Hi, I am trying to create a new variable called "Diff" by subtracting two columns. When those columns have missing variables, I want diff to be missing too. In a data step, I tried "diff = sales-cost;" and got an error. Then I tried "diff=sum(sales,-cost);" which worked but gave me values for all of diff, when there should be some missing. I want it to look like: sales cost diff . 8.99 . and right now it looks like: sales cost diff . 8.99 -8.99 Thanks!
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