Goal - The chart is to only display rows where expression value is not equal to x.
Suppress Zero - I wrapped all the equations within expression boxes in the chart to say, if x = 0 then display 0, or else do existing equation. This worked but it is not healthy looking. It is a bit of a hack so I dropped it!
Code Behind - I know I can achieve the goal if I do the equation in the code behind and quite tidily too but I wish it could be easier than this, for example, a click of a button or writing a code into a separate expression field in the chart with a command to not display the line.
Is there away around it other than those stated above?