User guide > Weighting > Grossing up or down using known factors

To apply a known factor to a subset of the data simply define a variable (usually called $WEIGHT) to hold the relevant value. For example to weight young people ($AGE/1) by a grossing up factor of 1.4:

dw $weight=1.0,

if $age/1, dw $weight=1.4,

select wr $weight,

If there are four age groups and we wish to use a different weighting factor for each group we can put the factors into a table in a Manip Stage and retrieve them later using a table look up definition. Because the table has only one dimension we need a variable with one item for the other dimension.

start control,

c=simple.asc,

cep,

finish control,

start data,

serial number in 1-5,

card characters binary 500,

ds $age=$110/1-4,

xt='Age',

x='Age\Child;Young;Middle aged;Old',

ds $true=t,

xt='Total only',

x='Total',

t #fact(f=nitb/nptb)=$age*$true,

finish data,

start manip,

mt #fact(r1-$,c1-$)=(1.2,1.7,0.65,1.0),

finish manip,

start tables,

dw $weight=$age(#fact),

select wr $weight,

t #1(f=puc/ptp/nunr)=$age*,

finish tables,

The four grossing up factors are placed in a table called #FACT which is "dummy" defined in the data stage. The relevant factor is then extracted from this table in the tables stage and used as the weight. Table 1 is produced to check that the weights have been correctly applied.