Trend line as expression based on Field A - Field B issue.
I am trying to use the expression based on the difference of two fields which I am displaying as Line to see the trend.
Trend is based calculated from
Blue value - Red value = green (displaying as a line to see the trend)
In an overall trend the output of the difference should not be negative.
A)when I am selecting the part of the combo chart the values are recalculated based on the selection and the trend is displaying negative values. Is there a way to prevent this and stop the trend to recalculate and just show the trend as overall trend.