Formula

java.lang.Object
- smile.data.formula.Formula

All Implemented Interfaces:

java.io.Serializable
```
public class Formula
extends java.lang.Object
implements java.io.Serializable
```
A formula extracts the variables from a context (e.g. Java Class or DataFrame).

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description
`Formula(HyperTerm[] predictors)` Constructor.
`Formula(java.lang.String response)` Constructor.
`Formula(java.lang.String response, HyperTerm[] predictors)` Constructor.
`Formula(Term response)` Constructor.
`Formula(Term response, HyperTerm[] predictors)` Constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`DataFrame`	`apply(DataFrame df)` Returns a data frame of predictors and response variable
`Tuple`	`apply(Tuple t)` Apply the formula on a tuple to generate the model data.
`StructType`	`bind(StructType inputSchema)` Binds the formula to a schema and returns the output schema of formula.
`static Formula`	`lhs(java.lang.String lhs)` Factory method.
`static Formula`	`lhs(Term lhs)` Factory method.
`smile.math.matrix.DenseMatrix`	`matrix(DataFrame df)` Creates a design matrix of predictors without bias column.
`smile.math.matrix.DenseMatrix`	`matrix(DataFrame df, boolean bias)` Creates a design matrix of predictors.
`static Formula`	`of(java.lang.String response, HyperTerm... predictors)` Factory method.
`static Formula`	`of(java.lang.String response, java.lang.String... predictors)` Factory method.
`static Formula`	`of(Term response, HyperTerm... predictors)` Factory method.
`Formula`	`predictors()` Returns a formula with only predictors.
`java.util.Optional<Term>`	`response()` Returns the response term.
`static Formula`	`rhs(HyperTerm... predictors)` Factory method.
`static Formula`	`rhs(java.lang.String... predictors)` Factory method.
`StructType`	`schema()` Returns the schema of output data frame.
`java.lang.String`	`toString()`
`DataFrame`	`x(DataFrame df)` Returns a data frame of predictors.
`Tuple`	`x(Tuple t)` Apply the formula on a tuple to generate the predictors data.
`double[]`	`xarray(Tuple t)` Returns the real values of predictors.
`StructType`	`xschema()` Returns the schema of design matrix.
`BaseVector`	`y(DataFrame df)` Returns the response vector.
`double`	`y(Tuple t)` Returns the real-valued response value.
`int`	`yint(Tuple t)` Returns the integer-valued response value.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Formula
```
public Formula(java.lang.String response)
```
    Constructor.
    
    Parameters:
    
    response - the response formula, i.e. dependent variable.
  - Formula
```
public Formula(Term response)
```
    Constructor.
    
    Parameters:
    
    response - the response formula, i.e. dependent variable.
  - Formula
```
public Formula(HyperTerm[] predictors)
```
    Constructor.
    
    Parameters:
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - Formula
```
public Formula(java.lang.String response,
               HyperTerm[] predictors)
```
    Constructor.
    
    Parameters:
    
    response - the left-hand side of formula, i.e. dependent variable.
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - Formula
```
public Formula(Term response,
               HyperTerm[] predictors)
```
    Constructor.
    
    Parameters:
    
    response - the left-hand side of formula, i.e. dependent variable.
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
- Method Detail
  - predictors
```
public Formula predictors()
```
    Returns a formula with only predictors.
  - response
```
public java.util.Optional<Term> response()
```
    Returns the response term.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - lhs
```
public static Formula lhs(java.lang.String lhs)
```
    Factory method.
    
    Parameters:
    
    lhs - the left-hand side of formula, i.e. dependent variable.
  - lhs
```
public static Formula lhs(Term lhs)
```
    Factory method.
    
    Parameters:
    
    lhs - the left-hand side of formula, i.e. dependent variable.
  - rhs
```
public static Formula rhs(java.lang.String... predictors)
```
    Factory method.
    
    Parameters:
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - rhs
```
public static Formula rhs(HyperTerm... predictors)
```
    Factory method.
    
    Parameters:
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - of
```
public static Formula of(java.lang.String response,
                         java.lang.String... predictors)
```
    Factory method.
    
    Parameters:
    
    response - the left-hand side of formula, i.e. dependent variable.
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - of
```
public static Formula of(java.lang.String response,
                         HyperTerm... predictors)
```
    Factory method.
    
    Parameters:
    
    response - the left-hand side of formula, i.e. dependent variable.
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - of
```
public static Formula of(Term response,
                         HyperTerm... predictors)
```
    Factory method.
    
    Parameters:
    
    response - the left-hand side of formula, i.e. dependent variable.
    
    predictors - the right-hand side of formula, i.e. independent/predictor variables.
  - schema
```
public StructType schema()
```
    Returns the schema of output data frame.
  - xschema
```
public StructType xschema()
```
    Returns the schema of design matrix.
  - bind
```
public StructType bind(StructType inputSchema)
```
    Binds the formula to a schema and returns the output schema of formula.
  - apply
```
public Tuple apply(Tuple t)
```
    Apply the formula on a tuple to generate the model data.
  - x
```
public Tuple x(Tuple t)
```
    Apply the formula on a tuple to generate the predictors data.
  - xarray
```
public double[] xarray(Tuple t)
```
    Returns the real values of predictors.
  - apply
```
public DataFrame apply(DataFrame df)
```
    Returns a data frame of predictors and response variable
    
    Parameters:
    
    df - The input DataFrame.
  - x
```
public DataFrame x(DataFrame df)
```
    Returns a data frame of predictors.
    
    Parameters:
    
    df - The input DataFrame.
  - matrix
```
public smile.math.matrix.DenseMatrix matrix(DataFrame df)
```
    Creates a design matrix of predictors without bias column.
    
    Parameters:
    
    df - The input DataFrame.
  - matrix
```
public smile.math.matrix.DenseMatrix matrix(DataFrame df,
                                            boolean bias)
```
    Creates a design matrix of predictors.
    
    Parameters:
    
    df - The input DataFrame.
    
    bias - If true, the design matrix includes an all-one column for intercept.
  - y
```
public BaseVector y(DataFrame df)
```
    Returns the response vector.
    
    Parameters:
    
    df - The input DataFrame.
  - y
```
public double y(Tuple t)
```
    Returns the real-valued response value.
  - yint
```
public int yint(Tuple t)
```
    Returns the integer-valued response value.

Class Formula

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Formula

Formula

Formula

Formula

Formula

Method Detail

predictors

response

toString

lhs

lhs

rhs

rhs

of

of

of

schema

xschema

bind

apply

x

xarray

apply

x

matrix

matrix

y

y

yint