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 # Structure IRockyPairScalars

 Last update: 09.03.2026 

<a id="structIRockyPairScalars"></a>

![](https://img.shields.io/badge/language-C%2B%2B-blue "C++")![](https://img.shields.io/badge/-public-brightgreen "public")

**\#include**

When running a simulation, an `<a href="structIRockyPairScalars.md#structIRockyPairScalars">IRockyPairScalars</a>` gives access to all pair scalars defined in the project. Pair scalars are special variables with a value attached to every combination of two particle groups and with each combination of a particle group and a geometry.

**Inherits from**:

- EntityScalars\\ rocky20::PairScalars &amp;gt;

## Members

- [add\_scalar](structIRockyPairScalars.md#structIRockyPairScalars_1ac4629dbc764141b132b43a4ed53c1412)
- [get\_scalar](structIRockyPairScalars.md#structIRockyPairScalars_1a2115866634ce54e7425ab949bb87d006)
- [max\_scalar](structIRockyPairScalars.md#structIRockyPairScalars_1ac5e39d90b8b54baf30023e7665d55555)
- [set\_scalar](structIRockyPairScalars.md#structIRockyPairScalars_1a5b7525f5f3d361571c0a2de51c61f189)

## Public functions

### Function get\_scalar

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![](https://img.shields.io/badge/-public-brightgreen "public")!\[\]\[const\]

```cpp
ROCKY_FUNCTIONS double IRockyPairScalars::get_scalar(int scalar_index) const

```

**If a custom scalar variable was defined during the setup of the module,**:

the value currently stored can be accessed with this method.

**Parameters**:

- **scalar\_index**: The integer index that was associated to the scalar variable during the setup of the module.

**Returns**:

The value currently stored in the scalar variable.

**Parameters**:

- int **scalar\_index**

**Return type**: ROCKY\_FUNCTIONS double

### Function set\_scalar

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![](https://img.shields.io/badge/-public-brightgreen "public")!\[\]\[const\]

```cpp
ROCKY_FUNCTIONS void IRockyPairScalars::set_scalar(int scalar_index, double value) const

```

**If a custom scalar variable was defined during the setup of the module,**:

this method can be used to store a value on it.

**Parameters**:

- **scalar\_index**: The integer index that was associated to the scalar variable during the setup of the module.
- **value**: The value that must be stored.

**Parameters**:

- int **scalar\_index**
- double **value**

**Return type**: ROCKY\_FUNCTIONS void

### Function add\_scalar

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![](https://img.shields.io/badge/-public-brightgreen "public")!\[\]\[const\]

```cpp
ROCKY_FUNCTIONS void IRockyPairScalars::add_scalar(int scalar_index, double value) const

```

**If a custom scalar variable was defined during the setup of the module,**:

this method can be used to sum a value to the current one stored in it.

**Parameters**:

- **scalar\_index**: The integer index that was associated to the scalar variable during the setup of the module.
- **value**: The value that must be summed to the current stored value.

**Parameters**:

- int **scalar\_index**
- double **value**

**Return type**: ROCKY\_FUNCTIONS void

### Function max\_scalar

<a id="structIRockyPairScalars_1ac5e39d90b8b54baf30023e7665d55555"></a>

![](https://img.shields.io/badge/-public-brightgreen "public")!\[\]\[const\]

```cpp
ROCKY_FUNCTIONS void IRockyPairScalars::max_scalar(int scalar_index, double value) const

```

**If a custom scalar variable was defined during the setup of the module,**:

this method can be used to make the scalar store the maximum of a set of values. A common use of this method is, for instance, to find the maximum among a set of values associated to the contacts of a particle.

**Parameters**:

- **scalar\_index**: The integer index that was associated to the scalar variable during the setup of the module.
- **value**: A value that must be checked if it is greater than the current stored value.

**Parameters**:

- int **scalar\_index**
- double **value**

**Return type**: ROCKY\_FUNCTIONS void

\[const\]: <https://img.shields.io/badge/-const-lightblue> (const)