MDD {FuzzyStatTra}

Median Distance Deviation of a trapezoidal fuzzy sample with respect to a fuzzy number

Description

This function calculates the scale measure Median Distance Deviation (MDD) for a matrix of trapezoidal fuzzy numbers F with respect to a fuzzy number U. The employed metric in the calculation can be the 1-norm distance, the mid/spr distance or the (\varphi,\theta)-wabl/ldev/rdev distance. The function first checks if the input matrix F is given in the correct form (tested by checkingTra) and also the input fuzzy number U (tested by checking or checkingTra).

Usage

MDD(F, U, type, a = 1, b = 1, theta = 1/3)

Arguments

F

matrix of dimension n x 4 containing n trapezoidal fuzzy numbers characterized by their four values inf0,inf1,sup1,sup0. The function implicitly checks if the matrix is in the correct form (tested by checkingTra).

U

can be a matrix of dimension 1 x 4 (trapezoidal fuzzy number) or an array of dimension nl x 3 x 1 (general fuzzy number), where nl is the number of considered \alpha-levels and 3 the number of columns of the array: the first column will be the \alpha-levels, the second one their infimum values and the third one their supremum values. The function implicitly checks if the fuzzy number U is in the correct form (tested by checking if U is an array and tested by checkingTra if U is a matrix).

type

number 1, 2 or 3: if type==1, the 1-norm distance will be considered in the calculation of the measure MDD. If type==2, the mid/spr distance will be considered. By contrast, if type==3, the (\varphi,\theta)-wabl/ldev/rdev distance will be used.

a

number >0, by default a=1. It is the first parameter of a beta distribution which corresponds to a weighting measure on [0,1] in the mid/spr distance or in the (\varphi,\theta)-wabl/ldev/rdev distance.

b

number >0, by default b=1. It is the second parameter of a beta distribution which corresponds to a weighting measure on [0,1] in the mid/spr distance or in the (\varphi,\theta)-wabl/ldev/rdev distance.

theta

number >0, by default theta=1/3. It is the weight of the spread in the mid/spr distance and the weight of the ldev and rdev in the (\varphi,\theta)-wabl/ldev/rdev distance.

Details

See examples

Value

The function returns the scale measure MDD, which is a real number.

Note

In case you find (almost surely existing) bugs or have recommendations for improving the functions comments are welcome to the above mentioned mail addresses.

Author(s)

Asun Lubiano <[e-mail]>, Sara de la Rosa de Saa <[e-mail]>

References

[1] De la Rosa de Saa, S.; Lubiano M.A.; Sinova, B.; Filzmoser, P.: Robust scale estimators for fuzzy data, Advances in Data Analysis and Classification, pp. 1-28 (2015)

See Also

checkingTra, checking, TransfTra, Rho1Tra, Rho1, DthetaphiTra, Dthetaphi, DwablphiTra, Dwablphi

Examples

# Example 1:
F=SimulCASE3(10)
U=Mean(F)
MDD(F,U,3,1,2,1)

# Example 2:
F=SimulCASE2(10)
U=Median1norm(F)
MDD(F,U,2)

# Example 3:
F=SimulCASE1(100)
U=matrix(c(1,2,3,2),nrow=1)
MDD(F,U,1)

# Example 4:
F=SimulCASE1(100)
U=array(1:60,dim=c(10,2,3))
MDD(F,U,2,1,2,1)