# checking: Checking correct data format In SAFD: Statistical Analysis of Fuzzy Data

## Description

The function checks if the input data is of the correct form of a polygonal fuzzy number, i.e. a dataframe with the columns "x" and "alpha" fulfilling the following conditions: (1) alpha-values have to be in [0,1] with the minimum alpha-level being 0 and maximum being 1, (2) the x-values have to be non-missing and non-decreasing, (3) the alpha-levels have to increase from 0 to 1 and afterwards decrease from 1 to 0 in the same way (i.e. the alpha-column consists of an increasing vector from 0 to 1 plus the same vector in decreasing order). As a consequence the dataframe always has an even number of rows, see examples. The function is used internally in almost all the other functions to do a preliminary checking if the input data is of the correct form.

## Usage

 `1` ```checking(X, com = 1) ```

## Arguments

 `X` ...can be any data frame. `com` ...numeric, if `com`=1 then, in case of an error, a comment is printed. By default `com`=1.

See examples

## Value

The function returns the value 1 if the input fulfills all conditions, if not, 0 is returned.

## 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)

Wolfgang Trutschnig <[email protected]>, Asun Lubiano <[email protected]>

See Also as `checking2`, `translator`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39``` ```#Example 1: data(XX) a<-checking(XX[[1]],1) a #Example 2: X<-data.frame(y=c(-2,-0.75,-0.25,0.5,1),alpha=c(0,0.6,0.9,0.9,0)) a<-checking(X) a #Example 3: X<-data.frame(x=c(-2,-0.75,-0.25,0.5,1),alpha=c(0,0.6,0.9,0.9,0)) a<-checking(X) a #Example 4: X<-data.frame(x=c(-2,-0.75,-0.25,-0.5,1),alpha=c(0,0.6,1,1,0)) a<-checking(X) a #Example 5: X<-data.frame(x=c(-2,-0.75,-0.25,0.5,1),alpha=c(0.3,0,1,0,0.3)) a<-checking(X) a #Example 6: Y<-data.frame(x=c(-2,-0.75,-0.25,0.5,1),alpha=c(0,0.3,1,0,0.3)) a<-checking(Y) a #Example 7: Z<-data.frame(x=c(-2,-0.75,-0.25,0.5,1),alpha=c(0,0.6,1,1,0)) a<-checking(Z) a #Example 8: U<-data.frame(x=c(-1,0,1),alpha=c(0,1,0)) a<-checking(U,) a ```