Use Nick's SVGs for the tooltips rather than text symbols. Result is better, I feel like the code could be DRY'd up but not quite sure how at this point...
n.b. I had to change from separate point/header/footer formats to the all-in-one formatter function because since I'd changed the X Axis categories there was bug in the header of the tooltip, and fixing it wasn't possible because headerFormat string only takes very basic substitutions and it is now (necessarily) a bit complex to pull out the name of the x-axis category.
Use Nick's SVGs for the tooltips rather than text symbols. Result is better, I feel like the code could be DRY'd up but not quite sure how at this point...
n.b. I had to change from separate point/header/footer formats to the all-in-one
formatterfunction because since I'd changed the X Axis categories there was bug in the header of the tooltip, and fixing it wasn't possible becauseheaderFormatstring only takes very basic substitutions and it is now (necessarily) a bit complex to pull out the name of the x-axis category.