RT {MTSYS}

Function to generate a unit space for the Recognition-Taguchi (RT) method

Description

RT generates a unit space for the Recognition-Taguchi (RT) method. In general_MT, the inversed correlation matrix is used for A and the data are transformed by the function to be generated by generates_dimensionality_reduction_function based on unit_space_data. In the transformation, the p variables in unit_space_data are reduced into 2 synthetic variables.

Usage

RT(unit_space_data, includes_transformed_data = FALSE, ...)

Arguments

unit_space_data

Matrix with n rows (samples) and p columns (variables). Data to generate the unit space. All data should be continuous values and should not have missing values.

includes_transformed_data

If TRUE, then the transformed data are included in a return object.

...

Passed to solve for computing the inverse of the correlation matrix.

Value

RT returns an object of S3 class "RT". An object of class "RT" is a list containing the following components:

A

2 x 2 matrix. Inversed correlation matrix of the transformed unit_space_data.

calc_A

function(x) solve(cor(x), ...).

transforms_data

Function to be generated from generates_dimensionality_reduction_function based on unit_space_data.

distance

Vector with length n. Distances from the unit space to each sample.

n

The number of samples.

q

The number of variables after the data transformation. q is always 2.

x

If includes_transformed_data is TRUE, then the transformed data are included.

References

Taguchi, G. (2006). Objective Function and Generic Function (11). Journal of Quality Engineering Society, 14(2), 5-9. (In Japanese)

Huda, F., Kajiwara, I., Hosoya, N., & Kawamura, S. (2013). Bolt loosening analysis and diagnosis by non-contact laser excitation vibration tests. Mechanical systems and signal processing, 40(2), 589-604.

See Also

solve, general_MT, generates_dimensionality_reduction_function, and diagnosis.MT

Examples

# 40 data for versicolor in the iris dataset
iris_versicolor <- iris[61:100, -5]

unit_space_RT <- RT(unit_space_data = iris_versicolor,
                    includes_transformed_data = TRUE)

# The following "tol" is a parameter passed to the solve function.
unit_space_RT <- RT(unit_space_data = iris_versicolor,
                    includes_transformed_data = TRUE,
                    tol = 1e-9)

(unit_space_RT$distance)