Create a flag variable whose value is missing when multiple variables are not missing.

[pmpradhan]

My data is 

A   B  C 

1   0  1

0  0   0

1  1   0

0  0   1

1  1   1

What to create a flag variable which is missing when A or B or C have 1 and flag variable should be . when all three of them have 0

WANT dataset like

A   B  C nmiss

1   0  1    .

0  0   0   1

1  1   0    .

0  0   1    .

1  1   1    .

Any quick way to do this?

[pau13rown · Accepted solution]

if sum(a,b,c)=0 then flag=1;

else flag=.;

[pmpradhan]

Thank you!