streamlined error bar settings

Depicting error bars in spotfire during exploratory data analysis is laborious, because when the variable being graphed is changed, the column used to generate the error bars as well as the aggregation function used to set the error bars must be re-set.

Almost all of the time, I want to use the same column that is being used to generate the data points to generate the error bars. For example if I am plotting average(absorbance 600 nm) on the y axis, I will usually want my error bars to represent something like StDev(absorbance 600 nm).

It would be nice to be able to check a box in the error bar menu to "use x/y-axis variable to generate error bars." Or alternately to have the variable that is being graphed on the axis in question show up by default when the user clicks into the upper/lower error bar menu.

It might also be useful to be able to click and drag the settings from "upper error bar" into the "lower error bar" field. Or to have some other mechanism for cloning error bar settings. Usually I want symmetrical error bars and I have to do the same work twice.

Re ordering the aggregation functions listed might also be useful. For example standard deviation and standard error are commonly used aggregation functions for error bars; average is not going to be a commonly used agg function for error bars.