New column to label positive or negative

[#1]

I have data in column :direction that is either positive, negative, or blank determined by a Lag formula 'in the column.

I created a new column :updown where I wanted to look at row of :direction. If it's positive or blank, I want updown for that row to be "Up", otherwise I want it to say "Down". This will simplify data filtering since we just want to split up multi-directional voltage data.

//Check Whether positive or negative
For(i=1, i<=N Rows(dt), i++,
if(:direction[i] < 0,
 :updown[i] << Set Value("Down");,
 :updown[i] << Set Value("Up");
);
);

I've done something similar previously but it doesn't seem to be working. I've tried a few different syntax options and nothing has worked.

Thanks in advance for your help!

[#2 · Accepted solution]

I think you just need to  do this

//Check Whether positive or negative
For(i=1, i<=N Rows(dt), i++,
if(:direction[i] < 0,
 :updown[i] ="Down";,
 :updown[i] = "Up";
);
);

An alternative is to use a formula

column(dt, "updown") << Set Formula( If(:direction <0, "Down", "Up"))