Dissimilarity

Dissimilarity

It represents a one-way table with dissimilarities between "objects".

Creating a Dissimilarity from data in a text file

Suppose you have three objects A, B and C. In one way or another, you have acquired the following (symmetric) dissimilarities: δ_AB = 2 (= δ_BA) , δ_AC = 1 (= δ_CA), and δ_BC = 1.4 (= δ_CB), where δ_AB represents the dissimilarity between object A and object B.

You can create a simple text file like the following:

   
"ooTextFile"  ! The line by which Praat can recognize your file

   
"Dissimilarity" ! The line that tells Praat about the contents

   
3     "A"  "B"  "C"   ! Number of columns, and column labels

   
3                     ! Number of rows

   
"A"    0    2    1    ! Row label (A), A-B value, A-C value

   
"B"    2    0  1.4    ! Row label (B), B-A value, B-C value

   
"C"    1    1.4  0    ! Row label (C), C-A value, C-B value

Notice that:

• the row and column labels are identical.

• the matrix elements on the diagonal are zero.

• the matrix is symmetrical.

This text file can be read with the Read from file... command. Since a Dissimilarity object has the data structure of a square symmetrical TableOfReal, you could also start from an appropriate TableOfReal object and cast it to a Dissimilarity object.