Using gnumeric, how do I sum the positive values in a range, without creating a new column?
I'm thinking something along the lines of:
SUM(B21:B25, #>0&)
or
SUM(SELECT(B21:B25, #>0&))
"#>0&" is Mathematica-ese for a function returning true if its argument is greater than 0, false otherwise.
More generically: how do I apply an aggregate function to cells in a range that meet a specific condition?
Try using the SUMIF function:
=SUMIF(B21:B25, ">0")
The gnumeric documentation linked above doesn't contain very much detail on the usage of the SUMIF function. The documentation claims that it is Excel compatible, so you may have some luck reading the documentation for Excel's SUMIF function if you want any more information.