water.rapids.ast.prims.advmath

Class AstTfIdf

java.lang.Object

water.Iced<T>

water.rapids.ast.AstRoot<T>

water.rapids.ast.AstPrimitive<AstTfIdf>

water.rapids.ast.prims.advmath.AstTfIdf

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Cloneable, Freezable<AstTfIdf>

public class AstTfIdf
extends AstPrimitive<AstTfIdf>

Primitive AST operation to compute TF-IDF values for given document corpus.

Parameters:

• frame - Input frame containing data for whose TF-IDF values should be computed
• doc_id_idx - Index of a column containing document IDs
• text_idx - Index of a column containing words/documents (depending on the preprocess parameter)
• preprocess - Flag indicating whether input should be pre-processed or not
• case_sensitive - Flag indicating whether input should be treated as a case sensitive data

Content of a column with index content_idx:

• See TfIdfPreprocessorTask - (default) when pre-processing is enabled
• word - when pre-processing is disabled

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AstTfIdf()

Method Summary

Modifier and Type	Method and Description
Val	apply(Env env, Env.StackHelp stk, AstRoot[] asts) Primary method to invoke this function, passing all the parameters as the `asts` list.
java.lang.String[]	args() List of argument names.
int	nargs() Number of function's arguments + 1.
java.lang.String	str() String representation of this Ast object in the Rapids language.

Methods inherited from class water.rapids.ast.AstPrimitive

description, example, exec

Methods inherited from class water.rapids.ast.AstRoot

toString

Methods inherited from class water.Iced

asBytes, clone, copyOver, frozenType, read, readExternal, readJSON, reloadFromBytes, toJsonBytes, toJsonString, write, writeExternal, writeJSON

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AstTfIdf

public AstTfIdf()

Method Detail

nargs

public int nargs()

Description copied from class: AstPrimitive

Number of function's arguments + 1. Thus, a binary operator like '+' should be declared with 3 nargs: ["+", lhs, rhs]. For variable-argument functions this method should return -1.

Specified by:

nargs in class AstPrimitive<AstTfIdf>

args

public java.lang.String[] args()

Description copied from class: AstPrimitive

List of argument names. The length of the returned array should be equal to `nargs() - 1` (unless `nargs()` returns -1, in which case this function may return {"..."} or something similar).

Specified by:

args in class AstPrimitive<AstTfIdf>

apply

public Val apply(Env env,
                 Env.StackHelp stk,
                 AstRoot[] asts)

Description copied from class: AstPrimitive

Primary method to invoke this function, passing all the parameters as the `asts` list.

Specified by:

apply in class AstPrimitive<AstTfIdf>

Parameters:

env - Current execution environment. Variables are looked up here.

stk - TODO need clarification

asts - List of AstRoot expressions that are arguments to the function. First element in this list is the function itself.

Returns:

value resulting from calling the function with the provided list of arguments.

str

public java.lang.String str()

Description copied from class: AstRoot

String representation of this Ast object in the Rapids language. For AstPrimitives this is the name of the function; for AstParameters this is either the name of the variable, or the value of the numeric constant that the parameter represents. For more complicated constructs such as AstExec or AstFunction this method should return those objects as a Rapids string.

Specified by:

str in class AstRoot<AstTfIdf>