My suggestion is to use a long IF..THEN/ELSEIF statement to make the bins, that way it'll easily handle the edge conditions and the variety of sizes in the middle. I've done this on a number of occasions and it works fine, the only issue I've found is that I haven't been able to construct a canonical histogram where there is no space between the bars.
Thanks Jonathan, I suspected I might be left with a very large IF statement (as that is how I managed to do it in Excel). Would I be better off just making this a calculated field and leaving bins out of it? I could then just do a CNT on the data when in my graph and it should act like a normal column of data?
Yes, leave the bins out of it. They only create even divisions of data, and in your case you need uneven divisions. Once you have create the calculated field, and put on the Columns shelf, the measure on the rows shelf with the CNT() aggregation will automatically aggregate for each "bin".
Legend! I wish the help documentation clearly stated that bins are only useful for even divisions of data. The way it is worded, it makes it sound like I can use CASE statements in the bin itself.
Well....time to get IF'ing!