Difference between values in two rows

[MS_Egyptian]

Hi,

any one knows how to get difference between two rows in DI. i.e. following is the orginal Table

Date	Value
06/12/2013	150
07/12/2013	160
08/12/2013	180
09/12/2013	200
10/12/2013	250

and We need to generate a new column called Difference as the following table:

Date	Value	Difference
06/12/2013	150
07/12/2013	160	10
08/12/2013	180	20
09/12/2013	200	20
10/12/2013	250	50

[Linlin · Accepted solution]

data want;

set have;

difference=dif(value);

run;

Message was edited by: Linlin

[mrtball]

Hello Linlin,

This solves my issue in terms of calculating differences across my dataset, however I dont want to run this for each record in the table everytime I insert a new row in the table - do you know if there is a function / piece of code which will basically calculate the difference between the last row and the new row being inserted and then insert the value? Also is this kind of difference calc only possible in Datastep?

Thanks,
Tom

[mp254]

Date	Value	Difference
06/12/2013	250	50
07/12/2013	200	40
08/12/2013	160	30
09/12/2013	130	10
10/12/2013	120	0

How to get the difference output like this?

[Ranny]

how to keep the first value as it is?