cross_validation.sql_in File Reference

SQL functions for cross validation. More...

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Functions
void	cv_linregr_train (varchar tbl_source, varchar col_ind_var, varchar col_dep_var, varchar tbl_result)
	Simple interface of cross-validation, which has no limitation on lock number. More...
void	cv_linregr_predict (varchar tbl_model, varchar tbl_newdata, varchar col_ind_var, varchar col_id, varchar tbl_predict)
	A wrapper for linear regression prediction.
boolean	logregr_predict (float8[] coef, float8[] col_ind)
	A prediction function for logistic regression. More...
void	cv_logregr_predict (varchar tbl_model, varchar tbl_newdata, varchar col_ind_var, varchar col_id, varchar tbl_predict)
	A prediction function for logistic regression The result is stored in the table of tbl_predict. More...
integer	logregr_accuracy (float8[] coef, float8[] col_ind, boolean col_dep)
	Metric function for logistic regression. More...
void	cv_logregr_accuracy (varchar tbl_predict, varchar tbl_source, varchar col_id, varchar col_dep_var, varchar tbl_accuracy)
	Metric function for logistic regression. More...

Detailed Description

Date

January 2011

See Also

For a brief introduction to the usage of cross validation, see the module description Cross Validation.

Definition in file cross_validation.sql_in.

Function Documentation

void cv_linregr_train	(	varchar	tbl_source,
		varchar	col_ind_var,
		varchar	col_dep_var,
		varchar	tbl_result
	)

Parameters

module_name	Module to be cross validated
func_args	Arguments of modelling function of the module, including the table name of data
param_to_try	The name of the paramter that CV runs through
param_values	The values of the parameter that CV will try
data_id	Name of the unique ID associated with each row. Provide NULL if there is no such column in the data table
id_is_random	Whether the provided ID is randomly assigned to each row
validation_result	Table name to store the output of CV function, see the Output for format. It will be automatically created by CV function
fold_num	How many fold cross-validation Print the help message for a given module's cross-validation. Print the supported module names for cross_validation A wrapper for linear regression

Definition at line 366 of file cross_validation.sql_in.

void cv_logregr_accuracy	(	varchar	tbl_predict,
		varchar	tbl_source,
		varchar	col_id,
		varchar	col_dep_var,
		varchar	tbl_accuracy
	)

It computes the percentage of correct predictions. The result is stored in the table of tbl_accuracy

Definition at line 481 of file cross_validation.sql_in.

void cv_logregr_predict	(	varchar	tbl_model,
		varchar	tbl_newdata,
		varchar	col_ind_var,
		varchar	col_id,
		varchar	tbl_predict
	)

This function can be used together with cross-validation

Definition at line 447 of file cross_validation.sql_in.

integer logregr_accuracy	(	float8[]	coef,
		float8[]	col_ind,
		boolean	col_dep
	)

Parameters

coef	Logistic fitting coefficients. Note: MADlib logregr_train function does not produce a seperate intercept term as elastic_net_train function.
col_ind	Independent variable, an array
col_dep	Dependent variable

returns 1 if the prediction is the same as col_dep, otherwise 0

Definition at line 467 of file cross_validation.sql_in.

boolean logregr_predict	(	float8[]	coef,
		float8[]	col_ind
	)

Parameters

coef	Coefficients. Note: MADlib logregr_train function does not produce a seperate intercept term as elastic_net_train function.
col_ind	Independent variable, which must be an array

Definition at line 434 of file cross_validation.sql_in.