## Libraries.Compute.Statistics.DataFrameColumnCalculation Documentation

The Calculation class is a general class that can be sent to an individual column to calculate a value on it. Calculations can either be Iterable, meaning that the column will pass individual values to the calculation, or not Iterable, which means the column will call Calculate(Column column), asking the system to do the entire calculation all at once. This allows the calculations to work on streams of data, in addition to raw data sets. The way this works is that if the calculation is iterable, the column itself will go through its data, one by one, and pass the items to the calculation. This may be numbers, integers, or some other data type and any of them can be empty values as undefined (indicating an empty value in the data set). This allows many calculations to have very small implementations, just a few lines, for many kinds of statistical calculations. Finally, calculations can be made re-usable by implementing the Empty call, which resets calculations to their default state.

*Inherits from: *Libraries.Language.Object

## Summary

### Actions Summary Table

Actions | Description |
---|---|

Add(Libraries.Language.Object value) | If the calculation otherwise has no primitive type, it sends it to the column as a raw object. |

Add(Libraries.Language.Types.Integer value) | If the calculation returns true from IsIterable, this is an Integer object that was passed to the calculation. |

Add(Libraries.Language.Types.Boolean value) | If the calculation returns true from IsIterable, this is a Boolean object that was passed to the calculation. |

Add(Libraries.Language.Types.Number value) | If the calculation returns true from IsIterable, this is a Number object that was passed to the calculation. |

Add(Libraries.Language.Types.Text value) | If the calculation returns true from IsIterable, this is a Text object that was passed to the calculation. |

Calculate(Libraries.Compute.Statistics.DataFrameColumn column) | This action can calculate the equation from a particular column. |

Compare(Libraries.Language.Object object) | This action compares two object hash codes and returns an integer. |

Empty() | This action deletes any saved data in the calculation and returns it to its default state. |

End(Libraries.Compute.Statistics.DataFrameColumn column) | This action is called at the end of a calculation. |

Equals(Libraries.Language.Object object) | This action determines if two objects are equal based on their hash code values. |

GetHashCode() | This action gets the hash code for an object. |

IsIterable() | If this action returns true, each element of the column will be sent to this calculation one by one. |

Start(Libraries.Compute.Statistics.DataFrameColumn column) | This action is called at the start of a calculation and passes the column that will be computed upon, so that the calculation can obtain any information it needs from the column. |

## Actions Documentation

### Add(Libraries.Language.Object value)

If the calculation otherwise has no primitive type, it sends it to the column as a raw object. Columns might use this if they have custom types.

#### Parameters

### Add(Libraries.Language.Types.Integer value)

If the calculation returns true from IsIterable, this is an Integer object that was passed to the calculation. This may be undefined, which indicates that the column did not contain a value at this position in the column.

#### Parameters

### Add(Libraries.Language.Types.Boolean value)

If the calculation returns true from IsIterable, this is a Boolean object that was passed to the calculation. This may be undefined, which indicates that the column did not contain a value at this position in the column.

#### Parameters

### Add(Libraries.Language.Types.Number value)

If the calculation returns true from IsIterable, this is a Number object that was passed to the calculation. This may be undefined, which indicates that the column did not contain a value at this position in the column.

#### Parameters

### Add(Libraries.Language.Types.Text value)

If the calculation returns true from IsIterable, this is a Text object that was passed to the calculation. This may be undefined, which indicates that the column did not contain a value at this position in the column.

#### Parameters

### Calculate(Libraries.Compute.Statistics.DataFrameColumn column)

This action can calculate the equation from a particular column. By default this action will only be called if the Calculation is not Iterable. Because the Column class is not guaranteed to have any particular data type, individual Calculation classes may need to cast to a particular column or data type to perform their operations. If a calculation is Iterable, the column will pass all of its data, one by one, to the calculation instead.

#### Parameters

### Compare(Libraries.Language.Object object)

This action compares two object hash codes and returns an integer. The result is larger if this hash code is larger than the object passed as a parameter, smaller, or equal. In this case, -1 means smaller, 0 means equal, and 1 means larger. This action was changed in Quorum 7 to return an integer, instead of a CompareResult object, because the previous implementation was causing efficiency issues.

**Example Code**

```
Object o
Object t
integer result = o:Compare(t) //1 (larger), 0 (equal), or -1 (smaller)
```

#### Parameters

- Libraries.Language.Object: The object to compare to.

#### Return

integer: The Compare result, Smaller, Equal, or Larger.

### Empty()

This action deletes any saved data in the calculation and returns it to its default state.

### End(Libraries.Compute.Statistics.DataFrameColumn column)

This action is called at the end of a calculation.

#### Parameters

### Equals(Libraries.Language.Object object)

This action determines if two objects are equal based on their hash code values.

**Example Code**

```
use Libraries.Language.Object
use Libraries.Language.Types.Text
Object o
Text t
boolean result = o:Equals(t)
```

#### Parameters

- Libraries.Language.Object: The to be compared.

#### Return

boolean: True if the hash codes are equal and false if they are not equal.

### GetHashCode()

This action gets the hash code for an object.

**Example Code**

```
Object o
integer hash = o:GetHashCode()
```

#### Return

integer: The integer hash code of the object.

### IsIterable()

If this action returns true, each element of the column will be sent to this calculation one by one. If this is false, the column should ask this class to conduct the calculation all at once using the Calculate action.

#### Return

boolean:

### Start(Libraries.Compute.Statistics.DataFrameColumn column)

This action is called at the start of a calculation and passes the column that will be computed upon, so that the calculation can obtain any information it needs from the column.