Libraries.Compute.Statistics.DataFrameColumn

This class represents a column on the system. Columns do not have a type themselves, but all subclasses can be made to have any arbitrary type, even custom ones. Columns by default can accept calculations, which send elements to the calculation of the appropriate type and conduct operations. DataFrame objects use the appropriate subclass of column automatically when reading in data frames from disk, based upon the first item in the spreadsheet. Note that in most cases, a user will not interact directly with this class. It is a parent class that encapsulates some common functionality, but typically one would pass a calculation or other operation to this class. The raw data of a column can also be manipulated directly, but type information must be checked through the appropriate actions (e.g., IsBooleanColumn). This is to balance the need to sometimes iterate through a column with the opposite need to manipulate its data directly.

Example Code

use Libraries.Compute.Statistics.DataFrame
    use Libraries.Compute.Statistics.DataFrameColumn

    //Load a comma separated file
    DataFrame frame
    frame:Load("Data.csv") 
    DataFrameColumn col = frame:GetColumn(0)
    output col:ToText()

Columns may optionally add data from a text representation of that data. This can be in any arbitrary format determined by the column implementor. The Add action does the auto-conversion, while the set values are only accepted if that data type is allowed. The broad purpose is to allow this action to read in from an arbitrary text source and add it to the column.

This action conducts a calculation on this column. The calculation begins by issuing a Start action. Then if it is an iterable action, sends each data point to the class for processing. If not, it is asked to conduct the entire operation at once on the full data set. Finally, it issues an end action.

This action returns a HashTable with AsText key values and counts of the items in the column.

This action returns whether or not this column type can be converted to a Vector of numbers.

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)

Regardless of the type of this column, the system will attempt to convert it to a BooleanColumn. This may cause an error to be thrown if the types are not compatible. Attrribute: Returns the newly converted column

Regardless of the type of this column, the system will attempt to convert it to an IntegerColumn. This may cause an error to be thrown if the types are not compatible. Attrribute: Returns the newly converted column

Regardless of the type of this column, the system will attempt to convert it to a NumberColumn. This may cause an error to be thrown if the types are not compatible. Attrribute: Returns the newly converted column

Regardless of the type of this column, the system will attempt to convert it to a TextColumn. This may cause an error to be thrown if the types are not compatible. Attrribute: Returns the newly converted column

Some column types can be converted to a raw vector of numbers. All other column types throw an error if they cannot convert. This vector conversion stores numbers more tightly in primitive form, so no undefined values are allowed, but the system can process on the vector more quickly and efficiently.

This action does a deep copy of the row between the 0-indexed rowStart and rowEnd. The two extra parameters indicate whether to sort the column or whether to require that it be unique.

This action conducts a deep copy of the column.

This action conducts a deep copy of the column. The two parameters indicate whether to sort the column or whether to require that it be unique.

This action does a deep copy of the row between the 0-indexed rowStart and rowEnd.

Copy from a row to copy from. Specifically, this grabs a value from the 'from' parameter inside the passed column value. It then places this row value into the to position inside of this column. This operation is destructive, meaning that the old value of the to position is destroyed. An error is thrown if the to value is invalid, below 0 or greater than the size. If the columns are not compatible, this throws an error. For example, if we try to set a number to a non-number column, this is an error.

Example Code

use Libraries.Compute.Statistics.DataFrame
        use Libraries.Compute.Statistics.DataFrameColumn
        DataFrame frame
        frame:Load("Data.csv")
        DataFrameColumn col1 = frame:GetColumn(0)
        DataFrameColumn col2 = frame:GetColumn(1)

        //Assuming the types are compatible
        col1:CopyToRow(col1, 1, 2)
        output frame:ToText()

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)

Regardless of the type of the column, this action attempts to convert the item at the index to a boolean. Attrribute: Parameter index the item to be converted

Regardless of the type of the column, this action attempts to convert the item at the index to an integer. Attrribute: Parameter index the item to be converted

Regardless of the type of the column, this action attempts to convert the item at the index to a number. Attrribute: Parameter index the item to be converted

Regardless of the type of the column, this action attempts to convert the item at the index to text. Attrribute: Parameter index the item to be converted

This action gets the hash code for an object.

Example Code

Object o
        integer hash = o:GetHashCode()

This gets the header for this column.

This action returns the number of rows.

This action returns the number of items in this column that are undefined.

This action returns a default text string for undefined values.

This action detects whether this column ultimately stores booleans inside of it. This type of information is implementation dependent, as arbitrary columns can store these values however they see fit.

This action detects whether this column ultimately stores integers inside of it. This type of information is implementation dependent, as arbitrary columns can store these values however they see fit.

This action detects whether this column ultimately stores numbers inside of it. This type of information is implementation dependent, as arbitrary columns can store these numbers however they see fit.

This action detects whether this column ultimately stores text inside of it. This type of information is implementation dependent, as arbitrary columns can store these values however they see fit.

This action detects whether a particular index is an undefined value in the column.

This action moves the value in row left to the value in row right.

This action sends an individual data point to a calculation, typed appropriately by its subclass.

This action sets the index to a boolean if and only if this is a boolean column. Attrribute: Parameter index the item to be converted

This action sets the index to an integer if and only if this is an integer column. Attrribute: Parameter index the item to be converted

This action sets the index to a number if and only if this is a number column. Attrribute: Parameter index the item to be converted

This action sets the index to text if and only if this is a text column. Attrribute: Parameter index the item to be converted

This sets the header for this column.

This action sets the size of the column to the parameter and then fills it with undefined values.

This action swaps two values in the column.

This is a convenience action that converts the entire column to a text format. This allows it to be sent to the console or a text editor for viewing.