Need help for using Lag functionHello everyone!
Hope someone could help me with this:
What is is the expected output of the following code?

After evaluation I get the following Log:

And the new columns just looks like this:

SliderID column is :

Hope someone could enlighten me with this! thanks in advance! 
Re: Need help for using Lag functionthat was enlightening! appreciated the brief explanation on how the formula works!
Re: Need help for using Lag functionthis worked for me! thanks a lot! 
Re: Need help for using Lag functionLooking at the data, I don't see any repeated SliderID values, so it might be working correctly. You might use
try(dABCE<<DELETEROWS></DELETEROWS>
to catch and ignore the error when there is nothing to delete.
edit: well, not try, if it isn't throwing an error. Maybe this.
Re: Need help for using Lag functionYour formula
:SliderID == Lag(:SiiderID, 1 )
is a boolean operation. When the current rows value of SliderID is equal to the previous row's value os SliderID, "Lag(:SliderID, 1)", the value of the comparison will be "True" and therefore it will return a numeric value of 1. If the comparison of the current row's value of SliderID is not equal to the previous row's value of SliderID, the returned value will be a 0.
@stephen_pearson modification of turning the formula into an "If" clause will result in the same values.
The error that is listed out, is a response to the line
dABCR << Delete Rows;
and it is being returned, because no rows had been selected as a result of the line
dABCR << Select Where(SN == 1);
The only correction to this line would be to scope the column reference by placing a ":" in front of SN
dABCR << Select Where(:SN==1);
Re: Need help for using Lag functionYour formula is missing an if statement. It should be something like
Formula(If(:sliderID == lag(:sliderID,1),1,0))
I would recommend you get all the steps working by using the menus and mouse clicks before trying to script it.