Description
Linear regression model evaluation begins with scoring an input data that
includes the actual values of the dependent variable. The standard error of
estimate for the model is calculated and reported and is compared to the
standard error of estimate reported when the model was built. The standard
error of estimate is calculated as the square root of the average squared
residual value over all the observations (as shown below):
standard error of estimate = sqrt( sum((y-y1)**2)/(n-p-1) )
,
where
y1 - the actual value of the dependent variable
y - the predicted value
n - the number of observations
p - the number of independent variables (substituting n-p in the denominator if there is no constant term)
Usage
td_lin_reg_evaluator_valib(data, model, ...)
Arguments
data |
Required Argument. |
model |
Required Argument. |
... |
Specifies any other parameters that are required for future purpose. |
Value
Function returns an object of class "td_lin_reg_evaluator_valib"
which is a named list containing object of class "tbl_teradata".
Named list member can be referenced directly with the "$" operator
using name: result.
Examples
# Notes:
# 1. To execute Vantage Analytic Library functions, set option
# 'val.install.location' to the database name where Vantage analytic
# library functions are installed.
# 2. Datasets used in these examples can be loaded using Vantage Analytic
# Library installer.
# Set the option 'val.install.location'.
options(val.install.location = "SYSLIB")
# Get remote data source connection.
con <- td_get_context()$connection
# Create an object of class "tbl_teradata".
df <- tbl(con, "customer")
print(df)
# Example 1: Shows how linear regression model evaluation is performed.
# First generate the model using td_lin_reg_valib() function.
lin_reg_obj <- td_lin_reg_valib(data=df,
columns=c("age", "years_with_bank",
"nbr_children"),
response.column="income")
# Print the model.
print(lin_reg_obj$model)
# Evaluate the data using the linear regression model generated above.
obj <- td_lin_reg_evaluator_valib(data=df,
model=lin_reg_obj$model)
# Print the results.
print(obj$result)