on the X-axis                    |
| Digram Format    | Specifies whether the diagram should be output as SVG or PNG |

### status variables
The status variables/categories are created automatically. Deleting individual ones can lead to malfunctions.

#### Status variables

| Name                         | Type           | Description                                              |
| ---------------------------- | -------------- | -------------------------------------------------------- |
| Function                     | string         | Specifies the mathematical function of the graph         |
| b                            | Float          | Describes the y-axis intercept of the graph              |
| m                            | Float          | Describes the slope of the graph                         |
| Coefficient of determination | Float          | Describes how exactly the graph fits the point cloud     |
| Start Date                   | Integer        | Date from which the point cloud should start             |
| End Date                     | Integer        | Date to which the point cloud goes                       |
| Chart                        | String / Media | Returns the chart as PNG or SVG depending on the setting |

## LR_Download

Source: https://www.symcon.de/en/service/documentation/module-reference/logic/variable-comparison/lr-download/

`void LR_Download(int $InstanceID)`

_Requires Symcon >= 6.0_

Regenerates the graph and outputs an address

**Parameters**

- `$InstanceID` (int): ID of the Instance

**Returns** (void): No return.

ID of the Instance

**Example**

```text
LR_Download(12345);
```

## LR_GenerateChart

Source: https://www.symcon.de/en/service/documentation/module-reference/logic/variable-comparison/lr-generatechart/

`array LR_GenerateChart(int $InstanceID)`

_Requires Symcon >= 6.0_

Regenerates the chart and returns it as SVG and PNG.

**Parameters**

- `$InstanceID` (int): Id of the Instance

**Returns** (array): SVG and PNG diagram

Id of the Instance

**Example**

```text
LR_GenerateChart(12345);
```

## LR_UpdateChart

Source: https://www.symcon.de/en/service/documentation/module-reference/logic/variable-comparison/lr-updatechart/

`void LR_UpdateChart(int $InstanceID)`

_Requires Symcon >= 6.0_

**Parameters**

- `$InstanceID` (int): ID of the Instance

**Returns** (void): No return.

ID of the Instance

**Example**

```text
LR_UpdateChart(12345);
```