HOW TO USE DISTRAN


DISTANCE TRANSPOSE STANDARDIZATION (1)
PROGRAM WRITTEN BY F. J. CARMONE


The DISTRAN program computes a matrix of interpoint distances from a data matrix of stimuli by variable "scores". The program can handle up to 75 points (Stimulus objects) and 75 variables. The distances can be computed for any number of such data matrices (that is, for any number of subjects). An option exists for standardizing the data matrix by columns before computing distances. An average-distance matrix across all subjects can also be computed. The relevant formulas are given below:

Let

represent the data matrix for the ith subject of r observations on n stimuli. We assume there are M such matrices.

Let D(i) = (d(i)jk)represent the matrix of interpoint distances

between the pair of points j and k for the ith subject. Let

_    _
D = (djk)
represent the matrix of interpoint distances for the

average subject.

If the data are standardized, let

represent the data matrix for the ith subject. This is computed simply by the formula

(zijt) = ((xijt) - (xit) ) / sit

where xit and sit are respectively, the mean and standard deviation for the tth variable of the ith subject. With no standardization the distance dijk is given by the formula:

In the case of standardization, the z values take the place of x values. The distance, djk, for the average subject is computed by the formula:


DISTRAN Parameters:

LINE 1: PARAMETER LINE: N,M,STNDD,ITRAN,NUMGEN,IW,ITM (FREE FORMAT)

1. 2. 3.

4. 5.
6.

LINE 2: INPUT DATA FORMAT (UP TO 80 COLUMNS IN F FORMAT)

LINE 3:FORMAT FOR WEIGHTS, OR IF WEIGHTS ARE NOT USED, LINE 3 ONWARDS IS THE DATA LIST.


DISTRAN Output:

1. The raw data including the means and standard deviations.

2. Standardized data coordinates. (When appropriate).

3. Transpose of input data matrix when requested.

4. The standardized (or non-standardized) interpoint distances in half matrix form.

5. The mean interpoint distance of the standardized configuration.

6. Matrix of average distances when ITM greater than 1.

NOTES

1. This discussion of Distran is taken from P. E. Green and V. R. Rao Applied Multidimensional Scaling, Dryden Press (1972), pp. 187.


SAMPLE DISTRAN DATA

    8  2  1  0  0  2
  (3X, 2F2.0)  
  001 2 3    
  002 4 2    
  003 2 1    
  004 7 2    
  005 1 3    
  006 3 1    
  007 1 5    
  008 2 5    
  001 1 2    
  002 4 5    
  003 4 1    
  004 1 3    
  005 2 3    
  006 2 1    
  007 1 6    
  008 1 2 


SAMPLE DISTRAN OUTPUT

                                      DISTRAN
                        DISTANCE TRANSPOSE STANDARDIZATION
                           WRITTEN BY F. J. CARMONE  JR.
                                  PC-MDS VERSION

     ANALYSIS TITLE: DISTRAN TEST DATA
     DATA IS READ FROM FILE:  DISTRAN.DAT
     OUTPUT PRINT FILE IS: TEST.PRN                                    
     FINAL OUTPUT DATA FILE IS: TEST.DAT                               
     NUMBER OF ROWS(POINTS) =     8
     NUMBER OF COLUMNS(DIMENSIONS) =     2
      (3X, 2F2.0)                                                      
	  WEIGHTS
        1.00   1.00

     RAW DATA--MEANS--STD DEVIATIONS
             1        2
    1 .200E+01 .300E+01
    2 .400E+01 .200E+01
    3 .200E+01 .100E+01
    4 .700E+01 .200E+01
    5 .100E+01 .300E+01
    6 .300E+01 .100E+01
    7 .100E+01 .500E+01
    8 .200E+01 .500E+01

     MEANS
      .275E+01 .275E+01

     STD DEVIATIONS
      .185E+01 .148E+01

     STANDARDIZED DATA POINTS
          1        2
    1-.405E+00 .169E+00
    2 .674E+00-.507E+00
    3-.405E+00-.118E+01
    4 .229E+01-.507E+00
    5-.944E+00 .169E+00
    6 .135E+00-.118E+01
    7-.944E+00 .152E+01
    8-.405E+00 .152E+01

     STANDARDIZED INTERPOINT DISTANCES
           1       2       3       4       5       6       7   8 
    2   .13E+01
    3   .14E+01 .13E+01
    4   .28E+01 .16E+01 .28E+01
    5   .54E+00 .18E+01 .15E+01 .33E+01
    6   .15E+01 .86E+00 .54E+00 .23E+01 .17E+01
    7   .15E+01 .26E+01 .28E+01 .38E+01 .14E+01 .29E+01
    8   .14E+01 .23E+01 .27E+01 .34E+01 .15E+01 .28E+01 .54E+00
      MEAN INTERPOINT DISTANCE =    1.941

     RAW DATA--MEANS--STD DEVIATIONS
     RAW DATA
             1        2
    1 .100E+01 .200E+01
    2 .400E+01 .500E+01
    3 .400E+01 .100E+01
    4 .100E+01 .300E+01
    5 .200E+01 .300E+01
    6 .200E+01 .100E+01
    7 .100E+01 .600E+01
    8 .100E+01 .200E+01

     MEANS
      .200E+01 .288E+01

     STD DEVIATIONS
      .122E+01 .169E+01

     STANDARDIZED DATA POINTS
          1        2
    1-.816E+00-.517E+00
    2 .163E+01 .126E+01
    3 .163E+01-.111E+01
    4-.816E+00 .739E-01
    5 .000E+00 .739E-01
    6 .000E+00-.111E+01
    7-.816E+00 .185E+01
    8-.816E+00-.517E+00

     STANDARDIZED INTERPOINT DISTANCES
           1       2       3       4       5       6       7    8
    2   .30E+01
    3   .25E+01 .24E+01
    4   .59E+00 .27E+01 .27E+01
    5   .10E+01 .20E+01 .20E+01 .82E+00
    6   .10E+01 .29E+01 .16E+01 .14E+01 .12E+01
    7   .24E+01 .25E+01 .38E+01 .18E+01 .20E+01 .31E+01
    8   .00E+00 .30E+01 .25E+01 .59E+00 .10E+01 .10E+01 .24E+01

     MEAN INTERPOINT DISTANCE =    1.928

DISTRAN TEST DATA                                                     
AVERAGE DISTANCES MATRIX
           1       2       3       4       5       6       7    8
    2   .21E+01
    3   .19E+01 .18E+01
    4   .17E+01 .22E+01 .28E+01
    5   .77E+00 .19E+01 .17E+01 .21E+01
    6   .12E+01 .19E+01 .11E+01 .18E+01 .15E+01
    7   .19E+01 .26E+01 .33E+01 .28E+01 .17E+01 .30E+01
    8   .68E+00 .27E+01 .26E+01 .20E+01 .12E+01 .19E+01 .15E+01