Package org.datavec.api.transform

Class TransformProcess.Builder

  • Enclosing class:
    TransformProcess
    public static class TransformProcess.Builder
extends Object
    Builder class for constructing a TransformProcess

    • Constructor Detail

      • Builder

        public Builder​(Schema initialSchema)

    • Method Detail

      • transform

        public TransformProcess.Builder transform​(Transform transform)
        Add a transformation to be executed after the previously-added operations have been executed
        Parameters:
        transform - Transform to execute

      • filter

        public TransformProcess.Builder filter​(Filter filter)
        Add a filter operation to be executed after the previously-added operations have been executed
        Parameters:
        filter - Filter operation to execute

      • filter

        public TransformProcess.Builder filter​(Condition condition)
        Add a filter operation, based on the specified condition. If condition is satisfied (returns true): remove the example or sequence
        If condition is not satisfied (returns false): keep the example or sequence
        Parameters:
        condition - Condition to filter on

      • removeColumns

        public TransformProcess.Builder removeColumns​(String... columnNames)
        Remove all of the specified columns, by name
        Parameters:
        columnNames - Names of the columns to remove

      • removeColumns

        public TransformProcess.Builder removeColumns​(Collection<String> columnNames)
        Remove all of the specified columns, by name
        Parameters:
        columnNames - Names of the columns to remove

      • removeAllColumnsExceptFor

        public TransformProcess.Builder removeAllColumnsExceptFor​(String... columnNames)
        Remove all columns, except for those that are specified here
        Parameters:
        columnNames - Names of the columns to keep

      • removeAllColumnsExceptFor

        public TransformProcess.Builder removeAllColumnsExceptFor​(Collection<String> columnNames)
        Remove all columns, except for those that are specified here
        Parameters:
        columnNames - Names of the columns to keep

      • renameColumn

        public TransformProcess.Builder renameColumn​(String oldName,
                                             String newName)
        Rename a single column
        Parameters:
        oldName - Original column name
        newName - New column name

      • renameColumns

        public TransformProcess.Builder renameColumns​(List<String> oldNames,
                                              List<String> newNames)
        Rename multiple columns
        Parameters:
        oldNames - List of original column names
        newNames - List of new column names

      • reorderColumns

        public TransformProcess.Builder reorderColumns​(String... newOrder)
        Reorder the columns using a partial or complete new ordering. If only some of the column names are specified for the new order, the remaining columns will be placed at the end, according to their current relative ordering
        Parameters:
        newOrder - Names of the columns, in the order they will appear in the output

      • duplicateColumn

        public TransformProcess.Builder duplicateColumn​(String column,
                                                String newName)
        Duplicate a single column
        Parameters:
        column - Name of the column to duplicate
        newName - Name of the new (duplicate) column

      • duplicateColumns

        public TransformProcess.Builder duplicateColumns​(List<String> columnNames,
                                                 List<String> newNames)
        Duplicate a set of columns
        Parameters:
        columnNames - Names of the columns to duplicate
        newNames - Names of the new (duplicated) columns

      • integerMathOp

        public TransformProcess.Builder integerMathOp​(String column,
                                              MathOp mathOp,
                                              int scalar)
        Perform a mathematical operation (add, subtract, scalar max etc) on the specified integer column, with a scalar
        Parameters:
        column - The integer column to perform the operation on
        mathOp - The mathematical operation
        scalar - The scalar value to use in the mathematical operation

      • integerColumnsMathOp

        public TransformProcess.Builder integerColumnsMathOp​(String newColumnName,
                                                     MathOp mathOp,
                                                     String... columnNames)
        Calculate and add a new integer column by performing a mathematical operation on a number of existing columns. New column is added to the end.
        Parameters:
        newColumnName - Name of the new/derived column
        mathOp - Mathematical operation to execute on the columns
        columnNames - Names of the columns to use in the mathematical operation

      • longMathOp

        public TransformProcess.Builder longMathOp​(String columnName,
                                           MathOp mathOp,
                                           long scalar)
        Perform a mathematical operation (add, subtract, scalar max etc) on the specified long column, with a scalar
        Parameters:
        columnName - The long column to perform the operation on
        mathOp - The mathematical operation
        scalar - The scalar value to use in the mathematical operation

      • longColumnsMathOp

        public TransformProcess.Builder longColumnsMathOp​(String newColumnName,
                                                  MathOp mathOp,
                                                  String... columnNames)
        Calculate and add a new long column by performing a mathematical operation on a number of existing columns. New column is added to the end.
        Parameters:
        newColumnName - Name of the new/derived column
        mathOp - Mathematical operation to execute on the columns
        columnNames - Names of the columns to use in the mathematical operation

      • floatMathOp

        public TransformProcess.Builder floatMathOp​(String columnName,
                                            MathOp mathOp,
                                            float scalar)
        Perform a mathematical operation (add, subtract, scalar max etc) on the specified double column, with a scalar
        Parameters:
        columnName - The float column to perform the operation on
        mathOp - The mathematical operation
        scalar - The scalar value to use in the mathematical operation

      • floatColumnsMathOp

        public TransformProcess.Builder floatColumnsMathOp​(String newColumnName,
                                                   MathOp mathOp,
                                                   String... columnNames)
        Calculate and add a new float column by performing a mathematical operation on a number of existing columns. New column is added to the end.
        Parameters:
        newColumnName - Name of the new/derived column
        mathOp - Mathematical operation to execute on the columns
        columnNames - Names of the columns to use in the mathematical operation

      • floatMathFunction

        public TransformProcess.Builder floatMathFunction​(String columnName,
                                                  MathFunction mathFunction)
        Perform a mathematical operation (such as sin(x), ceil(x), exp(x) etc) on a column
        Parameters:
        columnName - Column name to operate on
        mathFunction - MathFunction to apply to the column

      • doubleMathOp

        public TransformProcess.Builder doubleMathOp​(String columnName,
                                             MathOp mathOp,
                                             double scalar)
        Perform a mathematical operation (add, subtract, scalar max etc) on the specified double column, with a scalar
        Parameters:
        columnName - The double column to perform the operation on
        mathOp - The mathematical operation
        scalar - The scalar value to use in the mathematical operation

      • doubleColumnsMathOp

        public TransformProcess.Builder doubleColumnsMathOp​(String newColumnName,
                                                    MathOp mathOp,
                                                    String... columnNames)
        Calculate and add a new double column by performing a mathematical operation on a number of existing columns. New column is added to the end.
        Parameters:
        newColumnName - Name of the new/derived column
        mathOp - Mathematical operation to execute on the columns
        columnNames - Names of the columns to use in the mathematical operation

      • doubleMathFunction

        public TransformProcess.Builder doubleMathFunction​(String columnName,
                                                   MathFunction mathFunction)
        Perform a mathematical operation (such as sin(x), ceil(x), exp(x) etc) on a column
        Parameters:
        columnName - Column name to operate on
        mathFunction - MathFunction to apply to the column

      • timeMathOp

        public TransformProcess.Builder timeMathOp​(String columnName,
                                           MathOp mathOp,
                                           long timeQuantity,
                                           TimeUnit timeUnit)
        Perform a mathematical operation (add, subtract, scalar min/max only) on the specified time column
        Parameters:
        columnName - The integer column to perform the operation on
        mathOp - The mathematical operation
        timeQuantity - The quantity used in the mathematical op
        timeUnit - The unit that timeQuantity is specified in

      • categoricalToOneHot

        public TransformProcess.Builder categoricalToOneHot​(String... columnNames)
        Convert the specified column(s) from a categorical representation to a one-hot representation. This involves the creation of multiple new columns each.
        Parameters:
        columnNames - Names of the categorical column(s) to convert to a one-hot representation

      • categoricalToInteger

        public TransformProcess.Builder categoricalToInteger​(String... columnNames)
        Convert the specified column(s) from a categorical representation to an integer representation. This will replace the specified categorical column(s) with an integer repreesentation, where each integer has the value 0 to numCategories-1.
        Parameters:
        columnNames - Name of the categorical column(s) to convert to an integer representation

      • integerToCategorical

        public TransformProcess.Builder integerToCategorical​(String columnName,
                                                     List<String> categoryStateNames)
        Convert the specified column from an integer representation (assume values 0 to numCategories-1) to a categorical representation, given the specified state names
        Parameters:
        columnName - Name of the column to convert
        categoryStateNames - Names of the states for the categorical column

      • integerToCategorical

        public TransformProcess.Builder integerToCategorical​(String columnName,
                                                     Map<Integer,​String> categoryIndexNameMap)
        Convert the specified column from an integer representation to a categorical representation, given the specified mapping between integer indexes and state names
        Parameters:
        columnName - Name of the column to convert
        categoryIndexNameMap - Names of the states for the categorical column

      • integerToOneHot

        public TransformProcess.Builder integerToOneHot​(String columnName,
                                                int minValue,
                                                int maxValue)
        Convert an integer column to a set of 1 hot columns, based on the value in integer column
        Parameters:
        columnName - Name of the integer column
        minValue - Minimum value possible for the integer column (inclusive)
        maxValue - Maximum value possible for the integer column (inclusive)

      • addConstantColumn

        public TransformProcess.Builder addConstantColumn​(String newColumnName,
                                                  ColumnType newColumnType,
                                                  Writable fixedValue)
        Add a new column, where all values in the column are identical and as specified.
        Parameters:
        newColumnName - Name of the new column
        newColumnType - Type of the new column
        fixedValue - Value in the new column for all records

      • addConstantDoubleColumn

        public TransformProcess.Builder addConstantDoubleColumn​(String newColumnName,
                                                        double value)
        Add a new double column, where the value for that column (for all records) are identical
        Parameters:
        newColumnName - Name of the new column
        value - Value in the new column for all records

      • addConstantIntegerColumn

        public TransformProcess.Builder addConstantIntegerColumn​(String newColumnName,
                                                         int value)
        Add a new integer column, where th e value for that column (for all records) are identical
        Parameters:
        newColumnName - Name of the new column
        value - Value of the new column for all records

      • addConstantLongColumn

        public TransformProcess.Builder addConstantLongColumn​(String newColumnName,
                                                      long value)
        Add a new integer column, where the value for that column (for all records) are identical
        Parameters:
        newColumnName - Name of the new column
        value - Value in the new column for all records

      • convertToString

        public TransformProcess.Builder convertToString​(String inputColumn)
        Convert the specified column to a string.
        Parameters:
        inputColumn - the input column to convert
        Returns:
        builder pattern

      • convertToDouble

        public TransformProcess.Builder convertToDouble​(String inputColumn)
        Convert the specified column to a double.
        Parameters:
        inputColumn - the input column to convert
        Returns:
        builder pattern

      • convertToInteger

        public TransformProcess.Builder convertToInteger​(String inputColumn)
        Convert the specified column to an integer.
        Parameters:
        inputColumn - the input column to convert
        Returns:
        builder pattern

      • normalize

        public TransformProcess.Builder normalize​(String column,
                                          Normalize type,
                                          DataAnalysis da)
        Normalize the specified column with a given type of normalization
        Parameters:
        column - Column to normalize
        type - Type of normalization to apply
        da - DataAnalysis object

      • convertToSequence

        public TransformProcess.Builder convertToSequence​(String keyColumn,
                                                  SequenceComparator comparator)
        Convert a set of independent records/examples into a sequence, according to some key. Within each sequence, values are ordered using the provided SequenceComparator
        Parameters:
        keyColumn - Column to use as a key (values with the same key will be combined into sequences)
        comparator - A SequenceComparator to order the values within each sequence (for example, by time or String order)

      • convertToSequence

        public TransformProcess.Builder convertToSequence()
        Convert a set of independent records/examples into a sequence; each example is simply treated as a sequence of length 1, without any join/group operations. Note that more commonly, joining/grouping is required; use convertToSequence(List, SequenceComparator) for this functionality

      • convertToSequence

        public TransformProcess.Builder convertToSequence​(List<String> keyColumns,
                                                  SequenceComparator comparator)
        Convert a set of independent records/examples into a sequence, where each sequence is grouped according to one or more key values (i.e., the values in one or more columns) Within each sequence, values are ordered using the provided SequenceComparator
        Parameters:
        keyColumns - Column to use as a key (values with the same key will be combined into sequences)
        comparator - A SequenceComparator to order the values within each sequence (for example, by time or String order)

      • convertFromSequence

        public TransformProcess.Builder convertFromSequence()
        Convert a sequence to a set of individual values (by treating each value in each sequence as a separate example)

      • splitSequence

        public TransformProcess.Builder splitSequence​(SequenceSplit split)
        Split sequences into 1 or more other sequences. Used for example to split large sequences into a set of smaller sequences
        Parameters:
        split - SequenceSplit that defines how splits will occur

      • trimSequence

        public TransformProcess.Builder trimSequence​(int numStepsToTrim,
                                             boolean trimFromStart)
        SequenceTrimTranform removes the first or last N values in a sequence. Note that the resulting sequence may be of length 0, if the input sequence is less than or equal to N.
        Parameters:
        numStepsToTrim - Number of time steps to trim from the sequence
        trimFromStart - If true: Trim values from the start of the sequence. If false: trim values from the end.

      • trimSequenceToLength

        public TransformProcess.Builder trimSequenceToLength​(int maxLength)
        Trim the sequence to the specified length (number of sequence steps).
        Sequences longer than the specified maximum will be trimmed to exactly the maximum. Shorter sequences will not be modified.
        Parameters:
        maxLength - Maximum sequence length (number of time steps)

      • trimOrPadSequenceToLength

        public TransformProcess.Builder trimOrPadSequenceToLength​(int length,
                                                          @NonNull
                                                          @NonNull List<Writable> pad)
        Trim or pad the sequence to the specified length (number of sequence steps).
        Sequences longer than the specified maximum will be trimmed to exactly the maximum. Shorter sequences will be padded with as many copies of the "pad" array to make the sequence length equal the specified maximum.
        Note that the 'pad' list (i.e., values to pad with) must be equal in length to the number of columns (values per time step)
        Parameters:
        length - Required length - trim sequences longer than this, pad sequences shorter than this
        pad - Values to pad at the end of the sequence

      • offsetSequence

        public TransformProcess.Builder offsetSequence​(List<String> columnsToOffset,
                                               int offsetAmount,
                                               SequenceOffsetTransform.OperationType operationType)
        Perform a sequence of operation on the specified columns. Note that this also truncates sequences by the specified offset amount by default. Use transform(new SequenceOffsetTransform(...) to change this. See SequenceOffsetTransform for details on exactly what this operation does and how.
        Parameters:
        columnsToOffset - Columns to offset
        offsetAmount - Amount to offset the specified columns by (positive offset: 'columnsToOffset' are moved to later time steps)
        operationType - Whether the offset should be done in-place or by adding a new column

      • reduce

        public TransformProcess.Builder reduce​(IAssociativeReducer reducer)
        Reduce (i.e., aggregate/combine) a set of examples (typically by key). Note: In the current implementation, reduction operations can be performed only on standard (i.e., non-sequence) data
        Parameters:
        reducer - Reducer to use

      • reduceSequence

        public TransformProcess.Builder reduceSequence​(IAssociativeReducer reducer)
        Reduce (i.e., aggregate/combine) a set of sequence examples - for each sequence individually. Note: This method results in non-sequence data. If you would instead prefer sequences of length 1 after the reduction, use transform(new ReduceSequenceTransform(reducer)).
        Parameters:
        reducer - Reducer to use to reduce each window

      • reduceSequenceByWindow

        public TransformProcess.Builder reduceSequenceByWindow​(IAssociativeReducer reducer,
                                                       WindowFunction windowFunction)
        Reduce (i.e., aggregate/combine) a set of sequence examples - for each sequence individually - using a window function. For example, take all records/examples in each 24-hour period (i.e., using window function), and convert them into a singe value (using the reducer). In this example, the output is a sequence, with time period of 24 hours.
        Parameters:
        reducer - Reducer to use to reduce each window
        windowFunction - Window function to find apply on each sequence individually

      • sequenceMovingWindowReduce

        public TransformProcess.Builder sequenceMovingWindowReduce​(String columnName,
                                                           int lookback,
                                                           ReduceOp op)
        SequenceMovingWindowReduceTransform: Adds a new column, where the value is derived by:
        (a) using a window of the last N values in a single column,
        (b) Apply a reduction op on the window to calculate a new value
        for example, this transformer can be used to implement a simple moving average of the last N values, or determine the minimum or maximum values in the last N time steps.

        For example, for a simple moving average, length 20: new SequenceMovingWindowReduceTransform("myCol", 20, ReduceOp.Mean)

        Parameters:
        columnName - Column name to perform windowing on
        lookback - Look back period for windowing
        op - Reduction operation to perform on each window

      • calculateSortedRank

        public TransformProcess.Builder calculateSortedRank​(String newColumnName,
                                                    String sortOnColumn,
                                                    WritableComparator comparator)
        CalculateSortedRank: calculate the rank of each example, after sorting example. For example, we might have some numerical "score" column, and we want to know for the rank (sort order) for each example, according to that column.
        The rank of each example (after sorting) will be added in a new Long column. Indexing is done from 0; examples will have values 0 to dataSetSize-1.

        Currently, CalculateSortedRank can only be applied on standard (i.e., non-sequence) data Furthermore, the current implementation can only sort on one column

        Parameters:
        newColumnName - Name of the new column (will contain the rank for each example)
        sortOnColumn - Column to sort on
        comparator - Comparator used to sort examples

      • calculateSortedRank

        public TransformProcess.Builder calculateSortedRank​(String newColumnName,
                                                    String sortOnColumn,
                                                    WritableComparator comparator,
                                                    boolean ascending)
        CalculateSortedRank: calculate the rank of each example, after sorting example. For example, we might have some numerical "score" column, and we want to know for the rank (sort order) for each example, according to that column.
        The rank of each example (after sorting) will be added in a new Long column. Indexing is done from 0; examples will have values 0 to dataSetSize-1.

        Currently, CalculateSortedRank can only be applied on standard (i.e., non-sequence) data Furthermore, the current implementation can only sort on one column

        Parameters:
        newColumnName - Name of the new column (will contain the rank for each example)
        sortOnColumn - Column to sort on
        comparator - Comparator used to sort examples
        ascending - If true: sort ascending. False: descending

      • stringToCategorical

        public TransformProcess.Builder stringToCategorical​(String columnName,
                                                    List<String> stateNames)
        Convert the specified String column to a categorical column. The state names must be provided.
        Parameters:
        columnName - Name of the String column to convert to categorical
        stateNames - State names of the category

      • stringRemoveWhitespaceTransform

        public TransformProcess.Builder stringRemoveWhitespaceTransform​(String columnName)
        Remove all whitespace characters from the values in the specified String column
        Parameters:
        columnName - Name of the column to remove whitespace from

      • stringMapTransform

        public TransformProcess.Builder stringMapTransform​(String columnName,
                                                   Map<String,​String> mapping)
        Replace one or more String values in the specified column with new values.

        Keys in the map are the original values; the Values in the map are their replacements. If a String appears in the data but does not appear in the provided map (as a key), that String values will not be modified.

        Parameters:
        columnName - Name of the column in which to do replacement
        mapping - Map of oldValues -> newValues

      • stringToTimeTransform

        public TransformProcess.Builder stringToTimeTransform​(String column,
                                                      String format,
                                                      org.joda.time.DateTimeZone dateTimeZone)
        Convert a String column (containing a date/time String) to a time column (by parsing the date/time String)
        Parameters:
        column - String column containing the date/time Strings
        format - Format of the strings. Time format is specified as per http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html
        dateTimeZone - Timezone of the column

      • stringToTimeTransform

        public TransformProcess.Builder stringToTimeTransform​(String column,
                                                      String format,
                                                      org.joda.time.DateTimeZone dateTimeZone,
                                                      Locale locale)
        Convert a String column (containing a date/time String) to a time column (by parsing the date/time String)
        Parameters:
        column - String column containing the date/time Strings
        format - Format of the strings. Time format is specified as per http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html
        dateTimeZone - Timezone of the column
        locale - Locale of the column

      • appendStringColumnTransform

        public TransformProcess.Builder appendStringColumnTransform​(String column,
                                                            String toAppend)
        Append a String to a specified column
        Parameters:
        column - Column to append the value to
        toAppend - String to append to the end of each writable

      • conditionalReplaceValueTransform

        public TransformProcess.Builder conditionalReplaceValueTransform​(String column,
                                                                 Writable newValue,
                                                                 Condition condition)
        Replace the values in a specified column with a specified new value, if some condition holds. If the condition does not hold, the original values are not modified.
        Parameters:
        column - Column to operate on
        newValue - Value to use as replacement, if condition is satisfied
        condition - Condition that must be satisfied for replacement

      • conditionalReplaceValueTransformWithDefault

        public TransformProcess.Builder conditionalReplaceValueTransformWithDefault​(String column,
                                                                            Writable yesVal,
                                                                            Writable noVal,
                                                                            Condition condition)
        Replace the values in a specified column with a specified "yes" value, if some condition holds. Replace it with a "no" value, otherwise.
        Parameters:
        column - Column to operate on
        yesVal - Value to use as replacement, if condition is satisfied
        noVal - Value to use as replacement, if condition is not satisfied
        condition - Condition that must be satisfied for replacement

      • conditionalCopyValueTransform

        public TransformProcess.Builder conditionalCopyValueTransform​(String columnToReplace,
                                                              String sourceColumn,
                                                              Condition condition)
        Replace the value in a specified column with a new value taken from another column, if a condition is satisfied/true.
        Note that the condition can be any generic condition, including on other column(s), different to the column that will be modified if the condition is satisfied/true.
        Parameters:
        columnToReplace - Name of the column in which values will be replaced (if condition is satisfied)
        sourceColumn - Name of the column from which the new values will be
        condition - Condition to use

      • replaceStringTransform

        public TransformProcess.Builder replaceStringTransform​(String columnName,
                                                       Map<String,​String> mapping)
        Replace one or more String values in the specified column that match regular expressions.

        Keys in the map are the regular expressions; the Values in the map are their String replacements. For example:

        Original Regex Replacement Result
        Data_Vec _ DataVec
        B1C2T3 \\d one BoneConeTone
        '  4.25 ' ^\\s+|\\s+$ '4.25'
        Parameters:
        columnName - Name of the column in which to do replacement
        mapping - Map of old values or regular expression to new values

      • ndArrayScalarOpTransform

        public TransformProcess.Builder ndArrayScalarOpTransform​(String columnName,
                                                         MathOp op,
                                                         double value)
        Element-wise NDArray math operation (add, subtract, etc) on an NDArray column
        Parameters:
        columnName - Name of the NDArray column to perform the operation on
        op - Operation to perform
        value - Value for the operation

      • ndArrayColumnsMathOpTransform

        public TransformProcess.Builder ndArrayColumnsMathOpTransform​(String newColumnName,
                                                              MathOp mathOp,
                                                              String... columnNames)
        Perform an element wise mathematical operation (such as add, subtract, multiply) on NDArray columns. The existing columns are unchanged, a new NDArray column is added
        Parameters:
        newColumnName - Name of the new NDArray column
        mathOp - Operation to perform
        columnNames - Name of the columns used as input to the operation

      • ndArrayMathFunctionTransform

        public TransformProcess.Builder ndArrayMathFunctionTransform​(String columnName,
                                                             MathFunction mathFunction)
        Apply an element wise mathematical function (sin, tanh, abs etc) to an NDArray column. This operation is performed in place.
        Parameters:
        columnName - Name of the column to perform the operation on
        mathFunction - Mathematical function to apply

      • ndArrayDistanceTransform

        public TransformProcess.Builder ndArrayDistanceTransform​(String newColumnName,
                                                         Distance distance,
                                                         String firstCol,
                                                         String secondCol)
        Calculate a distance (cosine similarity, Euclidean, Manhattan) on two equal-sized NDArray columns. This operation adds a new Double column (with the specified name) with the result.
        Parameters:
        newColumnName - Name of the new column (result) to add
        distance - Distance to apply
        firstCol - first column to use in the distance calculation
        secondCol - second column to use in the distance calculation

      • firstDigitTransform

        public TransformProcess.Builder firstDigitTransform​(String inputColumn,
                                                    String outputColumn)
        FirstDigitTransform converts a column to a categorical column, with values being the first digit of the number.
        For example, "3.1415" becomes "3" and "2.0" becomes "2".
        Negative numbers ignore the sign: "-7.123" becomes "7".
        Note that two FirstDigitTransform.Modes are supported, which determines how non-numerical entries should be handled:
        EXCEPTION_ON_INVALID: output has 10 category values ("0", ..., "9"), and any non-numerical values result in an exception
        INCLUDE_OTHER_CATEGORY: output has 11 category values ("0", ..., "9", "Other"), all non-numerical values are mapped to "Other"

        FirstDigitTransform is useful (combined with CategoricalToOneHotTransform and Reductions) to implement Benford's law.
        Parameters:
        inputColumn - Input column name
        outputColumn - Output column name. If same as input, input column is replaced

      • firstDigitTransform

        public TransformProcess.Builder firstDigitTransform​(String inputColumn,
                                                    String outputColumn,
                                                    FirstDigitTransform.Mode mode)
        FirstDigitTransform converts a column to a categorical column, with values being the first digit of the number.
        For example, "3.1415" becomes "3" and "2.0" becomes "2".
        Negative numbers ignore the sign: "-7.123" becomes "7".
        Note that two FirstDigitTransform.Modes are supported, which determines how non-numerical entries should be handled:
        EXCEPTION_ON_INVALID: output has 10 category values ("0", ..., "9"), and any non-numerical values result in an exception
        INCLUDE_OTHER_CATEGORY: output has 11 category values ("0", ..., "9", "Other"), all non-numerical values are mapped to "Other"

        FirstDigitTransform is useful (combined with CategoricalToOneHotTransform and Reductions) to implement Benford's law.
        Parameters:
        inputColumn - Input column name
        outputColumn - Output column name. If same as input, input column is replaced
        mode - See FirstDigitTransform.Mode