*Input Programs are highly depend of the format of datafiles. I have assumed that the format given in your email is exact. *I use the character in the 4th position of each line to differentiate the type of records. *Thus RECORD TYPE 'E' is the first line for each case *RECORD TYPE 'l' contains the number of links, etc. *The records containing the links have a blank in the 4th column. *The final file (the output of the syntax) contains one case per caseid, the number of links and the list of all links for that caseid. *The syntax can be run as is and will demonstrate its operation using the inline data. To run the syntax on your data, *follow the instructions given below. Ray. **** SYNTAX *** NEW FILE. *FILE TYPE MIXED FILE='nodes.txt' RECORD=REC_ID 4 (A). **************************************. * To read your external data file instead of the inline data: 1) add a * at the beginning of the next command 2) remove the * at the beginning of the prior command 3) replace nodes.txt by the path and name of your data file 4) delete everything between BEGIN DATA and END DATA. **************************************. FILE TYPE MIXED RECORD=REC_ID 4 (A). RECORD TYPE 'E'. DATA LIST FIXED / caseid 27-34(A). LEAVE caseid. RECORD TYPE 'l'. DATA LIST FIXED / nb_links 1-2. RECORD TYPE ' '. DATA LIST FIXED / node1 5-6 node2 11-12. END FILE TYPE. BEGIN DATA PFNET D:\\SHARON\\PCKNOT\\DD\\M19A.PRX 16 nodes 19 links 1 minimum link weight 3 maximum link weight links: node1 node2 Weight type 1 2 1 x 1 10 1 x 2 5 1 x 2 7 1 x 2 16 1 x 3 13 3 x 4 9 2 x 4 10 2 x 4 16 2 x 5 7 1 x 5 11 2 x 5 15 1 x 6 8 3 x 7 11 2 x 8 12 2 x 9 14 2 x 11 15 2 x 12 13 2 x 13 14 2 x PFNET D:\\SHARON\\PCKNOT\\DD\\M19B.PRX 16 nodes 15 links 1 minimum link weight 3 maximum link weight links: node1 node2 Weight type 1 2 1 x 2 10 1 x 3 5 1 x 3 7 1 x 3 16 1 x 4 13 3 x 5 9 2 x 5 10 2 x 6 7 1 x 7 8 3 x 8 11 2 x 9 12 2 x 10 14 2 x 12 15 2 x 13 14 2 x END DATA. DO IF $casenum=1. COMPUTE nb=1. ELSE. COMPUTE nb=(caseid=lag(caseid))*lag(nb)+1. END IF. VECTOR nod1_(25F8.0) nod2_(25F8.0). DO IF nb>2. COMPUTE nod1_(nb-2)=node1. COMPUTE nod2_(nb-2)=node2. END IF. *If the maximum number of links can exceeds 25, the replace all 25s below by the maximum applicable. AGGREGATE /OUTFILE=* /BREAK=caseid /nb_links = MAX(nb_links) /nod1_1 TO nod1_25= MAX(nod1_1 TO nod1_25) /nod2_1 TO nod2_25= MAX(nod2_1 TO nod2_25).