lag function Error

[Coa_SAs]

Hi All,

I have attached SAS Data Set, New_Gold needs to calculate as 

If _n_ then .

if _n_=2 then (Obs2-Obs1)^2

if _n_=3 then (obs3-obs2)^2

if _n_=4 then (Obs4-Obs3)^2 etc

As a first step I am using Lag function.

New_Gold=Lag(1_GoldS)

I am getting the follwing error, Please advise.

ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *, **, +, ',', -, /, <, <=, <>, =, >, ><, >=, AND, EQ, GE,
GT, IN, LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, ^=, |, ||, ~=.

ERROR 72-185: The LAG function call has too many arguments.

[Reeza]

The function is called is LAG<n> where <n> represents the amount of lag.

Your code should be:
lag1(variable_name).

Variables don't typically start with numbers, so perhaps its just a typo?

[Coa_SAs]

Hi All,

I have data as attached. New_Gold needs to calculate as 

If _n_ then .

if _n_=2 then (Obs2-Obs1)^2

if _n_=3 then (obs3-obs2)^2

 if _n_=4 then (Obs4-Obs3)^2 etc

As a first step I am using Lag function.

New_Gold=Lag(1_GoldS)

I am getting the follwing error, Please advise.

ERROR 22-322: Syntax error, expecting one of the following: !, !!, &, *, **, +, ',', -, /, <, <=, <>, =, >, ><, >=, AND, EQ, GE,
GT, IN, LE, LT, MAX, MIN, NE, NG, NL, NOTIN, OR, ^=, |, ||, ~=.

ERROR 72-185: The LAG function call has too many arguments.

[Reeza]

Do you understand my comment? If not, please post your whole code and log. The code posted above isn't valid SAS syntax. As mentioned variables rarely start with numbers (1_GoldS)

[Coa_SAs]

Thanks Reeza for your quick reply, I got it.

[Reeza]

Please mark the question as answered.

[Astounding · Accepted solution]

Seems like you could get what you want with:

new_gold = dif(GoldS)**2;

It will generate a missing value on the first observation, but that is expected.

If you are stuck on using LAG instead of DIF:

new_gold = lag(GoldS);

if _n_=1 then new_gold=.;

else new_gold = (GoldS - new_gold)**2;

Note that SAS uses ** (not ^) to indicate raising to a power.

Good luck.