Matrix has not been set to a value and Invalid operand to operation.

[desireatem]

proc iml;

use kaplan;

read all  var{time Survival survival1};

close;

Survival1 = DM[,3]; Survival = DM[,2]; time = DM[,1];

n = nrow(DM);

segment = J(nrow(DM),1,1); print segment;

do i = 3 to nrow(DM);

if Survival1=Survival then SS=Survival1;

else if Survival1<Survival then SS=survival1-survival1[i+1];

end;

do i = 2 to nrow(DM);

if time=time then TT=time;

else if time<time then TT=time[i+1]-time;

end;

create kaplann var{time Survival survival1 TT DX DX};

append;

quit;

ERROR: (execution) Matrix has not been set to a value.

operation : [ at line 1985 column 16

operands  : DM, , *LIT1002

DM      0 row       0 col     (type ?, size 0)

*LIT1002      1 row       1 col     (numeric)

         3

statement : ASSIGN at line 1985 column 2

ERROR: (execution) Matrix has not been set to a value.

operation : [ at line 1985 column 35

operands  : DM, , *LIT1003

DM      0 row       0 col     (type ?, size 0)

*LIT1003      1 row       1 col     (numeric)

         2

statement : ASSIGN at line 1985 column 22

ERROR: (execution) Matrix has not been set to a value.

operation : [ at line 1985 column 50

operands  : DM, , *LIT1004

DM      0 row       0 col     (type ?, size 0)

*LIT1004      1 row       1 col     (numeric)

         1

statement : ASSIGN at line 1985 column 41

ERROR: (execution) Invalid operand to operation.

operation : J at line 1988 column 12

operands  : _TEM1001, *LIT1005, *LIT1006

_TEM1001      1 row       1 col     (numeric)

         0

*LIT1005      1 row       1 col     (numeric)

         1

*LIT1006      1 row       1 col     (numeric)

         1

statement : ASSIGN at line 1988 column 1

ERROR: Matrix segment has not been set to a value.

statement : PRINT at line 1988 column 28

WARNING: Variable DX already exists on file WORK.KAPLANN.

[desireatem]

proc iml;

use kaplan;

read all  var{TIME SURVIVAL SURVIVAL1} into DM;

close;

SURVIVAL1 = DM[,3]; SURVIVAL = DM[,2]; TIME = DM[,1];

n = nrow(DM);

segment = J(nrow(DM),1,1); *print segment;

SS=J(nrow(survival1),1,1);

do i = 1 to n ;

if i=n then SS=0;

else if i<n then SS=SURVIVAL1-SURVIVAL1[i+1];

end;

TT=J(nrow(time),1,1);

do i = 1 to n;

if i = n then TT=0;

else if i < n then TT=time[i+1]-time;

end;

create kaplann var{time Survival survival1 SS TT };

append;

quit;

proc print data=kaplann;

run;