How to input distance matrix in SPSS to do Twostep cluster analysis?

[Terence Tien]

I already have a distance matrix (1609*1609) and each distance is between 0~1. I want to cluster 1609 items into natural groups by using Twostep cluster in SPSS. I want to use the distance matrix as input for Twostep cluster analysis. How to modify the syntax to do that? Or I cannot do it?

DATASET ACTIVATE dataname1.
TWOSTEP CLUSTER
  /CATEGORICAL VARIABLES=ROWTYPE VARNAME
  /CONTINUOUS VARIABLES=A1 to A1609 *Ignore the A2 to A1608 here.
  /DISTANCE LIKELIHOOD
  /NUMCLUSTERS AUTO 15 BIC
  /HANDLENOISE 0
  /MEMALLOCATE 64
  /CRITERIA INITHRESHOLD(0) MXBRANCH(8) MXLEVEL(3)
  /VIEWMODEL DISPLAY=YES
  /SAVE VARIABLE=TSC_4920.

Thanks in advance.